/***
* ==++==
*
* Copyright (c) Microsoft Corporation. All rights reserved.
*
* ==--==
* =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*
* ppl.h
*
* Parallel Patterns Library
*
* =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
****/
#pragma once
#include <crtdefs.h>
#include <concrt.h>
#include <stdexcept>
#include <iterator>
#include <functional>
#include <memory>
#include <type_traits>
#include <algorithm>
#include <pplconcrt.h>
#define _PPL_H
#pragma pack(push,_CRT_PACKING)
#pragma push_macro("new")
#undef new
// Define the level of tracing to use
#define _TRACE_LEVEL_INFORMATION 4
/// <summary>
/// The <c>Concurrency</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 Concurrency
{
namespace details
{
_CRTIMP2 size_t __cdecl _GetCombinableSize();
} // namespace details
class structured_task_group;
class task_group;
/// <summary>
/// The <c>task_handle</c> class represents an individual parallel work item. It encapsulates the instructions and the data required
/// to execute a piece of work.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the work represented by the <c>task_handle</c> object.
/// </typeparam>
/// <remarks>
/// <c>task_handle</c> objects can be used in conjunction with a <c>structured_task_group</c> or a more general <c>task_group</c> object,
/// to decompose work into parallel tasks. For more information, see <see cref="Task Parallelism"/>.
/// <para>Note that the creator of a <c>task_handle</c> object is responsible for maintaining the lifetime of the created
/// <c>task_handle</c> object until it is no longer required by the Concurrency Runtime. Typically, this means that the <c>task_handle</c>
/// object must not destruct until either the <c>wait</c> or <c>run_and_wait</c> method of the <c>task_group</c> or
/// <c>structured_task_group</c> to which it is queued has been called.</para>
/// <para><c>task_handle</c> objects are typically used in conjunction with C++ lambdas. Because you do not know the true type of the lambda,
/// the <see cref="make_task Function">make_task</see> function is typically used to create a <c>task_handle</c> object.</para>
/// <para>The runtime creates a copy of the work function that you pass to a <c>task_handle</c> object. Therefore, any state changes that occur in a
/// function object that you pass to a <c>task_handle</c> object will not appear in your copy of that function object.</para>
/// </remarks>
/// <seealso cref="task_group Class"/>
/// <seealso cref="structured_task_group Class"/>
/// <seealso cref="make_task Function"/>
/// <seealso cref="task_group::run Method"/>
/// <seealso cref="task_group::wait Method"/>
/// <seealso cref="task_group::run_and_wait Method"/>
/// <seealso cref="structured_task_group::run Method"/>
/// <seealso cref="structured_task_group::wait Method"/>
/// <seealso cref="structured_task_group::run_and_wait Method"/>
/**/
template<typename _Function>
class task_handle : public ::Concurrency::details::_UnrealizedChore
{
public:
/// <summary>
/// Constructs a new <c>task_handle</c> object. The work of the task is performed by invoking the function specified as
/// a parameter to the constructor.
/// </summary>
/// <param name="_Func">
/// The function that will be invoked to execute the work represented by the <c>task_handle</c> 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 <c>void operator()()</c>.
/// </param>
/// <remarks>
/// The runtime creates a copy of the work function that you pass to the constructor. Therefore, any state changes that occur in a function
/// object that you pass to a <c>task_handle</c> object will not appear in your copy of that function object.
/// </remarks>
/**/
task_handle(const _Function& _Func) : _M_function(_Func)
{
m_pFunction = reinterpret_cast <TaskProc> (&::Concurrency::details::_UnrealizedChore::_InvokeBridge<task_handle>);
}
/// <summary>
/// Destroys the <c>task_handle</c> object.
/// </summary>
/**/
~task_handle()
{
//
// We only need to perform a liveness check if the client owns the lifetime of the handle. Doing this for runtime owned handles
// is not only unnecessary -- it is also dangerous.
//
if (_OwningCollection() != NULL && !_GetRuntimeOwnsLifetime())
{
_CheckTaskCollection();
}
}
/// <summary>
/// The function call operator that the runtime invokes to perform the work of the task handle.
/// </summary>
/**/
void operator()() const
{
_M_function();
}
private:
friend class task_group;
friend class structured_task_group;
// The function object invoked to perform the body of the task.
_Function _M_function;
task_handle const & operator=(task_handle const&); // no assignment operator
};
/// <summary>
/// A factory method for creating a <c>task_handle</c> object.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the work represented by the <c>task_handle</c> object.
/// </typeparam>
/// <param name="_Func">
/// The function that will be invoked to execute the work represented by the <c>task_handle</c> 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 <c>void operator()()</c>.
/// </param>
/// <returns>
/// A <c>task_handle</c> object.
/// </returns>
/// <remarks>
/// This function is useful when you need to create a <c>task_handle</c> object with a lambda expression, because it allows you to
/// create the object without knowing the true type of the lambda functor.
/// </remarks>
/// <seealso cref="task_handle Class"/>
/// <seealso cref="task_group Class"/>
/// <seealso cref="structured_task_group Class"/>
/**/
template <class _Function>
task_handle<_Function> make_task(const _Function& _Func)
{
return task_handle<_Function>(_Func);
}
/// <summary>
/// The <c>structured_task_group</c> class represents a highly structured collection of parallel work. You can queue individual parallel tasks to
/// a <c>structured_task_group</c> using <c>task_handle</c> objects, and wait for them to complete, or cancel the task group before they have finished
/// executing, which will abort any tasks that have not begun execution.
/// </summary>
/// <remarks>
/// There are a number of severe restrictions placed on usage of a <c>structured_task_group</c> object in order to gain performance:
/// <list type="bullet">
/// <item>
/// <description>A single <c>structured_task_group</c> object cannot be used by multiple threads. All operations on a <c>structured_task_group</c> object
/// must be performed by the thread that created the object. The two exceptions to this rule are the member functions <c>cancel</c> and
/// <c>is_canceling</c>. The object may not be in the capture list of a lambda expression and be used within a task, unless the task is using one
/// of the cancellation operations.</description>
/// </item>
/// <item>
/// <description>All tasks scheduled to a <c>structured_task_group</c> object are scheduled through the use of <c>task_handle</c> objects which
/// you must explicitly manage the lifetime of.</description>
/// </item>
/// <item>
/// <description>Multiple groups may only be used in absolutely nested order. If two <c>structured_task_group</c> objects are declared, the second
/// one being declared (the inner one) must destruct before any method except <c>cancel</c> or <c>is_canceling</c> is called on the first one
/// (the outer one). This condition holds true in both the case of simply declaring multiple <c>structured_task_group</c> objects within the same
/// or functionally nested scopes as well as the case of a task that was queued to the <c>structured_task_group</c> via the <c>run</c> or
/// <c>run_and_wait</c> methods.</description>
/// </item>
/// <item>
/// <description>Unlike the general <c>task_group</c> class, all states in the <c>structured_task_group</c> class are final. After you have queued tasks to the
/// group and waited for them to complete, you may not use the same group again.</description>
/// </item>
/// </list>
/// <para>For more information, see <see cref="Task Parallelism"/>.</para>
/// </remarks>
/// <seealso cref="task_group Class"/>
/// <seealso cref="task_handle Class"/>
/**/
class structured_task_group
{
public:
/// <summary>
/// Constructs a new <c>structured_task_group</c> object.
/// </summary>
/// <remarks>
/// The constructor that takes a cancellation token creates a <c>structured_task_group</c> that will be canceled when the source associated with
/// the token is canceled. Providing an explicit cancellation token also isolates this structured task group from participating in an implicit
/// cancellation from a parent group with a different token or no token.
/// </remarks>
/// <seealso cref="Task Parallelism"/>
/**/
structured_task_group()
{
}
/// <summary>
/// Constructs a new <c>structured_task_group</c> object.
/// </summary>
/// <param name="_CancellationToken">
/// A cancellation token to associate with this structured task group. The structured task group will be canceled when the token is canceled.
/// </param>
/// <remarks>
/// The constructor that takes a cancellation token creates a <c>structured_task_group</c> that will be canceled when the source associated with
/// the token is canceled. Providing an explicit cancellation token also isolates this structured task group from participating in an implicit
/// cancellation from a parent group with a different token or no token.
/// </remarks>
/// <seealso cref="Task Parallelism"/>
/**/
structured_task_group(cancellation_token _CancellationToken) :
_M_task_collection(_CancellationToken._GetImpl() != NULL ? _CancellationToken._GetImpl() : Concurrency::details::_CancellationTokenState::_None())
{
}
/// <summary>
/// Destroys a <c>structured_task_group</c> object. You are expected to call either the <c>wait</c> or <c>run_and_wait</c> method on the
/// object prior to the destructor executing, unless the destructor is executing as a result of stack unwinding due to an exception.
/// </summary>
/// <remarks>
/// If the destructor runs as the result of normal execution (for example, not stack unwinding due to an exception) and neither the <c>wait</c> nor
/// <c>run_and_wait</c> methods have been called, the destructor may throw a <see cref="missing_wait Class">missing_wait</see> exception.
/// </remarks>
/// <seealso cref="structured_task_group::wait Method"/>
/// <seealso cref="structured_task_group::run_and_wait Method"/>
/**/
~structured_task_group()
{
}
/// <summary>
/// Schedules a task on the <c>structured_task_group</c> object. The caller manages the lifetime of the <c>task_handle</c> object passed
/// in the <paramref name="_Task_handle"/> parameter. The version that takes the parameter <paramref name="_Placement"/> causes the task
/// to be biased towards executing at the location specified by that parameter.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the body of the task handle.
/// </typeparam>
/// <param name="_Task_handle">
/// A handle to the work being scheduled. Note that the caller has responsibility for the lifetime of this object. The runtime will
/// continue to expect it to live until either the <c>wait</c> or <c>run_and_wait</c> method has been called on this
/// <c>structured_task_group</c> object.
/// </param>
/// <remarks>
/// The runtime creates a copy of the work function that you pass to this method. Any state changes that occur in a function object that you
/// pass to this method will not appear in your copy of that function object.
