concurrency namespace functions

Alloc

Allocates a block of memory of the size specified from the Concurrency Runtime Caching Suballocator.

void* __cdecl Alloc(size_t _NumBytes);

Parameters

_NumBytes
The number of bytes of memory to allocate.

Return Value

A pointer to newly allocated memory.

Remarks

For more information about which scenarios in your application could benefit from using the Caching Suballocator, see Task Scheduler.

asend

An asynchronous send operation, which schedules a task to propagate the data to the target block.

template <class T>
bool asend(
    _Inout_ ITarget<T>* _Trg,
    const T& _Data);

template <class T>
bool asend(
    ITarget<T>& _Trg,
    const T& _Data);

Parameters

T
The type of the data to be sent.

_Trg
A pointer or reference to the target to which data is sent.

_Data
A reference to the data to be sent.

Return Value

true if the message was accepted before the method returned, false otherwise.

Remarks

For more information, see Message Passing Functions.

cancel_current_task

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 canceled state.

It is not a supported scenario to call this function if you are not within the body of a task. Doing so will result in undefined behavior such as a crash or unresponsiveness in your application.

inline __declspec(noreturn) void __cdecl cancel_current_task();

clear

Clears the concurrent queue, destroying any currently enqueued elements. This method is not concurrency-safe.

template<typename T, class _Ax>
void concurrent_queue<T, _Ax>::clear();

Parameters

T

_Ax

create_async

Creates a Windows Runtime asynchronous construct based on a user supplied lambda or function object. The return type of create_async is one of either IAsyncAction^, IAsyncActionWithProgress<TProgress>^, IAsyncOperation<TResult>^, or IAsyncOperationWithProgress<TResult, TProgress>^ based on the signature of the lambda passed to the method.

template<typename _Function>
__declspec(noinline) auto create_async(const _Function& _Func)
    -> decltype(ref new details::_AsyncTaskGeneratorThunk<_Function>(_Func));

Parameters

_Function
Type.

_Func
The lambda or function object from which to create a Windows Runtime asynchronous construct.

Return Value

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.

Remarks

The return type of the lambda determines whether the construct is an action or an operation.

Lambdas that return void cause the creation of actions. Lambdas that return a result of type TResult cause the creation of operations of TResult.

The lambda may also return a task<TResult> which encapsulates the aysnchronous 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 create_async. 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.

The lambda may take either zero, one or two arguments. The valid arguments are progress_reporter<TProgress> and cancellation_token, 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 create_async to return an asynchronous construct which reports progress of type TProgress each time the report 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.

If the body of the lambda or function object returns a result (and not a task<TResult>), the lamdba will be executed asynchronously within the process MTA in the context of a task the Runtime implicitly creates for it. The IAsyncInfo::Cancel method will cause cancellation of the implicit task.

If the body of the lambda returns a task, the lamba executes inline, and by declaring the lambda to take an argument of type cancellation_token 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 register_callback method on the token to cause the Runtime to invoke a callback when you call IAsyncInfo::Cancel on the async operation or action produced..

This function is only available to Windows Runtime apps.

CreateResourceManager

Returns an interface that represents the singleton instance of the Concurrency Runtime's Resource Manager. The Resource Manager is responsible for assigning resources to schedulers that want to cooperate with each other.

IResourceManager* __cdecl CreateResourceManager();

Return Value

An IResourceManager interface.

Remarks

Multiple subsequent calls to this method will return the same instance of the Resource Manager. Each call to the method increments a reference count on the Resource Manager, and must be matched with a call to the IResourceManager::Release method when your scheduler is done communicating with the Resource Manager.

unsupported_os is thrown if the operating system is not supported by the Concurrency Runtime.

create_task

Creates a PPL task object. create_task can be used anywhere you would have used a task constructor. It is provided mainly for convenience, because it allows use of the auto keyword while creating tasks.

template<typename T>
__declspec(noinline) auto create_task(T _Param, const task_options& _TaskOptions = task_options())
    -> task<typename details::_TaskTypeFromParam<T>::T>;

template<typename _ReturnType>
__declspec( noinline) task<_ReturnType> create_task(const task<_ReturnType>& _Task);

Parameters

T
The type of the parameter from which the task is to be constructed.

_ReturnType
Type.

_Param
The parameter from which the task is to be constructed. This could be a lambda or function object, a task_completion_event object, a different task object, or a Windows::Foundation::IAsyncInfo interface if you are using tasks in your UWP app.

_TaskOptions
The task options.

_Task
The task to create.

Return Value

A new task of type T, that is inferred from _Param.

Remarks

The first overload behaves like a task constructor that takes a single parameter.

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 task object as the first parameter.

The type of the returned task is inferred from the first parameter to the function. If _Param is a task_completion_event<T>, a task<T>, or a functor that returns either type T or task<T>, the type of the created task is task<T>.

In a UWP app, if _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 task<T>. If _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 task<void>.

DisableTracing

Disables tracing in the Concurrency Runtime. This function is deprecated because ETW tracing is unregistered by default.

__declspec(deprecated("Concurrency::DisableTracing is a deprecated function.")) _CRTIMP HRESULT __cdecl DisableTracing();

Return Value

If tracing was correctly disabled, S_OK is returned. If tracing was not previously initiated, E_NOT_STARTED is returned

EnableTracing

Enables tracing in the Concurrency Runtime. This function is deprecated because ETW tracing is now on by default.

__declspec(deprecated("Concurrency::EnableTracing is a deprecated function.")) _CRTIMP HRESULT __cdecl EnableTracing();

Return Value

If tracing was correctly initiated, S_OK is returned; otherwise, E_NOT_STARTED is returned.

