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/***
* Copyright (C) Microsoft. All rights reserved.
* Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
*
* =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*
* Parallel Patterns Library - PPLx Tasks
*
* For the latest on this and related APIs, please see: https://github.com/Microsoft/cpprestsdk
*
* =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
****/
#pragma once
#ifndef PPLXTASKS_H
#define PPLXTASKS_H
#include "cpprest/details/cpprest_compat.h"
#if (defined(_MSC_VER) && (_MSC_VER >= 1800)) && !CPPREST_FORCE_PPLX
#include <ppltasks.h>
namespace pplx = Concurrency;
namespace Concurrency
{
/// <summary>
/// Sets the ambient scheduler to be used by the PPL constructs.
/// </summary>
_ASYNCRTIMP void __cdecl set_cpprestsdk_ambient_scheduler(const std::shared_ptr<scheduler_interface>& _Scheduler);
/// <summary>
/// Gets the ambient scheduler to be used by the PPL constructs
/// </summary>
_ASYNCRTIMP const std::shared_ptr<scheduler_interface>& __cdecl get_cpprestsdk_ambient_scheduler();
} // namespace Concurrency
#if (_MSC_VER >= 1900)
#include <concrt.h>
namespace Concurrency
{
namespace extensibility
{
typedef ::std::condition_variable condition_variable_t;
typedef ::std::mutex critical_section_t;
typedef ::std::unique_lock<::std::mutex> scoped_critical_section_t;
typedef ::Concurrency::event event_t;
typedef ::Concurrency::reader_writer_lock reader_writer_lock_t;
typedef ::Concurrency::reader_writer_lock::scoped_lock scoped_rw_lock_t;
typedef ::Concurrency::reader_writer_lock::scoped_lock_read scoped_read_lock_t;
typedef ::Concurrency::details::_ReentrantBlockingLock recursive_lock_t;
typedef recursive_lock_t::_Scoped_lock scoped_recursive_lock_t;
} // namespace extensibility
} // namespace Concurrency
#endif // _MSC_VER >= 1900
#else
#include "pplx/pplx.h"
#if defined(__ANDROID__)
#include <jni.h>
void cpprest_init(JavaVM*);
#endif
// Cannot build using a compiler that is older than dev10 SP1
#if defined(_MSC_VER)
#if _MSC_FULL_VER < 160040219 /*IFSTRIP=IGN*/
#error ERROR: Visual Studio 2010 SP1 or later is required to build ppltasks
#endif /*IFSTRIP=IGN*/
#endif /* defined(_MSC_VER) */
#include <algorithm>
#include <atomic>
#include <exception>
#include <functional>
#include <utility>
#include <vector>
#if defined(_MSC_VER)
#include <intrin.h>
#if defined(__cplusplus_winrt)
#include <agile.h>
#include <ctxtcall.h>
#include <winapifamily.h>
#include <windows.h>
#ifndef _UITHREADCTXT_SUPPORT
#ifdef WINAPI_FAMILY /*IFSTRIP=IGN*/
// It is safe to include winapifamily as WINAPI_FAMILY was defined by the user
#include <winapifamily.h>
#if WINAPI_FAMILY == WINAPI_FAMILY_APP
// UI thread context support is not required for desktop and Windows Store apps
#define _UITHREADCTXT_SUPPORT 0
#elif WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP
// UI thread context support is not required for desktop and Windows Store apps
#define _UITHREADCTXT_SUPPORT 0
#else /* WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP */
#define _UITHREADCTXT_SUPPORT 1
#endif /* WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP */
#else /* WINAPI_FAMILY */
// Not supported without a WINAPI_FAMILY setting.
#define _UITHREADCTXT_SUPPORT 0
#endif /* WINAPI_FAMILY */
#endif /* _UITHREADCTXT_SUPPORT */
#if _UITHREADCTXT_SUPPORT
#include <uithreadctxt.h>
#endif /* _UITHREADCTXT_SUPPORT */
#pragma detect_mismatch("PPLXTASKS_WITH_WINRT", "1")
#else /* defined(__cplusplus_winrt) */
#pragma detect_mismatch("PPLXTASKS_WITH_WINRT", "0")
#endif /* defined(__cplusplus_winrt) */
#endif /* defined(_MSC_VER) */
#ifdef _DEBUG
#define _DBG_ONLY(X) X
#else
#define _DBG_ONLY(X)
#endif // #ifdef _DEBUG
// std::copy_exception changed to std::make_exception_ptr from VS 2010 to VS 11.
#ifdef _MSC_VER
#if _MSC_VER < 1700 /*IFSTRIP=IGN*/
namespace std
{
template<class _E>
exception_ptr make_exception_ptr(_E _Except)
{
return copy_exception(_Except);
}
} // namespace std
#endif /* _MSC_VER < 1700 */
#ifndef PPLX_TASK_ASYNC_LOGGING
#if _MSC_VER >= 1800 && defined(__cplusplus_winrt)
#define PPLX_TASK_ASYNC_LOGGING 1 // Only enable async logging under dev12 winrt
#else
#define PPLX_TASK_ASYNC_LOGGING 0
#endif
#endif /* !PPLX_TASK_ASYNC_LOGGING */
#endif /* _MSC_VER */
#pragma pack(push, _CRT_PACKING)
#if defined(_MSC_VER)
#pragma warning(push)
#pragma warning(disable : 28197)
#pragma warning(disable : 4100) // Unreferenced formal parameter - needed for document generation
#pragma warning(disable : 4127) // constant express in if condition - we use it for meta programming
#endif /* defined(_MSC_VER) */
// All CRT public header files are required to be protected from the macro new
#pragma push_macro("new")
#undef new
// stuff ported from Dev11 CRT
// NOTE: this doesn't actually match std::declval. it behaves differently for void!
// so don't blindly change it to std::declval.
namespace stdx
{
template<class _T>
_T&& declval();
}
/// <summary>
/// The <c>pplx</c> namespace provides classes and functions that give you access to the Concurrency Runtime,
/// a concurrent programming framework for C++. For more information, see <see cref="Concurrency Runtime"/>.
/// </summary>
/**/
namespace pplx
{
/// <summary>
/// A type that represents the terminal state of a task. Valid values are <c>completed</c> and <c>canceled</c>.
/// </summary>
/// <seealso cref="task Class"/>
/**/
typedef task_group_status task_status;
template<typename _Type>
class task;
template<>
class task<void>;
// In debug builds, default to 10 frames, unless this is overridden prior to #includ'ing ppltasks.h. In retail builds,
// default to only one frame.
#ifndef PPLX_TASK_SAVE_FRAME_COUNT
#ifdef _DEBUG
#define PPLX_TASK_SAVE_FRAME_COUNT 10
#else
#define PPLX_TASK_SAVE_FRAME_COUNT 1
#endif
#endif
/// <summary>
/// Helper macro to determine how many stack frames need to be saved. When any number less or equal to 1 is specified,
/// only one frame is captured and no stackwalk will be involved. Otherwise, the number of callstack frames will be
/// captured.
/// </summary>
/// <ramarks>
/// This needs to be defined as a macro rather than a function so that if we're only gathering one frame,
/// _ReturnAddress() will evaluate to client code, rather than a helper function inside of _TaskCreationCallstack,
/// itself.
/// </remarks>
#if PPLX_TASK_SAVE_FRAME_COUNT > 1
#if defined(__cplusplus_winrt) && !defined(_DEBUG)
#pragma message( \
"WARNING: Redefining PPLX_TASK_SAVE_FRAME_COUNT under Release build for non-desktop applications is not supported; only one frame will be captured!")
#define PPLX_CAPTURE_CALLSTACK() ::pplx::details::_TaskCreationCallstack::_CaptureSingleFrameCallstack(_ReturnAddress())
#else
#define PPLX_CAPTURE_CALLSTACK() \
::pplx::details::_TaskCreationCallstack::_CaptureMultiFramesCallstack(PPLX_TASK_SAVE_FRAME_COUNT)
#endif
#else
#define PPLX_CAPTURE_CALLSTACK() ::pplx::details::_TaskCreationCallstack::_CaptureSingleFrameCallstack(_ReturnAddress())
#endif
/// <summary>
/// Returns an indication of whether the task that is currently executing has received a request to cancel its
/// execution. Cancellation is requested on a task if the task was created with a cancellation token, and
/// the token source associated with that token is canceled.
/// </summary>
/// <returns>
/// <c>true</c> if the currently executing task has received a request for cancellation, <c>false</c> otherwise.
/// </returns>
/// <remarks>
/// If you call this method in the body of a task and it returns <c>true</c>, you must respond with a call to
/// <see cref="cancel_current_task Function">cancel_current_task</see> to acknowledge the cancellation request,
/// after performing any cleanup you need. This will abort the execution of the task and cause it to enter into
/// the <c>canceled</c> state. If you do not respond and continue execution, or return instead of calling
/// <c>cancel_current_task</c>, the task will enter the <c>completed</c> state when it is done.
/// state.
/// <para>A task is not cancelable if it was created without a cancellation token.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/// <seealso cref="cancellation_token_source Class"/>
/// <seealso cref="cancellation_token Class"/>
/// <seealso cref="cancel_current_task Function"/>
/**/
inline bool _pplx_cdecl is_task_cancellation_requested()
{
return ::pplx::details::_TaskCollection_t::_Is_cancellation_requested();
}
/// <summary>
/// Cancels the currently executing task. This function can be called from within the body of a task to abort the
/// task's execution and cause it to enter the <c>canceled</c> state. While it may be used in response to
/// the <see cref="is_task_cancellation_requested Function">is_task_cancellation_requested</see> function, you may
/// also use it by itself, to initiate cancellation of the task that is currently executing.
/// <para>It is not a supported scenario to call this function if you are not within the body of a <c>task</c>.
/// Doing so will result in undefined behavior such as a crash or a hang in your application.</para>
/// </summary>
/// <seealso cref="task Class"/>
/**/
inline __declspec(noreturn) void _pplx_cdecl cancel_current_task() { throw task_canceled(); }
namespace details
{
/// <summary>
/// Callstack container, which is used to capture and preserve callstacks in ppltasks.
/// Members of this class is examined by vc debugger, thus there will be no public access methods.
/// Please note that names of this class should be kept stable for debugger examining.
/// </summary>
class _TaskCreationCallstack
{
private:
// If _M_SingleFrame != nullptr, there will be only one frame of callstacks, which is stored in _M_SingleFrame;
// otherwise, _M_Frame will store all the callstack frames.
void* _M_SingleFrame;
std::vector<void*> _M_frames;
public:
_TaskCreationCallstack() { _M_SingleFrame = nullptr; }
// Store one frame of callstack. This function works for both Debug / Release CRT.
static _TaskCreationCallstack _CaptureSingleFrameCallstack(void* _SingleFrame)
{
_TaskCreationCallstack _csc;
_csc._M_SingleFrame = _SingleFrame;
return _csc;
}
// Capture _CaptureFrames number of callstack frames. This function only work properly for Desktop or Debug CRT.
__declspec(noinline) static _TaskCreationCallstack _CaptureMultiFramesCallstack(size_t _CaptureFrames)
{
_TaskCreationCallstack _csc;
_csc._M_frames.resize(_CaptureFrames);
// skip 2 frames to make sure callstack starts from user code
_csc._M_frames.resize(::pplx::details::platform::CaptureCallstack(&_csc._M_frames[0], 2, _CaptureFrames));
return _csc;
}
};
typedef unsigned char _Unit_type;
struct _TypeSelectorNoAsync
{
};
struct _TypeSelectorAsyncOperationOrTask
{
};
struct _TypeSelectorAsyncOperation : public _TypeSelectorAsyncOperationOrTask
{
};
struct _TypeSelectorAsyncTask : public _TypeSelectorAsyncOperationOrTask
{
};
struct _TypeSelectorAsyncAction
{
};
struct _TypeSelectorAsyncActionWithProgress
{
};
struct _TypeSelectorAsyncOperationWithProgress
{
};
template<typename _Ty>
struct _NormalizeVoidToUnitType
{
typedef _Ty _Type;
};
template<>
struct _NormalizeVoidToUnitType<void>
{
typedef _Unit_type _Type;
};
template<typename _T>
struct _IsUnwrappedAsyncSelector
{
static const bool _Value = true;
};
template<>
struct _IsUnwrappedAsyncSelector<_TypeSelectorNoAsync>
{
static const bool _Value = false;
};
template<typename _Ty>
struct _UnwrapTaskType
{
typedef _Ty _Type;
};
template<typename _Ty>
struct _UnwrapTaskType<task<_Ty>>
{
typedef _Ty _Type;
};
template<typename _T>
_TypeSelectorAsyncTask _AsyncOperationKindSelector(task<_T>);
_TypeSelectorNoAsync _AsyncOperationKindSelector(...);
#if defined(__cplusplus_winrt)
template<typename _Type>
struct _Unhat
{
typedef _Type _Value;
};
template<typename _Type>
struct _Unhat<_Type ^>
{
typedef _Type _Value;
};
value struct _NonUserType
{
public:
int _Dummy;
};
template<typename _Type, bool _IsValueTypeOrRefType = __is_valid_winrt_type(_Type)>
struct _ValueTypeOrRefType
{
typedef _NonUserType _Value;
};
template<typename _Type>
struct _ValueTypeOrRefType<_Type, true>
{
typedef _Type _Value;
};
template<typename _T1, typename _T2>
_T2 _ProgressTypeSelector(Windows::Foundation::IAsyncOperationWithProgress<_T1, _T2> ^);
template<typename _T1>
_T1 _ProgressTypeSelector(Windows::Foundation::IAsyncActionWithProgress<_T1> ^);
template<typename _Type>
struct _GetProgressType
{
typedef decltype(_ProgressTypeSelector(stdx::declval<_Type>())) _Value;
};
template<typename _Type>
struct _IsIAsyncInfo
{
static const bool _Value = __is_base_of(Windows::Foundation::IAsyncInfo, typename _Unhat<_Type>::_Value);
};
template<typename _T>
_TypeSelectorAsyncOperation _AsyncOperationKindSelector(Windows::Foundation::IAsyncOperation<_T> ^);
_TypeSelectorAsyncAction _AsyncOperationKindSelector(Windows::Foundation::IAsyncAction ^);
template<typename _T1, typename _T2>
_TypeSelectorAsyncOperationWithProgress _AsyncOperationKindSelector(
Windows::Foundation::IAsyncOperationWithProgress<_T1, _T2> ^);
template<typename _T>
_TypeSelectorAsyncActionWithProgress _AsyncOperationKindSelector(Windows::Foundation::IAsyncActionWithProgress<_T> ^);
template<typename _Type, bool _IsAsync = _IsIAsyncInfo<_Type>::_Value>
struct _TaskTypeTraits
{
typedef typename _UnwrapTaskType<_Type>::_Type _TaskRetType;
typedef decltype(_AsyncOperationKindSelector(stdx::declval<_Type>())) _AsyncKind;
typedef typename _NormalizeVoidToUnitType<_TaskRetType>::_Type _NormalizedTaskRetType;
static const bool _IsAsyncTask = _IsAsync;
static const bool _IsUnwrappedTaskOrAsync = _IsUnwrappedAsyncSelector<_AsyncKind>::_Value;
};
template<typename _Type>
struct _TaskTypeTraits<_Type, true>
{
typedef decltype(((_Type) nullptr)->GetResults()) _TaskRetType;
typedef _TaskRetType _NormalizedTaskRetType;
typedef decltype(_AsyncOperationKindSelector((_Type) nullptr)) _AsyncKind;
static const bool _IsAsyncTask = true;
static const bool _IsUnwrappedTaskOrAsync = _IsUnwrappedAsyncSelector<_AsyncKind>::_Value;
};
#else /* defined (__cplusplus_winrt) */
template<typename _Type>
struct _IsIAsyncInfo
{
static const bool _Value = false;
};
template<typename _Type, bool _IsAsync = false>
struct _TaskTypeTraits
{
typedef typename _UnwrapTaskType<_Type>::_Type _TaskRetType;
typedef decltype(_AsyncOperationKindSelector(stdx::declval<_Type>())) _AsyncKind;
typedef typename _NormalizeVoidToUnitType<_TaskRetType>::_Type _NormalizedTaskRetType;
static const bool _IsAsyncTask = false;
static const bool _IsUnwrappedTaskOrAsync = _IsUnwrappedAsyncSelector<_AsyncKind>::_Value;
};
#endif /* defined (__cplusplus_winrt) */
template<typename _Function>
auto _IsCallable(_Function _Func, int) -> decltype(_Func(), std::true_type())
{
(void)(_Func);
return std::true_type();
}
template<typename _Function>
std::false_type _IsCallable(_Function, ...)
{
return std::false_type();
}
template<>
struct _TaskTypeTraits<void>
{
typedef void _TaskRetType;
typedef _TypeSelectorNoAsync _AsyncKind;
typedef _Unit_type _NormalizedTaskRetType;
static const bool _IsAsyncTask = false;
static const bool _IsUnwrappedTaskOrAsync = false;
};
template<typename _Type>
task<_Type> _To_task(_Type t);
template<typename _Func>
task<void> _To_task_void(_Func f);
struct _BadContinuationParamType
{
};
template<typename _Function, typename _Type>
auto _ReturnTypeHelper(_Type t, _Function _Func, int, int) -> decltype(_Func(_To_task(t)));
template<typename _Function, typename _Type>
auto _ReturnTypeHelper(_Type t, _Function _Func, int, ...) -> decltype(_Func(t));
template<typename _Function, typename _Type>
auto _ReturnTypeHelper(_Type t, _Function _Func, ...) -> _BadContinuationParamType;
template<typename _Function, typename _Type>
auto _IsTaskHelper(_Type t, _Function _Func, int, int) -> decltype(_Func(_To_task(t)), std::true_type());
template<typename _Function, typename _Type>
std::false_type _IsTaskHelper(_Type t, _Function _Func, int, ...);
template<typename _Function>
auto _VoidReturnTypeHelper(_Function _Func, int, int) -> decltype(_Func(_To_task_void(_Func)));
template<typename _Function>
auto _VoidReturnTypeHelper(_Function _Func, int, ...) -> decltype(_Func());
template<typename _Function>
auto _VoidIsTaskHelper(_Function _Func, int, int) -> decltype(_Func(_To_task_void(_Func)), std::true_type());
template<typename _Function>
std::false_type _VoidIsTaskHelper(_Function _Func, int, ...);
template<typename _Function, typename _ExpectedParameterType>
struct _FunctionTypeTraits
{
typedef decltype(
_ReturnTypeHelper(stdx::declval<_ExpectedParameterType>(), stdx::declval<_Function>(), 0, 0)) _FuncRetType;
static_assert(!std::is_same<_FuncRetType, _BadContinuationParamType>::value,
"incorrect parameter type for the callable object in 'then'; consider _ExpectedParameterType or "
"task<_ExpectedParameterType> (see below)");
typedef decltype(
_IsTaskHelper(stdx::declval<_ExpectedParameterType>(), stdx::declval<_Function>(), 0, 0)) _Takes_task;
};
template<typename _Function>
struct _FunctionTypeTraits<_Function, void>
{
typedef decltype(_VoidReturnTypeHelper(stdx::declval<_Function>(), 0, 0)) _FuncRetType;
typedef decltype(_VoidIsTaskHelper(stdx::declval<_Function>(), 0, 0)) _Takes_task;
};
template<typename _Function, typename _ReturnType>
struct _ContinuationTypeTraits
{
typedef task<
typename _TaskTypeTraits<typename _FunctionTypeTraits<_Function, _ReturnType>::_FuncRetType>::_TaskRetType>
_TaskOfType;
};
// _InitFunctorTypeTraits is used to decide whether a task constructed with a lambda should be unwrapped. Depending on
// how the variable is declared, the constructor may or may not perform unwrapping. For eg.
//
// This declaration SHOULD NOT cause unwrapping
// task<task<void>> t1([]() -> task<void> {
// task<void> t2([]() {});
// return t2;
// });
//
// This declaration SHOULD cause unwrapping
// task<void>> t1([]() -> task<void> {
// task<void> t2([]() {});
// return t2;
// });
// If the type of the task is the same as the return type of the function, no unwrapping should take place. Else normal
// rules apply.
template<typename _TaskType, typename _FuncRetType>
struct _InitFunctorTypeTraits
{
typedef typename _TaskTypeTraits<_FuncRetType>::_AsyncKind _AsyncKind;
static const bool _IsAsyncTask = _TaskTypeTraits<_FuncRetType>::_IsAsyncTask;
static const bool _IsUnwrappedTaskOrAsync = _TaskTypeTraits<_FuncRetType>::_IsUnwrappedTaskOrAsync;
};
template<typename T>
struct _InitFunctorTypeTraits<T, T>
{
typedef _TypeSelectorNoAsync _AsyncKind;
static const bool _IsAsyncTask = false;
static const bool _IsUnwrappedTaskOrAsync = false;
};
/// <summary>
/// Helper object used for LWT invocation.
/// </summary>
struct _TaskProcThunk
{
_TaskProcThunk(const std::function<void()>& _Callback) : _M_func(_Callback) {}
static void _pplx_cdecl _Bridge(void* _PData)
{
_TaskProcThunk* _PThunk = reinterpret_cast<_TaskProcThunk*>(_PData);
_Holder _ThunkHolder(_PThunk);
_PThunk->_M_func();
}
private:
// RAII holder
struct _Holder
{
_Holder(_TaskProcThunk* _PThunk) : _M_pThunk(_PThunk) {}
~_Holder() { delete _M_pThunk; }
_TaskProcThunk* _M_pThunk;
private:
_Holder& operator=(const _Holder&);
};
std::function<void()> _M_func;
_TaskProcThunk& operator=(const _TaskProcThunk&);
};
/// <summary>
/// Schedule a functor with automatic inlining. Note that this is "fire and forget" scheduling, which cannot be
/// waited on or canceled after scheduling.
/// This schedule method will perform automatic inlining base on <paramref value="_InliningMode"/>.
/// </summary>
/// <param name="_Func">
/// The user functor need to be scheduled.
/// </param>
/// <param name="_InliningMode">
/// The inlining scheduling policy for current functor.
/// </param>
static void _ScheduleFuncWithAutoInline(const std::function<void()>& _Func, _TaskInliningMode_t _InliningMode)
{
_TaskCollection_t::_RunTask(&_TaskProcThunk::_Bridge, new _TaskProcThunk(_Func), _InliningMode);
}
class _ContextCallback
{
typedef std::function<void(void)> _CallbackFunction;
#if defined(__cplusplus_winrt)
public:
static _ContextCallback _CaptureCurrent()
{
_ContextCallback _Context;
_Context._Capture();
return _Context;
}
~_ContextCallback() { _Reset(); }
_ContextCallback(bool _DeferCapture = false)
{
if (_DeferCapture)
{
_M_context._M_captureMethod = _S_captureDeferred;
}
else
{
_M_context._M_pContextCallback = nullptr;
}
}
// Resolves a context that was created as _S_captureDeferred based on the environment (ancestor, current context).
void _Resolve(bool _CaptureCurrent)
{
if (_M_context._M_captureMethod == _S_captureDeferred)
{
_M_context._M_pContextCallback = nullptr;
if (_CaptureCurrent)
{
if (_IsCurrentOriginSTA())
{
_Capture();
}
#if _UITHREADCTXT_SUPPORT
else
{
// This method will fail if not called from the UI thread.
HRESULT _Hr = CaptureUiThreadContext(&_M_context._M_pContextCallback);
if (FAILED(_Hr))
{
_M_context._M_pContextCallback = nullptr;
}
}
#endif /* _UITHREADCTXT_SUPPORT */
}
}
}
void _Capture()
{
HRESULT _Hr =
CoGetObjectContext(IID_IContextCallback, reinterpret_cast<void**>(&_M_context._M_pContextCallback));
if (FAILED(_Hr))
{
_M_context._M_pContextCallback = nullptr;
}
}
_ContextCallback(const _ContextCallback& _Src) { _Assign(_Src._M_context._M_pContextCallback); }
_ContextCallback(_ContextCallback&& _Src)
{
_M_context._M_pContextCallback = _Src._M_context._M_pContextCallback;
_Src._M_context._M_pContextCallback = nullptr;
}
_ContextCallback& operator=(const _ContextCallback& _Src)
{
if (this != &_Src)
{
_Reset();
_Assign(_Src._M_context._M_pContextCallback);
}
return *this;
}
_ContextCallback& operator=(_ContextCallback&& _Src)
{
if (this != &_Src)
{
_M_context._M_pContextCallback = _Src._M_context._M_pContextCallback;
_Src._M_context._M_pContextCallback = nullptr;
}
return *this;
}
bool _HasCapturedContext() const
{
_ASSERTE(_M_context._M_captureMethod != _S_captureDeferred);
return (_M_context._M_pContextCallback != nullptr);
}
void _CallInContext(_CallbackFunction _Func) const
{
if (!_HasCapturedContext())
{
_Func();
}
else
{
ComCallData callData;
ZeroMemory(&callData, sizeof(callData));
callData.pUserDefined = reinterpret_cast<void*>(&_Func);
HRESULT _Hr = _M_context._M_pContextCallback->ContextCallback(
&_Bridge, &callData, IID_ICallbackWithNoReentrancyToApplicationSTA, 5, nullptr);
if (FAILED(_Hr))
{
throw ::Platform::Exception::CreateException(_Hr);
}
}
}
bool operator==(const _ContextCallback& _Rhs) const
{
return (_M_context._M_pContextCallback == _Rhs._M_context._M_pContextCallback);
}
bool operator!=(const _ContextCallback& _Rhs) const { return !(operator==(_Rhs)); }
private:
void _Reset()
{
if (_M_context._M_captureMethod != _S_captureDeferred && _M_context._M_pContextCallback != nullptr)
{
_M_context._M_pContextCallback->Release();
}
}
void _Assign(IContextCallback* _PContextCallback)
{
_M_context._M_pContextCallback = _PContextCallback;
if (_M_context._M_captureMethod != _S_captureDeferred && _M_context._M_pContextCallback != nullptr)
{
_M_context._M_pContextCallback->AddRef();
}
}
static HRESULT __stdcall _Bridge(ComCallData* _PParam)
{
_CallbackFunction* pFunc = reinterpret_cast<_CallbackFunction*>(_PParam->pUserDefined);
(*pFunc)();
return S_OK;
}
// Returns the origin information for the caller (runtime / Windows Runtime apartment as far as task continuations
// need know)
static bool _IsCurrentOriginSTA()
{
APTTYPE _AptType;
APTTYPEQUALIFIER _AptTypeQualifier;
HRESULT hr = CoGetApartmentType(&_AptType, &_AptTypeQualifier);
if (SUCCEEDED(hr))
{
// We determine the origin of a task continuation by looking at where .then is called, so we can tell
// whether to need to marshal the continuation back to the originating apartment. If an STA thread is in
// executing in a neutral apartment when it schedules a continuation, we will not marshal continuations back
// to the STA, since variables used within a neutral apartment are expected to be apartment neutral.
switch (_AptType)
{
case APTTYPE_MAINSTA:
case APTTYPE_STA: return true;
default: break;
}
}
return false;
}
union {
IContextCallback* _M_pContextCallback;
size_t _M_captureMethod;
} _M_context;
static const size_t _S_captureDeferred = 1;
#else /* defined (__cplusplus_winrt) */
public:
static _ContextCallback _CaptureCurrent() { return _ContextCallback(); }
_ContextCallback(bool = false) {}
_ContextCallback(const _ContextCallback&) {}
_ContextCallback(_ContextCallback&&) {}
_ContextCallback& operator=(const _ContextCallback&) { return *this; }
_ContextCallback& operator=(_ContextCallback&&) { return *this; }
bool _HasCapturedContext() const { return false; }
void _Resolve(bool) const {}
void _CallInContext(_CallbackFunction _Func) const { _Func(); }
bool operator==(const _ContextCallback&) const { return true; }
bool operator!=(const _ContextCallback&) const { return false; }
#endif /* defined (__cplusplus_winrt) */
};
template<typename _Type>
struct _ResultHolder
{
void Set(const _Type& _type) { _Result = _type; }
_Type Get() { return _Result; }
_Type _Result;
};
#if defined(__cplusplus_winrt)
template<typename _Type>
struct _ResultHolder<_Type ^>
{
void Set(_Type ^ const& _type) { _M_Result = _type; }
_Type ^ Get() { return _M_Result.Get(); } private :
// ::Platform::Agile handle specialization of all hats
// including ::Platform::String and ::Platform::Array
::Platform::Agile<_Type ^> _M_Result;
};
//
// The below are for composability with tasks auto-created from when_any / when_all / && / || constructs.
//
template<typename _Type>
struct _ResultHolder<std::vector<_Type ^>>
{
void Set(const std::vector<_Type ^>& _type)
{
_Result.reserve(_type.size());
for (auto _PTask = _type.begin(); _PTask != _type.end(); ++_PTask)
{
_Result.emplace_back(*_PTask);
}
}
std::vector<_Type ^> Get()
{
// Return vectory<T^> with the objects that are marshaled in the proper apartment
std::vector<_Type ^> _Return;
_Return.reserve(_Result.size());
for (auto _PTask = _Result.begin(); _PTask != _Result.end(); ++_PTask)
{
_Return.push_back(
_PTask->Get()); // Platform::Agile will marshal the object to appropriate apartment if necessary
}
return _Return;
}
std::vector<::Platform::Agile<_Type ^>> _Result;
};
template<typename _Type>
struct _ResultHolder<std::pair<_Type ^, void*>>
{
void Set(const std::pair<_Type ^, size_t>& _type) { _M_Result = _type; }
std::pair<_Type ^, size_t> Get() { return std::make_pair(_M_Result.first.Get(), _M_Result.second); }
private:
std::pair<::Platform::Agile<_Type ^>, size_t> _M_Result;
};
#endif /* defined (__cplusplus_winrt) */
// An exception thrown by the task body is captured in an exception holder and it is shared with all value based
// continuations rooted at the task. The exception is 'observed' if the user invokes get()/wait() on any of the tasks
// that are sharing this exception holder. If the exception is not observed by the time the internal object owned by the
// shared pointer destructs, the process will fail fast.
struct _ExceptionHolder
{
private:
void ReportUnhandledError()
{
#if _MSC_VER >= 1800 && defined(__cplusplus_winrt)
if (_M_winRTException != nullptr)
{
::Platform::Details::ReportUnhandledError(_M_winRTException);
}
#endif /* defined (__cplusplus_winrt) */
}
public:
explicit _ExceptionHolder(const std::exception_ptr& _E, const _TaskCreationCallstack& _stackTrace)
: _M_exceptionObserved(0)
, _M_stdException(_E)
, _M_stackTrace(_stackTrace)
#if defined(__cplusplus_winrt)
, _M_winRTException(nullptr)
#endif /* defined (__cplusplus_winrt) */
{
}
#if defined(__cplusplus_winrt)
explicit _ExceptionHolder(::Platform::Exception ^ _E, const _TaskCreationCallstack& _stackTrace)
: _M_exceptionObserved(0), _M_winRTException(_E), _M_stackTrace(_stackTrace)
{
}
#endif /* defined (__cplusplus_winrt) */
__declspec(noinline) ~_ExceptionHolder()
{
if (_M_exceptionObserved == 0)
{
// If you are trapped here, it means an exception thrown in task chain didn't get handled.