/// <para>If the <c>structured_task_group</c> destructs as the result of stack unwinding from an exception, you do not need to guarantee
/// that a call has been made to either the <c>wait</c> or <c>run_and_wait</c> method. In this case, the destructor will appropriately
/// cancel and wait for the task represented by the <paramref name="_Task_handle"/> parameter to complete.</para>
/// <para>Throws an <see cref="invalid_multiple_scheduling Class">invalid_multiple_scheduling</see> exception if the task handle given by
/// the <paramref name="_Task_handle"/> parameter has already been scheduled onto a task group object via the <c>run</c> method and there has been
/// no intervening call to either the <c>wait</c> or <c>run_and_wait</c> method on that task group.</para>
/// </remarks>
/// <seealso cref="structured_task_group::wait Method"/>
/// <seealso cref="structured_task_group::run_and_wait Method"/>
/// <seealso cref="Task Parallelism"/>
/// <seealso cref="location class"/>
/**/
template<class _Function>
void run(task_handle<_Function>& _Task_handle)
{
_Task_handle._SetRuntimeOwnsLifetime(false);
_M_task_collection._Schedule(&_Task_handle);
}
/// <summary>
/// Schedules a task on the <c>structured_task_group</c> object. The caller manages the lifetime of the <c>task_handle</c> object passed
/// in the <paramref name="_Task_handle"/> parameter. The version that takes the parameter <paramref name="_Placement"/> causes the task
/// to be biased towards executing at the location specified by that parameter.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the body of the task handle.
/// </typeparam>
/// <param name="_Task_handle">
/// A handle to the work being scheduled. Note that the caller has responsibility for the lifetime of this object. The runtime will
/// continue to expect it to live until either the <c>wait</c> or <c>run_and_wait</c> method has been called on this
/// <c>structured_task_group</c> object.
/// </param>
/// <param name="_Placement">
/// A reference to the location where the task represented by the <paramref name="_Task_handle"/> parameter should execute.
/// </param>
/// <remarks>
/// The runtime creates a copy of the work function that you pass to this method. Any state changes that occur in a function object that you
/// pass to this method will not appear in your copy of that function object.
/// <para>If the <c>structured_task_group</c> destructs as the result of stack unwinding from an exception, you do not need to guarantee
/// that a call has been made to either the <c>wait</c> or <c>run_and_wait</c> method. In this case, the destructor will appropriately
/// cancel and wait for the task represented by the <paramref name="_Task_handle"/> parameter to complete.</para>
/// <para>Throws an <see cref="invalid_multiple_scheduling Class">invalid_multiple_scheduling</see> exception if the task handle given by
/// the <paramref name="_Task_handle"/> parameter has already been scheduled onto a task group object via the <c>run</c> method and there has been
/// no intervening call to either the <c>wait</c> or <c>run_and_wait</c> method on that task group.</para>
/// </remarks>
/// <seealso cref="structured_task_group::wait Method"/>
/// <seealso cref="structured_task_group::run_and_wait Method"/>
/// <seealso cref="Task Parallelism"/>
/// <seealso cref="location class"/>
/**/
template<class _Function>
void run(task_handle<_Function>& _Task_handle, location& _Placement)
{
_Task_handle._SetRuntimeOwnsLifetime(false);
_M_task_collection._Schedule(&_Task_handle, &_Placement);
}
/// <summary>
/// Waits until all work on the <c>structured_task_group</c> has completed or is canceled.
/// </summary>
/// <returns>
/// An indication of whether the wait was satisfied or the task group was canceled, due to either an explicit cancel operation or an exception
/// being thrown from one of its tasks. For more information, see <see cref="task_group_status Enumeration">task_group_status</see>
/// </returns>
/// <remarks>
/// Note that one or more of the tasks scheduled to this <c>structured_task_group</c> object may execute inline on the calling context.
/// <para>If one or more of the tasks scheduled to this <c>structured_task_group</c> object throws an exception, the
/// runtime will select one such exception of its choosing and propagate it out of the call to the <c>wait</c> method.</para>
/// <para>After this function returns, the <c>structured_task_group</c> object is considered in a final state and should not be used. Note that
/// utilization after the <c>wait</c> method returns will result in undefined behavior.</para>
/// <para>In the non-exceptional path of execution, you have a mandate to call either this method or the <c>run_and_wait</c> method before
/// the destructor of the <c>structured_task_group</c> executes.</para>
/// </remarks>
/// <seealso cref="structured_task_group::wait Method"/>
/// <seealso cref="structured_task_group::run_and_wait Method"/>
/// <seealso cref="Task Parallelism"/>
/**/
task_group_status wait()
{
//
// The underlying scheduler's definitions map exactly to the PPL's. No translation beyond the cast is necessary.
//
return (task_group_status)_M_task_collection._Wait();
}
/// <summary>
/// Schedules a task to be run inline on the calling context with the assistance of the <c>structured_task_group</c> object for full
/// cancellation support. If a <c>task_handle</c> object is passed as a parameter to <c>run_and_wait</c>, the caller is
/// responsible for managing the lifetime of the <c>task_handle</c> object. The function then waits until all work on the
/// <c>structured_task_group</c> object has either completed or been canceled.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the body of the task handle.
/// </typeparam>
/// <param name="_Task_handle">
/// A handle to the task which will be run inline on the calling context. Note that the caller has responsibility for the lifetime of this object.
/// The runtime will continue to expect it to live until the <c>run_and_wait</c> method finishes execution.
/// </param>
/// <returns>
/// An indication of whether the wait was satisfied or the task group was canceled, due to either an explicit cancel operation or an exception
/// being thrown from one of its tasks. For more information, see <see cref="task_group_status Enumeration">task_group_status</see>
/// </returns>
/// <remarks>
/// Note that one or more of the tasks scheduled to this <c>structured_task_group</c> object may execute inline on the calling context.
/// <para>If one or more of the tasks scheduled to this <c>structured_task_group</c> object throws an exception, the
/// runtime will select one such exception of its choosing and propagate it out of the call to the <c>run_and_wait</c> method.</para>
/// <para>After this function returns, the <c>structured_task_group</c> object is considered in a final state and should not be used.
/// Note that utilization after the <c>run_and_wait</c> method returns will result in undefined behavior.</para>
/// <para>In the non-exceptional path of execution, you have a mandate to call either this method or the <c>wait</c> method before
/// the destructor of the <c>structured_task_group</c> executes.</para>
/// </remarks>
/// <seealso cref="structured_task_group::run Method"/>
/// <seealso cref="structured_task_group::wait Method"/>
/// <seealso cref="Task Parallelism"/>
/**/
template<class _Function>
task_group_status run_and_wait(task_handle<_Function>& _Task_handle)
{
//
// The underlying scheduler's definitions map exactly to the PPL's. No translation beyond the cast is necessary.
//
return (task_group_status)_M_task_collection._RunAndWait(&_Task_handle);
}
/// <summary>
/// Schedules a task to be run inline on the calling context with the assistance of the <c>structured_task_group</c> object for full
/// cancellation support. If a <c>task_handle</c> object is passed as a parameter to <c>run_and_wait</c>, the caller is
/// responsible for managing the lifetime of the <c>task_handle</c> object. The function then waits until all work on the
/// <c>structured_task_group</c> object has either completed or been canceled.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the task.
/// </typeparam>
/// <param name="_Func">
/// A function which will be called to invoke the body of the work. This may be a lambda or other object which supports
/// a version of the function call operator with the signature <c>void operator()()</c>.
/// </param>
/// <returns>
/// An indication of whether the wait was satisfied or the task group was canceled, due to either an explicit cancel operation or an exception
/// being thrown from one of its tasks. For more information, see <see cref="task_group_status Enumeration">task_group_status</see>
/// </returns>
/// <remarks>
/// Note that one or more of the tasks scheduled to this <c>structured_task_group</c> object may execute inline on the calling context.
/// <para>If one or more of the tasks scheduled to this <c>structured_task_group</c> object throws an exception, the
/// runtime will select one such exception of its choosing and propagate it out of the call to the <c>run_and_wait</c> method.</para>
/// <para>After this function returns, the <c>structured_task_group</c> object is considered in a final state and should not be used.
/// Note that utilization after the <c>run_and_wait</c> method returns will result in undefined behavior.</para>
/// <para>In the non-exceptional path of execution, you have a mandate to call either this method or the <c>wait</c> method before
/// the destructor of the <c>structured_task_group</c> executes.</para>
/// </remarks>
/// <seealso cref="structured_task_group::run Method"/>
/// <seealso cref="structured_task_group::wait Method"/>
/// <seealso cref="Task Parallelism"/>
/**/
template<class _Function>
task_group_status run_and_wait(const _Function& _Func)
{
//
// The underlying scheduler's definitions map exactly to the PPL's. No translation beyond the cast is necessary.
//
task_handle<_Function> _Task(_Func);
return (task_group_status)_M_task_collection._RunAndWait(&_Task);
}
/// <summary>
/// Makes a best effort attempt to cancel the sub-tree of work rooted at this task group. Every task scheduled on the task group
/// will get canceled transitively if possible.
/// </summary>
/// <remarks>
/// For more information, see <see cref="Cancellation in the PPL"/>.
/// </remarks>
/**/
void cancel()
{
_M_task_collection._Cancel();
}
/// <summary>
/// Informs the caller whether or not the task group is currently in the midst of a cancellation. This
/// does not necessarily indicate that the <c>cancel</c> method was called on the <c>structured_task_group</c> object
/// (although such certainly qualifies this method to return <c>true</c>). It may be the case that the <c>structured_task_group</c> object
/// is executing inline and a task group further up in the work tree was canceled. In cases such as these where the runtime can determine ahead
/// of time that cancellation will flow through this <c>structured_task_group</c> object, <c>true</c> will be returned as well.
/// </summary>
/// <returns>
/// An indication of whether the <c>structured_task_group</c> object is in the midst of a cancellation (or is guaranteed to be shortly).
/// </returns>
/// <remarks>
/// For more information, see <see cref="Cancellation in the PPL"/>.
/// </remarks>
/**/
bool is_canceling()
{
return _M_task_collection._IsCanceling();
}
private:
// Disallow passing in an r-value for a task handle argument
template<class _Function> void run(task_handle<_Function>&& _Task_handle);
// The underlying group of tasks as known to the runtime.
::Concurrency::details::_StructuredTaskCollection _M_task_collection;
};
/// <summary>
/// The <c>task_group</c> class represents a collection of parallel work which can be waited on or canceled.
/// </summary>
/// <remarks>
/// Unlike the heavily restricted <c>structured_task_group</c> class, the <c>task_group</c> class is much more general construct.