Free

Releases a block of memory previously allocated by the Alloc method to the Concurrency Runtime Caching Suballocator.

void __cdecl Free(_Pre_maybenull_ _Post_invalid_ void* _PAllocation);

Parameters

_PAllocation
A pointer to memory previously allocated by the Alloc method which is to be freed. If the parameter _PAllocation is set to the value NULL, this method will ignore it and return immediately.

Remarks

For more information about which scenarios in your application could benefit from using the Caching Suballocator, see Task Scheduler.

get_ambient_scheduler

inline std::shared_ptr<::Concurrency::scheduler_interface> get_ambient_scheduler();

Return Value

GetExecutionContextId

Returns a unique identifier that can be assigned to an execution context that implements the IExecutionContext interface.

unsigned int __cdecl GetExecutionContextId();

Return Value

A unique identifier for an execution context.

Remarks

Use this method to obtain an identifier for your execution context before you pass an IExecutionContext interface as a parameter to any of the methods offered by the Resource Manager.

GetOSVersion

Returns the operating system version.

IResourceManager::OSVersion __cdecl GetOSVersion();

Return Value

An enumerated value representing the operating system.

Remarks

unsupported_os is thrown if the operating system is not supported by the Concurrency Runtime.

GetProcessorCount

Returns the number of hardware threads on the underlying system.

unsigned int __cdecl GetProcessorCount();

Return Value

The number of hardware threads.

Remarks

unsupported_os is thrown if the operating system is not supported by the Concurrency Runtime.

GetProcessorNodeCount

Returns the number of NUMA nodes or processor packages on the underlying system.

unsigned int __cdecl GetProcessorNodeCount();

Return Value

The number of NUMA nodes or processor packages.

Remarks

If the system contains more NUMA nodes than processor packages, the number of NUMA nodes is returned, otherwise, the number of processor packages is returned.

unsupported_os is thrown if the operating system is not supported by the Concurrency Runtime.

GetSchedulerId

Returns a unique identifier that can be assigned to a scheduler that implements the IScheduler interface.

unsigned int __cdecl GetSchedulerId();

Return Value

A unique identifier for a scheduler.

Remarks

Use this method to obtain an identifier for your scheduler before you pass an IScheduler interface as a parameter to any of the methods offered by the Resource Manager.

internal_assign_iterators

template<typename T, class _Ax>
template<class _I>
void concurrent_vector<T, _Ax>::internal_assign_iterators(
   _I first,
   _I last);

Parameters

T

_Ax

_I

first

last

interruption_point

Creates an interruption point for cancellation. If a cancellation is in progress in the context where this function is called, this will throw an internal exception that aborts the execution of the currently executing parallel work. If cancellation is not in progress, the function does nothing.

inline void interruption_point();

Remarks

You should not catch the internal cancellation exception thrown by the interruption_point() function. The exception will be caught and handled by the runtime, and catching it may cause your program to behave abnormally.

is_current_task_group_canceling

Returns an indication of whether the task group which is currently executing inline on the current context is in the midst of an active cancellation (or will be shortly). Note that if there is no task group currently executing inline on the current context, false will be returned.

bool __cdecl is_current_task_group_canceling();

Return Value

true if the task group which is currently executing is canceling, false otherwise.

Remarks

For more information, see Cancellation.

make_choice

Constructs a choice messaging block from an optional Scheduler or ScheduleGroup and two or more input sources.

template<typename T1, typename T2, typename... Ts>
choice<std::tuple<T1, T2, Ts...>> make_choice(
    Scheduler& _PScheduler,
    T1  _Item1,
    T2  _Item2,
    Ts... _Items);

template<typename T1, typename T2, typename... Ts>
choice<std::tuple<T1, T2, Ts...>> make_choice(
    ScheduleGroup& _PScheduleGroup,
    T1  _Item1,
    T2  _Item2,
    Ts... _Items);

template<typename T1, typename T2, typename... Ts>
choice<std::tuple<T1, T2, Ts...>> make_choice(
    T1  _Item1,
    T2  _Item2,
    Ts... _Items);

Parameters

T1
The message block type of the first source.

T2
The message block type of the second source.

_PScheduler
The Scheduler object within which the propagation task for the choice messaging block is scheduled.

_Item1
The first source.

_Item2
The second source.

_Items
Additional sources.

_PScheduleGroup
The ScheduleGroup object within which the propagation task for the choice messaging block is scheduled. The Scheduler object used is implied by the schedule group.

Return Value

A choice message block with two or more input sources.

make_greedy_join

Constructs a greedy multitype_join messaging block from an optional Scheduler or ScheduleGroup and two or more input sources.

template<typename T1, typename T2, typename... Ts>
multitype_join<std::tuple<T1, T2, Ts...>,greedy> make_greedy_join(
    Scheduler& _PScheduler,
    T1 _Item1,
    T2 _Item2,
    Ts... _Items);

template<typename T1, typename T2, typename... Ts>
multitype_join<std::tuple<T1, T2, Ts...>, greedy> make_greedy_join(
    ScheduleGroup& _PScheduleGroup,
    T1 _Item1,
    T2 _Item2,
    Ts... _Items);

template<typename T1, typename T2, typename... Ts>
multitype_join<std::tuple<T1, T2, Ts...>, greedy> make_greedy_join(
    T1 _Item1,
    T2 _Items,
    Ts... _Items);

Parameters

T1
The message block type of the first source.

T2
The message block type of the second source.

_PScheduler
The Scheduler object within which the propagation task for the multitype_join messaging block is scheduled.

_Item1
The first source.

_Item2
The second source.

_Items
Additional sources.

_PScheduleGroup
The ScheduleGroup object within which the propagation task for the multitype_join messaging block is scheduled. The Scheduler object used is implied by the schedule group.