// Please add task-based continuation to handle all exceptions coming from tasks.
// this->_M_stackTrace keeps the creation callstack of the task generates this exception.
_REPORT_PPLTASK_UNOBSERVED_EXCEPTION();
}
}
void _RethrowUserException()
{
if (_M_exceptionObserved == 0)
{
atomic_exchange(_M_exceptionObserved, 1l);
}
#if defined(__cplusplus_winrt)
if (_M_winRTException != nullptr)
{
throw _M_winRTException;
}
#endif /* defined (__cplusplus_winrt) */
std::rethrow_exception(_M_stdException);
}
// A variable that remembers if this exception was every rethrown into user code (and hence handled by the user).
// Exceptions that are unobserved when the exception holder is destructed will terminate the process.
atomic_long _M_exceptionObserved;
// Either _M_stdException or _M_winRTException is populated based on the type of exception encountered.
std::exception_ptr _M_stdException;
#if defined(__cplusplus_winrt)
::Platform::Exception ^ _M_winRTException;
#endif /* defined (__cplusplus_winrt) */
// Disassembling this value will point to a source instruction right after a call instruction. If the call is to
// create_task, a task constructor or the then method, the task created by that method is the one that encountered
// this exception. If the call is to task_completion_event::set_exception, the set_exception method was the source
// of the exception. DO NOT REMOVE THIS VARIABLE. It is extremely helpful for debugging.
_TaskCreationCallstack _M_stackTrace;
};
#if defined(__cplusplus_winrt)
/// <summary>
/// Base converter class for converting asynchronous interfaces to IAsyncOperation
/// </summary>
template<typename _AsyncOperationType, typename _CompletionHandlerType, typename _Result>
ref struct _AsyncInfoImpl abstract : Windows::Foundation::IAsyncOperation<_Result>
{
internal :
// The async action, action with progress or operation with progress that this stub forwards to.
::Platform::Agile<_AsyncOperationType>
_M_asyncInfo;
Windows::Foundation::AsyncOperationCompletedHandler<_Result> ^ _M_CompletedHandler;
_AsyncInfoImpl(_AsyncOperationType _AsyncInfo) : _M_asyncInfo(_AsyncInfo) {}
public:
virtual void Cancel() { _M_asyncInfo.Get()->Cancel(); }
virtual void Close() { _M_asyncInfo.Get()->Close(); }
virtual property Windows::Foundation::HResult ErrorCode
{
Windows::Foundation::HResult get() { return _M_asyncInfo.Get()->ErrorCode; }
}
virtual property UINT Id
{
UINT get() { return _M_asyncInfo.Get()->Id; }
}
virtual property Windows::Foundation::AsyncStatus Status
{
Windows::Foundation::AsyncStatus get() { return _M_asyncInfo.Get()->Status; }
}
virtual _Result GetResults() { throw std::runtime_error("derived class must implement"); }
virtual property Windows::Foundation::AsyncOperationCompletedHandler<_Result> ^ Completed {
Windows::Foundation::AsyncOperationCompletedHandler<_Result> ^ get() { return _M_CompletedHandler; }
void set(Windows::Foundation::AsyncOperationCompletedHandler<_Result> ^ value)
{
_M_CompletedHandler = value;
_M_asyncInfo.Get()->Completed =
ref new _CompletionHandlerType([&](_AsyncOperationType, Windows::Foundation::AsyncStatus status) {
_M_CompletedHandler->Invoke(this, status);
});
}
}
};
/// <summary>
/// Class _IAsyncOperationWithProgressToAsyncOperationConverter is used to convert an instance of
/// IAsyncOperationWithProgress<T> into IAsyncOperation<T>
/// </summary>
template<typename _Result, typename _Progress>
ref struct _IAsyncOperationWithProgressToAsyncOperationConverter sealed
: _AsyncInfoImpl<Windows::Foundation::IAsyncOperationWithProgress<_Result, _Progress> ^
, Windows::Foundation::AsyncOperationWithProgressCompletedHandler<_Result, _Progress>, _Result>
{
internal : _IAsyncOperationWithProgressToAsyncOperationConverter(
Windows::Foundation::IAsyncOperationWithProgress<_Result, _Progress> ^ _Operation)
: _AsyncInfoImpl<Windows::Foundation::IAsyncOperationWithProgress<_Result, _Progress> ^,
Windows::Foundation::AsyncOperationWithProgressCompletedHandler<_Result, _Progress>,
_Result>(_Operation)
{
}
public:
virtual _Result GetResults() override { return _M_asyncInfo.Get()->GetResults(); }
};
/// <summary>
/// Class _IAsyncActionToAsyncOperationConverter is used to convert an instance of IAsyncAction into
/// IAsyncOperation<_Unit_type>
/// </summary>
ref struct _IAsyncActionToAsyncOperationConverter sealed
: _AsyncInfoImpl<Windows::Foundation::IAsyncAction ^
, Windows::Foundation::AsyncActionCompletedHandler, details::_Unit_type>
{
internal : _IAsyncActionToAsyncOperationConverter(Windows::Foundation::IAsyncAction ^ _Operation)
: _AsyncInfoImpl<Windows::Foundation::IAsyncAction ^
, Windows::Foundation::AsyncActionCompletedHandler, details::_Unit_type>(_Operation)
{
}
public:
virtual details::_Unit_type GetResults() override
{
// Invoke GetResults on the IAsyncAction to allow exceptions to be thrown to higher layers before returning a
// dummy value.
_M_asyncInfo.Get()->GetResults();
return details::_Unit_type();
}
};
/// <summary>
/// Class _IAsyncActionWithProgressToAsyncOperationConverter is used to convert an instance of
/// IAsyncActionWithProgress into IAsyncOperation<_Unit_type>
/// </summary>
template<typename _Progress>
ref struct _IAsyncActionWithProgressToAsyncOperationConverter sealed
: _AsyncInfoImpl<Windows::Foundation::IAsyncActionWithProgress<_Progress> ^
, Windows::Foundation::AsyncActionWithProgressCompletedHandler<_Progress>, details::_Unit_type>
{
internal
: _IAsyncActionWithProgressToAsyncOperationConverter(Windows::Foundation::IAsyncActionWithProgress<_Progress> ^
_Action)
: _AsyncInfoImpl<Windows::Foundation::IAsyncActionWithProgress<_Progress> ^,
Windows::Foundation::AsyncActionWithProgressCompletedHandler<_Progress>,
details::_Unit_type>(_Action)
{
}
public:
virtual details::_Unit_type GetResults() override
{
// Invoke GetResults on the IAsyncActionWithProgress to allow exceptions to be thrown before returning a dummy
// value.
_M_asyncInfo.Get()->GetResults();
return details::_Unit_type();
}
};
#endif /* defined (__cplusplus_winrt) */
} // namespace details
/// <summary>
/// The <c>task_continuation_context</c> class allows you to specify where you would like a continuation to be
/// executed. It is only useful to use this class from a Windows Store app. For non-Windows Store apps, the task
/// continuation's execution context is determined by the runtime, and not configurable.
/// </summary>
/// <seealso cref="task Class"/>
/**/
class task_continuation_context : public details::_ContextCallback
{
public:
/// <summary>
/// Creates the default task continuation context.
/// </summary>
/// <returns>
/// The default continuation context.
/// </returns>
/// <remarks>
/// The default context is used if you don't specify a continuation context when you call the <c>then</c>
/// method. In Windows applications for Windows 7 and below, as well as desktop applications on Windows 8 and
/// higher, the runtime determines where task continuations will execute. However, in a Windows Store app, the
/// default continuation context for a continuation on an apartment aware task is the apartment where
/// <c>then</c> is invoked. <para>An apartment aware task is a task that unwraps a Windows Runtime
/// <c>IAsyncInfo</c> interface, or a task that is descended from such a task. Therefore, if you schedule a
/// continuation on an apartment aware task in a Windows Runtime STA, the continuation will execute in that
/// STA.</para> <para>A continuation on a non-apartment aware task will execute in a context the Runtime
/// chooses.</para>
/// </remarks>
/**/
static task_continuation_context use_default()
{
#if defined(__cplusplus_winrt)
// The callback context is created with the context set to CaptureDeferred and resolved when it is used in
// .then()
return task_continuation_context(
true); // sets it to deferred, is resolved in the constructor of _ContinuationTaskHandle
#else /* defined (__cplusplus_winrt) */
return task_continuation_context();
#endif /* defined (__cplusplus_winrt) */
}
#if defined(__cplusplus_winrt)
/// <summary>
/// Creates a task continuation context which allows the Runtime to choose the execution context for a
/// continuation.
/// </summary>
/// <returns>
/// A task continuation context that represents an arbitrary location.
/// </returns>
/// <remarks>
/// When this continuation context is used the continuation will execute in a context the runtime chooses even
/// if the antecedent task is apartment aware. <para><c>use_arbitrary</c> can be used to turn off the default
/// behavior for a continuation on an apartment aware task created in an STA. </para> <para>This method is only
/// available to Windows Store apps.</para>
/// </remarks>
/**/
static task_continuation_context use_arbitrary()
{
task_continuation_context _Arbitrary(true);
_Arbitrary._Resolve(false);
return _Arbitrary;
}
/// <summary>
/// Returns a task continuation context object that represents the current execution context.
/// </summary>
/// <returns>
/// The current execution context.
/// </returns>
/// <remarks>
/// This method captures the caller's Windows Runtime context so that continuations can be executed in the right
/// apartment. <para>The value returned by <c>use_current</c> can be used to indicate to the Runtime that the
/// continuation should execute in the captured context (STA vs MTA) regardless of whether or not the antecedent
/// task is apartment aware. An apartment aware task is a task that unwraps a Windows Runtime <c>IAsyncInfo</c>
/// interface, or a task that is descended from such a task. </para> <para>This method is only available to
/// Windows Store apps.</para>
/// </remarks>
/**/
static task_continuation_context use_current()
{
task_continuation_context _Current(true);
_Current._Resolve(true);
return _Current;
}
#endif /* defined (__cplusplus_winrt) */
private:
task_continuation_context(bool _DeferCapture = false) : details::_ContextCallback(_DeferCapture) {}
};
class task_options;
namespace details
{
struct _Internal_task_options
{
bool _M_hasPresetCreationCallstack;
_TaskCreationCallstack _M_presetCreationCallstack;
void _set_creation_callstack(const _TaskCreationCallstack& _callstack)
{
_M_hasPresetCreationCallstack = true;
_M_presetCreationCallstack = _callstack;
}
_Internal_task_options() { _M_hasPresetCreationCallstack = false; }
};
inline _Internal_task_options& _get_internal_task_options(task_options& options);
inline const _Internal_task_options& _get_internal_task_options(const task_options& options);
} // namespace details
/// <summary>
/// Represents the allowed options for creating a task
/// </summary>
class task_options
{
public:
/// <summary>
/// Default list of task creation options
/// </summary>
task_options()
: _M_Scheduler(get_ambient_scheduler())
, _M_CancellationToken(cancellation_token::none())
, _M_ContinuationContext(task_continuation_context::use_default())
, _M_HasCancellationToken(false)
, _M_HasScheduler(false)
{
}
/// <summary>
/// Task option that specify a cancellation token
/// </summary>
task_options(cancellation_token _Token)
: _M_Scheduler(get_ambient_scheduler())
, _M_CancellationToken(_Token)
, _M_ContinuationContext(task_continuation_context::use_default())
, _M_HasCancellationToken(true)
, _M_HasScheduler(false)
{
}
/// <summary>
/// Task option that specify a continuation context. This is valid only for continuations (then)
/// </summary>
task_options(task_continuation_context _ContinuationContext)
: _M_Scheduler(get_ambient_scheduler())
, _M_CancellationToken(cancellation_token::none())
, _M_ContinuationContext(_ContinuationContext)
, _M_HasCancellationToken(false)
, _M_HasScheduler(false)
{
}
/// <summary>
/// Task option that specify a cancellation token and a continuation context. This is valid only for
/// continuations (then)
/// </summary>
task_options(cancellation_token _Token, task_continuation_context _ContinuationContext)
: _M_Scheduler(get_ambient_scheduler())
, _M_CancellationToken(_Token)
, _M_ContinuationContext(_ContinuationContext)
, _M_HasCancellationToken(false)
, _M_HasScheduler(false)
{
}
/// <summary>
/// Task option that specify a scheduler with shared lifetime
/// </summary>
template<typename _SchedType>
task_options(std::shared_ptr<_SchedType> _Scheduler)
: _M_Scheduler(std::move(_Scheduler))
, _M_CancellationToken(cancellation_token::none())
, _M_ContinuationContext(task_continuation_context::use_default())
, _M_HasCancellationToken(false)
, _M_HasScheduler(true)
{
}
/// <summary>
/// Task option that specify a scheduler reference
/// </summary>
task_options(scheduler_interface& _Scheduler)
: _M_Scheduler(&_Scheduler)
, _M_CancellationToken(cancellation_token::none())
, _M_ContinuationContext(task_continuation_context::use_default())
, _M_HasCancellationToken(false)
, _M_HasScheduler(true)
{
}
/// <summary>
/// Task option that specify a scheduler
/// </summary>
task_options(scheduler_ptr _Scheduler)
: _M_Scheduler(std::move(_Scheduler))
, _M_CancellationToken(cancellation_token::none())
, _M_ContinuationContext(task_continuation_context::use_default())
, _M_HasCancellationToken(false)
, _M_HasScheduler(true)
{
}
/// <summary>
/// Task option copy constructor
/// </summary>
task_options(const task_options& _TaskOptions)
: _M_Scheduler(_TaskOptions.get_scheduler())
, _M_CancellationToken(_TaskOptions.get_cancellation_token())
, _M_ContinuationContext(_TaskOptions.get_continuation_context())
, _M_HasCancellationToken(_TaskOptions.has_cancellation_token())
, _M_HasScheduler(_TaskOptions.has_scheduler())
{
}
/// <summary>
/// Sets the given token in the options
/// </summary>
void set_cancellation_token(cancellation_token _Token)
{
_M_CancellationToken = _Token;
_M_HasCancellationToken = true;
}
/// <summary>
/// Sets the given continuation context in the options
/// </summary>
void set_continuation_context(task_continuation_context _ContinuationContext)
{
_M_ContinuationContext = _ContinuationContext;
}
/// <summary>
/// Indicates whether a cancellation token was specified by the user
/// </summary>
bool has_cancellation_token() const { return _M_HasCancellationToken; }
/// <summary>
/// Returns the cancellation token
/// </summary>
cancellation_token get_cancellation_token() const { return _M_CancellationToken; }
/// <summary>
/// Returns the continuation context
/// </summary>
task_continuation_context get_continuation_context() const { return _M_ContinuationContext; }
/// <summary>
/// Indicates whether a scheduler n was specified by the user
/// </summary>
bool has_scheduler() const { return _M_HasScheduler; }
/// <summary>
/// Returns the scheduler
/// </summary>
scheduler_ptr get_scheduler() const { return _M_Scheduler; }
private:
task_options const& operator=(task_options const& _Right);
friend details::_Internal_task_options& details::_get_internal_task_options(task_options&);
friend const details::_Internal_task_options& details::_get_internal_task_options(const task_options&);
scheduler_ptr _M_Scheduler;
cancellation_token _M_CancellationToken;
task_continuation_context _M_ContinuationContext;
details::_Internal_task_options _M_InternalTaskOptions;
bool _M_HasCancellationToken;
bool _M_HasScheduler;
};
namespace details
{
inline _Internal_task_options& _get_internal_task_options(task_options& options)
{
return options._M_InternalTaskOptions;
}
inline const _Internal_task_options& _get_internal_task_options(const task_options& options)
{
return options._M_InternalTaskOptions;
}
struct _Task_impl_base;
template<typename _ReturnType>
struct _Task_impl;
template<typename _ReturnType>
struct _Task_ptr
{
typedef std::shared_ptr<_Task_impl<_ReturnType>> _Type;
static _Type _Make(_CancellationTokenState* _Ct, scheduler_ptr _Scheduler_arg)
{
return std::make_shared<_Task_impl<_ReturnType>>(_Ct, _Scheduler_arg);
}
};
typedef _TaskCollection_t::_TaskProcHandle_t _UnrealizedChore_t;
typedef std::shared_ptr<_Task_impl_base> _Task_ptr_base;
// The weak-typed base task handler for continuation tasks.
struct _ContinuationTaskHandleBase : _UnrealizedChore_t
{
_ContinuationTaskHandleBase* _M_next;
task_continuation_context _M_continuationContext;
bool _M_isTaskBasedContinuation;
// This field gives inlining scheduling policy for current chore.
_TaskInliningMode_t _M_inliningMode;
virtual _Task_ptr_base _GetTaskImplBase() const = 0;
_ContinuationTaskHandleBase()
: _M_next(nullptr)
, _M_continuationContext(task_continuation_context::use_default())
, _M_isTaskBasedContinuation(false)
, _M_inliningMode(details::_NoInline)
{
}
virtual ~_ContinuationTaskHandleBase() {}
};
#if PPLX_TASK_ASYNC_LOGGING
// GUID used for identifying causality logs from PPLTask
const ::Platform::Guid _PPLTaskCausalityPlatformID(
0x7A76B220, 0xA758, 0x4E6E, 0xB0, 0xE0, 0xD7, 0xC6, 0xD7, 0x4A, 0x88, 0xFE);
__declspec(selectany) volatile long _isCausalitySupported = 0;
inline bool _IsCausalitySupported()
{
#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
if (_isCausalitySupported == 0)
{
long _causality = 1;
OSVERSIONINFOEX _osvi = {};
_osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
// The Causality is supported on Windows version higher than Windows 8
_osvi.dwMajorVersion = 6;
_osvi.dwMinorVersion = 3;
DWORDLONG _conditionMask = 0;
VER_SET_CONDITION(_conditionMask, VER_MAJORVERSION, VER_GREATER_EQUAL);
VER_SET_CONDITION(_conditionMask, VER_MINORVERSION, VER_GREATER_EQUAL);
if (::VerifyVersionInfo(&_osvi, VER_MAJORVERSION | VER_MINORVERSION, _conditionMask))
{
_causality = 2;
}
_isCausalitySupported = _causality;
return _causality == 2;
}
return _isCausalitySupported == 2 ? true : false;
#else
return true;
#endif
}
// Stateful logger rests inside task_impl_base.
struct _TaskEventLogger
{
_Task_impl_base* _M_task;
bool _M_scheduled;
bool _M_taskPostEventStarted;
// Log before scheduling task
void _LogScheduleTask(bool _isContinuation)
{
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceOperationCreation(
::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required,
::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID,
reinterpret_cast<unsigned long long>(_M_task),
_isContinuation ? "pplx::PPLTask::ScheduleContinuationTask" : "pplx::PPLTask::ScheduleTask",
0);
_M_scheduled = true;
}
}
// It will log the cancel event but not canceled state. _LogTaskCompleted will log the terminal state, which
// includes cancel state.
void _LogCancelTask()
{
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceOperationRelation(
::Windows::Foundation::Diagnostics::CausalityTraceLevel::Important,
::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID,
reinterpret_cast<unsigned long long>(_M_task),
::Windows::Foundation::Diagnostics::CausalityRelation::Cancel);
}
}
// Log when task reaches terminal state. Note: the task can reach a terminal state (by cancellation or exception)
// without having run
void _LogTaskCompleted();
// Log when task body (which includes user lambda and other scheduling code) begin to run
void _LogTaskExecutionStarted() {}
// Log when task body finish executing
void _LogTaskExecutionCompleted()
{
if (_M_taskPostEventStarted && details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceSynchronousWorkCompletion(
::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required,
::Windows::Foundation::Diagnostics::CausalitySource::Library,
::Windows::Foundation::Diagnostics::CausalitySynchronousWork::CompletionNotification);
}
}
// Log right before user lambda being invoked
void _LogWorkItemStarted()
{
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceSynchronousWorkStart(
::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required,
::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID,
reinterpret_cast<unsigned long long>(_M_task),
::Windows::Foundation::Diagnostics::CausalitySynchronousWork::Execution);
}
}
// Log right after user lambda being invoked
void _LogWorkItemCompleted()
{
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceSynchronousWorkCompletion(
::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required,
::Windows::Foundation::Diagnostics::CausalitySource::Library,
::Windows::Foundation::Diagnostics::CausalitySynchronousWork::Execution);
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceSynchronousWorkStart(
::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required,
::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID,
reinterpret_cast<unsigned long long>(_M_task),
::Windows::Foundation::Diagnostics::CausalitySynchronousWork::CompletionNotification);
_M_taskPostEventStarted = true;
}
}
_TaskEventLogger(_Task_impl_base* _task) : _M_task(_task)
{
_M_scheduled = false;
_M_taskPostEventStarted = false;
}
};
// Exception safe logger for user lambda
struct _TaskWorkItemRAIILogger
{
_TaskEventLogger& _M_logger;
_TaskWorkItemRAIILogger(_TaskEventLogger& _taskHandleLogger) : _M_logger(_taskHandleLogger)
{
_M_logger._LogWorkItemStarted();
}
~_TaskWorkItemRAIILogger() { _M_logger._LogWorkItemCompleted(); }
_TaskWorkItemRAIILogger& operator=(const _TaskWorkItemRAIILogger&); // cannot be assigned
};
#else
inline void _LogCancelTask(_Task_impl_base*) {}
struct _TaskEventLogger
{
void _LogScheduleTask(bool) {}
void _LogCancelTask() {}
void _LogWorkItemStarted() {}
void _LogWorkItemCompleted() {}
void _LogTaskExecutionStarted() {}
void _LogTaskExecutionCompleted() {}
void _LogTaskCompleted() {}
_TaskEventLogger(_Task_impl_base*) {}
};
struct _TaskWorkItemRAIILogger
{
_TaskWorkItemRAIILogger(_TaskEventLogger&) {}
};
#endif
/// <summary>
/// The _PPLTaskHandle is the strong-typed task handle base. All user task functions need to be wrapped in this task
/// handler to be executable by PPL. By deriving from a different _BaseTaskHandle, it can be used for both initial
/// tasks and continuation tasks. For initial tasks, _PPLTaskHandle will be derived from _UnrealizedChore_t, and for
/// continuation tasks, it will be derived from _ContinuationTaskHandleBase. The life time of the _PPLTaskHandle
/// object is be managed by runtime if task handle is scheduled.
/// </summary>
/// <typeparam name="_ReturnType">
/// The result type of the _Task_impl.
/// </typeparam>
/// <typeparam name="_DerivedTaskHandle">
/// The derived task handle class. The <c>operator ()</c> needs to be implemented.
/// </typeparam>
/// <typeparam name="_BaseTaskHandle">
/// The base class from which _PPLTaskHandle should be derived. This is either _UnrealizedChore_t or
/// _ContinuationTaskHandleBase.
/// </typeparam>
template<typename _ReturnType, typename _DerivedTaskHandle, typename _BaseTaskHandle>
struct _PPLTaskHandle : _BaseTaskHandle
{
_PPLTaskHandle(const typename _Task_ptr<_ReturnType>::_Type& _PTask) : _M_pTask(_PTask) {}
virtual ~_PPLTaskHandle()
{
// Here is the sink of all task completion code paths
_M_pTask->_M_taskEventLogger._LogTaskCompleted();
}
virtual void invoke() const
{
// All exceptions should be rethrown to finish cleanup of the task collection. They will be caught and handled
// by the runtime.
_ASSERTE((bool)_M_pTask);
if (!_M_pTask->_TransitionedToStarted())
{
static_cast<const _DerivedTaskHandle*>(this)->_SyncCancelAndPropagateException();
return;
}
_M_pTask->_M_taskEventLogger._LogTaskExecutionStarted();
try
{
// All derived task handle must implement this contract function.
static_cast<const _DerivedTaskHandle*>(this)->_Perform();
}
catch (const task_canceled&)
{
_M_pTask->_Cancel(true);
}
catch (const _Interruption_exception&)
{
_M_pTask->_Cancel(true);
}
#if defined(__cplusplus_winrt)
catch (::Platform::Exception ^ _E)
{
_M_pTask->_CancelWithException(_E);
}
#endif /* defined (__cplusplus_winrt) */
catch (...)
{
_M_pTask->_CancelWithException(std::current_exception());
}
_M_pTask->_M_taskEventLogger._LogTaskExecutionCompleted();
}
// Cast _M_pTask pointer to "type-less" _Task_impl_base pointer, which can be used in _ContinuationTaskHandleBase.
// The return value should be automatically optimized by R-value ref.
_Task_ptr_base _GetTaskImplBase() const { return _M_pTask; }
typename _Task_ptr<_ReturnType>::_Type _M_pTask;
private:
_PPLTaskHandle const& operator=(_PPLTaskHandle const&); // no assignment operator
};
/// <summary>
/// The base implementation of a first-class task. This class contains all the non-type specific
/// implementation details of the task.
/// </summary>
/**/
struct _Task_impl_base
{
enum _TaskInternalState
{
// Tracks the state of the task, rather than the task collection on which the task is scheduled
_Created,
_Started,
_PendingCancel,
_Completed,
_Canceled
};
// _M_taskEventLogger - 'this' : used in base member initializer list
#if defined(_MSC_VER)
#pragma warning(push)
#pragma warning(disable : 4355)
#endif
_Task_impl_base(_CancellationTokenState* _PTokenState, scheduler_ptr _Scheduler_arg)
: _M_TaskState(_Created)
, _M_fFromAsync(false)
, _M_fUnwrappedTask(false)
, _M_pRegistration(nullptr)
, _M_Continuations(nullptr)
, _M_TaskCollection(_Scheduler_arg)
, _M_taskEventLogger(this)
{
// Set cancellation token
_M_pTokenState = _PTokenState;
_ASSERTE(_M_pTokenState != nullptr);
if (_M_pTokenState != _CancellationTokenState::_None()) _M_pTokenState->_Reference();
}
#if defined(_MSC_VER)
#pragma warning(pop)
#endif
virtual ~_Task_impl_base()
{
_ASSERTE(_M_pTokenState != nullptr);
if (_M_pTokenState != _CancellationTokenState::_None())
{
_M_pTokenState->_Release();
}
}
task_status _Wait()
{
bool _DoWait = true;
#if defined(__cplusplus_winrt)
if (_IsNonBlockingThread())
{
// In order to prevent Windows Runtime STA threads from blocking the UI, calling task.wait() task.get() is
// illegal if task has not been completed.
if (!_IsCompleted() && !_IsCanceled())
{
throw invalid_operation("Illegal to wait on a task in a Windows Runtime STA");
}
else
{
// Task Continuations are 'scheduled' *inside* the chore that is executing on the ancestors's task
// group. If a continuation needs to be marshaled to a different apartment, instead of scheduling, we
// make a synchronous cross apartment COM call to execute the continuation. If it then happens to do
// something which waits on the ancestor (say it calls .get(), which task based continuations are wont
// to do), waiting on the task group results in on the chore that is making this synchronous callback,
// which causes a deadlock. To avoid this, we test the state ancestor's event , and we will NOT wait on
// if it has finished execution (which means now we are on the inline synchronous callback).
_DoWait = false;
}
}
#endif /* defined (__cplusplus_winrt) */
if (_DoWait)
{
// If this task was created from a Windows Runtime async operation, do not attempt to inline it. The
// async operation will take place on a thread in the appropriate apartment Simply wait for the completed
// event to be set.
if (_M_fFromAsync)
{
_M_TaskCollection._Wait();
}
else
{
// Wait on the task collection to complete. The task collection is guaranteed to still be
// valid since the task must be still within scope so that the _Task_impl_base destructor
// has not yet been called. This call to _Wait potentially inlines execution of work.
try
{
// Invoking wait on a task collection resets the state of the task collection. This means that
// if the task collection itself were canceled, or had encountered an exception, only the first
// call to wait will receive this status. However, both cancellation and exceptions flowing through
// tasks set state in the task impl itself.
// When it returns canceled, either work chore or the cancel thread should already have set task's
// state properly -- canceled state or completed state (because there was no interruption point).
// For tasks with unwrapped tasks, we should not change the state of current task, since the
// unwrapped task are still running.
_M_TaskCollection._RunAndWait();
}
catch (details::_Interruption_exception&)
{
// The _TaskCollection will never be an interruption point since it has a none token.
_ASSERTE(false);
}
catch (task_canceled&)
{
// task_canceled is a special exception thrown by cancel_current_task. The spec states that
// cancel_current_task must be called from code that is executed within the task (throwing it from
// parallel work created by and waited upon by the task is acceptable). We can safely assume that
// the task wrapper _PPLTaskHandle::operator() has seen the exception and canceled the task. Swallow
// the exception here.
_ASSERTE(_IsCanceled());
}
#if defined(__cplusplus_winrt)
catch (::Platform::Exception ^ _E)
{
// Its possible the task body hasn't seen the exception, if so we need to cancel with exception
// here.
if (!_HasUserException())
{
_CancelWithException(_E);
}
// Rethrow will mark the exception as observed.
_M_exceptionHolder->_RethrowUserException();
}
#endif /* defined (__cplusplus_winrt) */
catch (...)
{
// Its possible the task body hasn't seen the exception, if so we need to cancel with exception
// here.
if (!_HasUserException())
{
_CancelWithException(std::current_exception());
}
// Rethrow will mark the exception as observed.
_M_exceptionHolder->_RethrowUserException();
}
// If the lambda body for this task (executed or waited upon in _RunAndWait above) happened to return a
// task which is to be unwrapped and plumbed to the output of this task, we must not only wait on the
// lambda body, we must wait on the **INNER** body. It is in theory possible that we could inline such
// if we plumb a series of things through; however, this takes the tact of simply waiting upon the
// completion signal.
if (_M_fUnwrappedTask)
{
_M_TaskCollection._Wait();
}
}
}
if (_HasUserException())
{
_M_exceptionHolder->_RethrowUserException();
}
else if (_IsCanceled())
{
return canceled;
}
_ASSERTE(_IsCompleted());
return completed;
}
/// <summary>
/// Requests cancellation on the task and schedules continuations if the task can be transitioned to a terminal
/// state.
/// </summary>
/// <param name="_SynchronousCancel">
/// Set to true if the cancel takes place as a result of the task body encountering an exception, or because an
/// ancestor or task_completion_event the task was registered with were canceled with an exception. A
/// synchronous cancel is one that assures the task could not be running on a different thread at the time the
/// cancellation is in progress. An asynchronous cancel is one where the thread performing the cancel has no
/// control over the thread that could be executing the task, that is the task could execute concurrently while
/// the cancellation is in progress.
/// </param>
/// <param name="_UserException">
/// Whether an exception other than the internal runtime cancellation exceptions caused this cancellation.
/// </param>
/// <param name="_PropagatedFromAncestor">
/// Whether this exception came from an ancestor task or a task_completion_event as opposed to an exception that
/// was encountered by the task itself. Only valid when _UserException is set to true.
/// </param>
/// <param name="_ExHolder">
/// The exception holder that represents the exception. Only valid when _UserException is set to true.