/// It does not have any of the restrictions described by <see cref="structured_task_group Class">structured_task_group</see>. <c>task_group</c>
/// objects may safely be used across threads and utilized in free-form ways. The disadvantage of the <c>task_group</c> construct is that
/// it may not perform as well as the <c>structured_task_group</c> construct for tasks which perform small amounts of work.
/// <para>For more information, see <see cref="Task Parallelism"/>.</para>
/// </remarks>
/// <seealso cref="structured_task_group Class"/>
/// <seealso cref="task_handle Class"/>
/**/
class task_group
{
public:
/// <summary>
/// Constructs a new <c>task_group</c> object.
/// </summary>
/// <remarks>
/// The constructor that takes a cancellation token creates a <c>task_group</c> that will be canceled when the source associated with
/// the token is canceled. Providing an explicit cancellation token also isolates this task group from participating in an implicit
/// cancellation from a parent group with a different token or no token.
/// </remarks>
/// <seealso cref="Task Parallelism"/>
/**/
task_group()
{
}
/// <summary>
/// Constructs a new <c>task_group</c> object.
/// </summary>
/// <param name="_CancellationToken">
/// A cancellation token to associate with this task group. The task group will be canceled when the token is canceled.
/// </param>
/// <remarks>
/// The constructor that takes a cancellation token creates a <c>task_group</c> that will be canceled when the source associated with
/// the token is canceled. Providing an explicit cancellation token also isolates this task group from participating in an implicit
/// cancellation from a parent group with a different token or no token.
/// </remarks>
/// <seealso cref="Task Parallelism"/>
/**/
task_group(cancellation_token _CancellationToken) :
_M_task_collection(_CancellationToken._GetImpl() != NULL ? _CancellationToken._GetImpl() : Concurrency::details::_CancellationTokenState::_None())
{
}
/// <summary>
/// Destroys a <c>task_group</c> object. You are expected to call the either the <c>wait</c> or <c>run_and_wait</c> method on the object
/// prior to the destructor executing, unless the destructor is executing as the result of stack unwinding due to an exception.
/// </summary>
/// <remarks>
/// If the destructor runs as the result of normal execution (for example, not stack unwinding due to an exception) and neither the <c>wait</c> nor
/// <c>run_and_wait</c> methods have been called, the destructor may throw a <see cref="missing_wait Class">missing_wait</see> exception.
/// </remarks>
/// <seealso cref="task_group::wait Method"/>
/// <seealso cref="task_group::run_and_wait Method"/>
/**/
~task_group()
{
}
/// <summary>
/// Schedules a task on the <c>task_group</c> object. If a <c>task_handle</c> object is passed as a parameter to <c>run</c>, the caller is
/// responsible for managing the lifetime of the <c>task_handle</c> object. The version of the method that takes a reference to a function
/// object as a parameter involves heap allocation inside the runtime which may be perform less well than using the version that takes a
/// reference to a <c>task_handle</c> object. The version which takes the parameter <paramref name="_Placement"/> causes the task to be biased
/// towards executing at the location specified by that parameter.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the body of the task handle.
/// </typeparam>
/// <param name="_Func">
/// A function which will be called to invoke the body of the task. This may be a lambda expression or other object which supports
/// a version of the function call operator with the signature <c>void operator()()</c>.
/// </param>
/// <remarks>
/// The runtime schedules the provided work function to run at a later time, which can be after the calling function returns.
/// This method uses a <see cref="task_handle Class">task_handle</see> object to hold a copy of the provided work function.
/// Therefore, any state changes that occur in a function object that you pass to this method will not appear in your copy of that function object.
/// In addition, make sure that the lifetime of any objects that you pass by pointer or by reference to the work function remain valid until
/// the work function returns.
/// <para>If the <c>task_group</c> destructs as the result of stack unwinding from an exception, you do not need to guarantee
/// that a call has been made to either the <c>wait</c> or <c>run_and_wait</c> method. In this case, the destructor will appropriately
/// cancel and wait for the task represented by the <paramref name="_Task_handle"/> parameter to complete.</para>
/// <para>The method throws an <see cref="invalid_multiple_scheduling Class">invalid_multiple_scheduling</see> exception if the task
/// handle given by the <paramref name="_Task_handle"/> parameter has already been scheduled onto a task group object via the <c>run</c>
/// method and there has been no intervening call to either the <c>wait</c> or <c>run_and_wait</c> method on that task group.</para>
/// </remarks>
/// <seealso cref="task_group::wait Method"/>
/// <seealso cref="task_group::run_and_wait Method"/>
/// <seealso cref="Task Parallelism"/>
/// <seealso cref="location class"/>
/**/
template<typename _Function>
void run(const _Function& _Func)
{
_M_task_collection._Schedule(::Concurrency::details::_UnrealizedChore::_InternalAlloc<task_handle<_Function>, _Function>(_Func));
}
/// <summary>
/// Schedules a task on the <c>task_group</c> object. If a <c>task_handle</c> object is passed as a parameter to <c>run</c>, the caller is
/// responsible for managing the lifetime of the <c>task_handle</c> object. The version of the method that takes a reference to a function
/// object as a parameter involves heap allocation inside the runtime which may be perform less well than using the version that takes a
/// reference to a <c>task_handle</c> object. The version which takes the parameter <paramref name="_Placement"/> causes the task to be biased
/// towards executing at the location specified by that parameter.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the body of the task handle.
/// </typeparam>
/// <param name="_Func">
/// A function which will be called to invoke the body of the task. This may be a lambda expression or other object which supports
/// a version of the function call operator with the signature <c>void operator()()</c>.
/// </param>
/// <param name="_Placement">
/// A reference to the location where the task represented by the <paramref name="_Func"/> parameter should execute.
/// </param>
/// <remarks>
/// The runtime schedules the provided work function to run at a later time, which can be after the calling function returns.
/// This method uses a <see cref="task_handle Class">task_handle</see> object to hold a copy of the provided work function.
/// Therefore, any state changes that occur in a function object that you pass to this method will not appear in your copy of that function object.
/// In addition, make sure that the lifetime of any objects that you pass by pointer or by reference to the work function remain valid until
/// the work function returns.
/// <para>If the <c>task_group</c> destructs as the result of stack unwinding from an exception, you do not need to guarantee
/// that a call has been made to either the <c>wait</c> or <c>run_and_wait</c> method. In this case, the destructor will appropriately
/// cancel and wait for the task represented by the <paramref name="_Task_handle"/> parameter to complete.</para>
/// <para>The method throws an <see cref="invalid_multiple_scheduling Class">invalid_multiple_scheduling</see> exception if the task
/// handle given by the <paramref name="_Task_handle"/> parameter has already been scheduled onto a task group object via the <c>run</c>
/// method and there has been no intervening call to either the <c>wait</c> or <c>run_and_wait</c> method on that task group.</para>
/// </remarks>
/// <seealso cref="task_group::wait Method"/>
/// <seealso cref="task_group::run_and_wait Method"/>
/// <seealso cref="Task Parallelism"/>
/// <seealso cref="location class"/>
/**/
template<typename _Function>
void run(const _Function& _Func, location& _Placement)
{
_M_task_collection._Schedule(::Concurrency::details::_UnrealizedChore::_InternalAlloc<task_handle<_Function>, _Function>(_Func), &_Placement);
}
/// <summary>
/// Schedules a task on the <c>task_group</c> object. If a <c>task_handle</c> object is passed as a parameter to <c>run</c>, the caller is
/// responsible for managing the lifetime of the <c>task_handle</c> object. The version of the method that takes a reference to a function
/// object as a parameter involves heap allocation inside the runtime which may be perform less well than using the version that takes a
/// reference to a <c>task_handle</c> object. The version which takes the parameter <paramref name="_Placement"/> causes the task to be biased
/// towards executing at the location specified by that parameter.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the body of the task handle.
/// </typeparam>
/// <param name="_Task_handle">
/// A handle to the work being scheduled. Note that the caller has responsibility for the lifetime of this object. The runtime will
/// continue to expect it to live until either the <c>wait</c> or <c>run_and_wait</c> method has been called on this
/// <c>task_group</c> object.
/// </param>
/// <remarks>
/// The runtime schedules the provided work function to run at a later time, which can be after the calling function returns.
/// This method uses a <see cref="task_handle Class">task_handle</see> object to hold a copy of the provided work function.
/// Therefore, any state changes that occur in a function object that you pass to this method will not appear in your copy of that function object.
/// In addition, make sure that the lifetime of any objects that you pass by pointer or by reference to the work function remain valid until
/// the work function returns.
/// <para>If the <c>task_group</c> destructs as the result of stack unwinding from an exception, you do not need to guarantee
/// that a call has been made to either the <c>wait</c> or <c>run_and_wait</c> method. In this case, the destructor will appropriately
/// cancel and wait for the task represented by the <paramref name="_Task_handle"/> parameter to complete.</para>
/// <para>The method throws an <see cref="invalid_multiple_scheduling Class">invalid_multiple_scheduling</see> exception if the task
/// handle given by the <paramref name="_Task_handle"/> parameter has already been scheduled onto a task group object via the <c>run</c>
/// method and there has been no intervening call to either the <c>wait</c> or <c>run_and_wait</c> method on that task group.</para>
/// </remarks>
/// <seealso cref="task_group::wait Method"/>
/// <seealso cref="task_group::run_and_wait Method"/>
/// <seealso cref="Task Parallelism"/>
/// <seealso cref="location class"/>
/**/
template<typename _Function>
void run(task_handle<_Function>& _Task_handle)
{
_Task_handle._SetRuntimeOwnsLifetime(false);
_M_task_collection._Schedule(&_Task_handle);
}
/// <summary>
/// Schedules a task on the <c>task_group</c> object. If a <c>task_handle</c> object is passed as a parameter to <c>run</c>, the caller is
/// responsible for managing the lifetime of the <c>task_handle</c> object. The version of the method that takes a reference to a function
/// object as a parameter involves heap allocation inside the runtime which may be perform less well than using the version that takes a
/// reference to a <c>task_handle</c> object. The version which takes the parameter <paramref name="_Placement"/> causes the task to be biased
/// towards executing at the location specified by that parameter.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the body of the task handle.