Return Value

A greedy multitype_join message block with two or more input sources.

make_join

Constructs a non_greedy multitype_join messaging block from an optional Scheduler or ScheduleGroup and two or more input sources.

template<typename T1, typename T2, typename... Ts>
multitype_join<std::tuple<T1, T2, Ts...>>
    make_join(
Scheduler& _PScheduler,
    T1 _Item1,
    T2 _Item2,
    Ts... _Items);

template<typename T1, typename T2, typename... Ts>
multitype_join<std::tuple<T1, T2, Ts...>> make_join(
ScheduleGroup& _PScheduleGroup,
    T1 _Item1,
    T2 _Item2,
    Ts... _Items);

template<typename T1, typename T2, typename... Ts>
multitype_join<std::tuple<T1, T2, Ts...>> make_join(
    T1 _Item1,
    T2 _Item2,
    Ts... _Items);

Parameters

T1
The message block type of the first source.

T2
The message block type of the second source.

_PScheduler
The Scheduler object within which the propagation task for the multitype_join messaging block is scheduled.

_Item1
The first source.

_Item2
The second source.

_Items
Additional sources.

_PScheduleGroup
The ScheduleGroup object within which the propagation task for the multitype_join messaging block is scheduled. The Scheduler object used is implied by the schedule group.

Return Value

A non_greedy multitype_join message block with two or more input sources.

make_task

A factory method for creating a task_handle object.

template <class _Function>
task_handle<_Function> make_task(const _Function& _Func);

Parameters

_Function
The type of the function object that will be invoked to execute the work represented by the task_handle object.

_Func
The function that will be invoked to execute the work represented by the task_handle object. This may be a lambda functor, a pointer to a function, or any object that supports a version of the function call operator with the signature void operator()().

Return Value

A task_handle object.

Remarks

This function is useful when you need to create a task_handle object with a lambda expression, because it allows you to create the object without knowing the true type of the lambda functor.

parallel_buffered_sort

Arranges the elements in a specified range into a non-descending order, or according to an ordering criterion specified by a binary predicate, in parallel. This function is semantically similar to std::sort in that it is a compare-based, unstable, in-place sort except that it needs O(n) additional space, and requires default initialization for the elements being sorted.

template<typename _Random_iterator>
inline void parallel_buffered_sort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End);

template<typename _Allocator,
    typename _Random_iterator>
inline void parallel_buffered_sort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End);

template<typename _Allocator,
    typename _Random_iterator>
inline void parallel_buffered_sort(
    const _Allocator& _Alloc,
    const _Random_iterator& _Begin,
    const _Random_iterator& _End);

template<typename _Random_iterator,
    typename _Function>
inline void parallel_buffered_sort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End,
    const _Function& _Func,
    const size_t _Chunk_size = 2048);

template<typename _Allocator,
    typename _Random_iterator,
    typename _Function>
inline void parallel_buffered_sort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End,
    const _Function& _Func,
    const size_t _Chunk_size = 2048);

template<typename _Allocator,
    typename _Random_iterator,
    typename _Function>
inline void parallel_buffered_sort(
    const _Allocator& _Alloc,
    const _Random_iterator& _Begin,
    const _Random_iterator& _End,
    const _Function& _Func,
    const size_t _Chunk_size = 2048);

Parameters

_Random_iterator
The iterator type of the input range.

_Allocator
The type of a C++ Standard Library compatible memory allocator.

_Function
The type of the binary comparator.

_Begin
A random-access iterator addressing the position of the first element in the range to be sorted.

_End
A random-access iterator addressing the position one past the final element in the range to be sorted.

_Alloc
An instance of a C++ Standard Library compatible memory allocator.

_Func
A user-defined predicate function object that defines the comparison criterion to be satisfied by successive elements in the ordering. A binary predicate takes two arguments and returns true when satisfied and false when not satisfied. This comparator function must impose a strict weak ordering on pairs of elements from the sequence.

_Chunk_size
The mimimum size of a chunk that will be split into two for parallel execution.

Remarks

All overloads require n * sizeof(T) additional space, where n is the number of elements to be sorted, and T is the element type. In most cases parallel_buffered_sort will show an improvement in performance over parallel_sort, and you should use it over parallel_sort if you have the memory available.

If you do not supply a binary comparator std::less is used as the default, which requires the element type to provide the operator operator<().

If you do not supply an allocator type or instance, the C++ Standard Library memory allocator std::allocator<T> is used to allocate the buffer.

The algorithm divides the input range into two chunks and successively divides each chunk into two sub-chunks for execution in parallel. The optional argument _Chunk_size can be used to indicate to the algorithm that it should handles chunks of size < _Chunk_size serially.

parallel_for

parallel_for iterates over a range of indices and executes a user-supplied function at each iteration, in parallel.

template <typename _Index_type, typename _Function, typename _Partitioner>
void parallel_for(
    _Index_type first,
    _Index_type last,
    _Index_type _Step,
    const _Function& _Func,
    _Partitioner&& _Part);

template <typename _Index_type, typename _Function>
void parallel_for(
    _Index_type first,
    _Index_type last,
    _Index_type _Step,
    const _Function& _Func);

template <typename _Index_type, typename _Function>
void parallel_for(
    _Index_type first,
    _Index_type last,
    const _Function& _Func,
    const auto_partitioner& _Part = auto_partitioner());

template <typename _Index_type, typename _Function>
void parallel_for(
    _Index_type first,
    _Index_type last,
    const _Function& _Func,
    const static_partitioner& _Part);

template <typename _Index_type, typename _Function>
void parallel_for(
    _Index_type first,
    _Index_type last,
    const _Function& _Func,
    const simple_partitioner& _Part);

template <typename _Index_type, typename _Function>
void parallel_for(
    _Index_type first,
    _Index_type last,
    const _Function& _Func,
    affinity_partitioner& _Part);

Parameters

_Index_type
The type of the index being used for the iteration.