/// </param>
virtual bool _CancelAndRunContinuations(bool _SynchronousCancel,
bool _UserException,
bool _PropagatedFromAncestor,
const std::shared_ptr<_ExceptionHolder>& _ExHolder) = 0;
bool _Cancel(bool _SynchronousCancel)
{
// Send in a dummy value for exception. It is not used when the first parameter is false.
return _CancelAndRunContinuations(_SynchronousCancel, false, false, _M_exceptionHolder);
}
bool _CancelWithExceptionHolder(const std::shared_ptr<_ExceptionHolder>& _ExHolder, bool _PropagatedFromAncestor)
{
// This task was canceled because an ancestor task encountered an exception.
return _CancelAndRunContinuations(true, true, _PropagatedFromAncestor, _ExHolder);
}
#if defined(__cplusplus_winrt)
bool _CancelWithException(::Platform::Exception ^ _Exception)
{
// This task was canceled because the task body encountered an exception.
_ASSERTE(!_HasUserException());
return _CancelAndRunContinuations(
true, true, false, std::make_shared<_ExceptionHolder>(_Exception, _GetTaskCreationCallstack()));
}
#endif /* defined (__cplusplus_winrt) */
bool _CancelWithException(const std::exception_ptr& _Exception)
{
// This task was canceled because the task body encountered an exception.
_ASSERTE(!_HasUserException());
return _CancelAndRunContinuations(
true, true, false, std::make_shared<_ExceptionHolder>(_Exception, _GetTaskCreationCallstack()));
}
void _RegisterCancellation(std::weak_ptr<_Task_impl_base> _WeakPtr)
{
_ASSERTE(details::_CancellationTokenState::_IsValid(_M_pTokenState));
auto _CancellationCallback = [_WeakPtr]() {
// Taking ownership of the task prevents dead lock during destruction
// if the destructor waits for the cancellations to be finished
auto _task = _WeakPtr.lock();
if (_task != nullptr) _task->_Cancel(false);
};
_M_pRegistration =
new details::_CancellationTokenCallback<decltype(_CancellationCallback)>(_CancellationCallback);
_M_pTokenState->_RegisterCallback(_M_pRegistration);
}
void _DeregisterCancellation()
{
if (_M_pRegistration != nullptr)
{
_M_pTokenState->_DeregisterCallback(_M_pRegistration);
_M_pRegistration->_Release();
_M_pRegistration = nullptr;
}
}
bool _IsCreated() { return (_M_TaskState == _Created); }
bool _IsStarted() { return (_M_TaskState == _Started); }
bool _IsPendingCancel() { return (_M_TaskState == _PendingCancel); }
bool _IsCompleted() { return (_M_TaskState == _Completed); }
bool _IsCanceled() { return (_M_TaskState == _Canceled); }
bool _HasUserException() { return static_cast<bool>(_M_exceptionHolder); }
const std::shared_ptr<_ExceptionHolder>& _GetExceptionHolder()
{
_ASSERTE(_HasUserException());
return _M_exceptionHolder;
}
bool _IsApartmentAware() { return _M_fFromAsync; }
void _SetAsync(bool _Async = true) { _M_fFromAsync = _Async; }
_TaskCreationCallstack _GetTaskCreationCallstack() { return _M_pTaskCreationCallstack; }
void _SetTaskCreationCallstack(const _TaskCreationCallstack& _Callstack) { _M_pTaskCreationCallstack = _Callstack; }
/// <summary>
/// Helper function to schedule the task on the Task Collection.
/// </summary>
/// <param name="_PTaskHandle">
/// The task chore handle that need to be executed.
/// </param>
/// <param name="_InliningMode">
/// The inlining scheduling policy for current _PTaskHandle.
/// </param>
void _ScheduleTask(_UnrealizedChore_t* _PTaskHandle, _TaskInliningMode_t _InliningMode)
{
try
{
_M_TaskCollection._ScheduleTask(_PTaskHandle, _InliningMode);
}
catch (const task_canceled&)
{
// task_canceled is a special exception thrown by cancel_current_task. The spec states that
// cancel_current_task must be called from code that is executed within the task (throwing it from parallel
// work created by and waited upon by the task is acceptable). We can safely assume that the task wrapper
// _PPLTaskHandle::operator() has seen the exception and canceled the task. Swallow the exception here.
_ASSERTE(_IsCanceled());
}
catch (const _Interruption_exception&)
{
// The _TaskCollection will never be an interruption point since it has a none token.
_ASSERTE(false);
}
catch (...)
{
// The exception could have come from two places:
// 1. From the chore body, so it already should have been caught and canceled.
// In this case swallow the exception.
// 2. From trying to actually schedule the task on the scheduler.
// In this case cancel the task with the current exception, otherwise the
// task will never be signaled leading to deadlock when waiting on the task.
if (!_HasUserException())
{
_CancelWithException(std::current_exception());
}
}
}
/// <summary>
/// Function executes a continuation. This function is recorded by a parent task implementation
/// when a continuation is created in order to execute later.
/// </summary>
/// <param name="_PTaskHandle">
/// The continuation task chore handle that need to be executed.
/// </param>
/**/
void _RunContinuation(_ContinuationTaskHandleBase* _PTaskHandle)
{
_Task_ptr_base _ImplBase = _PTaskHandle->_GetTaskImplBase();
if (_IsCanceled() && !_PTaskHandle->_M_isTaskBasedContinuation)
{
if (_HasUserException())
{
// If the ancestor encountered an exception, transfer the exception to the continuation
// This traverses down the tree to propagate the exception.
_ImplBase->_CancelWithExceptionHolder(_GetExceptionHolder(), true);
}
else
{
// If the ancestor was canceled, then your own execution should be canceled.
// This traverses down the tree to cancel it.
_ImplBase->_Cancel(true);
}
}
else
{
// This can only run when the ancestor has completed or it's a task based continuation that fires when a
// task is canceled (with or without a user exception).
_ASSERTE(_IsCompleted() || _PTaskHandle->_M_isTaskBasedContinuation);
_ASSERTE(!_ImplBase->_IsCanceled());
return _ImplBase->_ScheduleContinuationTask(_PTaskHandle);
}
// If the handle is not scheduled, we need to manually delete it.
delete _PTaskHandle;
}
// Schedule a continuation to run
void _ScheduleContinuationTask(_ContinuationTaskHandleBase* _PTaskHandle)
{
_M_taskEventLogger._LogScheduleTask(true);
// Ensure that the continuation runs in proper context (this might be on a Concurrency Runtime thread or in a
// different Windows Runtime apartment)
if (_PTaskHandle->_M_continuationContext._HasCapturedContext())
{
// For those continuations need to be scheduled inside captured context, we will try to apply automatic
// inlining to their inline modes, if they haven't been specified as _ForceInline yet. This change will
// encourage those continuations to be executed inline so that reduce the cost of marshaling. For normal
// continuations we won't do any change here, and their inline policies are completely decided by ._ThenImpl
// method.
if (_PTaskHandle->_M_inliningMode != details::_ForceInline)
{
_PTaskHandle->_M_inliningMode = details::_DefaultAutoInline;
}
_ScheduleFuncWithAutoInline(
[_PTaskHandle]() {
// Note that we cannot directly capture "this" pointer, instead, we should use _TaskImplPtr, a
// shared_ptr to the _Task_impl_base. Because "this" pointer will be invalid as soon as _PTaskHandle
// get deleted. _PTaskHandle will be deleted after being scheduled.
auto _TaskImplPtr = _PTaskHandle->_GetTaskImplBase();
if (details::_ContextCallback::_CaptureCurrent() == _PTaskHandle->_M_continuationContext)
{
_TaskImplPtr->_ScheduleTask(_PTaskHandle, details::_ForceInline);
}
else
{
//
// It's entirely possible that the attempt to marshal the call into a differing context will
// fail. In this case, we need to handle the exception and mark the continuation as canceled
// with the appropriate exception. There is one slight hitch to this:
//
// NOTE: COM's legacy behavior is to swallow SEH exceptions and marshal them back as HRESULTS.
// This will in effect turn an SEH into a C++ exception that gets tagged on the task. One
// unfortunate result of this is that various pieces of the task infrastructure will not be in a
// valid state after this in /EHsc (due to the lack of destructors running, etc...).
//
try
{
// Dev10 compiler needs this!
auto _PTaskHandle1 = _PTaskHandle;
_PTaskHandle->_M_continuationContext._CallInContext([_PTaskHandle1, _TaskImplPtr]() {
_TaskImplPtr->_ScheduleTask(_PTaskHandle1, details::_ForceInline);
});
}
#if defined(__cplusplus_winrt)
catch (::Platform::Exception ^ _E)
{
_TaskImplPtr->_CancelWithException(_E);
}
#endif /* defined (__cplusplus_winrt) */
catch (...)
{
_TaskImplPtr->_CancelWithException(std::current_exception());
}
}
},
_PTaskHandle->_M_inliningMode);
}
else
{
_ScheduleTask(_PTaskHandle, _PTaskHandle->_M_inliningMode);
}
}
/// <summary>
/// Schedule the actual continuation. This will either schedule the function on the continuation task's
/// implementation if the task has completed or append it to a list of functions to execute when the task
/// actually does complete.
/// </summary>
/// <typeparam name="_FuncInputType">
/// The input type of the task.
/// </typeparam>
/// <typeparam name="_FuncOutputType">
/// The output type of the task.
/// </typeparam>
/**/
void _ScheduleContinuation(_ContinuationTaskHandleBase* _PTaskHandle)
{
enum
{
_Nothing,
_Schedule,
_Cancel,
_CancelWithException
} _Do = _Nothing;
// If the task has canceled, cancel the continuation. If the task has completed, execute the continuation right
// away. Otherwise, add it to the list of pending continuations
{
::pplx::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
if (_IsCompleted() || (_IsCanceled() && _PTaskHandle->_M_isTaskBasedContinuation))
{
_Do = _Schedule;
}
else if (_IsCanceled())
{
if (_HasUserException())
{
_Do = _CancelWithException;
}
else
{
_Do = _Cancel;
}
}
else
{
// chain itself on the continuation chain.
_PTaskHandle->_M_next = _M_Continuations;
_M_Continuations = _PTaskHandle;
}
}
// Cancellation and execution of continuations should be performed after releasing the lock. Continuations off
// of async tasks may execute inline.
switch (_Do)
{
case _Schedule:
{
_PTaskHandle->_GetTaskImplBase()->_ScheduleContinuationTask(_PTaskHandle);
break;
}
case _Cancel:
{
// If the ancestor was canceled, then your own execution should be canceled.
// This traverses down the tree to cancel it.
_PTaskHandle->_GetTaskImplBase()->_Cancel(true);
delete _PTaskHandle;
break;
}
case _CancelWithException:
{
// If the ancestor encountered an exception, transfer the exception to the continuation
// This traverses down the tree to propagate the exception.
_PTaskHandle->_GetTaskImplBase()->_CancelWithExceptionHolder(_GetExceptionHolder(), true);
delete _PTaskHandle;
break;
}
case _Nothing:
default:
// In this case, we have inserted continuation to continuation chain,
// nothing more need to be done, just leave.
break;
}
}
void _RunTaskContinuations()
{
// The link list can no longer be modified at this point,
// since all following up continuations will be scheduled by themselves.
_ContinuationList _Cur = _M_Continuations, _Next;
_M_Continuations = nullptr;
while (_Cur)
{
// Current node might be deleted after running,
// so we must fetch the next first.
_Next = _Cur->_M_next;
_RunContinuation(_Cur);
_Cur = _Next;
}
}
#if defined(__cplusplus_winrt)
static bool _IsNonBlockingThread()
{
APTTYPE _AptType;
APTTYPEQUALIFIER _AptTypeQualifier;
HRESULT hr = CoGetApartmentType(&_AptType, &_AptTypeQualifier);
//
// If it failed, it's not a Windows Runtime/COM initialized thread. This is not a failure.
//
if (SUCCEEDED(hr))
{
switch (_AptType)
{
case APTTYPE_STA:
case APTTYPE_MAINSTA: return true; break;
case APTTYPE_NA:
switch (_AptTypeQualifier)
{
// A thread executing in a neutral apartment is either STA or MTA. To find out if this thread is
// allowed to wait, we check the app qualifier. If it is an STA thread executing in a neutral
// apartment, waiting is illegal, because the thread is responsible for pumping messages and
// waiting on a task could take the thread out of circulation for a while.
case APTTYPEQUALIFIER_NA_ON_STA:
case APTTYPEQUALIFIER_NA_ON_MAINSTA: return true; break;
}
break;
}
}
#if _UITHREADCTXT_SUPPORT
// This method is used to throw an exception in _Wait() if called within STA. We
// want the same behavior if _Wait is called on the UI thread.
if (SUCCEEDED(CaptureUiThreadContext(nullptr)))
{
return true;
}
#endif /* _UITHREADCTXT_SUPPORT */
return false;
}
template<typename _ReturnType, typename>
static void _AsyncInit(
const typename _Task_ptr<_ReturnType>::_Type& _OuterTask,
Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value> ^ _AsyncOp)
{
// This method is invoked either when a task is created from an existing async operation or
// when a lambda that creates an async operation executes.
// If the outer task is pending cancel, cancel the async operation before setting the completed handler. The COM
// reference on the IAsyncInfo object will be released when all ^references to the operation go out of scope.
// This assertion uses the existence of taskcollection to determine if the task was created from an event.
// That is no longer valid as even tasks created from a user lambda could have no underlying taskcollection
// when a custom scheduler is used.
// _ASSERTE((!_OuterTask->_M_TaskCollection._IsCreated() || _OuterTask->_M_fUnwrappedTask) &&
// !_OuterTask->_IsCanceled());
// Pass the shared_ptr by value into the lambda instead of using 'this'.
_AsyncOp->Completed = ref new Windows::Foundation::AsyncOperationCompletedHandler<_ReturnType>(
[_OuterTask](
Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value> ^
_Operation,
Windows::Foundation::AsyncStatus _Status) mutable {
if (_Status == Windows::Foundation::AsyncStatus::Canceled)
{
_OuterTask->_Cancel(true);
}
else if (_Status == Windows::Foundation::AsyncStatus::Error)
{
_OuterTask->_CancelWithException(
::Platform::Exception::ReCreateException(static_cast<int>(_Operation->ErrorCode.Value)));
}
else
{
_ASSERTE(_Status == Windows::Foundation::AsyncStatus::Completed);
_OuterTask->_FinalizeAndRunContinuations(_Operation->GetResults());
}
// Take away this shared pointers reference on the task instead of waiting for the delegate to be
// released. It could be released on a different thread after a delay, and not releasing the reference
// here could cause the tasks to hold on to resources longer than they should. As an example, without
// this reset, writing to a file followed by reading from it using the Windows Runtime Async APIs causes
// a sharing violation. Using const_cast is the workaround for failed mutable keywords
const_cast<_Task_ptr<_ReturnType>::_Type&>(_OuterTask).reset();
});
_OuterTask->_SetUnwrappedAsyncOp(_AsyncOp);
}
#endif /* defined (__cplusplus_winrt) */
template<typename _ReturnType, typename _InternalReturnType>
static void _AsyncInit(const typename _Task_ptr<_ReturnType>::_Type& _OuterTask,
const task<_InternalReturnType>& _UnwrappedTask)
{
_ASSERTE(_OuterTask->_M_fUnwrappedTask && !_OuterTask->_IsCanceled());
//
// We must ensure that continuations off _OuterTask (especially exception handling ones) continue to function in
// the presence of an exception flowing out of the inner task _UnwrappedTask. This requires an exception
// handling continuation off the inner task which does the appropriate funneling to the outer one. We use _Then
// instead of then to prevent the exception from being marked as observed by our internal continuation. This
// continuation must be scheduled regardless of whether or not the _OuterTask task is canceled.
//
_UnwrappedTask._Then(
[_OuterTask](task<_InternalReturnType> _AncestorTask) {
if (_AncestorTask._GetImpl()->_IsCompleted())
{
_OuterTask->_FinalizeAndRunContinuations(_AncestorTask._GetImpl()->_GetResult());
}
else
{
_ASSERTE(_AncestorTask._GetImpl()->_IsCanceled());
if (_AncestorTask._GetImpl()->_HasUserException())
{
// Set _PropagatedFromAncestor to false, since _AncestorTask is not an ancestor of
// _UnwrappedTask. Instead, it is the enclosing task.
_OuterTask->_CancelWithExceptionHolder(_AncestorTask._GetImpl()->_GetExceptionHolder(), false);
}
else
{
_OuterTask->_Cancel(true);
}
}
},
nullptr,
details::_DefaultAutoInline);
}
scheduler_ptr _GetScheduler() const { return _M_TaskCollection._GetScheduler(); }
// Tracks the internal state of the task
std::atomic<_TaskInternalState> _M_TaskState;
// Set to true either if the ancestor task had the flag set to true, or if the lambda that does the work of this
// task returns an async operation or async action that is unwrapped by the runtime.
bool _M_fFromAsync;
// Set to true when a continuation unwraps a task or async operation.
bool _M_fUnwrappedTask;
// An exception thrown by the task body is captured in an exception holder and it is shared with all value based
// continuations rooted at the task. The exception is 'observed' if the user invokes get()/wait() on any of the
// tasks that are sharing this exception holder. If the exception is not observed by the time the internal object
// owned by the shared pointer destructs, the process will fail fast.
std::shared_ptr<_ExceptionHolder> _M_exceptionHolder;
::pplx::extensibility::critical_section_t _M_ContinuationsCritSec;
// The cancellation token state.
_CancellationTokenState* _M_pTokenState;
// The registration on the token.
_CancellationTokenRegistration* _M_pRegistration;
typedef _ContinuationTaskHandleBase* _ContinuationList;
_ContinuationList _M_Continuations;
// The async task collection wrapper
::pplx::details::_TaskCollection_t _M_TaskCollection;
// Callstack for function call (constructor or .then) that created this task impl.
_TaskCreationCallstack _M_pTaskCreationCallstack;
_TaskEventLogger _M_taskEventLogger;
private:
// Must not be copied by value:
_Task_impl_base(const _Task_impl_base&);
_Task_impl_base const& operator=(_Task_impl_base const&);
};
#if PPLX_TASK_ASYNC_LOGGING
inline void _TaskEventLogger::_LogTaskCompleted()
{
if (_M_scheduled)
{
::Windows::Foundation::AsyncStatus _State;
if (_M_task->_IsCompleted())
_State = ::Windows::Foundation::AsyncStatus::Completed;
else if (_M_task->_HasUserException())
_State = ::Windows::Foundation::AsyncStatus::Error;
else
_State = ::Windows::Foundation::AsyncStatus::Canceled;
if (details::_IsCausalitySupported())
{
::Windows::Foundation::Diagnostics::AsyncCausalityTracer::TraceOperationCompletion(
::Windows::Foundation::Diagnostics::CausalityTraceLevel::Required,
::Windows::Foundation::Diagnostics::CausalitySource::Library,
_PPLTaskCausalityPlatformID,
reinterpret_cast<unsigned long long>(_M_task),
_State);
}
}
}
#endif
/// <summary>
/// The implementation of a first-class task. This structure contains the task group used to execute
/// the task function and handles the scheduling. The _Task_impl is created as a shared_ptr
/// member of the the public task class, so its destruction is handled automatically.
/// </summary>
/// <typeparam name="_ReturnType">
/// The result type of this task.
/// </typeparam>
/**/
template<typename _ReturnType>
struct _Task_impl : public _Task_impl_base
{
#if defined(__cplusplus_winrt)
typedef Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value>
_AsyncOperationType;
#endif // defined(__cplusplus_winrt)
_Task_impl(_CancellationTokenState* _Ct, scheduler_ptr _Scheduler_arg) : _Task_impl_base(_Ct, _Scheduler_arg)
{
#if defined(__cplusplus_winrt)
_M_unwrapped_async_op = nullptr;
#endif /* defined (__cplusplus_winrt) */
}
virtual ~_Task_impl()
{
// We must invoke _DeregisterCancellation in the derived class destructor. Calling it in the base class
// destructor could cause a partially initialized _Task_impl to be in the list of registrations for a
// cancellation token.
_DeregisterCancellation();
}
virtual bool _CancelAndRunContinuations(bool _SynchronousCancel,
bool _UserException,
bool _PropagatedFromAncestor,
const std::shared_ptr<_ExceptionHolder>& _ExceptionHolder_arg)
{
bool _RunContinuations = false;
{
::pplx::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
if (_UserException)
{
_ASSERTE(_SynchronousCancel && !_IsCompleted());
// If the state is _Canceled, the exception has to be coming from an ancestor.
_ASSERTE(!_IsCanceled() || _PropagatedFromAncestor);
// We should not be canceled with an exception more than once.
_ASSERTE(!_HasUserException());
// Mark _PropagatedFromAncestor as used.
(void)_PropagatedFromAncestor;
if (_M_TaskState == _Canceled)
{
// If the task has finished canceling there should not be any continuation records in the array.
return false;
}
else
{
_ASSERTE(_M_TaskState != _Completed);
_M_exceptionHolder = _ExceptionHolder_arg;
}
}
else
{
// Completed is a non-cancellable state, and if this is an asynchronous cancel, we're unable to do
// better than the last async cancel which is to say, cancellation is already initiated, so return
// early.
if (_IsCompleted() || _IsCanceled() || (_IsPendingCancel() && !_SynchronousCancel))
{
_ASSERTE(!_IsCompleted() || !_HasUserException());
return false;
}
_ASSERTE(!_SynchronousCancel || !_HasUserException());
}
if (_SynchronousCancel)
{
// Be aware that this set must be done BEFORE _M_Scheduled being set, or race will happen between this
// and wait()
_M_TaskState = _Canceled;
// Cancellation completes the task, so all dependent tasks must be run to cancel them
// They are canceled when they begin running (see _RunContinuation) and see that their
// ancestor has been canceled.
_RunContinuations = true;
}
else
{
_ASSERTE(!_UserException);
if (_IsStarted())
{
#if defined(__cplusplus_winrt)
if (_M_unwrapped_async_op != nullptr)
{
// We will only try to cancel async operation but not unwrapped tasks, since unwrapped tasks
// cannot be canceled without its token.
_M_unwrapped_async_op->Cancel();
}
#endif /* defined (__cplusplus_winrt) */
_M_TaskCollection._Cancel();
}
// The _M_TaskState variable transitions to _Canceled when cancellation is completed (the task is not
// executing user code anymore). In the case of a synchronous cancel, this can happen immediately,
// whereas with an asynchronous cancel, the task has to move from _Started to _PendingCancel before it
// can move to _Canceled when it is finished executing.
_M_TaskState = _PendingCancel;
_M_taskEventLogger._LogCancelTask();
}
}
// Only execute continuations and mark the task as completed if we were able to move the task to the _Canceled
// state.
if (_RunContinuations)
{
_M_TaskCollection._Complete();
if (_M_Continuations)
{
// Scheduling cancellation with automatic inlining.
_ScheduleFuncWithAutoInline([=]() { _RunTaskContinuations(); }, details::_DefaultAutoInline);
}
}
return true;
}
void _FinalizeAndRunContinuations(_ReturnType _Result)
{
_M_Result.Set(_Result);
{
//
// Hold this lock to ensure continuations being concurrently either get added
// to the _M_Continuations vector or wait for the result
//
::pplx::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
// A task could still be in the _Created state if it was created with a task_completion_event.
// It could also be in the _Canceled state for the same reason.
_ASSERTE(!_HasUserException() && !_IsCompleted());
if (_IsCanceled())
{
return;
}
// Always transition to "completed" state, even in the face of unacknowledged pending cancellation
_M_TaskState = _Completed;
}
_M_TaskCollection._Complete();
_RunTaskContinuations();
}
//
// This method is invoked when the starts executing. The task returns early if this method returns true.
//
bool _TransitionedToStarted()
{
::pplx::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
// Canceled state could only result from antecedent task's canceled state, but that code path will not reach
// here.
_ASSERTE(!_IsCanceled());
if (_IsPendingCancel()) return false;
_ASSERTE(_IsCreated());
_M_TaskState = _Started;
return true;
}
#if defined(__cplusplus_winrt)
void _SetUnwrappedAsyncOp(_AsyncOperationType ^ _AsyncOp)
{
::pplx::extensibility::scoped_critical_section_t _LockHolder(_M_ContinuationsCritSec);
// Cancel the async operation if the task itself is canceled, since the thread that canceled the task missed it.
if (_IsPendingCancel())
{
_ASSERTE(!_IsCanceled());
_AsyncOp->Cancel();
}
else
{
_M_unwrapped_async_op = _AsyncOp;
}
}
#endif /* defined (__cplusplus_winrt) */
// Return true if the task has reached a terminal state
bool _IsDone() { return _IsCompleted() || _IsCanceled(); }
_ReturnType _GetResult() { return _M_Result.Get(); }
_ResultHolder<_ReturnType> _M_Result; // this means that the result type must have a public default ctor.
#if defined(__cplusplus_winrt)
_AsyncOperationType ^ _M_unwrapped_async_op;
#endif /* defined (__cplusplus_winrt) */
};
template<typename _ResultType>
struct _Task_completion_event_impl
{
private:
_Task_completion_event_impl(const _Task_completion_event_impl&);
_Task_completion_event_impl& operator=(const _Task_completion_event_impl&);
public:
typedef std::vector<typename _Task_ptr<_ResultType>::_Type> _TaskList;
_Task_completion_event_impl() : _M_fHasValue(false), _M_fIsCanceled(false) {}
bool _HasUserException() { return _M_exceptionHolder != nullptr; }
~_Task_completion_event_impl()
{
for (auto _TaskIt = _M_tasks.begin(); _TaskIt != _M_tasks.end(); ++_TaskIt)
{
_ASSERTE(!_M_fHasValue && !_M_fIsCanceled);
// Cancel the tasks since the event was never signaled or canceled.
(*_TaskIt)->_Cancel(true);
}
}
// We need to protect the loop over the array, so concurrent_vector would not have helped
_TaskList _M_tasks;
::pplx::extensibility::critical_section_t _M_taskListCritSec;
_ResultHolder<_ResultType> _M_value;
std::shared_ptr<_ExceptionHolder> _M_exceptionHolder;
std::atomic<bool> _M_fHasValue;
std::atomic<bool> _M_fIsCanceled;
};
// Utility method for dealing with void functions
inline std::function<_Unit_type(void)> _MakeVoidToUnitFunc(const std::function<void(void)>& _Func)
{
return [=]() -> _Unit_type {
_Func();
return _Unit_type();
};
}
template<typename _Type>
std::function<_Type(_Unit_type)> _MakeUnitToTFunc(const std::function<_Type(void)>& _Func)
{
return [=](_Unit_type) -> _Type { return _Func(); };
}
template<typename _Type>
std::function<_Unit_type(_Type)> _MakeTToUnitFunc(const std::function<void(_Type)>& _Func)
{
return [=](_Type t) -> _Unit_type {
_Func(t);
return _Unit_type();
};
}
inline std::function<_Unit_type(_Unit_type)> _MakeUnitToUnitFunc(const std::function<void(void)>& _Func)
{
return [=](_Unit_type) -> _Unit_type {
_Func();
return _Unit_type();
};
}
} // namespace details
/// <summary>
/// The <c>task_completion_event</c> class allows you to delay the execution of a task until a condition is
/// satisfied, or start a task in response to an external event.
/// </summary>
/// <typeparam name="_ResultType">
/// The result type of this <c>task_completion_event</c> class.
/// </typeparam>
/// <remarks>
/// Use a task created from a task completion event when your scenario requires you to create a task that will
/// complete, and thereby have its continuations scheduled for execution, at some point in the future. The
/// <c>task_completion_event</c> must have the same type as the task you create, and calling the set method on the
/// task completion event with a value of that type will cause the associated task to complete, and provide that
/// value as a result to its continuations. <para>If the task completion event is never signaled, any tasks created
/// from it will be canceled when it is destructed.</para> <para><c>task_completion_event</c> behaves like a smart
/// pointer, and should be passed by value.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/**/
template<typename _ResultType>
class task_completion_event
{
public:
/// <summary>
/// Constructs a <c>task_completion_event</c> object.
/// </summary>
/**/
task_completion_event() : _M_Impl(std::make_shared<details::_Task_completion_event_impl<_ResultType>>()) {}
/// <summary>
/// Sets the task completion event.
/// </summary>
/// <param name="_Result">
/// The result to set this event with.
/// </param>
/// <returns>
/// The method returns <c>true</c> if it was successful in setting the event. It returns <c>false</c> if the
/// event is already set.
/// </returns>
/// <remarks>
/// In the presence of multiple or concurrent calls to <c>set</c>, only the first call will succeed and its
/// result (if any) will be stored in the task completion event. The remaining sets are ignored and the method
/// will return false. When you set a task completion event, all the tasks created from that event will
/// immediately complete, and its continuations, if any, will be scheduled. Task completion objects that have a
/// <typeparamref name="_ResultType"/> other than <c>void</c> will pass the value <paramref value="_Result"/> to
/// their continuations.
/// </remarks>
/**/
bool set(_ResultType _Result)
const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
// Subsequent sets are ignored. This makes races to set benign: the first setter wins and all others are
// ignored.
if (_IsTriggered())
{
return false;
}
_TaskList _Tasks;
bool _RunContinuations = false;
{
::pplx::extensibility::scoped_critical_section_t _LockHolder(_M_Impl->_M_taskListCritSec);
if (!_IsTriggered())
{
_M_Impl->_M_value.Set(_Result);
_M_Impl->_M_fHasValue = true;
_Tasks.swap(_M_Impl->_M_tasks);
_RunContinuations = true;
}
}
if (_RunContinuations)
{
for (auto _TaskIt = _Tasks.begin(); _TaskIt != _Tasks.end(); ++_TaskIt)
{
// If current task was canceled by a cancellation_token, it would be in cancel pending state.
if ((*_TaskIt)->_IsPendingCancel())
(*_TaskIt)->_Cancel(true);
else
{
// Tasks created with task_completion_events can be marked as async, (we do this in when_any and
// when_all if one of the tasks involved is an async task). Since continuations of async tasks can
// execute inline, we need to run continuations after the lock is released.
(*_TaskIt)->_FinalizeAndRunContinuations(_M_Impl->_M_value.Get());
}
}
if (_M_Impl->_HasUserException())
{
_M_Impl->_M_exceptionHolder.reset();
}
return true;
}
return false;
}
template<typename _E>
__declspec(noinline) // Ask for no inlining so that the _ReturnAddress intrinsic gives us the expected result
bool set_exception(
_E _Except) const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
// It is important that PPLX_CAPTURE_CALLSTACK() evaluate to the instruction after the call instruction for
// set_exception.
return _Cancel(std::make_exception_ptr(_Except), PPLX_CAPTURE_CALLSTACK());
}
/// <summary>
/// Propagates an exception to all tasks associated with this event.
/// </summary>
/// <param>
/// The exception_ptr that indicates the exception to set this event with.
/// </param>
/**/
__declspec(noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK gives us the expected result
bool set_exception(std::exception_ptr _ExceptionPtr)
const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
// It is important that PPLX_CAPTURE_CALLSTACK() evaluate to the instruction after the call instruction for
// set_exception.
return _Cancel(_ExceptionPtr, PPLX_CAPTURE_CALLSTACK());
}
/// <summary>
/// Internal method to cancel the task_completion_event. Any task created using this event will be marked as
/// canceled if it has not already been set.