/// </typeparam>
/// <param name="_Task_handle">
/// A handle to the work being scheduled. Note that the caller has responsibility for the lifetime of this object. The runtime will
/// continue to expect it to live until either the <c>wait</c> or <c>run_and_wait</c> method has been called on this
/// <c>task_group</c> object.
/// </param>
/// <param name="_Placement">
/// A reference to the location where the task represented by the <paramref name="_Func"/> parameter should execute.
/// </param>
/// <remarks>
/// The runtime schedules the provided work function to run at a later time, which can be after the calling function returns.
/// This method uses a <see cref="task_handle Class">task_handle</see> object to hold a copy of the provided work function.
/// Therefore, any state changes that occur in a function object that you pass to this method will not appear in your copy of that function object.
/// In addition, make sure that the lifetime of any objects that you pass by pointer or by reference to the work function remain valid until
/// the work function returns.
/// <para>If the <c>task_group</c> destructs as the result of stack unwinding from an exception, you do not need to guarantee
/// that a call has been made to either the <c>wait</c> or <c>run_and_wait</c> method. In this case, the destructor will appropriately
/// cancel and wait for the task represented by the <paramref name="_Task_handle"/> parameter to complete.</para>
/// <para>The method throws an <see cref="invalid_multiple_scheduling Class">invalid_multiple_scheduling</see> exception if the task
/// handle given by the <paramref name="_Task_handle"/> parameter has already been scheduled onto a task group object via the <c>run</c>
/// method and there has been no intervening call to either the <c>wait</c> or <c>run_and_wait</c> method on that task group.</para>
/// </remarks>
/// <seealso cref="task_group::wait Method"/>
/// <seealso cref="task_group::run_and_wait Method"/>
/// <seealso cref="Task Parallelism"/>
/// <seealso cref="location class"/>
/**/
template<typename _Function>
void run(task_handle<_Function>& _Task_handle, location& _Placement)
{
_Task_handle._SetRuntimeOwnsLifetime(false);
_M_task_collection._Schedule(&_Task_handle, &_Placement);
}
/// <summary>
/// Waits until all work on the <c>task_group</c> object has either completed or been canceled.
/// </summary>
/// <returns>
/// An indication of whether the wait was satisfied or the task group was canceled, due to either an explicit cancel operation or an exception
/// being thrown from one of its tasks. For more information, see <see cref="task_group_status Enumeration">task_group_status</see>.
/// </returns>
/// <remarks>
/// Note that one or more of the tasks scheduled to this <c>task_group</c> object may execute inline on the calling context.
/// <para>If one or more of the tasks scheduled to this <c>task_group</c> object throws an exception, the
/// runtime will select one such exception of its choosing and propagate it out of the call to the <c>wait</c> method.</para>
/// <para>Calling <c>wait</c> on a <c>task_group</c> object resets it to a clean state where it can be reused. This includes the case
/// where the <c>task_group</c> object was canceled.</para>
/// <para>In the non-exceptional path of execution, you have a mandate to call either this method or the <c>run_and_wait</c> method before
/// the destructor of the <c>task_group</c> executes.</para>
/// </remarks>
/**/
task_group_status wait()
{
//
// The underlying scheduler's definitions map exactly to the PPL's. No translation beyond the cast is necessary.
//
return static_cast<task_group_status>(_M_task_collection._Wait());
}
/// <summary>
/// Schedules a task to be run inline on the calling context with the assistance of the <c>task_group</c> object for full cancellation support.
/// The function then waits until all work on the <c>task_group</c> object has either completed or been canceled. If a <c>task_handle</c> object
/// is passed as a parameter to <c>run_and_wait</c>, the caller is responsible for managing the lifetime of the <c>task_handle</c> object.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the body of the task handle.
/// </typeparam>
/// <param name="_Task_handle">
/// A handle to the task which will be run inline on the calling context. Note that the caller has responsibility for the lifetime of this object.
/// The runtime will continue to expect it to live until the <c>run_and_wait</c> method finishes execution.
/// </param>
/// <returns>
/// An indication of whether the wait was satisfied or the task group was canceled, due to either an explicit cancel operation or an exception
/// being thrown from one of its tasks. For more information, see <see cref="task_group_status Enumeration">task_group_status</see>.
/// </returns>
/// <remarks>
/// Note that one or more of the tasks scheduled to this <c>task_group</c> object may execute inline on the calling context.
/// <para>If one or more of the tasks scheduled to this <c>task_group</c> object throws an exception, the
/// runtime will select one such exception of its choosing and propagate it out of the call to the <c>run_and_wait</c> method.</para>
/// <para>Upon return from the <c>run_and_wait</c> method on a <c>task_group</c> object, the runtime resets the object to a clean state where it can be
/// reused. This includes the case where the <c>task_group</c> object was canceled.</para>
/// <para>In the non-exceptional path of execution, you have a mandate to call either this method or the <c>wait</c> method before
/// the destructor of the <c>task_group</c> executes.</para>
/// </remarks>
/// <seealso cref="task_group::run Method"/>
/// <seealso cref="task_group::wait Method"/>
/// <seealso cref="Task Parallelism"/>
/**/
template<class _Function>
task_group_status run_and_wait(task_handle<_Function>& _Task_handle)
{
//
// The underlying scheduler's definitions map exactly to the PPL's. No translation beyond the cast is necessary.
//
_Task_handle._SetRuntimeOwnsLifetime(false);
return (task_group_status)_M_task_collection._RunAndWait(&_Task_handle);
}
/// <summary>
/// Schedules a task to be run inline on the calling context with the assistance of the <c>task_group</c> object for full cancellation support.
/// The function then waits until all work on the <c>task_group</c> object has either completed or been canceled. If a <c>task_handle</c> object
/// is passed as a parameter to <c>run_and_wait</c>, the caller is responsible for managing the lifetime of the <c>task_handle</c> object.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to execute the body of the task.
/// </typeparam>
/// <param name="_Func">
/// A function which will be called to invoke the body of the work. This may be a lambda expression or other object which supports
/// a version of the function call operator with the signature <c>void operator()()</c>.
/// </param>
/// <returns>
/// An indication of whether the wait was satisfied or the task group was canceled, due to either an explicit cancel operation or an exception
/// being thrown from one of its tasks. For more information, see <see cref="task_group_status Enumeration">task_group_status</see>.
/// </returns>
/// <remarks>
/// Note that one or more of the tasks scheduled to this <c>task_group</c> object may execute inline on the calling context.
/// <para>If one or more of the tasks scheduled to this <c>task_group</c> object throws an exception, the
/// runtime will select one such exception of its choosing and propagate it out of the call to the <c>run_and_wait</c> method.</para>
/// <para>Upon return from the <c>run_and_wait</c> method on a <c>task_group</c> object, the runtime resets the object to a clean state where it can be
/// reused. This includes the case where the <c>task_group</c> object was canceled.</para>
/// <para>In the non-exceptional path of execution, you have a mandate to call either this method or the <c>wait</c> method before
/// the destructor of the <c>task_group</c> executes.</para>
/// </remarks>
/// <seealso cref="task_group::run Method"/>
/// <seealso cref="task_group::wait Method"/>
/// <seealso cref="Task Parallelism"/>
/**/
template<class _Function>
task_group_status run_and_wait(const _Function& _Func)
{
//
// The underlying scheduler's definitions map exactly to the PPL's. No translation beyond the cast is necessary.
//
return (task_group_status)_M_task_collection._RunAndWait(::Concurrency::details::_UnrealizedChore::_InternalAlloc<task_handle<_Function>, _Function>(_Func));
}
/// <summary>
/// Makes a best effort attempt to cancel the sub-tree of work rooted at this task group. Every task scheduled on the task group
/// will get canceled transitively if possible.
/// </summary>
/// <remarks>
/// For more information, see <see cref="Cancellation in the PPL"/>.
/// </remarks>
/**/
void cancel()
{
_M_task_collection._Cancel();
}
/// <summary>
/// Informs the caller whether or not the task group is currently in the midst of a cancellation. This
/// does not necessarily indicate that the <c>cancel</c> method was called on the <c>task_group</c> object
/// (although such certainly qualifies this method to return <c>true</c>). It may be the case that the <c>task_group</c> object
/// is executing inline and a task group further up in the work tree was canceled. In cases such as these where the runtime can determine ahead
/// of time that cancellation will flow through this <c>task_group</c> object, <c>true</c> will be returned as well.
/// </summary>
/// <returns>
/// An indication of whether the <c>task_group</c> object is in the midst of a cancellation (or is guaranteed to be shortly).
/// </returns>
/// <remarks>
/// For more information, see <see cref="Cancellation in the PPL"/>.
/// </remarks>
/**/
bool is_canceling()
{
return _M_task_collection._IsCanceling();
}
private:
// Disallow passing in an r-value for a task handle argument
template<class _Function> void run(task_handle<_Function>&& _Task_handle);
// The underlying group of tasks as known to the runtime.
::Concurrency::details::_TaskCollection _M_task_collection;
};
/// <summary>
/// Executes a function object immediately and synchronously in the context of a given cancellation token.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked.
/// </typeparam>
/// <param name="_Func">
/// The function object which will be executed. This object must support the function call operator with a signature of void(void).
/// </param>
/// <param name="_Ct">
/// The cancellation token which will control implicit cancellation of the function object. Use <c>cancellation_token::none()</c> if you want the
/// function execute without any possibility of implicit cancellation from a parent task group being canceled.
/// </param>
/// <remarks>
/// Any interruption points in the function object will be triggered when the <c>cancellation_token</c> is canceled.
/// The explicit token <paramref name="_Ct"/> will isolate this <paramref name="_Func"/> from parent cancellation if the parent has a
/// different token or no token.
/// </remarks>
/**/
template<typename _Function>
void run_with_cancellation_token(const _Function& _Func, cancellation_token _Ct)
{
structured_task_group _Stg(_Ct);
_Stg.run_and_wait(_Func);
}
/// <summary>
/// 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.
/// </summary>
/// <remarks>
/// You should not catch the internal cancellation exception thrown by the <c>interruption_point()</c> function. The exception will be caught and handled by
/// the runtime, and catching it may cause your program to behave abnormally.
/// </remarks>
/**/
inline void interruption_point()
{
structured_task_group _Stg;
_Stg.wait();
}
/// <summary>
/// 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, <c>false</c> will be returned.
/// </summary>
/// <returns>
/// <c>true</c> if the task group which is currently executing is canceling, <c>false</c> otherwise.