_Function
The type of the function that will be executed at each iteration.

_Partitioner
The type of the partitioner that is used to partition the supplied range.

first
The first index to be included in the iteration.

last
The index one past the last index to be included in the iteration.

_Step
The value by which to step when iterating from first to last. The step must be positive. invalid_argument is thrown if the step is less than 1.

_Func
The function to be executed at each iteration. This may be a lambda expression, a function pointer, or any object that supports a version of the function call operator with the signature void operator()(_Index_type).

_Part
A reference to the partitioner object. The argument can be one of const auto_partitioner&, const static_partitioner&, const simple_partitioner& or affinity_partitioner& If an affinity_partitioner object is used, the reference must be a non-const l-value reference, so that the algorithm can store state for future loops to re-use.

Remarks

For more information, see Parallel Algorithms.

parallel_for_each

parallel_for_each applies a specified function to each element within a range, in parallel. It is semantically equivalent to the for_each function in the std namespace, except that iteration over the elements is performed in parallel, and the order of iteration is unspecified. The argument _Func must support a function call operator of the form operator()(T) where the parameter T is the item type of the container being iterated over.

template <typename _Iterator, typename _Function>
void parallel_for_each(
    _Iterator first,
    _Iterator last,
    const _Function& _Func);

template <typename _Iterator, typename _Function, typename _Partitioner>
void parallel_for_each(
    _Iterator first,
    _Iterator last,
    const _Function& _Func,
    _Partitioner&& _Part);

Parameters

_Iterator
The type of the iterator being used to iterate over the container.

_Function
The type of the function that will be applied to each element within the range.

_Partitioner
first
An iterator addressing the position of the first element to be included in parallel iteration.

last
An iterator addressing the position one past the final element to be included in parallel iteration.

_Func
A user-defined function object that is applied to each element in the range.

_Part
A reference to the partitioner object. The argument can be one of const auto_partitioner&, const static_partitioner&, const simple_partitioner& or affinity_partitioner& If an affinity_partitioner object is used, the reference must be a non-const l-value reference, so that the algorithm can store state for future loops to re-use.

Remarks

auto_partitioner will be used for the overload without an explicit partitioner.

For iterators that do not support random access, only auto_partitioner is supported.

For more information, see Parallel Algorithms.

parallel_invoke

Executes the function objects supplied as parameters in parallel, and blocks until they have finished executing. Each function object could be a lambda expression, a pointer to function, or any object that supports the function call operator with the signature void operator()().

template <typename _Function1, typename _Function2>
void parallel_invoke(
    const _Function1& _Func1,
    const _Function2& _Func2);

template <typename _Function1, typename _Function2, typename _Function3>
void parallel_invoke(
    const _Function1& _Func1,
    const _Function2& _Func2,
    const _Function3& _Func3);

template <typename _Function1,
    typename _Function2,
    typename _Function3,
    typename _Function4>
void parallel_invoke(
    const _Function1& _Func1,
    const _Function2& _Func2,
    const _Function3& _Func3,
    const _Function4& _Func4);

template <typename _Function1,
    typename _Function2,
    typename _Function3,
    typename _Function4,
    typename _Function5>
void parallel_invoke(
    const _Function1& _Func1,
    const _Function2& _Func2,
    const _Function3& _Func3,
    const _Function4& _Func4,
    const _Function5& _Func5);

template <typename _Function1,
    typename _Function2,
    typename _Function3,
    typename _Function4,
    typename _Function5,
    typename _Function6>
void parallel_invoke(
    const _Function1& _Func1,
    const _Function2& _Func2,
    const _Function3& _Func3,
    const _Function4& _Func4,
    const _Function5& _Func5,
    const _Function6& _Func6);

template <typename _Function1,
    typename _Function2,
    typename _Function3,
    typename _Function4,
    typename _Function5,
    typename _Function6,
    typename _Function7>
void parallel_invoke(
    const _Function1& _Func1,
    const _Function2& _Func2,
    const _Function3& _Func3,
    const _Function4& _Func4,
    const _Function5& _Func5,
    const _Function6& _Func6,
    const _Function7& _Func7);

template <typename _Function1,
    typename _Function2,
    typename _Function3,
    typename _Function4,
    typename _Function5,
    typename _Function6,
    typename _Function7,
    typename _Function8>
void parallel_invoke(
    const _Function1& _Func1,
    const _Function2& _Func2,
    const _Function3& _Func3,
    const _Function4& _Func4,
    const _Function5& _Func5,
    const _Function6& _Func6,
    const _Function7& _Func7,
    const _Function8& _Func8);

template <typename _Function1,
    typename _Function2,
    typename _Function3,
    typename _Function4,
    typename _Function5,
    typename _Function6,
    typename _Function7,
    typename _Function8,
    typename _Function9>
void parallel_invoke(
    const _Function1& _Func1,
    const _Function2& _Func2,
    const _Function3& _Func3,
    const _Function4& _Func4,
    const _Function5& _Func5,
    const _Function6& _Func6,
    const _Function7& _Func7,
    const _Function8& _Func8,
    const _Function9& _Func9);

template <typename _Function1,
    typename _Function2,
    typename _Function3,
    typename _Function4,
    typename _Function5,
    typename _Function6,
    typename _Function7,
    typename _Function8,
    typename _Function9,
    typename _Function10>
void parallel_invoke(
    const _Function1& _Func1,
    const _Function2& _Func2,
    const _Function3& _Func3,
    const _Function4& _Func4,
    const _Function5& _Func5,
    const _Function6& _Func6,
    const _Function7& _Func7,
    const _Function8& _Func8,
    const _Function9& _Func9,
    const _Function10& _Func10);

Parameters

_Function1
The type of the first function object to be executed in parallel.