/// </summary>
bool _Cancel() const
{
// Cancel with the stored exception if one exists.
return _CancelInternal();
}
/// <summary>
/// Internal method to cancel the task_completion_event with the exception provided. Any task created using this
/// event will be canceled with the same exception.
/// </summary>
template<typename _ExHolderType>
bool _Cancel(
_ExHolderType _ExHolder,
const details::_TaskCreationCallstack& _SetExceptionAddressHint = details::_TaskCreationCallstack()) const
{
bool _Canceled;
if (_StoreException(_ExHolder, _SetExceptionAddressHint))
{
_Canceled = _CancelInternal();
_ASSERTE(_Canceled);
}
else
{
_Canceled = false;
}
return _Canceled;
}
/// <summary>
/// Internal method that stores an exception in the task completion event. This is used internally by when_any.
/// Note, this does not cancel the task completion event. A task completion event with a stored exception
/// can bet set() successfully. If it is canceled, it will cancel with the stored exception, if one is present.
/// </summary>
template<typename _ExHolderType>
bool _StoreException(
_ExHolderType _ExHolder,
const details::_TaskCreationCallstack& _SetExceptionAddressHint = details::_TaskCreationCallstack()) const
{
::pplx::extensibility::scoped_critical_section_t _LockHolder(_M_Impl->_M_taskListCritSec);
if (!_IsTriggered() && !_M_Impl->_HasUserException())
{
// Create the exception holder only if we have ensured there we will be successful in setting it onto the
// task completion event. Failing to do so will result in an unobserved task exception.
_M_Impl->_M_exceptionHolder = _ToExceptionHolder(_ExHolder, _SetExceptionAddressHint);
return true;
}
return false;
}
/// <summary>
/// Tests whether current event has been either Set, or Canceled.
/// </summary>
bool _IsTriggered() const { return _M_Impl->_M_fHasValue || _M_Impl->_M_fIsCanceled; }
private:
static std::shared_ptr<details::_ExceptionHolder> _ToExceptionHolder(
const std::shared_ptr<details::_ExceptionHolder>& _ExHolder, const details::_TaskCreationCallstack&)
{
return _ExHolder;
}
static std::shared_ptr<details::_ExceptionHolder> _ToExceptionHolder(
std::exception_ptr _ExceptionPtr, const details::_TaskCreationCallstack& _SetExceptionAddressHint)
{
return std::make_shared<details::_ExceptionHolder>(_ExceptionPtr, _SetExceptionAddressHint);
}
template<typename T>
friend class task; // task can register itself with the event by calling the private _RegisterTask
template<typename T>
friend class task_completion_event;
typedef typename details::_Task_completion_event_impl<_ResultType>::_TaskList _TaskList;
/// <summary>
/// Cancels the task_completion_event.
/// </summary>
bool _CancelInternal() const
{
// Cancellation of task completion events is an internal only utility. Our usage is such that _CancelInternal
// will never be invoked if the task completion event has been set.
_ASSERTE(!_M_Impl->_M_fHasValue);
if (_M_Impl->_M_fIsCanceled)
{
return false;
}
_TaskList _Tasks;
bool _Cancel = false;
{
::pplx::extensibility::scoped_critical_section_t _LockHolder(_M_Impl->_M_taskListCritSec);
_ASSERTE(!_M_Impl->_M_fHasValue);
if (!_M_Impl->_M_fIsCanceled)
{
_M_Impl->_M_fIsCanceled = true;
_Tasks.swap(_M_Impl->_M_tasks);
_Cancel = true;
}
}
bool _UserException = _M_Impl->_HasUserException();
if (_Cancel)
{
for (auto _TaskIt = _Tasks.begin(); _TaskIt != _Tasks.end(); ++_TaskIt)
{
// Need to call this after the lock is released. See comments in set().
if (_UserException)
{
(*_TaskIt)->_CancelWithExceptionHolder(_M_Impl->_M_exceptionHolder, true);
}
else
{
(*_TaskIt)->_Cancel(true);
}
}
}
return _Cancel;
}
/// <summary>
/// Register a task with this event. This function is called when a task is constructed using
/// a task_completion_event.
/// </summary>
void _RegisterTask(const typename details::_Task_ptr<_ResultType>::_Type& _TaskParam)
{
::pplx::extensibility::scoped_critical_section_t _LockHolder(_M_Impl->_M_taskListCritSec);
// If an exception was already set on this event, then cancel the task with the stored exception.
if (_M_Impl->_HasUserException())
{
_TaskParam->_CancelWithExceptionHolder(_M_Impl->_M_exceptionHolder, true);
}
else if (_M_Impl->_M_fHasValue)
{
_TaskParam->_FinalizeAndRunContinuations(_M_Impl->_M_value.Get());
}
else
{
_M_Impl->_M_tasks.push_back(_TaskParam);
}
}
std::shared_ptr<details::_Task_completion_event_impl<_ResultType>> _M_Impl;
};
/// <summary>
/// The <c>task_completion_event</c> class allows you to delay the execution of a task until a condition is
/// satisfied, or start a task in response to an external event.
/// </summary>
/// <remarks>
/// Use a task created from a task completion event when your scenario requires you to create a task that will
/// complete, and thereby have its continuations scheduled for execution, at some point in the future. The
/// <c>task_completion_event</c> must have the same type as the task you create, and calling the set method on the
/// task completion event with a value of that type will cause the associated task to complete, and provide that
/// value as a result to its continuations. <para>If the task completion event is never signaled, any tasks created
/// from it will be canceled when it is destructed.</para> <para><c>task_completion_event</c> behaves like a smart
/// pointer, and should be passed by value.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/**/
template<>
class task_completion_event<void>
{
public:
/// <summary>
/// Sets the task completion event.
/// </summary>
/// <returns>
/// The method returns <c>true</c> if it was successful in setting the event. It returns <c>false</c> if the
/// event is already set.
/// </returns>
/// <remarks>
/// In the presence of multiple or concurrent calls to <c>set</c>, only the first call will succeed and its
/// result (if any) will be stored in the task completion event. The remaining sets are ignored and the method
/// will return false. When you set a task completion event, all the tasks created from that event will
/// immediately complete, and its continuations, if any, will be scheduled. Task completion objects that have a
/// <typeparamref name="_ResultType"/> other than <c>void</c> will pass the value <paramref value="_Result"/> to
/// their continuations.
/// </remarks>
/**/
bool set() const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
return _M_unitEvent.set(details::_Unit_type());
}
template<typename _E>
__declspec(noinline) // Ask for no inlining so that the _ReturnAddress intrinsic gives us the expected result
bool set_exception(
_E _Except) const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
return _M_unitEvent._Cancel(std::make_exception_ptr(_Except), PPLX_CAPTURE_CALLSTACK());
}
/// <summary>
/// Propagates an exception to all tasks associated with this event.
/// </summary>
/// <param>
/// The exception_ptr that indicates the exception to set this event with.
/// </param>
/**/
__declspec(
noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK intrinsic gives us the expected result
bool set_exception(std::exception_ptr _ExceptionPtr)
const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
// It is important that PPLX_CAPTURE_CALLSTACK() evaluate to the instruction after the call instruction for
// set_exception.
return _M_unitEvent._Cancel(_ExceptionPtr, PPLX_CAPTURE_CALLSTACK());
}
/// <summary>
/// Cancel the task_completion_event. Any task created using this event will be marked as canceled if it has
/// not already been set.
/// </summary>
void _Cancel() const // 'const' (even though it's not deep) allows to safely pass events by value into lambdas
{
_M_unitEvent._Cancel();
}
/// <summary>
/// Cancel the task_completion_event with the exception holder provided. Any task created using this event will
/// be canceled with the same exception.
/// </summary>
void _Cancel(const std::shared_ptr<details::_ExceptionHolder>& _ExHolder) const { _M_unitEvent._Cancel(_ExHolder); }
/// <summary>
/// Method that stores an exception in the task completion event. This is used internally by when_any.
/// Note, this does not cancel the task completion event. A task completion event with a stored exception
/// can bet set() successfully. If it is canceled, it will cancel with the stored exception, if one is present.
/// </summary>
bool _StoreException(const std::shared_ptr<details::_ExceptionHolder>& _ExHolder) const
{
return _M_unitEvent._StoreException(_ExHolder);
}
/// <summary>
/// Test whether current event has been either Set, or Canceled.
/// </summary>
bool _IsTriggered() const { return _M_unitEvent._IsTriggered(); }
private:
template<typename T>
friend class task; // task can register itself with the event by calling the private _RegisterTask
/// <summary>
/// Register a task with this event. This function is called when a task is constructed using
/// a task_completion_event.
/// </summary>
void _RegisterTask(details::_Task_ptr<details::_Unit_type>::_Type _TaskParam)
{
_M_unitEvent._RegisterTask(_TaskParam);
}
// The void event contains an event a dummy type so common code can be used for events with void and non-void
// results.
task_completion_event<details::_Unit_type> _M_unitEvent;
};
namespace details
{
//
// Compile-time validation helpers
//
// Task constructor validation: issue helpful diagnostics for common user errors. Do not attempt full validation here.
//
// Anything callable is fine
template<typename _ReturnType, typename _Ty>
auto _IsValidTaskCtor(_Ty _Param, int, int, int, int) -> decltype(_Param(), std::true_type());
#if defined(__cplusplus_winrt)
// Anything that has GetResults is fine: this covers all async operations
template<typename _ReturnType, typename _Ty>
auto _IsValidTaskCtor(_Ty _Param, int, int, int, ...) -> decltype(_Param->GetResults(), std::true_type());
#endif
// Allow parameters with set: this covers task_completion_event
template<typename _ReturnType, typename _Ty>
auto _IsValidTaskCtor(_Ty _Param, int, int, ...)
-> decltype(_Param.set(stdx::declval<_ReturnType>()), std::true_type());
template<typename _ReturnType, typename _Ty>
auto _IsValidTaskCtor(_Ty _Param, int, ...) -> decltype(_Param.set(), std::true_type());
// All else is invalid
template<typename _ReturnType, typename _Ty>
std::false_type _IsValidTaskCtor(_Ty _Param, ...);
template<typename _ReturnType, typename _Ty>
void _ValidateTaskConstructorArgs(_Ty _Param)
{
static_assert(std::is_same<decltype(_IsValidTaskCtor<_ReturnType>(_Param, 0, 0, 0, 0)), std::true_type>::value,
#if defined(__cplusplus_winrt)
"incorrect argument for task constructor; can be a callable object, an asynchronous operation, or a "
"task_completion_event"
#else /* defined (__cplusplus_winrt) */
"incorrect argument for task constructor; can be a callable object or a task_completion_event"
#endif /* defined (__cplusplus_winrt) */
);
#if defined(__cplusplus_winrt)
static_assert(!(std::is_same<_Ty, _ReturnType>::value && details::_IsIAsyncInfo<_Ty>::_Value),
"incorrect template argument for task; consider using the return type of the async operation");
#endif /* defined (__cplusplus_winrt) */
}
#if defined(__cplusplus_winrt)
// Helpers for create_async validation
//
// A parameter lambda taking no arguments is valid
template<typename _Ty>
static auto _IsValidCreateAsync(_Ty _Param, int, int, int, int) -> decltype(_Param(), std::true_type());
// A parameter lambda taking an cancellation_token argument is valid
template<typename _Ty>
static auto _IsValidCreateAsync(_Ty _Param, int, int, int, ...)
-> decltype(_Param(cancellation_token::none()), std::true_type());
// A parameter lambda taking a progress report argument is valid
template<typename _Ty>
static auto _IsValidCreateAsync(_Ty _Param, int, int, ...)
-> decltype(_Param(details::_ProgressReporterCtorArgType()), std::true_type());
// A parameter lambda taking a progress report and a cancellation_token argument is valid
template<typename _Ty>
static auto _IsValidCreateAsync(_Ty _Param, int, ...)
-> decltype(_Param(details::_ProgressReporterCtorArgType(), cancellation_token::none()), std::true_type());
// All else is invalid
template<typename _Ty>
static std::false_type _IsValidCreateAsync(_Ty _Param, ...);
#endif /* defined (__cplusplus_winrt) */
/// <summary>
/// A helper class template that makes only movable functions be able to be passed to std::function
/// </summary>
template<typename _Ty>
struct _NonCopyableFunctorWrapper
{
template<typename _Tx,
typename = typename std::enable_if<
!std::is_base_of<_NonCopyableFunctorWrapper<_Ty>, typename std::decay<_Tx>::type>::value>::type>
explicit _NonCopyableFunctorWrapper(_Tx&& f) : _M_functor {std::make_shared<_Ty>(std::forward<_Tx>(f))}
{
}
template<class... _Args>
auto operator()(_Args&&... args) -> decltype(std::declval<_Ty>()(std::forward<_Args>(args)...))
{
return _M_functor->operator()(std::forward<_Args>(args)...);
}
template<class... _Args>
auto operator()(_Args&&... args) const -> decltype(std::declval<_Ty>()(std::forward<_Args>(args)...))
{
return _M_functor->operator()(std::forward<_Args>(args)...);
}
std::shared_ptr<_Ty> _M_functor;
};
template<typename _Ty, typename Enable = void>
struct _CopyableFunctor
{
typedef _Ty _Type;
};
template<typename _Ty>
struct _CopyableFunctor<
_Ty,
typename std::enable_if<std::is_move_constructible<_Ty>::value && !std::is_copy_constructible<_Ty>::value>::type>
{
typedef _NonCopyableFunctorWrapper<_Ty> _Type;
};
} // namespace details
/// <summary>
/// A helper class template that transforms a continuation lambda that either takes or returns void, or both, into a
/// lambda that takes and returns a non-void type (details::_Unit_type is used to substitute for void). This is to
/// minimize the special handling required for 'void'.
/// </summary>
template<typename _InpType, typename _OutType>
class _Continuation_func_transformer
{
public:
static auto _Perform(std::function<_OutType(_InpType)> _Func) -> decltype(_Func) { return _Func; }
};
template<typename _OutType>
class _Continuation_func_transformer<void, _OutType>
{
public:
static auto _Perform(std::function<_OutType(void)> _Func) -> decltype(details::_MakeUnitToTFunc<_OutType>(_Func))
{
return details::_MakeUnitToTFunc<_OutType>(_Func);
}
};
template<typename _InType>
class _Continuation_func_transformer<_InType, void>
{
public:
static auto _Perform(std::function<void(_InType)> _Func) -> decltype(details::_MakeTToUnitFunc<_InType>(_Func))
{
return details::_MakeTToUnitFunc<_InType>(_Func);
}
};
template<>
class _Continuation_func_transformer<void, void>
{
public:
static auto _Perform(std::function<void(void)> _Func) -> decltype(details::_MakeUnitToUnitFunc(_Func))
{
return details::_MakeUnitToUnitFunc(_Func);
}
};
// A helper class template that transforms an intial task lambda returns void into a lambda that returns a non-void type
// (details::_Unit_type is used to substitute for void). This is to minimize the special handling required for 'void'.
template<typename _RetType>
class _Init_func_transformer
{
public:
static auto _Perform(std::function<_RetType(void)> _Func) -> decltype(_Func) { return _Func; }
};
template<>
class _Init_func_transformer<void>
{
public:
static auto _Perform(std::function<void(void)> _Func) -> decltype(details::_MakeVoidToUnitFunc(_Func))
{
return details::_MakeVoidToUnitFunc(_Func);
}
};
/// <summary>
/// The Parallel Patterns Library (PPL) <c>task</c> class. A <c>task</c> object represents work that can be executed
/// asynchronously, and concurrently with other tasks and parallel work produced by parallel algorithms in the
/// Concurrency Runtime. It produces a result of type <typeparamref name="_ResultType"/> on successful completion.
/// Tasks of type <c>task<void></c> produce no result. A task can be waited upon and canceled independently of
/// other tasks. It can also be composed with other tasks using continuations(<c>then</c>), and
/// join(<c>when_all</c>) and choice(<c>when_any</c>) patterns.
/// </summary>
/// <typeparam name="_ReturnType">
/// The result type of this task.
/// </typeparam>
/// <remarks>
/// For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.
/// </remarks>
/**/
template<typename _ReturnType>
class task
{
public:
/// <summary>
/// The type of the result an object of this class produces.
/// </summary>
/**/
typedef _ReturnType result_type;
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within
/// containers. A default constructed task cannot be used until you assign a valid task to it. Methods such as
/// <c>get</c>, <c>wait</c> or <c>then</c> will throw an <see cref="invalid_argument
/// Class">invalid_argument</see> exception when called on a default constructed task. <para>A task that is
/// created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the
/// task completion event is set.</para> <para>The version of the constructor that takes a cancellation token
/// creates a task that can be canceled using the <c>cancellation_token_source</c> the token was obtained from.
/// Tasks created without a cancellation token are not cancelable.</para> <para>Tasks created from a
/// <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes.
/// Similarly, tasks created from a lambda that returns a <c>task<result_type></c> reach their terminal
/// state when the inner task reaches its terminal state, and not when the lambda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by
/// multiple threads without the need for locks.</para> <para>The constructor overloads that take a
/// Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available to
/// Windows Store apps.</para> <para>For more information, see <see cref="Task Parallelism (Concurrency
/// Runtime)"/>.</para>
/// </remarks>
/**/
task() : _M_Impl(nullptr)
{
// The default constructor should create a task with a nullptr impl. This is a signal that the
// task is not usable and should throw if any wait(), get() or then() APIs are used.
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda, a function object, a
/// <c>task_completion_event<result_type></c> object, or a Windows::Foundation::IAsyncInfo if you are
/// using tasks in your Windows Store app. The lambda or function object should be a type equivalent to
/// <c>std::function<X(void)></c>, where X can be a variable of type <c>result_type</c>,
/// <c>task<result_type></c>, or a Windows::Foundation::IAsyncInfo in Windows Store apps.
/// </param>
/// <param name="_Token">
/// The cancellation token to associate with this task. A task created without a cancellation token cannot be
/// canceled. It implicitly receives the token <c>cancellation_token::none()</c>.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within
/// containers. A default constructed task cannot be used until you assign a valid task to it. Methods such as
/// <c>get</c>, <c>wait</c> or <c>then</c> will throw an <see cref="invalid_argument
/// Class">invalid_argument</see> exception when called on a default constructed task. <para>A task that is
/// created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the
/// task completion event is set.</para> <para>The version of the constructor that takes a cancellation token
/// creates a task that can be canceled using the <c>cancellation_token_source</c> the token was obtained from.
/// Tasks created without a cancellation token are not cancelable.</para> <para>Tasks created from a
/// <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes.
/// Similarly, tasks created from a lambda that returns a <c>task<result_type></c> reach their terminal
/// state when the inner task reaches its terminal state, and not when the lambda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by
/// multiple threads without the need for locks.</para> <para>The constructor overloads that take a
/// Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available to
/// Windows Store apps.</para> <para>For more information, see <see cref="Task Parallelism (Concurrency
/// Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Ty>
__declspec(noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK gives us the expected result
explicit task(_Ty _Param)
{
task_options _TaskOptions;
details::_ValidateTaskConstructorArgs<_ReturnType, _Ty>(_Param);
_CreateImpl(_TaskOptions.get_cancellation_token()._GetImplValue(), _TaskOptions.get_scheduler());
// Do not move the next line out of this function. It is important that PPLX_CAPTURE_CALLSTACK() evaluate to the
// the call site of the task constructor.
_SetTaskCreationCallstack(PPLX_CAPTURE_CALLSTACK());
_TaskInitMaybeFunctor(_Param, details::_IsCallable(_Param, 0));
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda, a function object, a
/// <c>task_completion_event<result_type></c> object, or a Windows::Foundation::IAsyncInfo if you are
/// using tasks in your Windows Store app. The lambda or function object should be a type equivalent to
/// <c>std::function<X(void)></c>, where X can be a variable of type <c>result_type</c>,
/// <c>task<result_type></c>, or a Windows::Foundation::IAsyncInfo in Windows Store apps.
/// </param>
/// <param name="_TaskOptions">
/// The task options include cancellation token, scheduler etc
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within
/// containers. A default constructed task cannot be used until you assign a valid task to it. Methods such as
/// <c>get</c>, <c>wait</c> or <c>then</c> will throw an <see cref="invalid_argument
/// Class">invalid_argument</see> exception when called on a default constructed task. <para>A task that is
/// created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the
/// task completion event is set.</para> <para>The version of the constructor that takes a cancellation token
/// creates a task that can be canceled using the <c>cancellation_token_source</c> the token was obtained from.
/// Tasks created without a cancellation token are not cancelable.</para> <para>Tasks created from a
/// <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes.
/// Similarly, tasks created from a lambda that returns a <c>task<result_type></c> reach their terminal
/// state when the inner task reaches its terminal state, and not when the lambda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by
/// multiple threads without the need for locks.</para> <para>The constructor overloads that take a
/// Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available to
/// Windows Store apps.</para> <para>For more information, see <see cref="Task Parallelism (Concurrency
/// Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Ty>
__declspec(noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK gives us the expected result
explicit task(_Ty _Param, const task_options& _TaskOptions)
{
details::_ValidateTaskConstructorArgs<_ReturnType, _Ty>(_Param);
_CreateImpl(_TaskOptions.get_cancellation_token()._GetImplValue(), _TaskOptions.get_scheduler());
// Do not move the next line out of this function. It is important that PPLX_CAPTURE_CALLSTACK() evaluate to the
// the call site of the task constructor.
_SetTaskCreationCallstack(details::_get_internal_task_options(_TaskOptions)._M_hasPresetCreationCallstack
? details::_get_internal_task_options(_TaskOptions)._M_presetCreationCallstack
: PPLX_CAPTURE_CALLSTACK());
_TaskInitMaybeFunctor(_Param, details::_IsCallable(_Param, 0));
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within
/// containers. A default constructed task cannot be used until you assign a valid task to it. Methods such as
/// <c>get</c>, <c>wait</c> or <c>then</c> will throw an <see cref="invalid_argument
/// Class">invalid_argument</see> exception when called on a default constructed task. <para>A task that is
/// created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the
/// task completion event is set.</para> <para>The version of the constructor that takes a cancellation token
/// creates a task that can be canceled using the <c>cancellation_token_source</c> the token was obtained from.
/// Tasks created without a cancellation token are not cancelable.</para> <para>Tasks created from a
/// <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes.
/// Similarly, tasks created from a lambda that returns a <c>task<result_type></c> reach their terminal
/// state when the inner task reaches its terminal state, and not when the lambda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by
/// multiple threads without the need for locks.</para> <para>The constructor overloads that take a
/// Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available to
/// Windows Store apps.</para> <para>For more information, see <see cref="Task Parallelism (Concurrency
/// Runtime)"/>.</para>
/// </remarks>
/**/
task(const task& _Other) : _M_Impl(_Other._M_Impl) {}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within
/// containers. A default constructed task cannot be used until you assign a valid task to it. Methods such as
/// <c>get</c>, <c>wait</c> or <c>then</c> will throw an <see cref="invalid_argument
/// Class">invalid_argument</see> exception when called on a default constructed task. <para>A task that is
/// created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the
/// task completion event is set.</para> <para>The version of the constructor that takes a cancellation token
/// creates a task that can be canceled using the <c>cancellation_token_source</c> the token was obtained from.
/// Tasks created without a cancellation token are not cancelable.</para> <para>Tasks created from a
/// <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes.
/// Similarly, tasks created from a lambda that returns a <c>task<result_type></c> reach their terminal
/// state when the inner task reaches its terminal state, and not when the lambda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by
/// multiple threads without the need for locks.</para> <para>The constructor overloads that take a
/// Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available to
/// Windows Store apps.</para> <para>For more information, see <see cref="Task Parallelism (Concurrency
/// Runtime)"/>.</para>
/// </remarks>
/**/
task(task&& _Other) : _M_Impl(std::move(_Other._M_Impl)) {}
/// <summary>
/// Replaces the contents of one <c>task</c> object with another.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// As <c>task</c> behaves like a smart pointer, after a copy assignment, this <c>task</c> objects represents
/// the same actual task as <paramref name="_Other"/> does.
/// </remarks>
/**/
task& operator=(const task& _Other)
{
if (this != &_Other)
{
_M_Impl = _Other._M_Impl;
}
return *this;
}
/// <summary>
/// Replaces the contents of one <c>task</c> object with another.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// As <c>task</c> behaves like a smart pointer, after a copy assignment, this <c>task</c> objects represents
/// the same actual task as <paramref name="_Other"/> does.
/// </remarks>
/**/
task& operator=(task&& _Other)
{
if (this != &_Other)
{
_M_Impl = std::move(_Other._M_Impl);
}
return *this;
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task<result_type></c>, where <c>result_type</c> is the
/// type of the result this task produces.
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref
/// name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo
/// interface, are only available to Windows Store apps. <para>For more information on how to use task
/// continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK gives us the expected result
auto then(_Function&& _Func) const ->
typename details::_ContinuationTypeTraits<_Function, _ReturnType>::_TaskOfType
{
task_options _TaskOptions;
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(PPLX_CAPTURE_CALLSTACK());
return _ThenImpl<_ReturnType, _Function>(std::forward<_Function>(_Func), _TaskOptions);
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task<result_type></c>, where <c>result_type</c> is the
/// type of the result this task produces.
/// </param>
/// <param name="_TaskOptions">
/// The task options include cancellation token, scheduler and continuation context. By default the former 3
/// options are inherited from the antecedent task
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref
/// name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo
/// interface, are only available to Windows Store apps. <para>For more information on how to use task
/// continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK gives us the expected result
auto then(_Function&& _Func, task_options _TaskOptions) const ->
typename details::_ContinuationTypeTraits<_Function, _ReturnType>::_TaskOfType
{
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(PPLX_CAPTURE_CALLSTACK());
return _ThenImpl<_ReturnType, _Function>(std::forward<_Function>(_Func), _TaskOptions);
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task<result_type></c>, where <c>result_type</c> is the
/// type of the result this task produces.
/// </param>
/// <param name="_CancellationToken">
/// The cancellation token to associate with the continuation task. A continuation task that is created without
/// a cancellation token will inherit the token of its antecedent task.
/// </param>
/// <param name="_ContinuationContext">
/// A variable that specifies where the continuation should execute. This variable is only useful when used in a
/// Windows Store style app. For more information, see <see cref="task_continuation_context
/// Class">task_continuation_context</see>
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref
/// name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo
/// interface, are only available to Windows Store apps. <para>For more information on how to use task
/// continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK gives us the expected result
auto then(_Function&& _Func,
cancellation_token _CancellationToken,
task_continuation_context _ContinuationContext) const ->
typename details::_ContinuationTypeTraits<_Function, _ReturnType>::_TaskOfType
{
task_options _TaskOptions(_CancellationToken, _ContinuationContext);
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(PPLX_CAPTURE_CALLSTACK());
return _ThenImpl<_ReturnType, _Function>(std::forward<_Function>(_Func), _TaskOptions);
}
/// <summary>
/// Waits for this task to reach a terminal state. It is possible for <c>wait</c> to execute the task inline, if
/// all of the tasks dependencies are satisfied, and it has not already been picked up for execution by a
/// background worker.
/// </summary>
/// <returns>
/// A <c>task_status</c> value which could be either <c>completed</c> or <c>canceled</c>. If the task
/// encountered an exception during execution, or an exception was propagated to it from an antecedent task,
/// <c>wait</c> will throw that exception.
/// </returns>
/**/
task_status wait() const
{
if (!_M_Impl)
{
throw invalid_operation("wait() cannot be called on a default constructed task.");
}
return _M_Impl->_Wait();
}
/// <summary>
/// Returns the result this task produced. If the task is not in a terminal state, a call to <c>get</c> will
/// wait for the task to finish. This method does not return a value when called on a task with a
/// <c>result_type</c> of <c>void</c>.
/// </summary>
/// <returns>
/// The result of the task.
/// </returns>
/// <remarks>
/// If the task is canceled, a call to <c>get</c> will throw a <see cref="task_canceled
/// Class">task_canceled</see> exception. If the task encountered an different exception or an exception was
/// propagated to it from an antecedent task, a call to <c>get</c> will throw that exception.
/// </remarks>
/**/
_ReturnType get() const
{
if (!_M_Impl)
{
throw invalid_operation("get() cannot be called on a default constructed task.");
}
if (_M_Impl->_Wait() == canceled)
{
throw task_canceled();
}
return _M_Impl->_GetResult();
}
/// <summary>
/// Determines if the task is completed.
/// </summary>
/// <returns>
/// True if the task has completed, false otherwise.
/// </returns>
/// <remarks>
/// The function returns true if the task is completed or canceled (with or without user exception).
/// </remarks>
bool is_done() const
{
if (!_M_Impl)
{
throw invalid_operation("is_done() cannot be called on a default constructed task.");
}
return _M_Impl->_IsDone();
}
/// <summary>
/// Returns the scheduler for this task
/// </summary>
/// <returns>
/// A pointer to the scheduler
/// </returns>
scheduler_ptr scheduler() const
{
if (!_M_Impl)
{
throw invalid_operation("scheduler() cannot be called on a default constructed task.");
}
return _M_Impl->_GetScheduler();
}
/// <summary>
/// Determines whether the task unwraps a Windows Runtime <c>IAsyncInfo</c> interface or is descended from such
/// a task.
/// </summary>
/// <returns>
/// <c>true</c> if the task unwraps an <c>IAsyncInfo</c> interface or is descended from such a task,
/// <c>false</c> otherwise.
/// </returns>
/**/
bool is_apartment_aware() const
{
if (!_M_Impl)
{
throw invalid_operation("is_apartment_aware() cannot be called on a default constructed task.");
}
return _M_Impl->_IsApartmentAware();
}
/// <summary>
/// Determines whether two <c>task</c> objects represent the same internal task.
/// </summary>
/// <returns>
/// <c>true</c> if the objects refer to the same underlying task, and <c>false</c> otherwise.
/// </returns>
/**/
bool operator==(const task<_ReturnType>& _Rhs) const { return (_M_Impl == _Rhs._M_Impl); }
/// <summary>
/// Determines whether two <c>task</c> objects represent different internal tasks.
/// </summary>
/// <returns>
/// <c>true</c> if the objects refer to different underlying tasks, and <c>false</c> otherwise.
/// </returns>
/**/
bool operator!=(const task<_ReturnType>& _Rhs) const { return !operator==(_Rhs); }
/// <summary>
/// Create an underlying task implementation.
/// </summary>
void _CreateImpl(details::_CancellationTokenState* _Ct, scheduler_ptr _Scheduler)
{
_ASSERTE(_Ct != nullptr);
_M_Impl = details::_Task_ptr<_ReturnType>::_Make(_Ct, _Scheduler);
if (_Ct != details::_CancellationTokenState::_None())
{
_M_Impl->_RegisterCancellation(_M_Impl);
}
}
/// <summary>
/// Return the underlying implementation for this task.
/// </summary>
const typename details::_Task_ptr<_ReturnType>::_Type& _GetImpl() const { return _M_Impl; }
/// <summary>
/// Set the implementation of the task to be the supplied implementation.
/// </summary>
void _SetImpl(const typename details::_Task_ptr<_ReturnType>::_Type& _Impl)
{
_ASSERTE(!_M_Impl);
_M_Impl = _Impl;
}
/// <summary>
/// Set the implementation of the task to be the supplied implementation using a move instead of a copy.