/// </returns>
/// <remarks>
/// For more information, see <see cref="Cancellation in the PPL"/>.
/// </remarks>
/// <seealso cref="task_group Class"/>
/// <seealso cref="structured_task_group Class"/>
/**/
_CRTIMP2 bool __cdecl is_current_task_group_canceling();
// Parallel Algorithms and Patterns
// Helper function that implements parallel_invoke with two functions
// Used by parallel_for and parallel_for_each implementations
template <typename _Function1, typename _Function2>
void _Parallel_invoke_impl(const _Function1& _Func1, const _Function2& _Func2)
{
structured_task_group _Task_group;
task_handle<_Function1> _Task_handle1(_Func1);
_Task_group.run(_Task_handle1);
// We inline the last item to prevent the unnecessary push/pop on the work queue.
task_handle<_Function2> _Task_handle2(_Func2);
_Task_group.run_and_wait(_Task_handle2);
}
/// <summary>
/// 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
/// <c>void operator()()</c>.
/// </summary>
/// <typeparam name="_Function1">
/// The type of the first function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function2">
/// The type of the second function object to be executed in parallel.
/// </typeparam>
/// <param name="_Func1">
/// The first function object to be executed in parallel.
/// </param>
/// <param name="_Func2">
/// The second function object to be executed in parallel.
/// </param>
/// <remarks>
/// Note that one or more of the function objects supplied as parameters may execute inline on the calling context.
/// <para>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 <c>parallel_invoke</c>.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
template <typename _Function1, typename _Function2>
void parallel_invoke(const _Function1& _Func1, const _Function2& _Func2)
{
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
_Parallel_invoke_impl(_Func1, _Func2);
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// 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
/// <c>void operator()()</c>.
/// </summary>
/// <typeparam name="_Function1">
/// The type of the first function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function2">
/// The type of the second function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function3">
/// The type of the third function object to be executed in parallel.
/// </typeparam>
/// <param name="_Func1">
/// The first function object to be executed in parallel.
/// </param>
/// <param name="_Func2">
/// The second function object to be executed in parallel.
/// </param>
/// <param name="_Func3">
/// The third function object to be executed in parallel.
/// </param>
/// <remarks>
/// Note that one or more of the function objects supplied as parameters may execute inline on the calling context.
/// <para>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 <c>parallel_invoke</c>.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
template <typename _Function1, typename _Function2, typename _Function3>
void parallel_invoke(const _Function1& _Func1, const _Function2& _Func2, const _Function3& _Func3)
{
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
structured_task_group _Task_group;
task_handle<_Function1> _Task_handle1(_Func1);
_Task_group.run(_Task_handle1);
task_handle<_Function2> _Task_handle2(_Func2);
_Task_group.run(_Task_handle2);
task_handle<_Function3> _Task_handle3(_Func3);
_Task_group.run_and_wait(_Task_handle3);
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// 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
/// <c>void operator()()</c>.
/// </summary>
/// <typeparam name="_Function1">
/// The type of the first function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function2">
/// The type of the second function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function3">
/// The type of the third function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function4">
/// The type of the fourth function object to be executed in parallel.
/// </typeparam>
/// <param name="_Func1">
/// The first function object to be executed in parallel.
/// </param>
/// <param name="_Func2">
/// The second function object to be executed in parallel.
/// </param>
/// <param name="_Func3">
/// The third function object to be executed in parallel.
/// </param>
/// <param name="_Func4">
/// The fourth function object to be executed in parallel.
/// </param>
/// <remarks>
/// Note that one or more of the function objects supplied as parameters may execute inline on the calling context.
/// <para>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 <c>parallel_invoke</c>.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
template <typename _Function1, typename _Function2, typename _Function3, typename _Function4>
void parallel_invoke(const _Function1& _Func1, const _Function2& _Func2, const _Function3& _Func3, const _Function4& _Func4)
{
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
structured_task_group _Task_group;
task_handle<_Function1> _Task_handle1(_Func1);
_Task_group.run(_Task_handle1);
task_handle<_Function2> _Task_handle2(_Func2);
_Task_group.run(_Task_handle2);
task_handle<_Function3> _Task_handle3(_Func3);
_Task_group.run(_Task_handle3);
task_handle<_Function4> _Task_handle4(_Func4);
_Task_group.run_and_wait(_Task_handle4);
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// 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
/// <c>void operator()()</c>.
/// </summary>
/// <typeparam name="_Function1">
/// The type of the first function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function2">
/// The type of the second function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function3">
/// The type of the third function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function4">
/// The type of the fourth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function5">
/// The type of the fifth function object to be executed in parallel.
/// </typeparam>
/// <param name="_Func1">
/// The first function object to be executed in parallel.
/// </param>
/// <param name="_Func2">
/// The second function object to be executed in parallel.
/// </param>
/// <param name="_Func3">
/// The third function object to be executed in parallel.
/// </param>
/// <param name="_Func4">
/// The fourth function object to be executed in parallel.
/// </param>
/// <param name="_Func5">
/// The fifth function object to be executed in parallel.
/// </param>
/// <remarks>
/// Note that one or more of the function objects supplied as parameters may execute inline on the calling context.
/// <para>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 <c>parallel_invoke</c>.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
structured_task_group _Task_group;
task_handle<_Function1> _Task_handle1(_Func1);
_Task_group.run(_Task_handle1);
task_handle<_Function2> _Task_handle2(_Func2);
_Task_group.run(_Task_handle2);
task_handle<_Function3> _Task_handle3(_Func3);
_Task_group.run(_Task_handle3);
task_handle<_Function4> _Task_handle4(_Func4);
_Task_group.run(_Task_handle4);
task_handle<_Function5> _Task_handle5(_Func5);
_Task_group.run_and_wait(_Task_handle5);
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// 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
/// <c>void operator()()</c>.
/// </summary>
/// <typeparam name="_Function1">
/// The type of the first function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function2">
/// The type of the second function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function3">
/// The type of the third function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function4">
/// The type of the fourth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function5">
/// The type of the fifth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function6">
/// The type of the sixth function object to be executed in parallel.
/// </typeparam>
/// <param name="_Func1">
/// The first function object to be executed in parallel.
/// </param>
/// <param name="_Func2">
/// The second function object to be executed in parallel.
/// </param>
/// <param name="_Func3">
/// The third function object to be executed in parallel.
/// </param>
/// <param name="_Func4">
/// The fourth function object to be executed in parallel.
/// </param>
/// <param name="_Func5">
/// The fifth function object to be executed in parallel.
/// </param>
/// <param name="_Func6">
/// The sixth function object to be executed in parallel.
/// </param>
/// <remarks>
/// Note that one or more of the function objects supplied as parameters may execute inline on the calling context.
/// <para>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 <c>parallel_invoke</c>.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
structured_task_group _Task_group;
task_handle<_Function1> _Task_handle1(_Func1);
_Task_group.run(_Task_handle1);
task_handle<_Function2> _Task_handle2(_Func2);
_Task_group.run(_Task_handle2);
task_handle<_Function3> _Task_handle3(_Func3);
_Task_group.run(_Task_handle3);
task_handle<_Function4> _Task_handle4(_Func4);
_Task_group.run(_Task_handle4);
task_handle<_Function5> _Task_handle5(_Func5);
_Task_group.run(_Task_handle5);
task_handle<_Function6> _Task_handle6(_Func6);
_Task_group.run_and_wait(_Task_handle6);
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// 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
/// <c>void operator()()</c>.
/// </summary>
/// <typeparam name="_Function1">
/// The type of the first function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function2">
/// The type of the second function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function3">
/// The type of the third function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function4">
/// The type of the fourth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function5">
/// The type of the fifth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function6">
/// The type of the sixth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function7">
/// The type of the seventh function object to be executed in parallel.
/// </typeparam>
/// <param name="_Func1">
/// The first function object to be executed in parallel.
/// </param>
/// <param name="_Func2">
/// The second function object to be executed in parallel.
/// </param>
/// <param name="_Func3">
/// The third function object to be executed in parallel.
/// </param>
/// <param name="_Func4">
/// The fourth function object to be executed in parallel.
/// </param>
/// <param name="_Func5">
/// The fifth function object to be executed in parallel.
/// </param>
/// <param name="_Func6">
/// The sixth function object to be executed in parallel.
/// </param>
/// <param name="_Func7">
/// The seventh function object to be executed in parallel.
/// </param>
/// <remarks>
/// Note that one or more of the function objects supplied as parameters may execute inline on the calling context.
/// <para>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 <c>parallel_invoke</c>.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
structured_task_group _Task_group;
task_handle<_Function1> _Task_handle1(_Func1);
_Task_group.run(_Task_handle1);
task_handle<_Function2> _Task_handle2(_Func2);
_Task_group.run(_Task_handle2);
task_handle<_Function3> _Task_handle3(_Func3);
_Task_group.run(_Task_handle3);
task_handle<_Function4> _Task_handle4(_Func4);
_Task_group.run(_Task_handle4);
task_handle<_Function5> _Task_handle5(_Func5);
_Task_group.run(_Task_handle5);
task_handle<_Function6> _Task_handle6(_Func6);
_Task_group.run(_Task_handle6);
task_handle<_Function7> _Task_handle7(_Func7);
_Task_group.run_and_wait(_Task_handle7);
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// 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
/// <c>void operator()()</c>.
/// </summary>
/// <typeparam name="_Function1">
/// The type of the first function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function2">
/// The type of the second function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function3">
/// The type of the third function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function4">
/// The type of the fourth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function5">
/// The type of the fifth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function6">
/// The type of the sixth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function7">
/// The type of the seventh function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function8">
/// The type of the eighth function object to be executed in parallel.
/// </typeparam>
/// <param name="_Func1">
/// The first function object to be executed in parallel.
/// </param>
/// <param name="_Func2">
/// The second function object to be executed in parallel.
/// </param>
/// <param name="_Func3">
/// The third function object to be executed in parallel.
/// </param>
/// <param name="_Func4">
/// The fourth function object to be executed in parallel.
/// </param>
/// <param name="_Func5">
/// The fifth function object to be executed in parallel.
/// </param>
/// <param name="_Func6">
/// The sixth function object to be executed in parallel.
/// </param>
/// <param name="_Func7">
/// The seventh function object to be executed in parallel.