_Function2
The type of the second function object to be executed in parallel.

_Function3
The type of the third function object to be executed in parallel.

_Function4
The type of the fourth function object to be executed in parallel.

_Function5
The type of the fifth function object to be executed in parallel.

_Function6
The type of the sixth function object to be executed in parallel.

_Function7
The type of the seventh function object to be executed in parallel.

_Function8
The type of the eighth function object to be executed in parallel.

_Function9
The type of the ninth function object to be executed in parallel.

_Function10
The type of the tenth function object to be executed in parallel.

_Func1
The first function object to be executed in parallel.

_Func2
The second function object to be executed in parallel.

_Func3
The third function object to be executed in parallel.

_Func4
The fourth function object to be executed in parallel.

_Func5
The fifth function object to be executed in parallel.

_Func6
The sixth function object to be executed in parallel.

_Func7
The seventh function object to be executed in parallel.

_Func8
The eighth function object to be executed in parallel.

_Func9
The ninth function object to be executed in parallel.

_Func10
The tenth function object to be executed in parallel.

Remarks

Note that one or more of the function objects supplied as parameters may execute inline on the calling context.

If one or more of the function objects passed as parameters to this function throws an exception, the runtime will select one such exception of its choosing and propagate it out of the call to parallel_invoke.

For more information, see Parallel Algorithms.

parallel_radixsort

Arranges elements in a specified range into an non descending order using a radix sorting algorithm. This is a stable sort function which requires a projection function that can project elements to be sorted into unsigned integer-like keys. Default initialization is required for the elements being sorted.

template<typename _Random_iterator>
inline void parallel_radixsort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End);

template<typename _Allocator, typename _Random_iterator>
inline void parallel_radixsort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End);

template<typename _Allocator, typename _Random_iterator>
inline void parallel_radixsort(
    const _Allocator& _Alloc,
    const _Random_iterator& _Begin,
    const _Random_iterator& _End);

template<typename _Random_iterator, typename _Function>
inline void parallel_radixsort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End,
    const _Function& _Proj_func,
    const size_t _Chunk_size = 256* 256);

template<typename _Allocator, typename _Random_iterator,
    typename _Function>
inline void parallel_radixsort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End,
    const _Function& _Proj_func,
    const size_t _Chunk_size = 256* 256);

template<typename _Allocator,
    typename _Random_iterator,
    typename _Function>
inline void parallel_radixsort(
    const _Allocator& _Alloc,
    const _Random_iterator& _Begin,
    const _Random_iterator& _End,
    const _Function& _Proj_func,
    const size_t _Chunk_size = 256* 256);

Parameters

_Random_iterator
The iterator type of the input range.

_Allocator
The type of a C++ Standard Library compatible memory allocator.

_Function
The type of the projection function.

_Begin
A random-access iterator addressing the position of the first element in the range to be sorted.

_End
A random-access iterator addressing the position one past the final element in the range to be sorted.

_Alloc
An instance of a C++ Standard Library compatible memory allocator.

_Proj_func
A user-defined projection function object that converts an element into an integral value.

_Chunk_size
The mimimum size of a chunk that will be split into two for parallel execution.

Remarks

All overloads require n * sizeof(T) additional space, where n is the number of elements to be sorted, and T is the element type. An unary projection functor with the signature I _Proj_func(T) is required to return a key when given an element, where T is the element type and I is an unsigned integer-like type.

If you do not supply a projection function, a default projection function which simply returns the element is used for integral types. The function will fail to compile if the element is not an integral type in the absence of a projection function.

If you do not supply an allocator type or instance, the C++ Standard Library memory allocator std::allocator<T> is used to allocate the buffer.

The algorithm divides the input range into two chunks and successively divides each chunk into two sub-chunks for execution in parallel. The optional argument _Chunk_size can be used to indicate to the algorithm that it should handles chunks of size < _Chunk_size serially.

parallel_reduce

Computes the sum of all elements in a specified range by computing successive partial sums, or computes the result of successive partial results similarly obtained from using a specified binary operation other than sum, in parallel. parallel_reduce is semantically similar to std::accumulate, except that it requires the binary operation to be associative, and requires an identity value instead of an initial value.

template<typename _Forward_iterator>
inline typename std::iterator_traits<_Forward_iterator>::value_type parallel_reduce(
    _Forward_iterator _Begin,
    _Forward_iterator _End,
    const typename std::iterator_traits<_Forward_iterator>::value_type& _Identity);

template<typename _Forward_iterator, typename _Sym_reduce_fun>
inline typename std::iterator_traits<_Forward_iterator>::value_type parallel_reduce(
    _Forward_iterator _Begin,
    _Forward_iterator _End,
    const typename std::iterator_traits<_Forward_iterator>::value_type& _Identity,
    _Sym_reduce_fun _Sym_fun);

template<typename _Reduce_type,
    typename _Forward_iterator,
    typename _Range_reduce_fun,
    typename _Sym_reduce_fun>
inline _Reduce_type parallel_reduce(
    _Forward_iterator _Begin,
    _Forward_iterator _End,
    const _Reduce_type& _Identity,
    const _Range_reduce_fun& _Range_fun,
    const _Sym_reduce_fun& _Sym_fun);

Parameters

_Forward_iterator
The iterator type of input range.

_Sym_reduce_fun
The type of the symmetric reduction function. This must be a function type with signature _Reduce_type _Sym_fun(_Reduce_type, _Reduce_type), where _Reduce_type is the same as the identity type and the result type of the reduction. For the third overload, this should be consistent with the output type of _Range_reduce_fun.

_Reduce_type
The type that the input will reduce to, which can be different from the input element type. The return value and identity value will has this type.