/// </summary>
void _SetImpl(typename details::_Task_ptr<_ReturnType>::_Type&& _Impl)
{
_ASSERTE(!_M_Impl);
_M_Impl = std::move(_Impl);
}
/// <summary>
/// Sets a property determining whether the task is apartment aware.
/// </summary>
void _SetAsync(bool _Async = true) { _GetImpl()->_SetAsync(_Async); }
/// <summary>
/// Sets a field in the task impl to the return callstack for calls to the task constructors and the then
/// method.
/// </summary>
void _SetTaskCreationCallstack(const details::_TaskCreationCallstack& _callstack)
{
_GetImpl()->_SetTaskCreationCallstack(_callstack);
}
/// <summary>
/// An internal version of then that takes additional flags and always execute the continuation inline by
/// default. When _ForceInline is set to false, continuations inlining will be limited to default
/// _DefaultAutoInline. This function is Used for runtime internal continuations only.
/// </summary>
template<typename _Function>
auto _Then(_Function&& _Func,
details::_CancellationTokenState* _PTokenState,
details::_TaskInliningMode_t _InliningMode = details::_ForceInline) const ->
typename details::_ContinuationTypeTraits<_Function, _ReturnType>::_TaskOfType
{
// inherit from antecedent
auto _Scheduler = _GetImpl()->_GetScheduler();
return _ThenImpl<_ReturnType, _Function>(std::forward<_Function>(_Func),
_PTokenState,
task_continuation_context::use_default(),
_Scheduler,
PPLX_CAPTURE_CALLSTACK(),
_InliningMode);
}
private:
template<typename T>
friend class task;
// The task handle type used to construct an 'initial task' - a task with no dependents.
template<typename _InternalReturnType, typename _Function, typename _TypeSelection>
struct _InitialTaskHandle
: details::_PPLTaskHandle<_ReturnType,
_InitialTaskHandle<_InternalReturnType, _Function, _TypeSelection>,
details::_UnrealizedChore_t>
{
_Function _M_function;
_InitialTaskHandle(const typename details::_Task_ptr<_ReturnType>::_Type& _TaskImpl, const _Function& _func)
: details::_PPLTaskHandle<_ReturnType,
_InitialTaskHandle<_InternalReturnType, _Function, _TypeSelection>,
details::_UnrealizedChore_t>::_PPLTaskHandle(_TaskImpl)
, _M_function(_func)
{
}
virtual ~_InitialTaskHandle() {}
template<typename _Func>
auto _LogWorkItemAndInvokeUserLambda(_Func&& _func) const -> decltype(_func())
{
details::_TaskWorkItemRAIILogger _LogWorkItem(this->_M_pTask->_M_taskEventLogger);
CASABLANCA_UNREFERENCED_PARAMETER(_LogWorkItem);
return _func();
}
void _Perform() const { _Init(_TypeSelection()); }
void _SyncCancelAndPropagateException() const { this->_M_pTask->_Cancel(true); }
//
// Overload 0: returns _InternalReturnType
//
// This is the most basic task with no unwrapping
//
void _Init(details::_TypeSelectorNoAsync) const
{
this->_M_pTask->_FinalizeAndRunContinuations(
_LogWorkItemAndInvokeUserLambda(_Init_func_transformer<_InternalReturnType>::_Perform(_M_function)));
}
//
// Overload 1: returns IAsyncOperation<_InternalReturnType>^ (only under /ZW)
// or
// returns task<_InternalReturnType>
//
// This is task whose functor returns an async operation or a task which will be unwrapped for continuation
// Depending on the output type, the right _AsyncInit gets invoked
//
void _Init(details::_TypeSelectorAsyncOperationOrTask) const
{
details::_Task_impl_base::_AsyncInit<_ReturnType, _InternalReturnType>(
this->_M_pTask, _LogWorkItemAndInvokeUserLambda(_M_function));
}
#if defined(__cplusplus_winrt)
//
// Overload 2: returns IAsyncAction^
//
// This is task whose functor returns an async action which will be unwrapped for continuation
//
void _Init(details::_TypeSelectorAsyncAction) const
{
details::_Task_impl_base::_AsyncInit<_ReturnType, _InternalReturnType>(
this->_M_pTask,
ref new details::_IAsyncActionToAsyncOperationConverter(_LogWorkItemAndInvokeUserLambda(_M_function)));
}
//
// Overload 3: returns IAsyncOperationWithProgress<_InternalReturnType, _ProgressType>^
//
// This is task whose functor returns an async operation with progress which will be unwrapped for continuation
//
void _Init(details::_TypeSelectorAsyncOperationWithProgress) const
{
typedef details::_GetProgressType<decltype(_M_function())>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_ReturnType, _InternalReturnType>(
this->_M_pTask,
ref new details::_IAsyncOperationWithProgressToAsyncOperationConverter<_InternalReturnType,
_ProgressType>(
_LogWorkItemAndInvokeUserLambda(_M_function)));
}
//
// Overload 4: returns IAsyncActionWithProgress<_ProgressType>^
//
// This is task whose functor returns an async action with progress which will be unwrapped for continuation
//
void _Init(details::_TypeSelectorAsyncActionWithProgress) const
{
typedef details::_GetProgressType<decltype(_M_function())>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_ReturnType, _InternalReturnType>(
this->_M_pTask,
ref new details::_IAsyncActionWithProgressToAsyncOperationConverter<_ProgressType>(
_LogWorkItemAndInvokeUserLambda(_M_function)));
}
#endif /* defined (__cplusplus_winrt) */
};
/// <summary>
/// The task handle type used to create a 'continuation task'.
/// </summary>
template<typename _InternalReturnType,
typename _ContinuationReturnType,
typename _Function,
typename _IsTaskBased,
typename _TypeSelection>
struct _ContinuationTaskHandle
: details::_PPLTaskHandle<typename details::_NormalizeVoidToUnitType<_ContinuationReturnType>::_Type,
_ContinuationTaskHandle<_InternalReturnType,
_ContinuationReturnType,
_Function,
_IsTaskBased,
_TypeSelection>,
details::_ContinuationTaskHandleBase>
{
typedef typename details::_NormalizeVoidToUnitType<_ContinuationReturnType>::_Type
_NormalizedContinuationReturnType;
typename details::_Task_ptr<_ReturnType>::_Type _M_ancestorTaskImpl;
typename details::_CopyableFunctor<typename std::decay<_Function>::type>::_Type _M_function;
template<class _ForwardedFunction>
_ContinuationTaskHandle(
const typename details::_Task_ptr<_ReturnType>::_Type& _AncestorImpl,
const typename details::_Task_ptr<_NormalizedContinuationReturnType>::_Type& _ContinuationImpl,
_ForwardedFunction&& _Func,
const task_continuation_context& _Context,
details::_TaskInliningMode_t _InliningMode)
: details::_PPLTaskHandle<typename details::_NormalizeVoidToUnitType<_ContinuationReturnType>::_Type,
_ContinuationTaskHandle<_InternalReturnType,
_ContinuationReturnType,
_Function,
_IsTaskBased,
_TypeSelection>,
details::_ContinuationTaskHandleBase>::_PPLTaskHandle(_ContinuationImpl)
, _M_ancestorTaskImpl(_AncestorImpl)
, _M_function(std::forward<_ForwardedFunction>(_Func))
{
this->_M_isTaskBasedContinuation = _IsTaskBased::value;
this->_M_continuationContext = _Context;
this->_M_continuationContext._Resolve(_AncestorImpl->_IsApartmentAware());
this->_M_inliningMode = _InliningMode;
}
virtual ~_ContinuationTaskHandle() {}
template<typename _Func, typename _Arg>
auto _LogWorkItemAndInvokeUserLambda(_Func&& _func, _Arg&& _value) const
-> decltype(_func(std::forward<_Arg>(_value)))
{
details::_TaskWorkItemRAIILogger _LogWorkItem(this->_M_pTask->_M_taskEventLogger);
CASABLANCA_UNREFERENCED_PARAMETER(_LogWorkItem);
return _func(std::forward<_Arg>(_value));
}
void _Perform() const { _Continue(_IsTaskBased(), _TypeSelection()); }
void _SyncCancelAndPropagateException() const
{
if (_M_ancestorTaskImpl->_HasUserException())
{
// If the ancestor encountered an exception, transfer the exception to the continuation
// This traverses down the tree to propagate the exception.
this->_M_pTask->_CancelWithExceptionHolder(_M_ancestorTaskImpl->_GetExceptionHolder(), true);
}
else
{
// If the ancestor was canceled, then your own execution should be canceled.
// This traverses down the tree to cancel it.
this->_M_pTask->_Cancel(true);
}
}
//
// Overload 0-0: _InternalReturnType -> _TaskType
//
// This is a straight task continuation which simply invokes its target with the ancestor's completion argument
//
void _Continue(std::false_type, details::_TypeSelectorNoAsync) const
{
this->_M_pTask->_FinalizeAndRunContinuations(_LogWorkItemAndInvokeUserLambda(
_Continuation_func_transformer<_InternalReturnType, _ContinuationReturnType>::_Perform(_M_function),
_M_ancestorTaskImpl->_GetResult()));
}
//
// Overload 0-1: _InternalReturnType -> IAsyncOperation<_TaskType>^ (only under /ZW)
// or
// _InternalReturnType -> task<_TaskType>
//
// This is a straight task continuation which returns an async operation or a task which will be unwrapped for
// continuation Depending on the output type, the right _AsyncInit gets invoked
//
void _Continue(std::false_type, details::_TypeSelectorAsyncOperationOrTask) const
{
typedef typename details::_FunctionTypeTraits<_Function, _InternalReturnType>::_FuncRetType _FuncOutputType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
_LogWorkItemAndInvokeUserLambda(
_Continuation_func_transformer<_InternalReturnType, _FuncOutputType>::_Perform(_M_function),
_M_ancestorTaskImpl->_GetResult()));
}
#if defined(__cplusplus_winrt)
//
// Overload 0-2: _InternalReturnType -> IAsyncAction^
//
// This is a straight task continuation which returns an async action which will be unwrapped for continuation
//
void _Continue(std::false_type, details::_TypeSelectorAsyncAction) const
{
typedef details::_FunctionTypeTraits<_Function, _InternalReturnType>::_FuncRetType _FuncOutputType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
ref new details::_IAsyncActionToAsyncOperationConverter(_LogWorkItemAndInvokeUserLambda(
_Continuation_func_transformer<_InternalReturnType, _FuncOutputType>::_Perform(_M_function),
_M_ancestorTaskImpl->_GetResult())));
}
//
// Overload 0-3: _InternalReturnType -> IAsyncOperationWithProgress<_TaskType, _ProgressType>^
//
// This is a straight task continuation which returns an async operation with progress which will be unwrapped
// for continuation
//
void _Continue(std::false_type, details::_TypeSelectorAsyncOperationWithProgress) const
{
typedef details::_FunctionTypeTraits<_Function, _InternalReturnType>::_FuncRetType _FuncOutputType;
auto _OpWithProgress = _LogWorkItemAndInvokeUserLambda(
_Continuation_func_transformer<_InternalReturnType, _FuncOutputType>::_Perform(_M_function),
_M_ancestorTaskImpl->_GetResult());
typedef details::_GetProgressType<decltype(_OpWithProgress)>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
ref new details::_IAsyncOperationWithProgressToAsyncOperationConverter<_ContinuationReturnType,
_ProgressType>(_OpWithProgress));
}
//
// Overload 0-4: _InternalReturnType -> IAsyncActionWithProgress<_ProgressType>^
//
// This is a straight task continuation which returns an async action with progress which will be unwrapped for
// continuation
//
void _Continue(std::false_type, details::_TypeSelectorAsyncActionWithProgress) const
{
typedef details::_FunctionTypeTraits<_Function, _InternalReturnType>::_FuncRetType _FuncOutputType;
auto _OpWithProgress = _LogWorkItemAndInvokeUserLambda(
_Continuation_func_transformer<_InternalReturnType, _FuncOutputType>::_Perform(_M_function),
_M_ancestorTaskImpl->_GetResult());
typedef details::_GetProgressType<decltype(_OpWithProgress)>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
ref new details::_IAsyncActionWithProgressToAsyncOperationConverter<_ProgressType>(_OpWithProgress));
}
#endif /* defined (__cplusplus_winrt) */
//
// Overload 1-0: task<_InternalReturnType> -> _TaskType
//
// This is an exception handling type of continuation which takes the task rather than the task's result.
//
void _Continue(std::true_type, details::_TypeSelectorNoAsync) const
{
typedef task<_InternalReturnType> _FuncInputType;
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
this->_M_pTask->_FinalizeAndRunContinuations(_LogWorkItemAndInvokeUserLambda(
_Continuation_func_transformer<_FuncInputType, _ContinuationReturnType>::_Perform(_M_function),
std::move(_ResultTask)));
}
//
// Overload 1-1: task<_InternalReturnType> -> IAsyncOperation<_TaskType>^
// or
// task<_TaskType>
//
// This is an exception handling type of continuation which takes the task rather than
// the task's result. It also returns an async operation or a task which will be unwrapped
// for continuation
//
void _Continue(std::true_type, details::_TypeSelectorAsyncOperationOrTask) const
{
// The continuation takes a parameter of type task<_Input>, which is the same as the ancestor task.
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask, _LogWorkItemAndInvokeUserLambda(_M_function, std::move(_ResultTask)));
}
#if defined(__cplusplus_winrt)
//
// Overload 1-2: task<_InternalReturnType> -> IAsyncAction^
//
// This is an exception handling type of continuation which takes the task rather than
// the task's result. It also returns an async action which will be unwrapped for continuation
//
void _Continue(std::true_type, details::_TypeSelectorAsyncAction) const
{
// The continuation takes a parameter of type task<_Input>, which is the same as the ancestor task.
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
ref new details::_IAsyncActionToAsyncOperationConverter(
_LogWorkItemAndInvokeUserLambda(_M_function, std::move(_ResultTask))));
}
//
// Overload 1-3: task<_InternalReturnType> -> IAsyncOperationWithProgress<_TaskType, _ProgressType>^
//
// This is an exception handling type of continuation which takes the task rather than
// the task's result. It also returns an async operation with progress which will be unwrapped
// for continuation
//
void _Continue(std::true_type, details::_TypeSelectorAsyncOperationWithProgress) const
{
// The continuation takes a parameter of type task<_Input>, which is the same as the ancestor task.
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
typedef details::_GetProgressType<decltype(_M_function(_ResultTask))>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
ref new details::_IAsyncOperationWithProgressToAsyncOperationConverter<_ContinuationReturnType,
_ProgressType>(
_LogWorkItemAndInvokeUserLambda(_M_function, std::move(_ResultTask))));
}
//
// Overload 1-4: task<_InternalReturnType> -> IAsyncActionWithProgress<_ProgressType>^
//
// This is an exception handling type of continuation which takes the task rather than
// the task's result. It also returns an async operation with progress which will be unwrapped
// for continuation
//
void _Continue(std::true_type, details::_TypeSelectorAsyncActionWithProgress) const
{
// The continuation takes a parameter of type task<_Input>, which is the same as the ancestor task.
task<_InternalReturnType> _ResultTask;
_ResultTask._SetImpl(std::move(_M_ancestorTaskImpl));
typedef details::_GetProgressType<decltype(_M_function(_ResultTask))>::_Value _ProgressType;
details::_Task_impl_base::_AsyncInit<_NormalizedContinuationReturnType, _ContinuationReturnType>(
this->_M_pTask,
ref new details::_IAsyncActionWithProgressToAsyncOperationConverter<_ProgressType>(
_LogWorkItemAndInvokeUserLambda(_M_function, std::move(_ResultTask))));
}
#endif /* defined (__cplusplus_winrt) */
};
/// <summary>
/// Initializes a task using a lambda, function pointer or function object.
/// </summary>
template<typename _InternalReturnType, typename _Function>
void _TaskInitWithFunctor(const _Function& _Func)
{
typedef typename details::_InitFunctorTypeTraits<_InternalReturnType, decltype(_Func())> _Async_type_traits;
_M_Impl->_M_fFromAsync = _Async_type_traits::_IsAsyncTask;
_M_Impl->_M_fUnwrappedTask = _Async_type_traits::_IsUnwrappedTaskOrAsync;
_M_Impl->_M_taskEventLogger._LogScheduleTask(false);
_M_Impl->_ScheduleTask(
new _InitialTaskHandle<_InternalReturnType, _Function, typename _Async_type_traits::_AsyncKind>(_GetImpl(),
_Func),
details::_NoInline);
}
/// <summary>
/// Initializes a task using a task completion event.
/// </summary>
void _TaskInitNoFunctor(task_completion_event<_ReturnType>& _Event) { _Event._RegisterTask(_M_Impl); }
#if defined(__cplusplus_winrt)
/// <summary>
/// Initializes a task using an asynchronous operation IAsyncOperation<T>^
/// </summary>
void _TaskInitAsyncOp(
Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value> ^ _AsyncOp)
{
_M_Impl->_M_fFromAsync = true;
// Mark this task as started here since we can set the state in the constructor without acquiring a lock. Once
// _AsyncInit returns a completion could execute concurrently and the task must be fully initialized before that
// happens.
_M_Impl->_M_TaskState = details::_Task_impl_base::_Started;
// Pass the shared pointer into _AsyncInit for storage in the Async Callback.
details::_Task_impl_base::_AsyncInit<_ReturnType, _ReturnType>(_M_Impl, _AsyncOp);
}
/// <summary>
/// Initializes a task using an asynchronous operation IAsyncOperation<T>^
/// </summary>
void _TaskInitNoFunctor(
Windows::Foundation::IAsyncOperation<typename details::_ValueTypeOrRefType<_ReturnType>::_Value> ^ _AsyncOp)
{
_TaskInitAsyncOp(_AsyncOp);
}
/// <summary>
/// Initializes a task using an asynchronous operation with progress IAsyncOperationWithProgress<T, P>^
/// </summary>
template<typename _Progress>
void _TaskInitNoFunctor(
Windows::Foundation::IAsyncOperationWithProgress<typename details::_ValueTypeOrRefType<_ReturnType>::_Value,
_Progress> ^
_AsyncOp)
{
_TaskInitAsyncOp(ref new details::_IAsyncOperationWithProgressToAsyncOperationConverter<
typename details::_ValueTypeOrRefType<_ReturnType>::_Value,
_Progress>(_AsyncOp));
}
#endif /* defined (__cplusplus_winrt) */
/// <summary>
/// Initializes a task using a callable object.
/// </summary>
template<typename _Function>
void _TaskInitMaybeFunctor(_Function& _Func, std::true_type)
{
_TaskInitWithFunctor<_ReturnType, _Function>(_Func);
}
/// <summary>
/// Initializes a task using a non-callable object.
/// </summary>
template<typename _Ty>
void _TaskInitMaybeFunctor(_Ty& _Param, std::false_type)
{
_TaskInitNoFunctor(_Param);
}
template<typename _InternalReturnType, typename _Function>
auto _ThenImpl(_Function&& _Func, const task_options& _TaskOptions) const ->
typename details::_ContinuationTypeTraits<_Function, _InternalReturnType>::_TaskOfType
{
if (!_M_Impl)
{
throw invalid_operation("then() cannot be called on a default constructed task.");
}
details::_CancellationTokenState* _PTokenState =
_TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _Scheduler = _TaskOptions.has_scheduler() ? _TaskOptions.get_scheduler() : _GetImpl()->_GetScheduler();
auto _CreationStack = details::_get_internal_task_options(_TaskOptions)._M_hasPresetCreationCallstack
? details::_get_internal_task_options(_TaskOptions)._M_presetCreationCallstack
: details::_TaskCreationCallstack();
return _ThenImpl<_InternalReturnType, _Function>(std::forward<_Function>(_Func),
_PTokenState,
_TaskOptions.get_continuation_context(),
_Scheduler,
_CreationStack);
}
/// <summary>
/// The one and only implementation of then for void and non-void tasks.
/// </summary>
template<typename _InternalReturnType, typename _Function>
auto _ThenImpl(_Function&& _Func,
details::_CancellationTokenState* _PTokenState,
const task_continuation_context& _ContinuationContext,
scheduler_ptr _Scheduler,
details::_TaskCreationCallstack _CreationStack,
details::_TaskInliningMode_t _InliningMode = details::_NoInline) const ->
typename details::_ContinuationTypeTraits<_Function, _InternalReturnType>::_TaskOfType
{
if (!_M_Impl)
{
throw invalid_operation("then() cannot be called on a default constructed task.");
}
typedef details::_FunctionTypeTraits<_Function, _InternalReturnType> _Function_type_traits;
typedef details::_TaskTypeTraits<typename _Function_type_traits::_FuncRetType> _Async_type_traits;
typedef typename _Async_type_traits::_TaskRetType _TaskType;
//
// A **nullptr** token state indicates that it was not provided by the user. In this case, we inherit the
// antecedent's token UNLESS this is a an exception handling continuation. In that case, we break the chain with
// a _None. That continuation is never canceled unless the user explicitly passes the same token.
//
if (_PTokenState == nullptr)
{
if (_Function_type_traits::_Takes_task::value)
{
_PTokenState = details::_CancellationTokenState::_None();
}
else
{
_PTokenState = _GetImpl()->_M_pTokenState;
}
}
task<_TaskType> _ContinuationTask;
_ContinuationTask._CreateImpl(_PTokenState, _Scheduler);
_ContinuationTask._GetImpl()->_M_fFromAsync = (_GetImpl()->_M_fFromAsync || _Async_type_traits::_IsAsyncTask);
_ContinuationTask._GetImpl()->_M_fUnwrappedTask = _Async_type_traits::_IsUnwrappedTaskOrAsync;
_ContinuationTask._SetTaskCreationCallstack(_CreationStack);
_GetImpl()->_ScheduleContinuation(
new _ContinuationTaskHandle<_InternalReturnType,
_TaskType,
_Function,
typename _Function_type_traits::_Takes_task,
typename _Async_type_traits::_AsyncKind>(_GetImpl(),
_ContinuationTask._GetImpl(),
std::forward<_Function>(_Func),
_ContinuationContext,
_InliningMode));
return _ContinuationTask;
}
// The underlying implementation for this task
typename details::_Task_ptr<_ReturnType>::_Type _M_Impl;
};
/// <summary>
/// The Parallel Patterns Library (PPL) <c>task</c> class. A <c>task</c> object represents work that can be executed
/// asynchronously, and concurrently with other tasks and parallel work produced by parallel algorithms in the
/// Concurrency Runtime. It produces a result of type <typeparamref name="_ResultType"/> on successful completion.
/// Tasks of type <c>task<void></c> produce no result. A task can be waited upon and canceled independently of
/// other tasks. It can also be composed with other tasks using continuations(<c>then</c>), and
/// join(<c>when_all</c>) and choice(<c>when_any</c>) patterns.
/// </summary>
/// <remarks>
/// For more information, see <see cref="Task Parallelism (Concurrency Runtime)"/>.
/// </remarks>
/**/
template<>
class task<void>
{
public:
/// <summary>
/// The type of the result an object of this class produces.
/// </summary>
/**/
typedef void result_type;
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within
/// containers. A default constructed task cannot be used until you assign a valid task to it. Methods such as
/// <c>get</c>, <c>wait</c> or <c>then</c> will throw an <see cref="invalid_argument
/// Class">invalid_argument</see> exception when called on a default constructed task. <para>A task that is
/// created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the
/// task completion event is set.</para> <para>The version of the constructor that takes a cancellation token
/// creates a task that can be canceled using the <c>cancellation_token_source</c> the token was obtained from.
/// Tasks created without a cancellation token are not cancelable.</para> <para>Tasks created from a
/// <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes.
/// Similarly, tasks created from a lambda that returns a <c>task<result_type></c> reach their terminal
/// state when the inner task reaches its terminal state, and not when the lambda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by
/// multiple threads without the need for locks.</para> <para>The constructor overloads that take a
/// Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available to
/// Windows Store apps.</para> <para>For more information, see <see cref="Task Parallelism (Concurrency
/// Runtime)"/>.</para>
/// </remarks>
/**/
task() : _M_unitTask()
{
// The default constructor should create a task with a nullptr impl. This is a signal that the
// task is not usable and should throw if any wait(), get() or then() APIs are used.
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda, a function object, a
/// <c>task_completion_event<result_type></c> object, or a Windows::Foundation::IAsyncInfo if you are
/// using tasks in your Windows Store app. The lambda or function object should be a type equivalent to
/// <c>std::function<X(void)></c>, where X can be a variable of type <c>result_type</c>,
/// <c>task<result_type></c>, or a Windows::Foundation::IAsyncInfo in Windows Store apps.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within
/// containers. A default constructed task cannot be used until you assign a valid task to it. Methods such as
/// <c>get</c>, <c>wait</c> or <c>then</c> will throw an <see cref="invalid_argument
/// Class">invalid_argument</see> exception when called on a default constructed task. <para>A task that is
/// created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the
/// task completion event is set.</para> <para>The version of the constructor that takes a cancellation token
/// creates a task that can be canceled using the <c>cancellation_token_source</c> the token was obtained from.
/// Tasks created without a cancellation token are not cancelable.</para> <para>Tasks created from a
/// <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes.
/// Similarly, tasks created from a lambda that returns a <c>task<result_type></c> reach their terminal
/// state when the inner task reaches its terminal state, and not when the lambda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by
/// multiple threads without the need for locks.</para> <para>The constructor overloads that take a
/// Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available to
/// Windows Store apps.</para> <para>For more information, see <see cref="Task Parallelism (Concurrency
/// Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Ty>
__declspec(noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK gives us the expected result
explicit task(_Ty _Param, const task_options& _TaskOptions = task_options())
{
details::_ValidateTaskConstructorArgs<void, _Ty>(_Param);
_M_unitTask._CreateImpl(_TaskOptions.get_cancellation_token()._GetImplValue(), _TaskOptions.get_scheduler());
// Do not move the next line out of this function. It is important that PPLX_CAPTURE_CALLSTACK() evaluate to the
// the call site of the task constructor.
_M_unitTask._SetTaskCreationCallstack(
details::_get_internal_task_options(_TaskOptions)._M_hasPresetCreationCallstack
? details::_get_internal_task_options(_TaskOptions)._M_presetCreationCallstack
: PPLX_CAPTURE_CALLSTACK());
_TaskInitMaybeFunctor(_Param, details::_IsCallable(_Param, 0));
}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within
/// containers. A default constructed task cannot be used until you assign a valid task to it. Methods such as
/// <c>get</c>, <c>wait</c> or <c>then</c> will throw an <see cref="invalid_argument
/// Class">invalid_argument</see> exception when called on a default constructed task. <para>A task that is
/// created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the
/// task completion event is set.</para> <para>The version of the constructor that takes a cancellation token
/// creates a task that can be canceled using the <c>cancellation_token_source</c> the token was obtained from.
/// Tasks created without a cancellation token are not cancelable.</para> <para>Tasks created from a
/// <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes.
/// Similarly, tasks created from a lambda that returns a <c>task<result_type></c> reach their terminal
/// state when the inner task reaches its terminal state, and not when the lambda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by
/// multiple threads without the need for locks.</para> <para>The constructor overloads that take a
/// Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available to
/// Windows Store apps.</para> <para>For more information, see <see cref="Task Parallelism (Concurrency
/// Runtime)"/>.</para>
/// </remarks>
/**/
task(const task& _Other) : _M_unitTask(_Other._M_unitTask) {}
/// <summary>
/// Constructs a <c>task</c> object.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// The default constructor for a <c>task</c> is only present in order to allow tasks to be used within
/// containers. A default constructed task cannot be used until you assign a valid task to it. Methods such as
/// <c>get</c>, <c>wait</c> or <c>then</c> will throw an <see cref="invalid_argument
/// Class">invalid_argument</see> exception when called on a default constructed task. <para>A task that is
/// created from a <c>task_completion_event</c> will complete (and have its continuations scheduled) when the
/// task completion event is set.</para> <para>The version of the constructor that takes a cancellation token
/// creates a task that can be canceled using the <c>cancellation_token_source</c> the token was obtained from.
/// Tasks created without a cancellation token are not cancelable.</para> <para>Tasks created from a
/// <c>Windows::Foundation::IAsyncInfo</c> interface or a lambda that returns an <c>IAsyncInfo</c> interface
/// reach their terminal state when the enclosed Windows Runtime asynchronous operation or action completes.
/// Similarly, tasks created from a lambda that returns a <c>task<result_type></c> reach their terminal
/// state when the inner task reaches its terminal state, and not when the lambda returns.</para>
/// <para><c>task</c> behaves like a smart pointer and is safe to pass around by value. It can be accessed by
/// multiple threads without the need for locks.</para> <para>The constructor overloads that take a
/// Windows::Foundation::IAsyncInfo interface or a lambda returning such an interface, are only available to
/// Windows Store apps.</para> <para>For more information, see <see cref="Task Parallelism (Concurrency
/// Runtime)"/>.</para>
/// </remarks>
/**/
task(task&& _Other) : _M_unitTask(std::move(_Other._M_unitTask)) {}
/// <summary>
/// Replaces the contents of one <c>task</c> object with another.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// As <c>task</c> behaves like a smart pointer, after a copy assignment, this <c>task</c> objects represents
/// the same actual task as <paramref name="_Other"/> does.
/// </remarks>
/**/
task& operator=(const task& _Other)
{
if (this != &_Other)
{
_M_unitTask = _Other._M_unitTask;
}
return *this;
}
/// <summary>
/// Replaces the contents of one <c>task</c> object with another.
/// </summary>
/// <param name="_Other">
/// The source <c>task</c> object.
/// </param>
/// <remarks>
/// As <c>task</c> behaves like a smart pointer, after a copy assignment, this <c>task</c> objects represents
/// the same actual task as <paramref name="_Other"/> does.
/// </remarks>
/**/
task& operator=(task&& _Other)
{
if (this != &_Other)
{
_M_unitTask = std::move(_Other._M_unitTask);
}
return *this;
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task<result_type></c>, where <c>result_type</c> is the
/// type of the result this task produces.
/// </param>
/// <param name="_CancellationToken">
/// The cancellation token to associate with the continuation task. A continuation task that is created without
/// a cancellation token will inherit the token of its antecedent task.
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref
/// name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo
/// interface, are only available to Windows Store apps. <para>For more information on how to use task
/// continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK gives us the expected result
auto then(_Function&& _Func, task_options _TaskOptions = task_options()) const ->
typename details::_ContinuationTypeTraits<_Function, void>::_TaskOfType
{
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(PPLX_CAPTURE_CALLSTACK());
return _M_unitTask._ThenImpl<void, _Function>(std::forward<_Function>(_Func), _TaskOptions);
}
/// <summary>
/// Adds a continuation task to this task.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked by this task.
/// </typeparam>
/// <param name="_Func">
/// The continuation function to execute when this task completes. This continuation function must take as input
/// a variable of either <c>result_type</c> or <c>task<result_type></c>, where <c>result_type</c> is the
/// type of the result this task produces.
/// </param>
/// <param name="_CancellationToken">
/// The cancellation token to associate with the continuation task. A continuation task that is created without
/// a cancellation token will inherit the token of its antecedent task.