/// </param>
/// <param name="_Func8">
/// The eighth function object to be executed in parallel.
/// </param>
/// <remarks>
/// Note that one or more of the function objects supplied as parameters may execute inline on the calling context.
/// <para>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 <c>parallel_invoke</c>.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
structured_task_group _Task_group;
task_handle<_Function1> _Task_handle1(_Func1);
_Task_group.run(_Task_handle1);
task_handle<_Function2> _Task_handle2(_Func2);
_Task_group.run(_Task_handle2);
task_handle<_Function3> _Task_handle3(_Func3);
_Task_group.run(_Task_handle3);
task_handle<_Function4> _Task_handle4(_Func4);
_Task_group.run(_Task_handle4);
task_handle<_Function5> _Task_handle5(_Func5);
_Task_group.run(_Task_handle5);
task_handle<_Function6> _Task_handle6(_Func6);
_Task_group.run(_Task_handle6);
task_handle<_Function7> _Task_handle7(_Func7);
_Task_group.run(_Task_handle7);
task_handle<_Function8> _Task_handle8(_Func8);
_Task_group.run_and_wait(_Task_handle8);
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// 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
/// <c>void operator()()</c>.
/// </summary>
/// <typeparam name="_Function1">
/// The type of the first function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function2">
/// The type of the second function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function3">
/// The type of the third function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function4">
/// The type of the fourth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function5">
/// The type of the fifth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function6">
/// The type of the sixth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function7">
/// The type of the seventh function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function8">
/// The type of the eighth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function9">
/// The type of the ninth function object to be executed in parallel.
/// </typeparam>
/// <param name="_Func1">
/// The first function object to be executed in parallel.
/// </param>
/// <param name="_Func2">
/// The second function object to be executed in parallel.
/// </param>
/// <param name="_Func3">
/// The third function object to be executed in parallel.
/// </param>
/// <param name="_Func4">
/// The fourth function object to be executed in parallel.
/// </param>
/// <param name="_Func5">
/// The fifth function object to be executed in parallel.
/// </param>
/// <param name="_Func6">
/// The sixth function object to be executed in parallel.
/// </param>
/// <param name="_Func7">
/// The seventh function object to be executed in parallel.
/// </param>
/// <param name="_Func8">
/// The eighth function object to be executed in parallel.
/// </param>
/// <param name="_Func9">
/// The ninth function object to be executed in parallel.
/// </param>
/// <remarks>
/// Note that one or more of the function objects supplied as parameters may execute inline on the calling context.
/// <para>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 <c>parallel_invoke</c>.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
structured_task_group _Task_group;
task_handle<_Function1> _Task_handle1(_Func1);
_Task_group.run(_Task_handle1);
task_handle<_Function2> _Task_handle2(_Func2);
_Task_group.run(_Task_handle2);
task_handle<_Function3> _Task_handle3(_Func3);
_Task_group.run(_Task_handle3);
task_handle<_Function4> _Task_handle4(_Func4);
_Task_group.run(_Task_handle4);
task_handle<_Function5> _Task_handle5(_Func5);
_Task_group.run(_Task_handle5);
task_handle<_Function6> _Task_handle6(_Func6);
_Task_group.run(_Task_handle6);
task_handle<_Function7> _Task_handle7(_Func7);
_Task_group.run(_Task_handle7);
task_handle<_Function8> _Task_handle8(_Func8);
_Task_group.run(_Task_handle8);
task_handle<_Function9> _Task_handle9(_Func9);
_Task_group.run_and_wait(_Task_handle9);
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// 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
/// <c>void operator()()</c>.
/// </summary>
/// <typeparam name="_Function1">
/// The type of the first function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function2">
/// The type of the second function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function3">
/// The type of the third function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function4">
/// The type of the fourth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function5">
/// The type of the fifth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function6">
/// The type of the sixth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function7">
/// The type of the seventh function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function8">
/// The type of the eighth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function9">
/// The type of the ninth function object to be executed in parallel.
/// </typeparam>
/// <typeparam name="_Function10">
/// The type of the tenth function object to be executed in parallel.
/// </typeparam>
/// <param name="_Func1">
/// The first function object to be executed in parallel.
/// </param>
/// <param name="_Func2">
/// The second function object to be executed in parallel.
/// </param>
/// <param name="_Func3">
/// The third function object to be executed in parallel.
/// </param>
/// <param name="_Func4">
/// The fourth function object to be executed in parallel.
/// </param>
/// <param name="_Func5">
/// The fifth function object to be executed in parallel.
/// </param>
/// <param name="_Func6">
/// The sixth function object to be executed in parallel.
/// </param>
/// <param name="_Func7">
/// The seventh function object to be executed in parallel.
/// </param>
/// <param name="_Func8">
/// The eighth function object to be executed in parallel.
/// </param>
/// <param name="_Func9">
/// The ninth function object to be executed in parallel.
/// </param>
/// <param name="_Func10">
/// The tenth function object to be executed in parallel.
/// </param>
/// <remarks>
/// Note that one or more of the function objects supplied as parameters may execute inline on the calling context.
/// <para>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 <c>parallel_invoke</c>.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
structured_task_group _Task_group;
task_handle<_Function1> _Task_handle1(_Func1);
_Task_group.run(_Task_handle1);
task_handle<_Function2> _Task_handle2(_Func2);
_Task_group.run(_Task_handle2);
task_handle<_Function3> _Task_handle3(_Func3);
_Task_group.run(_Task_handle3);
task_handle<_Function4> _Task_handle4(_Func4);
_Task_group.run(_Task_handle4);
task_handle<_Function5> _Task_handle5(_Func5);
_Task_group.run(_Task_handle5);
task_handle<_Function6> _Task_handle6(_Func6);
_Task_group.run(_Task_handle6);
task_handle<_Function7> _Task_handle7(_Func7);
_Task_group.run(_Task_handle7);
task_handle<_Function8> _Task_handle8(_Func8);
_Task_group.run(_Task_handle8);
task_handle<_Function9> _Task_handle9(_Func9);
_Task_group.run(_Task_handle9);
task_handle<_Function10> _Task_handle10(_Func10);
_Task_group.run_and_wait(_Task_handle10);
_Trace_ppl_function(PPLParallelInvokeEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// The <c>auto_partitioner</c> class represents the default method <c>parallel_for</c>, <c>parallel_for_each</c> and
/// <c>parallel_transform</c> use to partition the range they iterates over. This method of partitioning employes range stealing
/// for load balancing as well as per-iterate cancellation.
/// </summary>
/**/
class auto_partitioner
{
public:
/// <summary>
/// Constructs a <c>auto_partitioner</c> object.
/// </summary>
/**/
auto_partitioner() {}
/// <summary>
/// Destroys a <c>auto_partitioner</c> object.
/// </summary>
/**/
~auto_partitioner() {}
template<class _Type>
_Type _Get_num_chunks(_Type ) const
{
return static_cast<_Type>(Concurrency::details::_CurrentScheduler::_GetNumberOfVirtualProcessors());
}
};
/// <summary>
/// The <c>static_partitioner</c> class represents a static partitioning of the range iterated over by <c>parallel_for</c>. The partitioner
/// divides the range into as many chunks as there are workers available to the underyling scheduler.
/// </summary>
/**/
class static_partitioner
{
public:
/// <summary>
/// Constructs a <c>static_partitioner</c> object.
/// </summary>
/**/
static_partitioner()
{
}
/// <summary>
/// Destroys a <c>static_partitioner</c> object.
/// </summary>
/**/
~static_partitioner() {}
template<class _Type>
_Type _Get_num_chunks(_Type ) const
{
return static_cast<_Type>(Concurrency::details::_CurrentScheduler::_GetNumberOfVirtualProcessors());
}
};
/// <summary>
/// The <c>simple_partitioner</c> class represents a static partitioning of the range iterated over by <c>parallel_for</c>. The partitioner
/// divides the range into chunks such that each chunk has at least the number of iterations specified by the chunk size.
/// </summary>
/**/
class simple_partitioner
{
private:
typedef unsigned long long _Size_type;
public:
/// <summary>
/// Constructs a <c>simple_partitioner</c> object.
/// </summary>
/// <param name="_M_chunk_size">
/// Number of iterations per chunk.
/// </param>
/**/
explicit simple_partitioner(_Size_type _Chunk_size) : _M_chunk_size(_Chunk_size)
{
if (_Chunk_size == 0)
{
throw std::invalid_argument("_Chunk_size");
}
}
/// <summary>
/// Destroys a <c>simple_partitioner</c> object.
/// </summary>
/**/
~simple_partitioner() {}
template<class _Type>
_Type _Get_num_chunks(_Type _Range_arg) const
{
static_assert(sizeof(_Type) <= sizeof(_Size_type), "Potential truncation of _Range_arg");
_Size_type _Num_chunks = (static_cast<_Size_type>(_Range_arg) / _M_chunk_size);
if (_Num_chunks == 0)
{
_Num_chunks = 1;
}
return static_cast<_Type>(_Num_chunks);
}
private:
_Size_type _M_chunk_size;
};
/// <summary>
/// The <c>affinity_partitioner</c> class is similar to the <c>static_partitioner</c> class, but it improves cache affinity
/// by its choice of mapping subranges to worker threads. It can improve performance significantly when a loop is re-executed over
/// the same data set, and the data fits in cache. Note that the same <c>affinity_partitioner</c> object must be used with subsequent
/// iterations of a parallel loop that is executed over a particular data set, to benefit from data locality.
/// </summary>
/**/
class affinity_partitioner
{
public:
/// <summary>
/// Constructs an <c>affinity_partitioner</c> object.
/// </summary>
/**/
affinity_partitioner() : _M_num_chunks(0), _M_pChunk_locations(NULL)
{
}
/// <summary>
/// Destroys an <c>affinity_partitioner</c> object.
/// </summary>
/**/
~affinity_partitioner()
{
delete [] _M_pChunk_locations;
}
location& _Get_chunk_location(unsigned int _ChunkIndex)
{
return _M_pChunk_locations[_ChunkIndex];
}
template<class _Type>
_Type _Get_num_chunks(_Type )
{
if (_M_num_chunks == 0)
{
_Initialize_locations(Concurrency::details::_CurrentScheduler::_GetNumberOfVirtualProcessors());
}
return static_cast<_Type>(_M_num_chunks);
}
private:
// The number of chunks the partitioner will record affinity for.
unsigned int _M_num_chunks;
// Array of remembered locations.
location * _M_pChunk_locations;
void _Initialize_locations(unsigned int _Num_chunks)
{
_M_num_chunks = _Num_chunks;
_M_pChunk_locations = new location[_Num_chunks];
}
};
// Helper methods for scheduling and executing parallel tasks
// Disable C4180: qualifier applied to function type has no meaning; ignored
// Warning fires for passing Foo function pointer to parallel_for instead of &Foo.