_Range_reduce_fun
The type of the range reduction function. This must be a function type with signature _Reduce_type _Range_fun(_Forward_iterator, _Forward_iterator, _Reduce_type), _Reduce_type is the same as the identity type and the result type of the reduction.

_Begin
An input iterator addressing the first element in the range to be reduced.

_End
An input iterator addressing the element that is one position beyond the final element in the range to be reduced.

_Identity
The identity value _Identity is of the same type as the result type of the reduction and also the value_type of the iterator for the first and second overloads. For the third overload, the identity value must have the same type as the result type of the reduction, but can be different from the value_type of the iterator. It must have an appropriate value such that the range reduction operator _Range_fun, when applied to a range of a single element of type value_type and the identity value, behaves like a type cast of the value from type value_type to the identity type.

_Sym_fun
The symmetric function that will be used in the second of the reduction. Refer to Remarks for more information.

_Range_fun
The function that will be used in the first phase of the reduction. Refer to Remarks for more information.

Return Value

The result of the reduction.

Remarks

To perform a parallel reduction, the function divides the range into chunks based on the number of workers available to the underlying scheduler. The reduction takes place in two phases, the first phase performs a reduction within each chunk, and the second phase performs a reduction between the partial results from each chunk.

The first overload requires that the iterator's value_type, T, be the same as the identity value type as well as the reduction result type. The element type T must provide the operator T T::operator + (T) to reduce elements in each chunk. The same operator is used in the second phase as well.

The second overload also requires that the iterator's value_type be the same as the identity value type as well as the reduction result type. The supplied binary operator _Sym_fun is used in both reduction phases, with the identity value as the initial value for the first phase.

For the third overload, the identity value type must be the same as the reduction result type, but the iterator's value_type may be different from both. The range reduction function _Range_fun is used in the first phase with the identity value as the initial value, and the binary function _Sym_reduce_fun is applied to sub results in the second phase.

parallel_sort

Arranges the elements in a specified range into a non-descending order, or according to an ordering criterion specified by a binary predicate, in parallel. This function is semantically similar to std::sort in that it is a compare-based, unstable, in-place sort.

template<typename _Random_iterator>
inline void parallel_sort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End);

template<typename _Random_iterator,typename _Function>
inline void parallel_sort(
    const _Random_iterator& _Begin,
    const _Random_iterator& _End,
    const _Function& _Func,
    const size_t _Chunk_size = 2048);

Parameters

_Random_iterator
The iterator type of the input range.

_Function
The type of the binary comparison functor.

_Begin
A random-access iterator addressing the position of the first element in the range to be sorted.

_End
A random-access iterator addressing the position one past the final element in the range to be sorted.

_Func
A user-defined predicate function object that defines the comparison criterion to be satisfied by successive elements in the ordering. A binary predicate takes two arguments and returns true when satisfied and false when not satisfied. This comparator function must impose a strict weak ordering on pairs of elements from the sequence.

_Chunk_size
The minimum size of a chunk that will be split into two for parallel execution.

Remarks

The first overload uses the binary comparator std::less.

The second overloaded uses the supplied binary comparator that should have the signature bool _Func(T, T) where T is the type of the elements in the input range.

The algorithm divides the input range into two chunks and successively divides each chunk into two sub-chunks for execution in parallel. The optional argument _Chunk_size can be used to indicate to the algorithm that it should handles chunks of size < _Chunk_size serially.

parallel_transform

Applies a specified function object to each element in a source range, or to a pair of elements from two source ranges, and copies the return values of the function object into a destination range, in parallel. This functional is semantically equivalent to std::transform.

template <typename _Input_iterator1,
    typename _Output_iterator,
    typename _Unary_operator>
_Output_iterator parallel_transform(
    _Input_iterator1 first1,
    _Input_iterator1 last1,
    _Output_iterator _Result,
    const _Unary_operator& _Unary_op,
    const auto_partitioner& _Part = auto_partitioner());

template <typename _Input_iterator1,
    typename _Output_iterator,
    typename _Unary_operator>
_Output_iterator parallel_transform(
    _Input_iterator1 first1,
    _Input_iterator1 last1,
    _Output_iterator _Result,
    const _Unary_operator& _Unary_op,
    const static_partitioner& _Part);

template <typename _Input_iterator1,
    typename _Output_iterator,
    typename _Unary_operator>
_Output_iterator parallel_transform(
    _Input_iterator1 first1,
    _Input_iterator1 last1,
    _Output_iterator _Result,
    const _Unary_operator& _Unary_op,
    const simple_partitioner& _Part);

template <typename _Input_iterator1,
    typename _Output_iterator,
    typename _Unary_operator>
_Output_iterator parallel_transform(
    _Input_iterator1 first1,
    _Input_iterator1 last1,
    _Output_iterator _Result,
    const _Unary_operator& _Unary_op,
    affinity_partitioner& _Part);

template <typename _Input_iterator1,
    typename _Input_iterator2,
    typename _Output_iterator,
    typename _Binary_operator,
    typename _Partitioner>
_Output_iterator parallel_transform(
    _Input_iterator1 first1,
    _Input_iterator1 last1,
    _Input_iterator2
first2,
    _Output_iterator _Result,
    const _Binary_operator& _Binary_op,
    _Partitioner&& _Part);

template <typename _Input_iterator1,
    typename _Input_iterator2,
    typename _Output_iterator,
    typename _Binary_operator>
_Output_iterator parallel_transform(
    _Input_iterator1 first1,
    _Input_iterator1 last1,
    _Input_iterator2
first2,
    _Output_iterator _Result,
    const _Binary_operator& _Binary_op);

Parameters

_Input_iterator1
The type of the first or only input iterator.

_Output_iterator
The type of the output iterator.