/// </param>
/// <param name="_ContinuationContext">
/// A variable that specifies where the continuation should execute. This variable is only useful when used in a
/// Windows Store style app. For more information, see <see cref="task_continuation_context
/// Class">task_continuation_context</see>
/// </param>
/// <returns>
/// The newly created continuation task. The result type of the returned task is determined by what <paramref
/// name="_Func"/> returns.
/// </returns>
/// <remarks>
/// The overloads of <c>then</c> that take a lambda or functor that returns a Windows::Foundation::IAsyncInfo
/// interface, are only available to Windows Store apps. <para>For more information on how to use task
/// continuations to compose asynchronous work, see <see cref="Task Parallelism (Concurrency Runtime)"/>.</para>
/// </remarks>
/**/
template<typename _Function>
__declspec(noinline) // Ask for no inlining so that the PPLX_CAPTURE_CALLSTACK gives us the expected result
auto then(_Function&& _Func,
cancellation_token _CancellationToken,
task_continuation_context _ContinuationContext) const ->
typename details::_ContinuationTypeTraits<_Function, void>::_TaskOfType
{
task_options _TaskOptions(_CancellationToken, _ContinuationContext);
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(PPLX_CAPTURE_CALLSTACK());
return _M_unitTask._ThenImpl<void, _Function>(std::forward<_Function>(_Func), _TaskOptions);
}
/// <summary>
/// Waits for this task to reach a terminal state. It is possible for <c>wait</c> to execute the task inline, if
/// all of the tasks dependencies are satisfied, and it has not already been picked up for execution by a
/// background worker.
/// </summary>
/// <returns>
/// A <c>task_status</c> value which could be either <c>completed</c> or <c>canceled</c>. If the task
/// encountered an exception during execution, or an exception was propagated to it from an antecedent task,
/// <c>wait</c> will throw that exception.
/// </returns>
/**/
task_status wait() const { return _M_unitTask.wait(); }
/// <summary>
/// Returns the result this task produced. If the task is not in a terminal state, a call to <c>get</c> will
/// wait for the task to finish. This method does not return a value when called on a task with a
/// <c>result_type</c> of <c>void</c>.
/// </summary>
/// <remarks>
/// If the task is canceled, a call to <c>get</c> will throw a <see cref="task_canceled
/// Class">task_canceled</see> exception. If the task encountered an different exception or an exception was
/// propagated to it from an antecedent task, a call to <c>get</c> will throw that exception.
/// </remarks>
/**/
void get() const { _M_unitTask.get(); }
/// <summary>
/// Determines if the task is completed.
/// </summary>
/// <returns>
/// True if the task has completed, false otherwise.
/// </returns>
/// <remarks>
/// The function returns true if the task is completed or canceled (with or without user exception).
/// </remarks>
bool is_done() const { return _M_unitTask.is_done(); }
/// <summary>
/// Returns the scheduler for this task
/// </summary>
/// <returns>
/// A pointer to the scheduler
/// </returns>
scheduler_ptr scheduler() const { return _M_unitTask.scheduler(); }
/// <summary>
/// Determines whether the task unwraps a Windows Runtime <c>IAsyncInfo</c> interface or is descended from such
/// a task.
/// </summary>
/// <returns>
/// <c>true</c> if the task unwraps an <c>IAsyncInfo</c> interface or is descended from such a task,
/// <c>false</c> otherwise.
/// </returns>
/**/
bool is_apartment_aware() const { return _M_unitTask.is_apartment_aware(); }
/// <summary>
/// Determines whether two <c>task</c> objects represent the same internal task.
/// </summary>
/// <returns>
/// <c>true</c> if the objects refer to the same underlying task, and <c>false</c> otherwise.
/// </returns>
/**/
bool operator==(const task<void>& _Rhs) const { return (_M_unitTask == _Rhs._M_unitTask); }
/// <summary>
/// Determines whether two <c>task</c> objects represent different internal tasks.
/// </summary>
/// <returns>
/// <c>true</c> if the objects refer to different underlying tasks, and <c>false</c> otherwise.
/// </returns>
/**/
bool operator!=(const task<void>& _Rhs) const { return !operator==(_Rhs); }
/// <summary>
/// Create an underlying task implementation.
/// </summary>
void _CreateImpl(details::_CancellationTokenState* _Ct, scheduler_ptr _Scheduler)
{
_M_unitTask._CreateImpl(_Ct, _Scheduler);
}
/// <summary>
/// Return the underlying implementation for this task.
/// </summary>
const details::_Task_ptr<details::_Unit_type>::_Type& _GetImpl() const { return _M_unitTask._M_Impl; }
/// <summary>
/// Set the implementation of the task to be the supplied implementation.
/// </summary>
void _SetImpl(const details::_Task_ptr<details::_Unit_type>::_Type& _Impl) { _M_unitTask._SetImpl(_Impl); }
/// <summary>
/// Set the implementation of the task to be the supplied implementation using a move instead of a copy.
/// </summary>
void _SetImpl(details::_Task_ptr<details::_Unit_type>::_Type&& _Impl) { _M_unitTask._SetImpl(std::move(_Impl)); }
/// <summary>
/// Sets a property determining whether the task is apartment aware.
/// </summary>
void _SetAsync(bool _Async = true) { _M_unitTask._SetAsync(_Async); }
/// <summary>
/// Sets a field in the task impl to the return callstack for calls to the task constructors and the then
/// method.
/// </summary>
void _SetTaskCreationCallstack(const details::_TaskCreationCallstack& _callstack)
{
_M_unitTask._SetTaskCreationCallstack(_callstack);
}
/// <summary>
/// An internal version of then that takes additional flags and executes the continuation inline. Used for
/// runtime internal continuations only.
/// </summary>
template<typename _Function>
auto _Then(_Function&& _Func,
details::_CancellationTokenState* _PTokenState,
details::_TaskInliningMode_t _InliningMode = details::_ForceInline) const ->
typename details::_ContinuationTypeTraits<_Function, void>::_TaskOfType
{
// inherit from antecedent
auto _Scheduler = _GetImpl()->_GetScheduler();
return _M_unitTask._ThenImpl<void, _Function>(std::forward<_Function>(_Func),
_PTokenState,
task_continuation_context::use_default(),
_Scheduler,
PPLX_CAPTURE_CALLSTACK(),
_InliningMode);
}
private:
template<typename T>
friend class task;
template<typename T>
friend class task_completion_event;
/// <summary>
/// Initializes a task using a task completion event.
/// </summary>
void _TaskInitNoFunctor(task_completion_event<void>& _Event)
{
_M_unitTask._TaskInitNoFunctor(_Event._M_unitEvent);
}
#if defined(__cplusplus_winrt)
/// <summary>
/// Initializes a task using an asynchronous action IAsyncAction^
/// </summary>
void _TaskInitNoFunctor(Windows::Foundation::IAsyncAction ^ _AsyncAction)
{
_M_unitTask._TaskInitAsyncOp(ref new details::_IAsyncActionToAsyncOperationConverter(_AsyncAction));
}
/// <summary>
/// Initializes a task using an asynchronous action with progress IAsyncActionWithProgress<_P>^
/// </summary>
template<typename _P>
void _TaskInitNoFunctor(Windows::Foundation::IAsyncActionWithProgress<_P> ^ _AsyncActionWithProgress)
{
_M_unitTask._TaskInitAsyncOp(
ref new details::_IAsyncActionWithProgressToAsyncOperationConverter<_P>(_AsyncActionWithProgress));
}
#endif /* defined (__cplusplus_winrt) */
/// <summary>
/// Initializes a task using a callable object.
/// </summary>
template<typename _Function>
void _TaskInitMaybeFunctor(_Function& _Func, std::true_type)
{
_M_unitTask._TaskInitWithFunctor<void, _Function>(_Func);
}
/// <summary>
/// Initializes a task using a non-callable object.
/// </summary>
template<typename _T>
void _TaskInitMaybeFunctor(_T& _Param, std::false_type)
{
_TaskInitNoFunctor(_Param);
}
// The void task contains a task of a dummy type so common code can be used for tasks with void and non-void
// results.
task<details::_Unit_type> _M_unitTask;
};
namespace details
{
/// <summary>
/// The following type traits are used for the create_task function.
/// </summary>
#if defined(__cplusplus_winrt)
// Unwrap functions for asyncOperations
template<typename _Ty>
_Ty _GetUnwrappedType(Windows::Foundation::IAsyncOperation<_Ty> ^);
void _GetUnwrappedType(Windows::Foundation::IAsyncAction ^);
template<typename _Ty, typename _Progress>
_Ty _GetUnwrappedType(Windows::Foundation::IAsyncOperationWithProgress<_Ty, _Progress> ^);
template<typename _Progress>
void _GetUnwrappedType(Windows::Foundation::IAsyncActionWithProgress<_Progress> ^);
#endif /* defined (__cplusplus_winrt) */
// Unwrap task<T>
template<typename _Ty>
_Ty _GetUnwrappedType(task<_Ty>);
// Unwrap all supported types
template<typename _Ty>
auto _GetUnwrappedReturnType(_Ty _Arg, int) -> decltype(_GetUnwrappedType(_Arg));
// fallback
template<typename _Ty>
_Ty _GetUnwrappedReturnType(_Ty, ...);
/// <summary>
/// <c>_GetTaskType</c> functions will retrieve task type <c>T</c> in <c>task[T](Arg)</c>,
/// for given constructor argument <c>Arg</c> and its property "callable".
/// It will automatically unwrap argument to get the final return type if necessary.
/// </summary>
// Non-Callable
template<typename _Ty>
_Ty _GetTaskType(task_completion_event<_Ty>, std::false_type);
// Non-Callable
template<typename _Ty>
auto _GetTaskType(_Ty _NonFunc, std::false_type) -> decltype(_GetUnwrappedType(_NonFunc));
// Callable
template<typename _Ty>
auto _GetTaskType(_Ty _Func, std::true_type) -> decltype(_GetUnwrappedReturnType(_Func(), 0));
// Special callable returns void
void _GetTaskType(std::function<void()>, std::true_type);
struct _BadArgType
{
};
template<typename _Ty>
auto _FilterValidTaskType(_Ty _Param, int) -> decltype(_GetTaskType(_Param, _IsCallable(_Param, 0)));
template<typename _Ty>
_BadArgType _FilterValidTaskType(_Ty _Param, ...);
template<typename _Ty>
struct _TaskTypeFromParam
{
typedef decltype(_FilterValidTaskType(stdx::declval<_Ty>(), 0)) _Type;
};
} // namespace details
/// <summary>
/// Creates a PPL <see cref="task Class">task</see> object. <c>create_task</c> can be used anywhere you would have
/// used a task constructor. It is provided mainly for convenience, because it allows use of the <c>auto</c> keyword
/// while creating tasks.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda or function object, a
/// <c>task_completion_event</c> object, a different <c>task</c> object, or a Windows::Foundation::IAsyncInfo
/// interface if you are using tasks in your Windows Store app.
/// </param>
/// <returns>
/// A new task of type <c>T</c>, that is inferred from <paramref name="_Param"/>.
/// </returns>
/// <remarks>
/// The first overload behaves like a task constructor that takes a single parameter.
/// <para>The second overload associates the cancellation token provided with the newly created task. If you use
/// this overload you are not allowed to pass in a different <c>task</c> object as the first parameter.</para>
/// <para>The type of the returned task is inferred from the first parameter to the function. If <paramref
/// name="_Param"/> is a <c>task_completion_event<T></c>, a <c>task<T></c>, or a functor that returns
/// either type <c>T</c> or <c>task<T></c>, the type of the created task is <c>task<T></c>.</para>
/// <para>In a Windows Store app, if <paramref name="_Param"/> is of type
/// Windows::Foundation::IAsyncOperation<T>^ or Windows::Foundation::IAsyncOperationWithProgress<T,P>^,
/// or a functor that returns either of those types, the created task will be of type <c>task<T></c>. If
/// <paramref name="_Param"/> is of type Windows::Foundation::IAsyncAction^ or
/// Windows::Foundation::IAsyncActionWithProgress<P>^, or a functor that returns either of those types, the
/// created task will have type <c>task<void></c>.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _Ty>
__declspec(noinline) auto create_task(_Ty _Param, task_options _TaskOptions = task_options())
-> task<typename details::_TaskTypeFromParam<_Ty>::_Type>
{
static_assert(!std::is_same<typename details::_TaskTypeFromParam<_Ty>::_Type, details::_BadArgType>::value,
#if defined(__cplusplus_winrt)
"incorrect argument for create_task; can be a callable object, an asynchronous operation, or a "
"task_completion_event"
#else /* defined (__cplusplus_winrt) */
"incorrect argument for create_task; can be a callable object or a task_completion_event"
#endif /* defined (__cplusplus_winrt) */
);
details::_get_internal_task_options(_TaskOptions)._set_creation_callstack(PPLX_CAPTURE_CALLSTACK());
task<typename details::_TaskTypeFromParam<_Ty>::_Type> _CreatedTask(_Param, _TaskOptions);
return _CreatedTask;
}
/// <summary>
/// Creates a PPL <see cref="task Class">task</see> object. <c>create_task</c> can be used anywhere you would have
/// used a task constructor. It is provided mainly for convenience, because it allows use of the <c>auto</c> keyword
/// while creating tasks.
/// </summary>
/// <typeparam name="_Ty">
/// The type of the parameter from which the task is to be constructed.
/// </typeparam>
/// <param name="_Param">
/// The parameter from which the task is to be constructed. This could be a lambda or function object, a
/// <c>task_completion_event</c> object, a different <c>task</c> object, or a Windows::Foundation::IAsyncInfo
/// interface if you are using tasks in your Windows Store app.
/// </param>
/// <param name="_Token">
/// The cancellation token to associate with the task. When the source for this token is canceled, cancellation will
/// be requested on the task.
/// </param>
/// <returns>
/// A new task of type <c>T</c>, that is inferred from <paramref name="_Param"/>.
/// </returns>
/// <remarks>
/// The first overload behaves like a task constructor that takes a single parameter.
/// <para>The second overload associates the cancellation token provided with the newly created task. If you use
/// this overload you are not allowed to pass in a different <c>task</c> object as the first parameter.</para>
/// <para>The type of the returned task is inferred from the first parameter to the function. If <paramref
/// name="_Param"/> is a <c>task_completion_event<T></c>, a <c>task<T></c>, or a functor that returns
/// either type <c>T</c> or <c>task<T></c>, the type of the created task is <c>task<T></c>.</para>
/// <para>In a Windows Store app, if <paramref name="_Param"/> is of type
/// Windows::Foundation::IAsyncOperation<T>^ or Windows::Foundation::IAsyncOperationWithProgress<T,P>^,
/// or a functor that returns either of those types, the created task will be of type <c>task<T></c>. If
/// <paramref name="_Param"/> is of type Windows::Foundation::IAsyncAction^ or
/// Windows::Foundation::IAsyncActionWithProgress<P>^, or a functor that returns either of those types, the
/// created task will have type <c>task<void></c>.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
__declspec(noinline) task<_ReturnType> create_task(const task<_ReturnType>& _Task)
{
task<_ReturnType> _CreatedTask(_Task);
return _CreatedTask;
}
#if defined(__cplusplus_winrt)
namespace details
{
template<typename _T>
task<_T> _To_task_helper(Windows::Foundation::IAsyncOperation<_T> ^ op)
{
return task<_T>(op);
}
template<typename _T, typename _Progress>
task<_T> _To_task_helper(Windows::Foundation::IAsyncOperationWithProgress<_T, _Progress> ^ op)
{
return task<_T>(op);
}
inline task<void> _To_task_helper(Windows::Foundation::IAsyncAction ^ op) { return task<void>(op); }
template<typename _Progress>
task<void> _To_task_helper(Windows::Foundation::IAsyncActionWithProgress<_Progress> ^ op)
{
return task<void>(op);
}
template<typename _ProgressType>
class _ProgressDispatcherBase
{
public:
virtual ~_ProgressDispatcherBase() {}
virtual void _Report(const _ProgressType& _Val) = 0;
};
template<typename _ProgressType, typename _ClassPtrType>
class _ProgressDispatcher : public _ProgressDispatcherBase<_ProgressType>
{
public:
virtual ~_ProgressDispatcher() {}
_ProgressDispatcher(_ClassPtrType _Ptr) : _M_ptr(_Ptr) {}
virtual void _Report(const _ProgressType& _Val) { _M_ptr->_FireProgress(_Val); }
private:
_ClassPtrType _M_ptr;
};
class _ProgressReporterCtorArgType
{
};
} // namespace details
/// <summary>
/// The progress reporter class allows reporting progress notifications of a specific type. Each progress_reporter
/// object is bound to a particular asynchronous action or operation.
/// </summary>
/// <typeparam name="_ProgressType">
/// The payload type of each progress notification reported through the progress reporter.
/// </typeparam>
/// <remarks>
/// This type is only available to Windows Store apps.
/// </remarks>
/// <seealso cref="create_async Function"/>
/**/
template<typename _ProgressType>
class progress_reporter
{
typedef std::shared_ptr<details::_ProgressDispatcherBase<_ProgressType>> _PtrType;
public:
/// <summary>
/// Sends a progress report to the asynchronous action or operation to which this progress reporter is bound.
/// </summary>
/// <param name="_Val">
/// The payload to report through a progress notification.
/// </param>
/**/
void report(const _ProgressType& _Val) const { _M_dispatcher->_Report(_Val); }
template<typename _ClassPtrType>
static progress_reporter _CreateReporter(_ClassPtrType _Ptr)
{
progress_reporter _Reporter;
details::_ProgressDispatcherBase<_ProgressType>* _PDispatcher =
new details::_ProgressDispatcher<_ProgressType, _ClassPtrType>(_Ptr);
_Reporter._M_dispatcher = _PtrType(_PDispatcher);
return _Reporter;
}
progress_reporter() {}
private:
progress_reporter(details::_ProgressReporterCtorArgType);
_PtrType _M_dispatcher;
};
namespace details
{
//
// maps internal definitions for AsyncStatus and defines states that are not client visible
//
enum _AsyncStatusInternal
{
_AsyncCreated = -1, // externally invisible
// client visible states (must match AsyncStatus exactly)
_AsyncStarted = 0, // Windows::Foundation::AsyncStatus::Started,
_AsyncCompleted = 1, // Windows::Foundation::AsyncStatus::Completed,
_AsyncCanceled = 2, // Windows::Foundation::AsyncStatus::Canceled,
_AsyncError = 3, // Windows::Foundation::AsyncStatus::Error,
// non-client visible internal states
_AsyncCancelPending,
_AsyncClosed,
_AsyncUndefined
};
//
// designates whether the "GetResults" method returns a single result (after complete fires) or multiple results
// (which are progressively consumable between Start state and before Close is called)
//
enum _AsyncResultType
{
SingleResult = 0x0001,
MultipleResults = 0x0002
};
// ***************************************************************************
// Template type traits and helpers for async production APIs:
//
struct _ZeroArgumentFunctor
{
};
struct _OneArgumentFunctor
{
};
struct _TwoArgumentFunctor
{
};
// ****************************************
// CLASS TYPES:
// ********************
// TWO ARGUMENTS:
// non-void arg:
template<typename _Class, typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg1 _Arg1ClassHelperThunk(_ReturnType (_Class::*)(_Arg1, _Arg2) const);
// non-void arg:
template<typename _Class, typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg2 _Arg2ClassHelperThunk(_ReturnType (_Class::*)(_Arg1, _Arg2) const);
template<typename _Class, typename _ReturnType, typename _Arg1, typename _Arg2>
_ReturnType _ReturnTypeClassHelperThunk(_ReturnType (_Class::*)(_Arg1, _Arg2) const);
template<typename _Class, typename _ReturnType, typename _Arg1, typename _Arg2>
_TwoArgumentFunctor _ArgumentCountHelper(_ReturnType (_Class::*)(_Arg1, _Arg2) const);
// ********************
// ONE ARGUMENT:
// non-void arg:
template<typename _Class, typename _ReturnType, typename _Arg1>
_Arg1 _Arg1ClassHelperThunk(_ReturnType (_Class::*)(_Arg1) const);
// non-void arg:
template<typename _Class, typename _ReturnType, typename _Arg1>
void _Arg2ClassHelperThunk(_ReturnType (_Class::*)(_Arg1) const);
template<typename _Class, typename _ReturnType, typename _Arg1>
_ReturnType _ReturnTypeClassHelperThunk(_ReturnType (_Class::*)(_Arg1) const);
template<typename _Class, typename _ReturnType, typename _Arg1>
_OneArgumentFunctor _ArgumentCountHelper(_ReturnType (_Class::*)(_Arg1) const);
// ********************
// ZERO ARGUMENT:
// void arg:
template<typename _Class, typename _ReturnType>
void _Arg1ClassHelperThunk(_ReturnType (_Class::*)() const);
// void arg:
template<typename _Class, typename _ReturnType>
void _Arg2ClassHelperThunk(_ReturnType (_Class::*)() const);
// void arg:
template<typename _Class, typename _ReturnType>
_ReturnType _ReturnTypeClassHelperThunk(_ReturnType (_Class::*)() const);
template<typename _Class, typename _ReturnType>
_ZeroArgumentFunctor _ArgumentCountHelper(_ReturnType (_Class::*)() const);
// ****************************************
// POINTER TYPES:
// ********************
// TWO ARGUMENTS:
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__cdecl*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg2 _Arg2PFNHelperThunk(_ReturnType(__cdecl*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__cdecl*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_TwoArgumentFunctor _ArgumentCountHelper(_ReturnType(__cdecl*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__stdcall*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg2 _Arg2PFNHelperThunk(_ReturnType(__stdcall*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__stdcall*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_TwoArgumentFunctor _ArgumentCountHelper(_ReturnType(__stdcall*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__fastcall*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_Arg2 _Arg2PFNHelperThunk(_ReturnType(__fastcall*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__fastcall*)(_Arg1, _Arg2));
template<typename _ReturnType, typename _Arg1, typename _Arg2>
_TwoArgumentFunctor _ArgumentCountHelper(_ReturnType(__fastcall*)(_Arg1, _Arg2));
// ********************
// ONE ARGUMENT:
template<typename _ReturnType, typename _Arg1>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__cdecl*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
void _Arg2PFNHelperThunk(_ReturnType(__cdecl*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__cdecl*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_OneArgumentFunctor _ArgumentCountHelper(_ReturnType(__cdecl*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__stdcall*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
void _Arg2PFNHelperThunk(_ReturnType(__stdcall*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__stdcall*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_OneArgumentFunctor _ArgumentCountHelper(_ReturnType(__stdcall*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_Arg1 _Arg1PFNHelperThunk(_ReturnType(__fastcall*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
void _Arg2PFNHelperThunk(_ReturnType(__fastcall*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__fastcall*)(_Arg1));
template<typename _ReturnType, typename _Arg1>
_OneArgumentFunctor _ArgumentCountHelper(_ReturnType(__fastcall*)(_Arg1));
// ********************
// ZERO ARGUMENT:
template<typename _ReturnType>
void _Arg1PFNHelperThunk(_ReturnType(__cdecl*)());
template<typename _ReturnType>
void _Arg2PFNHelperThunk(_ReturnType(__cdecl*)());
template<typename _ReturnType>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__cdecl*)());
template<typename _ReturnType>
_ZeroArgumentFunctor _ArgumentCountHelper(_ReturnType(__cdecl*)());
template<typename _ReturnType>
void _Arg1PFNHelperThunk(_ReturnType(__stdcall*)());
template<typename _ReturnType>
void _Arg2PFNHelperThunk(_ReturnType(__stdcall*)());
template<typename _ReturnType>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__stdcall*)());
template<typename _ReturnType>
_ZeroArgumentFunctor _ArgumentCountHelper(_ReturnType(__stdcall*)());
template<typename _ReturnType>
void _Arg1PFNHelperThunk(_ReturnType(__fastcall*)());
template<typename _ReturnType>
void _Arg2PFNHelperThunk(_ReturnType(__fastcall*)());
template<typename _ReturnType>
_ReturnType _ReturnTypePFNHelperThunk(_ReturnType(__fastcall*)());
template<typename _ReturnType>
_ZeroArgumentFunctor _ArgumentCountHelper(_ReturnType(__fastcall*)());
template<typename _T>
struct _FunctorArguments
{
static const size_t _Count = 0;
};
template<>
struct _FunctorArguments<_OneArgumentFunctor>
{
static const size_t _Count = 1;
};
template<>
struct _FunctorArguments<_TwoArgumentFunctor>
{
static const size_t _Count = 2;
};
template<typename _T>
struct _FunctorTypeTraits
{
typedef decltype(_ArgumentCountHelper(&(_T::operator()))) _ArgumentCountType;
static const size_t _ArgumentCount = _FunctorArguments<_ArgumentCountType>::_Count;
typedef decltype(_ReturnTypeClassHelperThunk(&(_T::operator()))) _ReturnType;
typedef decltype(_Arg1ClassHelperThunk(&(_T::operator()))) _Argument1Type;
typedef decltype(_Arg2ClassHelperThunk(&(_T::operator()))) _Argument2Type;
};
template<typename _T>
struct _FunctorTypeTraits<_T*>
{
typedef decltype(_ArgumentCountHelper(stdx::declval<_T*>())) _ArgumentCountType;
static const size_t _ArgumentCount = _FunctorArguments<_ArgumentCountType>::_Count;
typedef decltype(_ReturnTypePFNHelperThunk(stdx::declval<_T*>())) _ReturnType;
typedef decltype(_Arg1PFNHelperThunk(stdx::declval<_T*>())) _Argument1Type;
typedef decltype(_Arg2PFNHelperThunk(stdx::declval<_T*>())) _Argument2Type;
};
template<typename _T>
struct _ProgressTypeTraits
{
static const bool _TakesProgress = false;
typedef void _ProgressType;
};
template<typename _T>
struct _ProgressTypeTraits<progress_reporter<_T>>
{
static const bool _TakesProgress = true;
typedef typename _T _ProgressType;
};
template<typename _T, size_t count = _FunctorTypeTraits<_T>::_ArgumentCount>
struct _CAFunctorOptions
{
static const bool _TakesProgress = false;
static const bool _TakesToken = false;
typedef void _ProgressType;
};
template<typename _T>
struct _CAFunctorOptions<_T, 1>
{
private:
typedef typename _FunctorTypeTraits<_T>::_Argument1Type _Argument1Type;
public:
static const bool _TakesProgress = _ProgressTypeTraits<_Argument1Type>::_TakesProgress;
static const bool _TakesToken = !_TakesProgress;
typedef typename _ProgressTypeTraits<_Argument1Type>::_ProgressType _ProgressType;
};
template<typename _T>
struct _CAFunctorOptions<_T, 2>
{
private:
typedef typename _FunctorTypeTraits<_T>::_Argument1Type _Argument1Type;
public:
static const bool _TakesProgress = true;
static const bool _TakesToken = true;
typedef typename _ProgressTypeTraits<_Argument1Type>::_ProgressType _ProgressType;
};
ref class _Zip
{
};
// ***************************************************************************
// Async Operation Task Generators
//
//
// Functor returns an IAsyncInfo - result needs to be wrapped in a task:
//
template<typename _AsyncSelector, typename _ReturnType>
struct _SelectorTaskGenerator
{
template<typename _Function>
static task<_ReturnType> _GenerateTask_0(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(_Func(), _taskOptinos);
}
template<typename _Function>
static task<_ReturnType> _GenerateTask_1C(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(_Func(_Cts.get_token()), _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_1P(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(_Func(_Progress), _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_2PC(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(_Func(_Progress, _Cts.get_token()), _taskOptinos);
}
};
template<typename _AsyncSelector>
struct _SelectorTaskGenerator<_AsyncSelector, void>
{
template<typename _Function>
static task<void> _GenerateTask_0(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(_Func(), _taskOptinos);
}
template<typename _Function>
static task<void> _GenerateTask_1C(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(_Func(_Cts.get_token()), _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_1P(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(_Func(_Progress), _taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_2PC(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(_Func(_Progress, _Cts.get_token()), _taskOptinos);
}
};
//
// Functor returns a result - it needs to be wrapped in a task:
//
template<typename _ReturnType>
struct _SelectorTaskGenerator<_TypeSelectorNoAsync, _ReturnType>
{
#pragma warning(push)
#pragma warning(disable : 4702)
template<typename _Function>
static task<_ReturnType> _GenerateTask_0(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(
[=]() -> _ReturnType {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
return _Func();
},
_taskOptinos);
}
#pragma warning(pop)
template<typename _Function>
static task<_ReturnType> _GenerateTask_1C(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(
[=]() -> _ReturnType {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
return _Func(_Cts.get_token());
},
_taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_1P(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(
[=]() -> _ReturnType {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
return _Func(_Progress);
},
_taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_2PC(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<_ReturnType>(
[=]() -> _ReturnType {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
return _Func(_Progress, _Cts.get_token());
},
_taskOptinos);
}
};
template<>
struct _SelectorTaskGenerator<_TypeSelectorNoAsync, void>
{
template<typename _Function>
static task<void> _GenerateTask_0(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(
[=]() {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
_Func();
},
_taskOptinos);
}
template<typename _Function>
static task<void> _GenerateTask_1C(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(
[=]() {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
_Func(_Cts.get_token());
},
_taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_1P(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(
[=]() {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
_Func(_Progress);
},
_taskOptinos);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_2PC(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
task_options _taskOptinos(_Cts.get_token());
details::_get_internal_task_options(_taskOptinos)._set_creation_callstack(_callstack);
return task<void>(
[=]() {
_Task_generator_oversubscriber_t _Oversubscriber;
(_Oversubscriber);
_Func(_Progress, _Cts.get_token());
},
_taskOptinos);
}
};
//
// Functor returns a task - the task can directly be returned:
//
template<typename _ReturnType>
struct _SelectorTaskGenerator<_TypeSelectorAsyncTask, _ReturnType>
{
template<typename _Function>
static task<_ReturnType> _GenerateTask_0(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _Func();
}
template<typename _Function>
static task<_ReturnType> _GenerateTask_1C(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _Func(_Cts.get_token());
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_1P(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _Func(_Progress);
}
template<typename _Function, typename _ProgressObject>
static task<_ReturnType> _GenerateTask_2PC(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _Func(_Progress, _Cts.get_token());
}
};
template<>
struct _SelectorTaskGenerator<_TypeSelectorAsyncTask, void>
{
template<typename _Function>
static task<void> _GenerateTask_0(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _Func();
}
template<typename _Function>
static task<void> _GenerateTask_1C(const _Function& _Func,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _Func(_Cts.get_token());
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_1P(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _Func(_Progress);
}
template<typename _Function, typename _ProgressObject>
static task<void> _GenerateTask_2PC(const _Function& _Func,
const _ProgressObject& _Progress,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _Func(_Progress, _Cts.get_token());
}
};
template<typename _Generator, bool _TakesToken, bool TakesProgress>
struct _TaskGenerator
{
};
template<typename _Generator>
struct _TaskGenerator<_Generator, false, false>
{
template<typename _Function, typename _ClassPtr, typename _ProgressType>
static auto _GenerateTask(const _Function& _Func,
_ClassPtr _Ptr,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
-> decltype(_Generator::_GenerateTask_0(_Func, _Cts, _callstack))
{
return _Generator::_GenerateTask_0(_Func, _Cts, _callstack);
}
};
template<typename _Generator>
struct _TaskGenerator<_Generator, true, false>
{
template<typename _Function, typename _ClassPtr, typename _ProgressType>
static auto _GenerateTask(const _Function& _Func,
_ClassPtr _Ptr,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
-> decltype(_Generator::_GenerateTask_0(_Func, _Cts, _callstack))
{
return _Generator::_GenerateTask_1C(_Func, _Cts, _callstack);
}
};
template<typename _Generator>
struct _TaskGenerator<_Generator, false, true>
{
template<typename _Function, typename _ClassPtr, typename _ProgressType>
static auto _GenerateTask(const _Function& _Func,
_ClassPtr _Ptr,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
-> decltype(_Generator::_GenerateTask_0(_Func, _Cts, _callstack))
{
return _Generator::_GenerateTask_1P(
_Func, progress_reporter<_ProgressType>::_CreateReporter(_Ptr), _Cts, _callstack);
}
};
template<typename _Generator>
struct _TaskGenerator<_Generator, true, true>
{
template<typename _Function, typename _ClassPtr, typename _ProgressType>
static auto _GenerateTask(const _Function& _Func,
_ClassPtr _Ptr,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
-> decltype(_Generator::_GenerateTask_0(_Func, _Cts, _callstack))
{
return _Generator::_GenerateTask_2PC(
_Func, progress_reporter<_ProgressType>::_CreateReporter(_Ptr), _Cts, _callstack);
}
};
// ***************************************************************************
// Async Operation Attributes Classes
//
// These classes are passed through the hierarchy of async base classes in order to hold multiple attributes of a given
// async construct in a single container. An attribute class must define:
//
// Mandatory:
// -------------------------
//
// _AsyncBaseType : The Windows Runtime interface which is being implemented.