#pragma warning(push)
#pragma warning(disable: 4180)
// Disable C6263: using _alloca in a loop; this can quickly overflow stack
#pragma warning(disable: 6263)
// Template class that invokes user function on a parallel_for_each
template <typename _Random_iterator, typename _Index_type, typename _Function, bool _Is_iterator>
class _Parallel_chunk_helper_invoke
{
public:
static void __cdecl _Invoke(const _Random_iterator& _First, _Index_type& _Index, const _Function& _Func)
{
_Func(_First[_Index]);
}
};
// Template specialized class that invokes user function on a parallel_for
template <typename _Random_iterator, typename _Index_type, typename _Function>
class _Parallel_chunk_helper_invoke<_Random_iterator, _Index_type, _Function, false>
{
public:
static void __cdecl _Invoke(const _Random_iterator& _First, _Index_type& _Index, const _Function& _Func)
{
_Func(static_cast<_Random_iterator>(_First + _Index));
}
};
// Represents a range of iteration
template<typename _Index_type>
class _Range
{
public:
// Construct an object for the range [_Current_iteration, _Last_iteration)
_Range(_Index_type _Current_iteration, _Index_type _Last_iteration) :
_M_current(_Current_iteration), _M_last(_Last_iteration)
{
// On creation, the range shall have at least 1 iteration.
_CONCRT_ASSERT(_Number_of_iterations() > 0);
}
// Send a portion of the range to the helper
void _Send_range(_Range<_Index_type> * _Helper_range)
{
// If there are no iterations other than the current one left until finish, there is no help
// needed. Set the pointer to a special value that helper will understand and continue
// doing the work.
_Index_type _Remaining_iterations = _Number_of_iterations();
if (_Remaining_iterations > 1)
{
// Compute the two pieces of the work range: one for the worker and one for helper class.
_M_last_iteration = _M_current_iteration + _Remaining_iterations / 2;
// There needs to be at least 1 iteration left because the current iteration cannot be sent.
_CONCRT_ASSERT(_Number_of_iterations() > 0);
}
// This is also a signal for the helper that a range has been sent to it.
_Helper_range->_M_current_iteration = _M_last_iteration;
}
// Steal the entire range and give it to the helper
void _Steal_range(_Range<_Index_type> * _Helper_range)
{
// We allow stealing only from a range that has atleast 1 iteration
_CONCRT_ASSERT(_Number_of_iterations() > 0);
_Index_type _Current_iter = _M_current_iteration;
_Helper_range->_M_current_iteration = _Current_iter + 1;
_Helper_range->_M_last_iteration = _M_last_iteration;
_M_last_iteration = _Current_iter + 1;
}
// Returns the number of iterations in this range
_Index_type _Number_of_iterations() const
{
return (_M_last_iteration - _M_current_iteration);
}
// Returns the current iteration in the range
_Index_type _Get_current_iteration() const
{
return _M_current;
}
// Sets the current iteration in the range
void _Set_current_iteration(const _Index_type _I)
{
_M_current = _I;
}
__declspec(property(get=_Get_current_iteration, put=_Set_current_iteration)) _Index_type _M_current_iteration;
// Returns the last iteration in the range
_Index_type _Get_last_iteration() const
{
return _M_last;
}
// Sets the last iteration in the range
void _Set_last_iteration(const _Index_type _I)
{
_M_last = _I;
}
__declspec(property(get=_Get_last_iteration, put=_Set_last_iteration)) _Index_type _M_last_iteration;
private:
// These members are volatile because they are updated by the helper
// and used by the worker.
volatile _Index_type _M_current;
volatile _Index_type _M_last;
};
// A proxy for the worker responsible for maintaining communication with the helper
template<typename _Index_type>
class _Worker_proxy
{
public:
_Worker_proxy(_Worker_proxy *_PParent_worker = NULL) :
_M_pHelper_range(NULL), _M_pParent_worker(_PParent_worker), _M_pWorker_range(NULL), _M_completion_count(0), _M_stop_iterating(0)
{
_M_context = Concurrency::details::_Context::_CurrentContext();
}
~_Worker_proxy()
{
// Make the check to avoid doing extra work in the non-exceptional cases
if (_M_completion_count != _Tree_Complete)
{
// On exception, notify our parent so it breaks out of its loop.
_Propagate_cancel();
// On exception, we need to set _M_completion_count to ensure that the helper breaks out of its spin wait.
_Set_done();
}
}
// Obtain a range from the worker
bool _Receive_range(_Range<_Index_type> * _Helper_range)
{
// If the worker already finished, then there is no work left for the helper
if (_M_completion_count)
{
return false;
}
_CONCRT_ASSERT(_Helper_range != NULL);
// There are two special values for _M_current_iteration that are not valid: one is the
// initial value of the working class which it will never share, and the other is
// the last exclusive iteration of the working class, which has no work to be done.
// We use the former value so that we can understand worker's response.
_Index_type _Cached_first_iteration = _Helper_range->_M_current_iteration;
// Following operation is not done via interlocked operation because it does not have to.
// Helper lazily registers that it would like to help the worker, but it allows for some
// time to elapse before that information has made it over to the worker. The idea
// is not to disturb the worker if it is not necessary. It is possible to add interlocked
// operation in the future if the time spent in the busy wait loop is too big.
_CONCRT_ASSERT(_M_pHelper_range == NULL);
_M_pHelper_range = _Helper_range;
::Concurrency::details::_SpinWaitBackoffNone spinWait(::Concurrency::details::_Context::_Yield);
// If the worker is done, it will flush the store buffer and signal the helper by
// changing _M_current_iteration in the helper's range.
while ((_Helper_range->_M_current_iteration == _Cached_first_iteration) && !_M_completion_count)
{
if ((_M_pWorker_range != NULL) && _M_context._IsSynchronouslyBlocked())
{
// Attempt to steal the entire range from the worker if it is synchronously blocked.
// Make sure that worker makes no forward progress while helper is attempting to
// steal its range. If worker does get unblocked, simply back off in the helper.
// Note that there could be another helper running if a range has already been
// sent to us.
long _Stop_iterating = _InterlockedIncrement(&_M_stop_iterating);
_CONCRT_ASSERT(_Stop_iterating > 0);
// We need to make a local copy as the pointer could be changed by the worker.
_Range<_Index_type> * _Worker_range = _M_pWorker_range;
// The order of comparison needs to be preserved. If the parent is blocked, then
// it cannot send a range (because _M_stop_iterating is already set). If it sent a range
// before being synchronously blocked, then we are no longer the helper. Refrain
// from intrusively stealing the range.
if ((_Worker_range != NULL) && _M_context._IsSynchronouslyBlocked()
&& (_Helper_range->_M_current_iteration == _Cached_first_iteration) && !_M_completion_count)
{
_CONCRT_ASSERT(_M_pHelper_range == _Helper_range);
_M_pHelper_range = NULL;
_Worker_range->_Steal_range(_Helper_range);
_CONCRT_ASSERT(_Helper_range->_M_current_iteration != _Cached_first_iteration);
}
// At this point, worker is either:
//
// a) no longer blocked so range will come to the helper naturally, or
// b) out of iterations because helper stole all of it
_Stop_iterating = _InterlockedDecrement(&_M_stop_iterating);
_CONCRT_ASSERT(_Stop_iterating >= 0);
}
else
{
// If there is no work received in a full spin, then start yielding the context
spinWait._SpinOnce();
}
}
// If the initial iteration is the same as the original first iteration then the
// worker class is sending the signal that it does not need any help.
if (_Helper_range->_M_current_iteration == _Cached_first_iteration)
{
return false;
}
return (_Helper_range->_Number_of_iterations() > 0);
}
// Send a portion of our range and notify the helper.
bool _Send_range(_Range<_Index_type> * _Worker_range)
{
// Worker range shall not be available for stealing at this time.
_CONCRT_ASSERT(_M_pWorker_range == NULL);
// Helper shall be registered.
_CONCRT_ASSERT(_M_pHelper_range != NULL);
// Send the range
_Worker_range->_Send_range(_M_pHelper_range);
// Notify the helper. The fence ensures that the prior updates are visible.
_InterlockedExchangePointer(reinterpret_cast<void * volatile *>(&_M_pHelper_range), NULL);
// The current iteration should still be left
_CONCRT_ASSERT(_Worker_range->_Number_of_iterations() >= 1);
// Indicate if we need another helper
return (_Worker_range->_Number_of_iterations() > 1);
}
// Let the helper know that it is ok to intrusively steal range from the worker by publishing the
// remaining range.
void _Enable_intrusive_steal(_Range<_Index_type> * _Worker_range)
{
_M_pWorker_range = _Worker_range;
}
// Prevent the helper from intrusively stealing range from the worker
void _Disable_intrusive_steal()
{
_M_pWorker_range = NULL;
_Wait_on_intrusive_steal();
}
bool _Is_helper_registered()
{
return (_M_pHelper_range != NULL);
}
bool _Is_done()
{
return (_M_completion_count != 0);
}
void _Set_done()
{
// Let the helper know that this class is done with work and flush the store buffer. This operation
// ensures that any buffered store to helper range in _Send_range is flushed and
// available in _Receive_range (so there will be no lost ranges).
_InterlockedExchange(&_M_completion_count, 1);
}
void _Set_tree_done()
{
// Make sure that **WE** know when our destructor hits that the entire tree is complete.