_Unary_operator
The type of the unary functor to be executed on each element in the input range.

_Input_iterator2
The type of second input iterator.

_Binary_operator
The type of the binary functor executed pairwise on elements from the two source ranges.

_Partitioner
first1
An input iterator addressing the position of the first element in the first or only source range to be operated on.

last1
An input iterator addressing the position one past the final element in the first or only source range to be operated on.

_Result
An output iterator addressing the position of the first element in the destination range.

_Unary_op
A user-defined unary function object that is applied to each element in the source range.

_Part
A reference to the partitioner object. The argument can be one of const auto_partitioner&, const static_partitioner&, const simple_partitioner& or affinity_partitioner& If an affinity_partitioner object is used, the reference must be a non-const l-value reference, so that the algorithm can store state for future loops to re-use.

first2
An input iterator addressing the position of the first element in the second source range to be operated on.

_Binary_op
A user-defined binary function object that is applied pairwise, in a forward order, to the two source ranges.

Return Value

An output iterator addressing the position one past the final element in the destination range that is receiving the output elements transformed by the function object.

Remarks

auto_partitioner will be used for the overloads without an explicit partitioner argument.

For iterators that do not support random access, only auto_partitioner is supported.

The overloads that take the argument _Unary_op transform the input range into the output range by applying the unary functor to each element in the input range. _Unary_op must support the function call operator with signature operator()(T) where T is the value type of the range being iterated over.

The overloads that take the argument _Binary_op transform two input ranges into the output range by applying the binary functor to one element from the first input range and one element from the second input range. _Binary_op must support the function call operator with signature operator()(T, U) where T, U are value types of the two input iterators.

For more information, see Parallel Algorithms.

receive

A general receive implementation, allowing a context to wait for data from exactly one source and filter the values that are accepted.

template <class T>
T receive(
    _Inout_ ISource<T>* _Src,
    unsigned int _Timeout = COOPERATIVE_TIMEOUT_INFINITE);

template <class T>
T receive(
    _Inout_ ISource<T>* _Src,
    typename ITarget<T>::filter_method const& _Filter_proc,
    unsigned int _Timeout = COOPERATIVE_TIMEOUT_INFINITE);

template <class T>
T receive(
    ISource<T>& _Src,
    unsigned int _Timeout = COOPERATIVE_TIMEOUT_INFINITE);

template <class T>
T receive(
    ISource<T>& _Src,
    typename ITarget<T>::filter_method const& _Filter_proc,
    unsigned int _Timeout = COOPERATIVE_TIMEOUT_INFINITE);

Parameters

T
The payload type.

_Src
A pointer or reference to the source from which data is expected.

_Timeout
The maximum time for which the method should for the data, in milliseconds.

_Filter_proc
A filter function which determines whether messages should be accepted.

Return Value

A value from the source, of the payload type.

Remarks

If the parameter _Timeout has a value other than the constant COOPERATIVE_TIMEOUT_INFINITE, the exception operation_timed_out is thrown if the specified amount of time expires before a message is received. If you want a zero length timeout, you should use the try_receive function, as opposed to calling receive with a timeout of 0 (zero), as it is more efficient and does not throw exceptions on timeouts.

For more information, see Message Passing Functions.

run_with_cancellation_token

Executes a function object immediately and synchronously in the context of a given cancellation token.

template<typename _Function>
void run_with_cancellation_token(
    const _Function& _Func,
    cancellation_token _Ct);

Parameters

_Function
The type of the function object that will be invoked.

_Func
The function object which will be executed. This object must support the function call operator with a signature of void(void).

_Ct
The cancellation token which will control implicit cancellation of the function object. Use cancellation_token::none() if you want the function execute without any possibility of implicit cancellation from a parent task group being canceled.

Remarks

Any interruption points in the function object will be triggered when the cancellation_token is canceled. The explicit token _Ct will isolate this _Func from parent cancellation if the parent has a different token or no token.

send

A synchronous send operation, which waits until the target either accepts or declines the message.

template <class T>
bool send(_Inout_ ITarget<T>* _Trg, const T& _Data);

template <class T>
bool send(ITarget<T>& _Trg, const T& _Data);

Parameters

T
The payload type.

_Trg
A pointer or reference to the target to which data is sent.

_Data
A reference to the data to be sent.

Return Value

true if the message was accepted, false otherwise.

Remarks

For more information, see Message Passing Functions.

set_ambient_scheduler

inline void set_ambient_scheduler(std::shared_ptr<::Concurrency::scheduler_interface> _Scheduler);

Parameters

_Scheduler
The ambient scheduler to set.

set_task_execution_resources

Restricts the execution resources used by the Concurrency Runtime internal worker threads to the affinity set specified.

It is valid to call this method only before the Resource Manager has been created, or between two Resource Manager lifetimes. It can be invoked multiple times as long as the Resource Manager does not exist at the time of invocation. After an affinity limit has been set, it remains in effect until the next valid call to the set_task_execution_resources method.

The affinity mask provided need not be a subset of the process affinity mask. The process affinity will be updated if necessary.

void __cdecl set_task_execution_resources(
    DWORD_PTR _ProcessAffinityMask);

void __cdecl set_task_execution_resources(
    unsigned short count,
    PGROUP_AFFINITY _PGroupAffinity);

Parameters

_ProcessAffinityMask
The affinity mask that the Concurrency Runtime worker threads are to be restricted to. Use this method on a system with greater than 64 hardware threads only if you want to limit the Concurrency Runtime to a subset of the current processor group. In general, you should use the version of the method that accepts an array of group affinities as a parameter, to restrict affinity on machines with greater than 64 hardware threads.

count
The number of GROUP_AFFINITY entries in the array specified by the parameter _PGroupAffinity.

_PGroupAffinity
An array of GROUP_AFFINITY entries.