// _CompletionDelegateType : The Windows Runtime completion delegate type for the interface.
// _ProgressDelegateType : If _TakesProgress is true, the Windows Runtime progress delegate type for the interface.
// If it is false, an empty Windows Runtime type. _ReturnType : The return type of the async construct
// (void for actions / non-void for operations)
//
// _TakesProgress : An indication as to whether or not
//
// _Generate_Task : A function adapting the user's function into what's necessary to produce the appropriate
// task
//
// Optional:
// -------------------------
//
template<typename _Function,
typename _ProgressType,
typename _ReturnType,
typename _TaskTraits,
bool _TakesToken,
bool _TakesProgress>
struct _AsyncAttributes
{
};
template<typename _Function, typename _ProgressType, typename _ReturnType, typename _TaskTraits, bool _TakesToken>
struct _AsyncAttributes<_Function, _ProgressType, _ReturnType, _TaskTraits, _TakesToken, true>
{
typedef typename Windows::Foundation::IAsyncOperationWithProgress<_ReturnType, _ProgressType> _AsyncBaseType;
typedef typename Windows::Foundation::AsyncOperationProgressHandler<_ReturnType, _ProgressType>
_ProgressDelegateType;
typedef typename Windows::Foundation::AsyncOperationWithProgressCompletedHandler<_ReturnType, _ProgressType>
_CompletionDelegateType;
typedef typename _ReturnType _ReturnType;
typedef typename _ProgressType _ProgressType;
typedef typename _TaskTraits::_AsyncKind _AsyncKind;
typedef typename _SelectorTaskGenerator<_AsyncKind, _ReturnType> _SelectorTaskGenerator;
typedef typename _TaskGenerator<_SelectorTaskGenerator, _TakesToken, true> _TaskGenerator;
static const bool _TakesProgress = true;
static const bool _TakesToken = _TakesToken;
template<typename _Function, typename _ClassPtr>
static task<_ReturnType> _Generate_Task(const _Function& _Func,
_ClassPtr _Ptr,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _TaskGenerator::_GenerateTask<_Function, _ClassPtr, _ProgressType>(_Func, _Ptr, _Cts, _callstack);
}
};
template<typename _Function, typename _ProgressType, typename _ReturnType, typename _TaskTraits, bool _TakesToken>
struct _AsyncAttributes<_Function, _ProgressType, _ReturnType, _TaskTraits, _TakesToken, false>
{
typedef typename Windows::Foundation::IAsyncOperation<_ReturnType> _AsyncBaseType;
typedef _Zip _ProgressDelegateType;
typedef typename Windows::Foundation::AsyncOperationCompletedHandler<_ReturnType> _CompletionDelegateType;
typedef typename _ReturnType _ReturnType;
typedef typename _TaskTraits::_AsyncKind _AsyncKind;
typedef typename _SelectorTaskGenerator<_AsyncKind, _ReturnType> _SelectorTaskGenerator;
typedef typename _TaskGenerator<_SelectorTaskGenerator, _TakesToken, false> _TaskGenerator;
static const bool _TakesProgress = false;
static const bool _TakesToken = _TakesToken;
template<typename _Function, typename _ClassPtr>
static task<_ReturnType> _Generate_Task(const _Function& _Func,
_ClassPtr _Ptr,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _TaskGenerator::_GenerateTask<_Function, _ClassPtr, _ProgressType>(_Func, _Ptr, _Cts, _callstack);
}
};
template<typename _Function, typename _ProgressType, typename _TaskTraits, bool _TakesToken>
struct _AsyncAttributes<_Function, _ProgressType, void, _TaskTraits, _TakesToken, true>
{
typedef typename Windows::Foundation::IAsyncActionWithProgress<_ProgressType> _AsyncBaseType;
typedef typename Windows::Foundation::AsyncActionProgressHandler<_ProgressType> _ProgressDelegateType;
typedef typename Windows::Foundation::AsyncActionWithProgressCompletedHandler<_ProgressType>
_CompletionDelegateType;
typedef void _ReturnType;
typedef typename _ProgressType _ProgressType;
typedef typename _TaskTraits::_AsyncKind _AsyncKind;
typedef typename _SelectorTaskGenerator<_AsyncKind, _ReturnType> _SelectorTaskGenerator;
typedef typename _TaskGenerator<_SelectorTaskGenerator, _TakesToken, true> _TaskGenerator;
static const bool _TakesProgress = true;
static const bool _TakesToken = _TakesToken;
template<typename _Function, typename _ClassPtr>
static task<_ReturnType> _Generate_Task(const _Function& _Func,
_ClassPtr _Ptr,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _TaskGenerator::_GenerateTask<_Function, _ClassPtr, _ProgressType>(_Func, _Ptr, _Cts, _callstack);
}
};
template<typename _Function, typename _ProgressType, typename _TaskTraits, bool _TakesToken>
struct _AsyncAttributes<_Function, _ProgressType, void, _TaskTraits, _TakesToken, false>
{
typedef typename Windows::Foundation::IAsyncAction _AsyncBaseType;
typedef _Zip _ProgressDelegateType;
typedef typename Windows::Foundation::AsyncActionCompletedHandler _CompletionDelegateType;
typedef void _ReturnType;
typedef typename _TaskTraits::_AsyncKind _AsyncKind;
typedef typename _SelectorTaskGenerator<_AsyncKind, _ReturnType> _SelectorTaskGenerator;
typedef typename _TaskGenerator<_SelectorTaskGenerator, _TakesToken, false> _TaskGenerator;
static const bool _TakesProgress = false;
static const bool _TakesToken = _TakesToken;
template<typename _Function, typename _ClassPtr>
static task<_ReturnType> _Generate_Task(const _Function& _Func,
_ClassPtr _Ptr,
cancellation_token_source _Cts,
const _TaskCreationCallstack& _callstack)
{
return _TaskGenerator::_GenerateTask<_Function, _ClassPtr, _ProgressType>(_Func, _Ptr, _Cts, _callstack);
}
};
template<typename _Function>
struct _AsyncLambdaTypeTraits
{
typedef typename _FunctorTypeTraits<_Function>::_ReturnType _ReturnType;
typedef typename _FunctorTypeTraits<_Function>::_Argument1Type _Argument1Type;
typedef typename _CAFunctorOptions<_Function>::_ProgressType _ProgressType;
static const bool _TakesProgress = _CAFunctorOptions<_Function>::_TakesProgress;
static const bool _TakesToken = _CAFunctorOptions<_Function>::_TakesToken;
typedef typename _TaskTypeTraits<_ReturnType> _TaskTraits;
typedef typename _AsyncAttributes<_Function,
_ProgressType,
typename _TaskTraits::_TaskRetType,
_TaskTraits,
_TakesToken,
_TakesProgress>
_AsyncAttributes;
};
// ***************************************************************************
// AsyncInfo (and completion) Layer:
//
//
// Internal base class implementation for async operations (based on internal Windows representation for ABI level async
// operations)
//
template<typename _Attributes, _AsyncResultType resultType = SingleResult>
ref class _AsyncInfoBase abstract : _Attributes::_AsyncBaseType
{
internal :
_AsyncInfoBase()
: _M_currentStatus(_AsyncStatusInternal::_AsyncCreated)
, _M_errorCode(S_OK)
, _M_completeDelegate(nullptr)
, _M_CompleteDelegateAssigned(0)
, _M_CallbackMade(0)
{
_M_id = ::pplx::details::platform::GetNextAsyncId();
}
public:
virtual typename _Attributes::_ReturnType GetResults()
{
throw ::Platform::Exception::CreateException(E_UNEXPECTED);
}
virtual property unsigned int Id
{
unsigned int get()
{
_CheckValidStateForAsyncInfoCall();
return _M_id;
}
void set(unsigned int id)
{
_CheckValidStateForAsyncInfoCall();
if (id == 0)
{
throw ::Platform::Exception::CreateException(E_INVALIDARG);
}
else if (_M_currentStatus != _AsyncStatusInternal::_AsyncCreated)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
_M_id = id;
}
}
virtual property Windows::Foundation::AsyncStatus Status
{
Windows::Foundation::AsyncStatus get()
{
_CheckValidStateForAsyncInfoCall();
_AsyncStatusInternal _Current = _M_currentStatus;
//
// Map our internal cancel pending to canceled. This way "pending canceled" looks to the outside as
// "canceled" but can still transition to "completed" if the operation completes without acknowledging the
// cancellation request
//
switch (_Current)
{
case _AsyncCancelPending: _Current = _AsyncCanceled; break;
case _AsyncCreated: _Current = _AsyncStarted; break;
default: break;
}
return static_cast<Windows::Foundation::AsyncStatus>(_Current);
}
}
virtual property Windows::Foundation::HResult ErrorCode
{
Windows::Foundation::HResult get()
{
_CheckValidStateForAsyncInfoCall();
Windows::Foundation::HResult _Hr;
_Hr.Value = _M_errorCode;
return _Hr;
}
}
virtual property typename _Attributes::_ProgressDelegateType ^
Progress {
typename typename _Attributes::_ProgressDelegateType ^ get() { return _GetOnProgress(); }
void set(typename _Attributes::_ProgressDelegateType ^ _ProgressHandler)
{
_PutOnProgress(_ProgressHandler);
}
}
virtual void
Cancel()
{
if (_TransitionToState(_AsyncCancelPending))
{
_OnCancel();
}
}
virtual void Close()
{
if (_TransitionToState(_AsyncClosed))
{
_OnClose();
}
else
{
if (_M_currentStatus != _AsyncClosed) // Closed => Closed transition is just ignored
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_STATE_CHANGE);
}
}
}
virtual property typename _Attributes::_CompletionDelegateType ^
Completed {
typename _Attributes::_CompletionDelegateType ^
get() {
_CheckValidStateForDelegateCall();
return _M_completeDelegate;
}
void set(typename _Attributes::_CompletionDelegateType ^ _CompleteHandler)
{
_CheckValidStateForDelegateCall();
// this delegate property is "write once"
if (InterlockedIncrement(&_M_CompleteDelegateAssigned) == 1)
{
_M_completeDelegateContext = _ContextCallback::_CaptureCurrent();
_M_completeDelegate = _CompleteHandler;
// Guarantee that the write of _M_completeDelegate is ordered with respect to the read of state
// below as perceived from _FireCompletion on another thread.
MemoryBarrier();
if (_IsTerminalState())
{
_FireCompletion();
}
}
else
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_DELEGATE_ASSIGNMENT);
}
}
}
protected private :
// _Start - this is not externally visible since async operations "hot start" before returning to the caller
void
_Start()
{
if (_TransitionToState(_AsyncStarted))
{
_OnStart();
}
else
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_STATE_CHANGE);
}
}
void _FireCompletion()
{
_TryTransitionToCompleted();
// we guarantee that completion can only ever be fired once
if (_M_completeDelegate != nullptr && InterlockedIncrement(&_M_CallbackMade) == 1)
{
_M_completeDelegateContext._CallInContext([=] {
_M_completeDelegate((_Attributes::_AsyncBaseType ^) this, this->Status);
_M_completeDelegate = nullptr;
});
}
}
virtual typename _Attributes::_ProgressDelegateType ^
_GetOnProgress() { throw ::Platform::Exception::CreateException(E_UNEXPECTED); }
virtual void _PutOnProgress(typename _Attributes::_ProgressDelegateType ^ _ProgressHandler)
{
throw ::Platform::Exception::CreateException(E_UNEXPECTED);
}
bool _TryTransitionToCompleted() { return _TransitionToState(_AsyncStatusInternal::_AsyncCompleted); }
bool _TryTransitionToCancelled() { return _TransitionToState(_AsyncStatusInternal::_AsyncCanceled); }
bool _TryTransitionToError(const HRESULT error)
{
_InterlockedCompareExchange(reinterpret_cast<volatile LONG*>(&_M_errorCode), error, S_OK);
return _TransitionToState(_AsyncStatusInternal::_AsyncError);
}
// This method checks to see if the delegate properties can be
// modified in the current state and generates the appropriate
// error hr in the case of violation.
inline void _CheckValidStateForDelegateCall()
{
if (_M_currentStatus == _AsyncClosed)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
}
// This method checks to see if results can be collected in the
// current state and generates the appropriate error hr in
// the case of a violation.
inline void _CheckValidStateForResultsCall()
{
_AsyncStatusInternal _Current = _M_currentStatus;
if (_Current == _AsyncError)
{
throw ::Platform::Exception::CreateException(_M_errorCode);
}
#pragma warning(push)
#pragma warning(disable : 4127) // Conditional expression is constant
// single result illegal before transition to Completed or Cancelled state
if (resultType == SingleResult)
#pragma warning(pop)
{
if (_Current != _AsyncCompleted)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
}
// multiple results can be called after Start has been called and before/after Completed
else if (_Current != _AsyncStarted && _Current != _AsyncCancelPending && _Current != _AsyncCanceled &&
_Current != _AsyncCompleted)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
}
// This method can be called by derived classes periodically to determine
// whether the asynchronous operation should continue processing or should
// be halted.
inline bool _ContinueAsyncOperation() { return (_M_currentStatus == _AsyncStarted); }
// These two methods are used to allow the async worker implementation do work on
// state transitions. No real "work" should be done in these methods. In other words
// they should not block for a long time on UI timescales.
virtual void _OnStart() = 0;
virtual void _OnClose() = 0;
virtual void _OnCancel() = 0;
private:
// This method is used to check if calls to the AsyncInfo properties
// (id, status, errorcode) are legal in the current state. It also
// generates the appropriate error hr to return in the case of an
// illegal call.
inline void _CheckValidStateForAsyncInfoCall()
{
_AsyncStatusInternal _Current = _M_currentStatus;
if (_Current == _AsyncClosed)
{
throw ::Platform::Exception::CreateException(E_ILLEGAL_METHOD_CALL);
}
else if (_Current == _AsyncCreated)
{
throw ::Platform::Exception::CreateException(E_ASYNC_OPERATION_NOT_STARTED);
}
}
inline bool _TransitionToState(const _AsyncStatusInternal _NewState)
{
_AsyncStatusInternal _Current = _M_currentStatus;
// This enforces the valid state transitions of the asynchronous worker object
// state machine.
switch (_NewState)
{
case _AsyncStatusInternal::_AsyncStarted:
if (_Current != _AsyncCreated)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncCompleted:
if (_Current != _AsyncStarted && _Current != _AsyncCancelPending)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncCancelPending:
if (_Current != _AsyncStarted)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncCanceled:
if (_Current != _AsyncStarted && _Current != _AsyncCancelPending)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncError:
if (_Current != _AsyncStarted && _Current != _AsyncCancelPending)
{
return false;
}
break;
case _AsyncStatusInternal::_AsyncClosed:
if (!_IsTerminalState(_Current))
{
return false;
}
break;
default: return false; break;
}
// attempt the transition to the new state
// Note: if currentStatus_ == _Current, then there was no intervening write
// by the async work object and the swap succeeded.
_AsyncStatusInternal _RetState = static_cast<_AsyncStatusInternal>(_InterlockedCompareExchange(
reinterpret_cast<volatile LONG*>(&_M_currentStatus), _NewState, static_cast<LONG>(_Current)));
// ICE returns the former state, if the returned state and the
// state we captured at the beginning of this method are the same,
// the swap succeeded.
return (_RetState == _Current);
}
inline bool _IsTerminalState() { return _IsTerminalState(_M_currentStatus); }
inline bool _IsTerminalState(_AsyncStatusInternal status)
{
return (status == _AsyncError || status == _AsyncCanceled || status == _AsyncCompleted ||
status == _AsyncClosed);
}
private:
_ContextCallback _M_completeDelegateContext;
typename _Attributes::_CompletionDelegateType ^ volatile _M_completeDelegate;
_AsyncStatusInternal volatile _M_currentStatus;
HRESULT volatile _M_errorCode;
unsigned int _M_id;
long volatile _M_CompleteDelegateAssigned;
long volatile _M_CallbackMade;
};
// ***************************************************************************
// Progress Layer (optional):
//
template<typename _Attributes, bool _HasProgress, _AsyncResultType _ResultType = SingleResult>
ref class _AsyncProgressBase abstract : _AsyncInfoBase<_Attributes, _ResultType>
{
};
template<typename _Attributes, _AsyncResultType _ResultType>
ref class _AsyncProgressBase<_Attributes, true, _ResultType> abstract : _AsyncInfoBase<_Attributes, _ResultType>
{
internal :
_AsyncProgressBase()
: _AsyncInfoBase<_Attributes, _ResultType>(), _M_progressDelegate(nullptr)
{
}
virtual typename _Attributes::_ProgressDelegateType ^ _GetOnProgress() override
{
_CheckValidStateForDelegateCall();
return _M_progressDelegate;
}
virtual void _PutOnProgress(typename _Attributes::_ProgressDelegateType ^ _ProgressHandler) override
{
_CheckValidStateForDelegateCall();
_M_progressDelegate = _ProgressHandler;
_M_progressDelegateContext = _ContextCallback::_CaptureCurrent();
}
void _FireProgress(const typename _Attributes::_ProgressType& _ProgressValue)
{
if (_M_progressDelegate != nullptr)
{
_M_progressDelegateContext._CallInContext(
[=] { _M_progressDelegate((_Attributes::_AsyncBaseType ^) this, _ProgressValue); });
}
}
private:
_ContextCallback _M_progressDelegateContext;
typename _Attributes::_ProgressDelegateType ^ _M_progressDelegate;
};
template<typename _Attributes, _AsyncResultType _ResultType = SingleResult>
ref class _AsyncBaseProgressLayer abstract : _AsyncProgressBase<_Attributes, _Attributes::_TakesProgress, _ResultType>
{
};
// ***************************************************************************
// Task Adaptation Layer:
//
//
// _AsyncTaskThunkBase provides a bridge between IAsync<Action/Operation> and task.
//
template<typename _Attributes, typename _ReturnType>
ref class _AsyncTaskThunkBase abstract : _AsyncBaseProgressLayer<_Attributes>
{
public:
virtual _ReturnType GetResults() override
{
_CheckValidStateForResultsCall();
return _M_task.get();
}
internal :
typedef task<_ReturnType>
_TaskType;
_AsyncTaskThunkBase(const _TaskType& _Task) : _M_task(_Task) {}
_AsyncTaskThunkBase() {}
protected:
virtual void _OnStart() override
{
_M_task.then([=](_TaskType _Antecedent) {
try
{
_Antecedent.get();
}
catch (task_canceled&)
{
_TryTransitionToCancelled();
}
catch (::Platform::Exception ^ _Ex)
{
_TryTransitionToError(_Ex->HResult);
}
catch (...)
{
_TryTransitionToError(E_FAIL);
}
_FireCompletion();
});
}
internal :
_TaskType _M_task;
cancellation_token_source _M_cts;
};
template<typename _Attributes>
ref class _AsyncTaskThunk : _AsyncTaskThunkBase<_Attributes, typename _Attributes::_ReturnType>
{
internal :
_AsyncTaskThunk(const _TaskType& _Task)
: _AsyncTaskThunkBase(_Task)
{
}
_AsyncTaskThunk() {}
protected:
virtual void _OnClose() override {}
virtual void _OnCancel() override { _M_cts.cancel(); }
};
// ***************************************************************************
// Async Creation Layer:
//
template<typename _Function>
ref class _AsyncTaskGeneratorThunk sealed
: _AsyncTaskThunk<typename _AsyncLambdaTypeTraits<_Function>::_AsyncAttributes>
{
internal :
typedef typename _AsyncLambdaTypeTraits<_Function>::_AsyncAttributes _Attributes;
typedef typename _AsyncTaskThunk<_Attributes> _Base;
typedef typename _Attributes::_AsyncBaseType _AsyncBaseType;
_AsyncTaskGeneratorThunk(const _Function& _Func, const _TaskCreationCallstack& _callstack)
: _M_func(_Func), _M_creationCallstack(_callstack)
{
// Virtual call here is safe as the class is declared 'sealed'
_Start();
}
protected:
//
// The only thing we must do different from the base class is we must spin the hot task on transition from
// Created->Started. Otherwise, let the base thunk handle everything.
//
virtual void _OnStart() override
{
//
// Call the appropriate task generator to actually produce a task of the expected type. This might adapt the
// user lambda for progress reports, wrap the return result in a task, or allow for direct return of a task
// depending on the form of the lambda.
//
_M_task = _Attributes::_Generate_Task(_M_func, this, _M_cts, _M_creationCallstack);
_Base::_OnStart();
}
virtual void _OnCancel() override { _Base::_OnCancel(); }
private:
_TaskCreationCallstack _M_creationCallstack;
_Function _M_func;
};
} // namespace details
/// <summary>
/// Creates a Windows Runtime asynchronous construct based on a user supplied lambda or function object. The return
/// type of <c>create_async</c> is one of either <c>IAsyncAction^</c>,
/// <c>IAsyncActionWithProgress<TProgress>^</c>, <c>IAsyncOperation<TResult>^</c>, or
/// <c>IAsyncOperationWithProgress<TResult, TProgress>^</c> based on the signature of the lambda passed to the
/// method.
/// </summary>
/// <param name="_Func">
/// The lambda or function object from which to create a Windows Runtime asynchronous construct.
/// </param>
/// <returns>
/// An asynchronous construct represented by an IAsyncAction^, IAsyncActionWithProgress<TProgress>^,
/// IAsyncOperation<TResult>^, or an IAsyncOperationWithProgress<TResult, TProgress>^. The interface
/// returned depends on the signature of the lambda passed into the function.
/// </returns>
/// <remarks>
/// The return type of the lambda determines whether the construct is an action or an operation.
/// <para>Lambdas that return void cause the creation of actions. Lambdas that return a result of type
/// <c>TResult</c> cause the creation of operations of TResult.</para> <para>The lambda may also return a
/// <c>task<TResult></c> which encapsulates the asynchronous work within itself or is the continuation of a
/// chain of tasks that represent the asynchronous work. In this case, the lambda itself is executed inline, since
/// the tasks are the ones that execute asynchronously, and the return type of the lambda is unwrapped to produce
/// the asynchronous construct returned by <c>create_async</c>. This implies that a lambda that returns a
/// task<void> will cause the creation of actions, and a lambda that returns a task<TResult> will cause
/// the creation of operations of TResult.</para> <para>The lambda may take either zero, one or two arguments. The
/// valid arguments are <c>progress_reporter<TProgress></c> and <c>cancellation_token</c>, in that order if
/// both are used. A lambda without arguments causes the creation of an asynchronous construct without the
/// capability for progress reporting. A lambda that takes a progress_reporter<TProgress> will cause
/// <c>create_async</c> to return an asynchronous construct which reports progress of type TProgress each time the
/// <c>report</c> method of the progress_reporter object is called. A lambda that takes a cancellation_token may use
/// that token to check for cancellation, or pass it to tasks that it creates so that cancellation of the
/// asynchronous construct causes cancellation of those tasks.</para>
/// <para>If the body of the lambda or function object returns a result (and not a task<TResult>), the lambda
/// will be executed asynchronously within the process MTA in the context of a task the Runtime implicitly creates
/// for it. The <c>IAsyncInfo::Cancel</c> method will cause cancellation of the implicit task.</para> <para>If the
/// body of the lambda returns a task, the lambda executes inline, and by declaring the lambda to take an argument
/// of type <c>cancellation_token</c> you can trigger cancellation of any tasks you create within the lambda by
/// passing that token in when you create them. You may also use the <c>register_callback</c> method on the token to
/// cause the Runtime to invoke a callback when you call <c>IAsyncInfo::Cancel</c> on the async operation or action
/// produced..</para> <para>This function is only available to Windows Store apps.</para>
/// </remarks>
/// <seealso cref="task Class"/>
/// <seealso cref="progress_reporter Class"/>
/// <seealso cref="cancelation_token Class"/>
/**/
template<typename _Function>
__declspec(noinline) details::_AsyncTaskGeneratorThunk<_Function> ^
create_async(const _Function& _Func) {
static_assert(std::is_same<decltype(details::_IsValidCreateAsync(_Func, 0, 0, 0, 0)), std::true_type>::value,
"argument to create_async must be a callable object taking zero, one or two arguments");
return ref new details::_AsyncTaskGeneratorThunk<_Function>(_Func, PPLX_CAPTURE_CALLSTACK());
}
#endif /* defined (__cplusplus_winrt) */
namespace details
{
// Helper struct for when_all operators to know when tasks have completed
template<typename _Type>
struct _RunAllParam
{
_RunAllParam() : _M_completeCount(0), _M_numTasks(0) {}
void _Resize(size_t _Len, bool _SkipVector = false)
{
_M_numTasks = _Len;
if (!_SkipVector)
{
_M_vector._Result.resize(_Len);
}
}
task_completion_event<_Unit_type> _M_completed;
_ResultHolder<std::vector<_Type>> _M_vector;
_ResultHolder<_Type> _M_mergeVal;
atomic_size_t _M_completeCount;
size_t _M_numTasks;
};
template<typename _Type>
struct _RunAllParam<std::vector<_Type>>
{
_RunAllParam() : _M_completeCount(0), _M_numTasks(0) {}
void _Resize(size_t _Len, bool _SkipVector = false)
{
_M_numTasks = _Len;
if (!_SkipVector)
{
_M_vector.resize(_Len);
}
}
task_completion_event<_Unit_type> _M_completed;
std::vector<_ResultHolder<std::vector<_Type>>> _M_vector;
atomic_size_t _M_completeCount;
size_t _M_numTasks;
};
// Helper struct specialization for void
template<>
struct _RunAllParam<_Unit_type>
{
_RunAllParam() : _M_completeCount(0), _M_numTasks(0) {}
void _Resize(size_t _Len) { _M_numTasks = _Len; }
task_completion_event<_Unit_type> _M_completed;
atomic_size_t _M_completeCount;
size_t _M_numTasks;
};
inline void _JoinAllTokens_Add(const cancellation_token_source& _MergedSrc,
_CancellationTokenState* _PJoinedTokenState)
{
if (_PJoinedTokenState != nullptr && _PJoinedTokenState != _CancellationTokenState::_None())
{
cancellation_token _T = cancellation_token::_FromImpl(_PJoinedTokenState);
_T.register_callback([=]() { _MergedSrc.cancel(); });
}
}
template<typename _ElementType, typename _Function, typename _TaskType>
void _WhenAllContinuationWrapper(_RunAllParam<_ElementType> * _PParam, _Function _Func, task<_TaskType> & _Task)
{
if (_Task._GetImpl()->_IsCompleted())
{
_Func();
if (atomic_increment(_PParam->_M_completeCount) == _PParam->_M_numTasks)
{
// Inline execute its direct continuation, the _ReturnTask
_PParam->_M_completed.set(_Unit_type());
// It's safe to delete it since all usage of _PParam in _ReturnTask has been finished.
delete _PParam;
}
}
else
{
_ASSERTE(_Task._GetImpl()->_IsCanceled());
if (_Task._GetImpl()->_HasUserException())
{
// _Cancel will return false if the TCE is already canceled with or without exception
_PParam->_M_completed._Cancel(_Task._GetImpl()->_GetExceptionHolder());
}
else
{
_PParam->_M_completed._Cancel();
}
if (atomic_increment(_PParam->_M_completeCount) == _PParam->_M_numTasks)
{
delete _PParam;
}
}
}
template<typename _ElementType, typename _Iterator>
struct _WhenAllImpl
{
static task<std::vector<_ElementType>> _Perform(const task_options& _TaskOptions,
_Iterator _Begin,
_Iterator _End)
{
_CancellationTokenState* _PTokenState =
_TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAllParam<_ElementType>();
cancellation_token_source _MergedSource;
// Step1: Create task completion event.
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_MergedSource.get_token());
task<_Unit_type> _All_tasks_completed(_PParam->_M_completed, _Options);
// The return task must be created before step 3 to enforce inline execution.
auto _ReturnTask = _All_tasks_completed._Then(
[=](_Unit_type) -> std::vector<_ElementType> { return _PParam->_M_vector.Get(); }, nullptr);
// Step2: Combine and check tokens, and count elements in range.
if (_PTokenState)
{
_JoinAllTokens_Add(_MergedSource, _PTokenState);
_PParam->_Resize(static_cast<size_t>(std::distance(_Begin, _End)));
}
else
{
size_t _TaskNum = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
_TaskNum++;
_JoinAllTokens_Add(_MergedSource, _PTask->_GetImpl()->_M_pTokenState);
}
_PParam->_Resize(_TaskNum);
}
// Step3: Check states of previous tasks.
if (_Begin == _End)
{
_PParam->_M_completed.set(_Unit_type());
delete _PParam;
}
else
{
size_t _Index = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PTask->_Then(
[_PParam, _Index](task<_ElementType> _ResultTask) {
auto _PParamCopy = _PParam;
auto _IndexCopy = _Index;
auto _Func = [_PParamCopy, _IndexCopy, &_ResultTask]() {
_PParamCopy->_M_vector._Result[_IndexCopy] = _ResultTask._GetImpl()->_GetResult();
};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
},
_CancellationTokenState::_None());
_Index++;
}
}
return _ReturnTask;
}
};
template<typename _ElementType, typename _Iterator>
struct _WhenAllImpl<std::vector<_ElementType>, _Iterator>
{
static task<std::vector<_ElementType>> _Perform(const task_options& _TaskOptions,
_Iterator _Begin,
_Iterator _End)
{
_CancellationTokenState* _PTokenState =
_TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAllParam<std::vector<_ElementType>>();
cancellation_token_source _MergedSource;
// Step1: Create task completion event.