Remarks

The method will throw an invalid_operation exception if a Resource Manager is present at the time it is invoked, and an invalid_argument exception if the affinity specified results in an empty set of resources.

The version of the method that takes an array of group affinities as a parameter should only be used on operating systems with version Windows 7 or higher. Otherwise, an invalid_operation exception is thrown.

Programmatically modifying the process affinity after this method has been invoked will not cause the Resource Manager to re-evaluate the affinity it is restricted to. Therefore, all changes to process affinity should be made before calling this method.

swap

Exchanges the elements of two concurrent_vector objects.

template<typename T, class _Ax>
inline void swap(
    concurrent_vector<T, _Ax>& _A,
    concurrent_vector<T, _Ax>& _B);

Parameters

T
The data type of the elements stored in the concurrent vectors.

_Ax
The allocator type of the concurrent vectors.

_A
The concurrent vector whose elements are to be exchanged with those of the concurrent vector _B.

_B
The concurrent vector providing the elements to be swapped, or the vector whose elements are to be exchanged with those of the concurrent vector _A.

Remarks

The template function is an algorithm specialized on the container class concurrent_vector to execute the member function _A. concurrent_vector::swap( _B). These are instances of the partial ordering of function templates by the compiler. When template functions are overloaded in such a way that the match of the template with the function call is not unique, then the compiler will select the most specialized version of the template function. The general version of the template function, template <class T> void swap(T&, T&), in the algorithm class works by assignment and is a slow operation. The specialized version in each container is much faster as it can work with the internal representation of the container class.

This method is not concurrency-safe. You must ensure that no other threads are performing operations on either of the concurrent vectors when you call this method.

task_from_exception

template<typename _TaskType, typename _ExType>
task<_TaskType> task_from_exception(
    _ExType _Exception,
    const task_options& _TaskOptions = task_options());

Parameters

_TaskType

_ExType

_Exception

_TaskOptions

Return Value

task_from_result

template<typename T>
task<T> task_from_result(
    T _Param,
    const task_options& _TaskOptions = task_options());

inline task<bool> task_from_result(ool _Param);

inline task<void> task_from_result(
    const task_options& _TaskOptions = task_options());

Parameters

T

_Param

_TaskOptions

Return Value

Trace_agents_register_name

Associates the given name to the message block or agent in the ETW trace.

template <class T>
void Trace_agents_register_name(
    _Inout_ T* _PObject,
    _In_z_ const wchar_t* _Name);

Parameters

T
The type of the object. This is typically a message block or an agent.

_PObject
A pointer to the message block or agent that is being named in the trace.

_Name
The name for the given object.

try_receive

A general try-receive implementation, allowing a context to look for data from exactly one source and filter the values that are accepted. If the data is not ready, the method will return false.

template <class T>
bool try_receive(_Inout_ ISource<T>* _Src, T& _value);

template <class T>
bool try_receive(
    _Inout_ ISource<T>* _Src,
    T& _value,
    typename ITarget<T>::filter_method const& _Filter_proc);

template <class T>
bool try_receive(ISource<T>& _Src, T& _value);

template <class T>
bool try_receive(
    ISource<T>& _Src,
    T& _value,
    typename ITarget<T>::filter_method const& _Filter_proc);

Parameters

T
The payload type

_Src
A pointer or reference to the source from which data is expected.

_value
A reference to a location where the result will be placed.

_Filter_proc
A filter function which determines whether messages should be accepted.

Return Value

A bool value indicating whether or not a payload was placed in _value.

Remarks

For more information, see Message Passing Functions.

wait

Pauses the current context for a specified amount of time.

void __cdecl wait(unsigned int _Milliseconds);

Parameters

_Milliseconds
The number of milliseconds the current context should be paused for. If the _Milliseconds parameter is set to the value 0, the current context should yield execution to other runnable contexts before continuing.

Remarks

If this method is called on a Concurrency Runtime scheduler context, the scheduler will find a different context to run on the underlying resource. Because the scheduler is cooperative in nature, this context cannot resume exactly after the number of milliseconds specified. If the scheduler is busy executing other tasks that do not cooperatively yield to the scheduler, the wait period could be indefinite.

when_all

Creates a task that will complete successfully when all of the tasks supplied as arguments complete successfully.

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));

Parameters

_Iterator
The type of the input iterator.

_Begin
The position of the first element in the range of elements to be combined into the resulting task.

_End
The position of the first element beyond the range of elements to be combined into the resulting task.

_TaskOptions
The task_options object.

Return Value

A task that completes successfully when all of the input tasks have completed successfully. If the input tasks are of type T, the output of this function will be a task<std::vector<T>>. If the input tasks are of type void the output task will also be a task<void>.

Remarks

when_all is a non-blocking function that produces a task as its result. Unlike task::wait, it is safe to call this function in a UWP app on the ASTA (Application STA) thread.

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 occurs, will be thrown if you call task::get or task::wait on that task.

For more information, see Task Parallelism.

when_any

Creates a task that will complete successfully when any of the tasks supplied as arguments completes successfully.

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));

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));

Parameters

_Iterator
The type of the input iterator.

_Begin
The position of the first element in the range of elements to be combined into the resulting task.

_End
The position of the first element beyond the range of elements to be combined into the resulting task.

_TaskOptions
_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.

Return Value

A task that completes successfully when any one of the input tasks has completed successfully. If the input tasks are of type T, the output of this function will be a task<std::pair<T, size_t>>>, 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 void the output is a task<size_t>, where the result is the index of the completing task.

Remarks

when_any is a non-blocking function that produces a task as its result. Unlike task::wait, it is safe to call this function in a UWP app on the ASTA (Application STA) thread.

For more information, see Task Parallelism.

See also

concurrency Namespace