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_MergedSource.get_token());
task<_Unit_type> _All_tasks_completed(_PParam->_M_completed, _Options);
// The return task must be created before step 3 to enforce inline execution.
auto _ReturnTask = _All_tasks_completed._Then(
[=](_Unit_type) -> std::vector<_ElementType> {
_ASSERTE(_PParam->_M_completeCount == _PParam->_M_numTasks);
std::vector<_ElementType> _Result;
for (size_t _I = 0; _I < _PParam->_M_numTasks; _I++)
{
const std::vector<_ElementType>& _Vec = _PParam->_M_vector[_I].Get();
_Result.insert(_Result.end(), _Vec.begin(), _Vec.end());
}
return _Result;
},
nullptr);
// Step2: Combine and check tokens, and count elements in range.
if (_PTokenState)
{
_JoinAllTokens_Add(_MergedSource, _PTokenState);
_PParam->_Resize(static_cast<size_t>(std::distance(_Begin, _End)));
}
else
{
size_t _TaskNum = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
_TaskNum++;
_JoinAllTokens_Add(_MergedSource, _PTask->_GetImpl()->_M_pTokenState);
}
_PParam->_Resize(_TaskNum);
}
// Step3: Check states of previous tasks.
if (_Begin == _End)
{
_PParam->_M_completed.set(_Unit_type());
delete _PParam;
}
else
{
size_t _Index = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PTask->_Then(
[_PParam, _Index](task<std::vector<_ElementType>> _ResultTask) {
auto _PParamCopy = _PParam;
auto _IndexCopy = _Index;
auto _Func = [_PParamCopy, _IndexCopy, &_ResultTask]() {
_PParamCopy->_M_vector[_IndexCopy].Set(_ResultTask._GetImpl()->_GetResult());
};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
},
_CancellationTokenState::_None());
_Index++;
}
}
return _ReturnTask;
}
};
template<typename _Iterator>
struct _WhenAllImpl<void, _Iterator>
{
static task<void> _Perform(const task_options& _TaskOptions, _Iterator _Begin, _Iterator _End)
{
_CancellationTokenState* _PTokenState =
_TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAllParam<_Unit_type>();
cancellation_token_source _MergedSource;
// Step1: Create task completion event.
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_MergedSource.get_token());
task<_Unit_type> _All_tasks_completed(_PParam->_M_completed, _Options);
// The return task must be created before step 3 to enforce inline execution.
auto _ReturnTask = _All_tasks_completed._Then([=](_Unit_type) {}, nullptr);
// Step2: Combine and check tokens, and count elements in range.
if (_PTokenState)
{
_JoinAllTokens_Add(_MergedSource, _PTokenState);
_PParam->_Resize(static_cast<size_t>(std::distance(_Begin, _End)));
}
else
{
size_t _TaskNum = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
_TaskNum++;
_JoinAllTokens_Add(_MergedSource, _PTask->_GetImpl()->_M_pTokenState);
}
_PParam->_Resize(_TaskNum);
}
// Step3: Check states of previous tasks.
if (_Begin == _End)
{
_PParam->_M_completed.set(_Unit_type());
delete _PParam;
}
else
{
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PTask->_Then(
[_PParam](task<void> _ResultTask) {
auto _Func = []() {};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
},
_CancellationTokenState::_None());
}
}
return _ReturnTask;
}
};
template<typename _ReturnType>
task<std::vector<_ReturnType>> _WhenAllVectorAndValue(
const task<std::vector<_ReturnType>>& _VectorTask, const task<_ReturnType>& _ValueTask, bool _OutputVectorFirst)
{
auto _PParam = new _RunAllParam<_ReturnType>();
cancellation_token_source _MergedSource;
// Step1: Create task completion event.
task<_Unit_type> _All_tasks_completed(_PParam->_M_completed, _MergedSource.get_token());
// The return task must be created before step 3 to enforce inline execution.
auto _ReturnTask = _All_tasks_completed._Then(
[=](_Unit_type) -> std::vector<_ReturnType> {
_ASSERTE(_PParam->_M_completeCount == 2);
auto _Result = _PParam->_M_vector.Get(); // copy by value
auto _mergeVal = _PParam->_M_mergeVal.Get();
if (_OutputVectorFirst == true)
{
_Result.push_back(_mergeVal);
}
else
{
_Result.insert(_Result.begin(), _mergeVal);
}
return _Result;
},
nullptr);
// Step2: Combine and check tokens.
_JoinAllTokens_Add(_MergedSource, _VectorTask._GetImpl()->_M_pTokenState);
_JoinAllTokens_Add(_MergedSource, _ValueTask._GetImpl()->_M_pTokenState);
// Step3: Check states of previous tasks.
_PParam->_Resize(2, true);
if (_VectorTask.is_apartment_aware() || _ValueTask.is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_VectorTask._Then(
[_PParam](task<std::vector<_ReturnType>> _ResultTask) {
auto _PParamCopy = _PParam;
auto _Func = [_PParamCopy, &_ResultTask]() {
auto _ResultLocal = _ResultTask._GetImpl()->_GetResult();
_PParamCopy->_M_vector.Set(_ResultLocal);
};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
},
_CancellationTokenState::_None());
_ValueTask._Then(
[_PParam](task<_ReturnType> _ResultTask) {
auto _PParamCopy = _PParam;
auto _Func = [_PParamCopy, &_ResultTask]() {
auto _ResultLocal = _ResultTask._GetImpl()->_GetResult();
_PParamCopy->_M_mergeVal.Set(_ResultLocal);
};
_WhenAllContinuationWrapper(_PParam, _Func, _ResultTask);
},
_CancellationTokenState::_None());
return _ReturnTask;
}
} // namespace details
/// <summary>
/// Creates a task that will complete successfully when all of the tasks supplied as arguments complete
/// successfully.
/// </summary>
/// <typeparam name="_Iterator">
/// The type of the input iterator.
/// </typeparam>
/// <param name="_Begin">
/// The position of the first element in the range of elements to be combined into the resulting task.
/// </param>
/// <param name="_End">
/// The position of the first element beyond the range of elements to be combined into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when all of the input tasks have completed successfully. If the input tasks
/// are of type <c>T</c>, the output of this function will be a <c>task<std::vector<T>></c>. If the
/// input tasks are of type <c>void</c> the output task will also be a <c>task<void></c>.
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled
/// state, and the exception, if one is encountered, will be thrown if you call <c>get()</c> or <c>wait()</c> on
/// that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _Iterator>
auto when_all(_Iterator _Begin, _Iterator _End, const task_options& _TaskOptions = task_options())
-> decltype(details::_WhenAllImpl<typename std::iterator_traits<_Iterator>::value_type::result_type,
_Iterator>::_Perform(_TaskOptions, _Begin, _End))
{
typedef typename std::iterator_traits<_Iterator>::value_type::result_type _ElementType;
return details::_WhenAllImpl<_ElementType, _Iterator>::_Perform(_TaskOptions, _Begin, _End);
}
/// <summary>
/// Creates a task that will complete successfully when both of the tasks supplied as arguments complete
/// successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when both of the input tasks have completed successfully. If the input tasks
/// are of type <c>T</c>, the output of this function will be a <c>task<std::vector<T>></c>. If the
/// input tasks are of type <c>void</c> the output task will also be a <c>task<void></c>. <para> To allow for
/// a construct of the sort taskA && taskB && taskC, which are combined in pairs, the &&
/// operator produces a <c>task<std::vector<T>></c> if either one or both of the tasks are of type
/// <c>task<std::vector<T>></c>.</para>
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled
/// state, and the exception, if one is encountered, will be thrown if you call <c>get()</c> or <c>wait()</c> on
/// that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
auto operator&&(const task<_ReturnType>& _Lhs, const task<_ReturnType>& _Rhs) -> decltype(when_all(&_Lhs, &_Lhs))
{
task<_ReturnType> _PTasks[2] = {_Lhs, _Rhs};
return when_all(_PTasks, _PTasks + 2);
}
/// <summary>
/// Creates a task that will complete successfully when both of the tasks supplied as arguments complete
/// successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when both of the input tasks have completed successfully. If the input tasks
/// are of type <c>T</c>, the output of this function will be a <c>task<std::vector<T>></c>. If the
/// input tasks are of type <c>void</c> the output task will also be a <c>task<void></c>. <para> To allow for
/// a construct of the sort taskA && taskB && taskC, which are combined in pairs, the &&
/// operator produces a <c>task<std::vector<T>></c> if either one or both of the tasks are of type
/// <c>task<std::vector<T>></c>.</para>
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled
/// state, and the exception, if one is encountered, will be thrown if you call <c>get()</c> or <c>wait()</c> on
/// that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
auto operator&&(const task<std::vector<_ReturnType>>& _Lhs, const task<_ReturnType>& _Rhs)
-> decltype(details::_WhenAllVectorAndValue(_Lhs, _Rhs, true))
{
return details::_WhenAllVectorAndValue(_Lhs, _Rhs, true);
}
/// <summary>
/// Creates a task that will complete successfully when both of the tasks supplied as arguments complete
/// successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when both of the input tasks have completed successfully. If the input tasks
/// are of type <c>T</c>, the output of this function will be a <c>task<std::vector<T>></c>. If the
/// input tasks are of type <c>void</c> the output task will also be a <c>task<void></c>. <para> To allow for
/// a construct of the sort taskA && taskB && taskC, which are combined in pairs, the &&
/// operator produces a <c>task<std::vector<T>></c> if either one or both of the tasks are of type
/// <c>task<std::vector<T>></c>.</para>
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled
/// state, and the exception, if one is encountered, will be thrown if you call <c>get()</c> or <c>wait()</c> on
/// that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
auto operator&&(const task<_ReturnType>& _Lhs, const task<std::vector<_ReturnType>>& _Rhs)
-> decltype(details::_WhenAllVectorAndValue(_Rhs, _Lhs, false))
{
return details::_WhenAllVectorAndValue(_Rhs, _Lhs, false);
}
/// <summary>
/// Creates a task that will complete successfully when both of the tasks supplied as arguments complete
/// successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when both of the input tasks have completed successfully. If the input tasks
/// are of type <c>T</c>, the output of this function will be a <c>task<std::vector<T>></c>. If the
/// input tasks are of type <c>void</c> the output task will also be a <c>task<void></c>. <para> To allow for
/// a construct of the sort taskA && taskB && taskC, which are combined in pairs, the &&
/// operator produces a <c>task<std::vector<T>></c> if either one or both of the tasks are of type
/// <c>task<std::vector<T>></c>.</para>
/// </returns>
/// <remarks>
/// If one of the tasks is canceled or throws an exception, the returned task will complete early, in the canceled
/// state, and the exception, if one is encountered, will be thrown if you call <c>get()</c> or <c>wait()</c> on
/// that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
auto operator&&(const task<std::vector<_ReturnType>>& _Lhs, const task<std::vector<_ReturnType>>& _Rhs)
-> decltype(when_all(&_Lhs, &_Lhs))
{
task<std::vector<_ReturnType>> _PTasks[2] = {_Lhs, _Rhs};
return when_all(_PTasks, _PTasks + 2);
}
namespace details
{
// Helper struct for when_any operators to know when tasks have completed
template<typename _CompletionType>
struct _RunAnyParam
{
_RunAnyParam() : _M_exceptionRelatedToken(nullptr), _M_completeCount(0), _M_numTasks(0), _M_fHasExplicitToken(false)
{
}
~_RunAnyParam()
{
if (_CancellationTokenState::_IsValid(_M_exceptionRelatedToken)) _M_exceptionRelatedToken->_Release();
}
task_completion_event<_CompletionType> _M_Completed;
cancellation_token_source _M_cancellationSource;
_CancellationTokenState* _M_exceptionRelatedToken;
atomic_size_t _M_completeCount;
size_t _M_numTasks;
bool _M_fHasExplicitToken;
};
template<typename _CompletionType, typename _Function, typename _TaskType>
void _WhenAnyContinuationWrapper(_RunAnyParam<_CompletionType>* _PParam, const _Function& _Func, task<_TaskType>& _Task)
{
bool _IsTokenCancled = !_PParam->_M_fHasExplicitToken &&
_Task._GetImpl()->_M_pTokenState != _CancellationTokenState::_None() &&
_Task._GetImpl()->_M_pTokenState->_IsCanceled();
if (_Task._GetImpl()->_IsCompleted() && !_IsTokenCancled)
{
_Func();
if (atomic_increment(_PParam->_M_completeCount) == _PParam->_M_numTasks)
{
delete _PParam;
}
}
else
{
_ASSERTE(_Task._GetImpl()->_IsCanceled() || _IsTokenCancled);
if (_Task._GetImpl()->_HasUserException() && !_IsTokenCancled)
{
if (_PParam->_M_Completed._StoreException(_Task._GetImpl()->_GetExceptionHolder()))
{
// This can only enter once.
_PParam->_M_exceptionRelatedToken = _Task._GetImpl()->_M_pTokenState;
_ASSERTE(_PParam->_M_exceptionRelatedToken);
// Deref token will be done in the _PParam destructor.
if (_PParam->_M_exceptionRelatedToken != _CancellationTokenState::_None())
{
_PParam->_M_exceptionRelatedToken->_Reference();
}
}
}
if (atomic_increment(_PParam->_M_completeCount) == _PParam->_M_numTasks)
{
// If no one has be completed so far, we need to make some final cancellation decision.
if (!_PParam->_M_Completed._IsTriggered())
{
// If we already explicit token, we can skip the token join part.
if (!_PParam->_M_fHasExplicitToken)
{
if (_PParam->_M_exceptionRelatedToken)
{
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _PParam->_M_exceptionRelatedToken);
}
else
{
// If haven't captured any exception token yet, there was no exception for all those tasks,
// so just pick a random token (current one) for normal cancellation.
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _Task._GetImpl()->_M_pTokenState);
}
}
// Do exception cancellation or normal cancellation based on whether it has stored exception.
_PParam->_M_Completed._Cancel();
}
delete _PParam;
}
}
}
template<typename _ElementType, typename _Iterator>
struct _WhenAnyImpl
{
static task<std::pair<_ElementType, size_t>> _Perform(const task_options& _TaskOptions,
_Iterator _Begin,
_Iterator _End)
{
if (_Begin == _End)
{
throw invalid_operation("when_any(begin, end) cannot be called on an empty container.");
}
_CancellationTokenState* _PTokenState =
_TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAnyParam<std::pair<std::pair<_ElementType, size_t>, _CancellationTokenState*>>();
if (_PTokenState)
{
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _PTokenState);
_PParam->_M_fHasExplicitToken = true;
}
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_PParam->_M_cancellationSource.get_token());
task<std::pair<std::pair<_ElementType, size_t>, _CancellationTokenState*>> _Any_tasks_completed(
_PParam->_M_Completed, _Options);
// Keep a copy ref to the token source
auto _CancellationSource = _PParam->_M_cancellationSource;
_PParam->_M_numTasks = static_cast<size_t>(std::distance(_Begin, _End));
size_t _Index = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_Any_tasks_completed._SetAsync();
}
_PTask->_Then(
[_PParam, _Index](task<_ElementType> _ResultTask) {
auto _PParamCopy = _PParam; // Dev10
auto _IndexCopy = _Index; // Dev10
auto _Func = [&_ResultTask, _PParamCopy, _IndexCopy]() {
_PParamCopy->_M_Completed.set(
std::make_pair(std::make_pair(_ResultTask._GetImpl()->_GetResult(), _IndexCopy),
_ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
},
_CancellationTokenState::_None());
_Index++;
}
// All _Any_tasks_completed._SetAsync() must be finished before this return continuation task being created.
return _Any_tasks_completed._Then(
[=](std::pair<std::pair<_ElementType, size_t>, _CancellationTokenState*> _Result)
-> std::pair<_ElementType, size_t> {
_ASSERTE(_Result.second);
if (!_PTokenState)
{
_JoinAllTokens_Add(_CancellationSource, _Result.second);
}
return _Result.first;
},
nullptr);
}
};
template<typename _Iterator>
struct _WhenAnyImpl<void, _Iterator>
{
static task<size_t> _Perform(const task_options& _TaskOptions, _Iterator _Begin, _Iterator _End)
{
if (_Begin == _End)
{
throw invalid_operation("when_any(begin, end) cannot be called on an empty container.");
}
_CancellationTokenState* _PTokenState =
_TaskOptions.has_cancellation_token() ? _TaskOptions.get_cancellation_token()._GetImplValue() : nullptr;
auto _PParam = new _RunAnyParam<std::pair<size_t, _CancellationTokenState*>>();
if (_PTokenState)
{
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _PTokenState);
_PParam->_M_fHasExplicitToken = true;
}
task_options _Options(_TaskOptions);
_Options.set_cancellation_token(_PParam->_M_cancellationSource.get_token());
task<std::pair<size_t, _CancellationTokenState*>> _Any_tasks_completed(_PParam->_M_Completed, _Options);
// Keep a copy ref to the token source
auto _CancellationSource = _PParam->_M_cancellationSource;
_PParam->_M_numTasks = static_cast<size_t>(std::distance(_Begin, _End));
size_t _Index = 0;
for (auto _PTask = _Begin; _PTask != _End; ++_PTask)
{
if (_PTask->is_apartment_aware())
{
_Any_tasks_completed._SetAsync();
}
_PTask->_Then(
[_PParam, _Index](task<void> _ResultTask) {
auto _PParamCopy = _PParam; // Dev10
auto _IndexCopy = _Index; // Dev10
auto _Func = [&_ResultTask, _PParamCopy, _IndexCopy]() {
_PParamCopy->_M_Completed.set(
std::make_pair(_IndexCopy, _ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
},
_CancellationTokenState::_None());
_Index++;
}
// All _Any_tasks_completed._SetAsync() must be finished before this return continuation task being created.
return _Any_tasks_completed._Then(
[=](std::pair<size_t, _CancellationTokenState*> _Result) -> size_t {
_ASSERTE(_Result.second);
if (!_PTokenState)
{
_JoinAllTokens_Add(_CancellationSource, _Result.second);
}
return _Result.first;
},
nullptr);
}
};
} // namespace details
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes
/// successfully.
/// </summary>
/// <typeparam name="_Iterator">
/// The type of the input iterator.
/// </typeparam>
/// <param name="_Begin">
/// The position of the first element in the range of elements to be combined into the resulting task.
/// </param>
/// <param name="_End">
/// The position of the first element beyond the range of elements to be combined into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when any one of the input tasks has completed successfully. If the input
/// tasks are of type <c>T</c>, the output of this function will be a <c>task<std::pair<T,
/// size_t>>></c>, where the first element of the pair is the result of the completing task, and the second
/// element is the index of the task that finished. If the input tasks are of type <c>void</c> the output is a
/// <c>task<size_t></c>, where the result is the index of the completing task.
/// </returns>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _Iterator>
auto when_any(_Iterator _Begin, _Iterator _End, const task_options& _TaskOptions = task_options())
-> decltype(details::_WhenAnyImpl<typename std::iterator_traits<_Iterator>::value_type::result_type,
_Iterator>::_Perform(_TaskOptions, _Begin, _End))
{
typedef typename std::iterator_traits<_Iterator>::value_type::result_type _ElementType;
return details::_WhenAnyImpl<_ElementType, _Iterator>::_Perform(_TaskOptions, _Begin, _End);
}
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes
/// successfully.
/// </summary>
/// <typeparam name="_Iterator">
/// The type of the input iterator.
/// </typeparam>
/// <param name="_Begin">
/// The position of the first element in the range of elements to be combined into the resulting task.
/// </param>
/// <param name="_End">
/// The position of the first element beyond the range of elements to be combined into the resulting task.
/// </param>
/// <param name="_CancellationToken">
/// The cancellation token which controls cancellation of the returned task. If you do not provide a cancellation
/// token, the resulting task will receive the cancellation token of the task that causes it to complete.
/// </param>
/// <returns>
/// A task that completes successfully when any one of the input tasks has completed successfully. If the input
/// tasks are of type <c>T</c>, the output of this function will be a <c>task<std::pair<T,
/// size_t>>></c>, where the first element of the pair is the result of the completing task, and the second
/// element is the index of the task that finished. If the input tasks are of type <c>void</c> the output is a
/// <c>task<size_t></c>, where the result is the index of the completing task.
/// </returns>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _Iterator>
auto when_any(_Iterator _Begin, _Iterator _End, cancellation_token _CancellationToken)
-> decltype(details::_WhenAnyImpl<typename std::iterator_traits<_Iterator>::value_type::result_type,
_Iterator>::_Perform(_CancellationToken._GetImplValue(), _Begin, _End))
{
typedef typename std::iterator_traits<_Iterator>::value_type::result_type _ElementType;
return details::_WhenAnyImpl<_ElementType, _Iterator>::_Perform(_CancellationToken._GetImplValue(), _Begin, _End);
}
/// <summary>
/// Creates a task that will complete successfully when either of the tasks supplied as arguments completes
/// successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when either of the input tasks has completed successfully. If the input tasks
/// are of type <c>T</c>, the output of this function will be a <c>task<std::vector<T></c>. If the input
/// tasks are of type <c>void</c> the output task will also be a <c>task<void></c>. <para> To allow for a
/// construct of the sort taskA || taskB && taskC, which are combined in pairs, with && taking
/// precedence over ||, the operator|| produces a <c>task<std::vector<T>></c> if one of the tasks is of
/// type <c>task<std::vector<T>></c> and the other one is of type <c>task<T>.</c></para>
/// </returns>
/// <remarks>
/// If both of the tasks are canceled or throw exceptions, the returned task will complete in the canceled state,
/// and one of the exceptions, if any are encountered, will be thrown when you call <c>get()</c> or <c>wait()</c> on
/// that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
task<_ReturnType> operator||(const task<_ReturnType>& _Lhs, const task<_ReturnType>& _Rhs)
{
auto _PParam = new details::_RunAnyParam<std::pair<_ReturnType, size_t>>();
task<std::pair<_ReturnType, size_t>> _Any_tasks_completed(_PParam->_M_Completed,
_PParam->_M_cancellationSource.get_token());
// Chain the return continuation task here to ensure it will get inline execution when _M_Completed.set is called,
// So that _PParam can be used before it getting deleted.
auto _ReturnTask = _Any_tasks_completed._Then(
[=](std::pair<_ReturnType, size_t> _Ret) -> _ReturnType {
_ASSERTE(_Ret.second);
_JoinAllTokens_Add(_PParam->_M_cancellationSource,
reinterpret_cast<details::_CancellationTokenState*>(_Ret.second));
return _Ret.first;
},
nullptr);
if (_Lhs.is_apartment_aware() || _Rhs.is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PParam->_M_numTasks = 2;
auto _Continuation = [_PParam](task<_ReturnType> _ResultTask) {
// Dev10 compiler bug
auto _PParamCopy = _PParam;
auto _Func = [&_ResultTask, _PParamCopy]() {
_PParamCopy->_M_Completed.set(
std::make_pair(_ResultTask._GetImpl()->_GetResult(),
reinterpret_cast<size_t>(_ResultTask._GetImpl()->_M_pTokenState)));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
};
_Lhs._Then(_Continuation, details::_CancellationTokenState::_None());
_Rhs._Then(_Continuation, details::_CancellationTokenState::_None());
return _ReturnTask;
}
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes
/// successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when either of the input tasks has completed successfully. If the input tasks
/// are of type <c>T</c>, the output of this function will be a <c>task<std::vector<T></c>. If the input
/// tasks are of type <c>void</c> the output task will also be a <c>task<void></c>. <para> To allow for a
/// construct of the sort taskA || taskB && taskC, which are combined in pairs, with && taking
/// precedence over ||, the operator|| produces a <c>task<std::vector<T>></c> if one of the tasks is of
/// type <c>task<std::vector<T>></c> and the other one is of type <c>task<T>.</c></para>
/// </returns>
/// <remarks>
/// If both of the tasks are canceled or throw exceptions, the returned task will complete in the canceled state,
/// and one of the exceptions, if any are encountered, will be thrown when you call <c>get()</c> or <c>wait()</c> on
/// that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
task<std::vector<_ReturnType>> operator||(const task<std::vector<_ReturnType>>& _Lhs, const task<_ReturnType>& _Rhs)
{
auto _PParam = new details::_RunAnyParam<std::pair<std::vector<_ReturnType>, details::_CancellationTokenState*>>();
task<std::pair<std::vector<_ReturnType>, details::_CancellationTokenState*>> _Any_tasks_completed(
_PParam->_M_Completed, _PParam->_M_cancellationSource.get_token());
// Chain the return continuation task here to ensure it will get inline execution when _M_Completed.set is called,
// So that _PParam can be used before it getting deleted.
auto _ReturnTask = _Any_tasks_completed._Then(
[=](std::pair<std::vector<_ReturnType>, details::_CancellationTokenState*> _Ret) -> std::vector<_ReturnType> {
_ASSERTE(_Ret.second);
_JoinAllTokens_Add(_PParam->_M_cancellationSource, _Ret.second);
return _Ret.first;
},
nullptr);
if (_Lhs.is_apartment_aware() || _Rhs.is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PParam->_M_numTasks = 2;
_Lhs._Then(
[_PParam](task<std::vector<_ReturnType>> _ResultTask) {
// Dev10 compiler bug
auto _PParamCopy = _PParam;
auto _Func = [&_ResultTask, _PParamCopy]() {
auto _Result = _ResultTask._GetImpl()->_GetResult();
_PParamCopy->_M_Completed.set(std::make_pair(_Result, _ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
},
details::_CancellationTokenState::_None());
_Rhs._Then(
[_PParam](task<_ReturnType> _ResultTask) {
auto _PParamCopy = _PParam;
auto _Func = [&_ResultTask, _PParamCopy]() {
auto _Result = _ResultTask._GetImpl()->_GetResult();
std::vector<_ReturnType> _Vec;
_Vec.push_back(_Result);
_PParamCopy->_M_Completed.set(std::make_pair(_Vec, _ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
},
details::_CancellationTokenState::_None());
return _ReturnTask;
}
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes
/// successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when either of the input tasks has completed successfully. If the input tasks
/// are of type <c>T</c>, the output of this function will be a <c>task<std::vector<T></c>. If the input
/// tasks are of type <c>void</c> the output task will also be a <c>task<void></c>. <para> To allow for a
/// construct of the sort taskA || taskB && taskC, which are combined in pairs, with && taking
/// precedence over ||, the operator|| produces a <c>task<std::vector<T>></c> if one of the tasks is of
/// type <c>task<std::vector<T>></c> and the other one is of type <c>task<T>.</c></para>
/// </returns>
/// <remarks>
/// If both of the tasks are canceled or throw exceptions, the returned task will complete in the canceled state,
/// and one of the exceptions, if any are encountered, will be thrown when you call <c>get()</c> or <c>wait()</c> on
/// that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _ReturnType>
auto operator||(const task<_ReturnType>& _Lhs, const task<std::vector<_ReturnType>>& _Rhs) -> decltype(_Rhs || _Lhs)
{
return _Rhs || _Lhs;
}
/// <summary>
/// Creates a task that will complete successfully when any of the tasks supplied as arguments completes
/// successfully.
/// </summary>
/// <typeparam name="_ReturnType">
/// The type of the returned task.
/// </typeparam>
/// <param name="_Lhs">
/// The first task to combine into the resulting task.
/// </param>
/// <param name="_Rhs">
/// The second task to combine into the resulting task.
/// </param>
/// <returns>
/// A task that completes successfully when either of the input tasks has completed successfully. If the input tasks
/// are of type <c>T</c>, the output of this function will be a <c>task<std::vector<T></c>. If the input
/// tasks are of type <c>void</c> the output task will also be a <c>task<void></c>. <para> To allow for a
/// construct of the sort taskA || taskB && taskC, which are combined in pairs, with && taking
/// precedence over ||, the operator|| produces a <c>task<std::vector<T>></c> if one of the tasks is of
/// type <c>task<std::vector<T>></c> and the other one is of type <c>task<T>.</c></para>
/// </returns>
/// <remarks>
/// If both of the tasks are canceled or throw exceptions, the returned task will complete in the canceled state,
/// and one of the exceptions, if any are encountered, will be thrown when you call <c>get()</c> or <c>wait()</c> on
/// that task.
/// </remarks>
/// <seealso cref="Task Parallelism (Concurrency Runtime)"/>
/**/
template<typename _Ty = task<void>, typename _Pair = std::pair<details::_Unit_type, details::_CancellationTokenState*>>
_Ty operator||(const task<void>& _Lhs_arg, const task<void>& _Rhs_arg)
{
const _Ty& _Lhs = _Lhs_arg;
const _Ty& _Rhs = _Rhs_arg;
auto _PParam = new details::_RunAnyParam<_Pair>();
task<std::pair<details::_Unit_type, details::_CancellationTokenState*>> _Any_task_completed(
_PParam->_M_Completed, _PParam->_M_cancellationSource.get_token());
// Chain the return continuation task here to ensure it will get inline execution when _M_Completed.set is called,
// So that _PParam can be used before it getting deleted.
auto _ReturnTask = _Any_task_completed._Then(
[=](_Pair _Ret) {
_ASSERTE(_Ret.second);
details::_JoinAllTokens_Add(_PParam->_M_cancellationSource, _Ret.second);
},
nullptr);
if (_Lhs.is_apartment_aware() || _Rhs.is_apartment_aware())
{
_ReturnTask._SetAsync();
}
_PParam->_M_numTasks = 2;
auto _Continuation = [_PParam](_Ty _ResultTask) mutable {
// Dev10 compiler needs this.
auto _PParam1 = _PParam;
auto _Func = [&_ResultTask, _PParam1]() {
_PParam1->_M_Completed.set(std::make_pair(details::_Unit_type(), _ResultTask._GetImpl()->_M_pTokenState));
};
_WhenAnyContinuationWrapper(_PParam, _Func, _ResultTask);
};
_Lhs._Then(_Continuation, details::_CancellationTokenState::_None());
_Rhs._Then(_Continuation, details::_CancellationTokenState::_None());
return _ReturnTask;
}
template<typename _Ty>
task<_Ty> task_from_result(_Ty _Param, const task_options& _TaskOptions = task_options())
{
task_completion_event<_Ty> _Tce;
_Tce.set(_Param);
return create_task(_Tce, _TaskOptions);
}
template<class _Ty = void>
inline task<_Ty> task_from_result(const task_options& _TaskOptions = task_options())
{
task_completion_event<_Ty> _Tce;
_Tce.set();
return create_task(_Tce, _TaskOptions);
}
template<typename _TaskType, typename _ExType>
task<_TaskType> task_from_exception(_ExType _Exception, const task_options& _TaskOptions = task_options())
{
task_completion_event<_TaskType> _Tce;
_Tce.set_exception(_Exception);
return create_task(_Tce, _TaskOptions);
}
} // namespace pplx
#pragma pop_macro("new")
#if defined(_MSC_VER)
#pragma warning(pop)
#endif
#pragma pack(pop)
#endif // (defined(_MSC_VER) && (_MSC_VER >= 1800))
#ifndef _CONCRT_H
#ifndef _LWRCASE_CNCRRNCY
#define _LWRCASE_CNCRRNCY
// Note to reader: we're using lower-case namespace names everywhere, but the 'Concurrency' namespace
// is capitalized for historical reasons. The alias let's us pretend that style issue doesn't exist.
namespace Concurrency
{
}
namespace concurrency = Concurrency;
#endif
#endif
#endif // PPLXTASKS_H