_M_completion_count = _Tree_Complete;
}
bool _Is_beacon_signaled()
{
return _M_beacon._Is_signaled();
}
bool _Verify_beacon_cancellation()
{
return _M_beacon._Confirm_cancel();
}
private:
// Spin wait for any intrusive steal that is in progress.
void _Wait_on_intrusive_steal()
{
// This code is used to synchronize with helper in case of worker cooperative blocking.
if (_M_stop_iterating != 0)
{
::Concurrency::details::_SpinWaitBackoffNone spinWait;
while (_M_stop_iterating != 0)
{
spinWait._SpinOnce();
}
}
}
void _NotifyCancel()
{
_M_beacon._Raise();
}
void _Propagate_cancel()
{
if (_M_pParent_worker != NULL)
{
_M_pParent_worker->_NotifyCancel();
}
}
// Constant indicating sub-tree completion
static const long _Tree_Complete = 2;
// Read in the loop
_Range<_Index_type> * volatile _M_pHelper_range;
// Read at the end of the loop
_Worker_proxy * _M_pParent_worker;
// Written rarely
::Concurrency::details::_Cancellation_beacon _M_beacon;
::Concurrency::details::_Context _M_context;
volatile long _M_completion_count;
// Written to in the loop
_Range<_Index_type> * volatile _M_pWorker_range;
volatile long _M_stop_iterating;
_Worker_proxy const & operator=(_Worker_proxy const&); // no assignment operator
};
// parallel_for -- Performs parallel iteration over a range of indices from _First to _Last,
// excluding _Last. The order in which each iteration is executed is unspecified and non-deterministic.
// Closure (binding) classes for invoking parallel_for and parallel_for_each, with chunks
// A dynamically rebalancing closure class used for packaging parallel_for or parallel_for_each for invocation in chunks.
// If some tasks finish earlier than others, helper tasks get executed which ensures further distribution of work.
template <typename _Random_iterator, typename _Index_type, typename _Function, typename _Partitioner, bool _Is_iterator>
class _Parallel_chunk_helper
{
public:
_Parallel_chunk_helper(_Index_type, const _Random_iterator& _First, _Index_type _First_iteration, _Index_type _Last_iteration, const _Index_type& _Step,
const _Function& _Func, const _Partitioner&, _Worker_proxy<_Index_type> * const _Parent_data = NULL) :
_M_first(_First), _M_first_iteration(_First_iteration), _M_last_iteration(_Last_iteration), _M_step(_Step), _M_function(_Func),
_M_parent_worker(_Parent_data)
{
// Empty constructor because members are already assigned
}
// Constructor overload that accepts a range
_Parallel_chunk_helper(const _Random_iterator& _First, const _Index_type& _Step, const _Function& _Func,
const _Range<_Index_type>& _Worker_range, _Worker_proxy<_Index_type> * const _Parent_data = NULL) :
_M_first(_First), _M_first_iteration(_Worker_range._M_current_iteration), _M_last_iteration(_Worker_range._M_last_iteration), _M_step(_Step), _M_function(_Func),
_M_parent_worker(_Parent_data)
{
// Empty constructor because members are already assigned
}
// The main helper function which iterates over the given collection and invokes user function on every iteration.
// Function is marked as const even though it does mutate some of its members (those are declared as mutable). This is done
// in order to easily communicate between a worker and a helper instance, without holding references to many local variables.
// However, this function does not mutate any state that is visible to anyone outside of this class, nor would that be
// possible due to the implicit copy of the functor that happens when a new task_handle is created.
void operator()() const
{
_Range<_Index_type> _Worker_range(_M_first_iteration, _M_last_iteration);
// This class has two modes: worker and helper. The originally split chunk is always a
// worker, while any subsequent class spawned from this class is in the helper
// mode, which is signified using a link to the worker class through _M_pOwning_worker
// handle. So, it will wait for work to be dished out by the working class while in helper mode.
if (_M_parent_worker != NULL && !_M_parent_worker->_Receive_range(&_Worker_range))
{
// If the worker class rejected the help, simply return
return;
}
// Keep the secondary, scaled, loop index for quick indexing into the data structure
_Index_type _Current_iteration = _Worker_range._M_current_iteration;
_Index_type _Scaled_index = _Current_iteration * _M_step;
// If there is only one iteration to be executed there is no need to initialize any
// helper classes (work is indivisible).
if (_Worker_range._Number_of_iterations() == 1)
{
// Execute one iteration
_Parallel_chunk_helper_invoke<_Random_iterator, _Index_type, _Function, _Is_iterator>::_Invoke(_M_first, _Scaled_index, _M_function);
return;
}
// If the execution reaches this point it means that this class now has a chunk of work
// that it needs to get done, so it has transitioned into the worker mode.
structured_task_group _Helper_group;
// Initialize fields that are needed in the helper
_Worker_proxy<_Index_type> _Worker(_M_parent_worker);
// Instantiate a helper class for this working class and put it on the work queue.
// If some thread is idle it will be able to steal the helper and help this class
// finish its work by stealing a piece of the work range.
task_handle<_Parallel_chunk_helper> _Helper_task(_Parallel_chunk_helper(_M_first, _M_step, _M_function, _Worker_range, &_Worker));
_Helper_group.run(_Helper_task);
::Concurrency::details::_MallocaListHolder<task_handle<_Parallel_chunk_helper>> _Holder;
// Normally, for a cancellation semantic in cooperation with the helper, we would run_and_wait the below code on the Helper_group. Unfortunately,
// the capture by reference of things which must be shared (_Worker, and so forth) will cause the loop below to add additional indirection
// instructions. The loop below *MUST* be as tight as possible with the defined semantics. Instead, we will manually notify our parent if the
// worker's destructor runs without hitting the bottom of our chunk. This is done through notification on the beacon.
for (_Index_type _I = _Current_iteration; _I < _Worker_range._M_last_iteration; (_I++, _Worker_range._M_current_iteration =_I, _Scaled_index += _M_step))
{
if (_Worker._Is_beacon_signaled())
{
// Either a parent task group is canceled or one of the other iterations
// threw an exception. Abort the remaining iterations
//
// Note that this could be a false positive that we must verify.
if (_Worker._Is_done() || _Worker._Verify_beacon_cancellation())
{
break;
}
}
if (_Worker._Is_helper_registered())
{
// The helper class (there can only be one) registered to help this class with the work.
// Thus, figure out if this class needs help and split the range among the two classes.
if (_Worker._Send_range(&_Worker_range))
{
// Construct every new instance of a helper class on the stack because it is beneficial to use
// a structured task group where the class itself is responsible for task handle's lifetime.
task_handle<_Parallel_chunk_helper> * _Helper_subtask = _Holder._AddRawMallocaNode(_malloca(_Holder._GetAllocationSize()));
new(_Helper_subtask) task_handle<_Parallel_chunk_helper>
(_Parallel_chunk_helper(_M_first, _M_step, _M_function, _Worker_range, &_Worker));
// If _Send_range returns true, that means that there is still some non-trivial
// work to be done, so this class will potentially need another helper.
_Helper_group.run(*_Helper_subtask);
}
}
// Allow intrusive stealing by the helper
_Worker._Enable_intrusive_steal(&_Worker_range);
// Execute one iteration: the element is at scaled index away from the first element.
_Parallel_chunk_helper_invoke<_Random_iterator, _Index_type, _Function, _Is_iterator>::_Invoke(_M_first, _Scaled_index, _M_function);
// Helper shall not steal a range after this call
_Worker._Disable_intrusive_steal();
}
// Indicate that the worker is done with its iterations.
_Worker._Set_done();
// Wait for all worker/helper iterations to finish
_Helper_group.wait();
// Make sure that we've signaled that the tree is complete. This is used to detect any exception out of either _Parallel_chunk_helper_invoke or
// _Helper_group.wait() above as a cancellation of the loop which must propagate upwards because we do not wrap the loop body in run_and_wait.
_Worker._Set_tree_done();
}
private:
const _Random_iterator& _M_first;
const _Index_type& _M_step;
const _Function& _M_function;
const _Index_type _M_first_iteration;
const _Index_type _M_last_iteration;
_Worker_proxy<_Index_type> * const _M_parent_worker;
_Parallel_chunk_helper const & operator=(_Parallel_chunk_helper const&); // no assignment operator
};
template <typename _Random_iterator, typename _Index_type, typename _Function, typename _Partitioner, bool _Is_iterator>
class _Parallel_fixed_chunk_helper
{
public:
_Parallel_fixed_chunk_helper(_Index_type, const _Random_iterator& _First, _Index_type _First_iteration,
_Index_type _Last_iteration, const _Index_type& _Step, const _Function& _Func, const _Partitioner&) :
_M_first(_First), _M_first_iteration(_First_iteration), _M_last_iteration(_Last_iteration), _M_step(_Step), _M_function(_Func)
{
// Empty constructor because members are already assigned
}
void operator()() const
{
// Keep the secondary, scaled, loop index for quick indexing into the data structure
_Index_type _Scaled_index = _M_first_iteration * _M_step;
for (_Index_type _I = _M_first_iteration; _I < _M_last_iteration; (_I++, _Scaled_index += _M_step))
{
// Execute one iteration: the element is at scaled index away from the first element.
_Parallel_chunk_helper_invoke<_Random_iterator, _Index_type, _Function, _Is_iterator>::_Invoke(_M_first, _Scaled_index, _M_function);
}
}
private:
const _Random_iterator& _M_first;
const _Index_type& _M_step;
const _Function& _M_function;
const _Index_type _M_first_iteration;
const _Index_type _M_last_iteration;
_Parallel_fixed_chunk_helper const & operator=(_Parallel_fixed_chunk_helper const&); // no assignment operator
};
template <typename _Random_iterator, typename _Index_type, typename _Function, bool _Is_iterator>
class _Parallel_localized_chunk_helper
{
public:
typedef _Parallel_fixed_chunk_helper<_Random_iterator, _Index_type, _Function, static_partitioner, _Is_iterator> _Base;
_Parallel_localized_chunk_helper(_Index_type _Chunk_index, const _Random_iterator& _First, _Index_type _First_iteration, _Index_type _Last_iteration, const _Index_type& _Step,
const _Function& _Func, affinity_partitioner& _Part) :
_M_fixed_helper(_Chunk_index, _First, _First_iteration, _Last_iteration, _Step, _Func, static_partitioner()),
_M_chunk_location(_Part._Get_chunk_location(static_cast<unsigned int>(_Chunk_index)))
{
// Empty constructor because members are already assigned
}
// Override the operator() in the base class. Note that this is not a virtual override.
void operator()() const
{
// Check here if location needs to be saved.
if (_M_chunk_location._Is_system())
{
_M_chunk_location = location::current();
}
_M_fixed_helper();
}
private:
location& _M_chunk_location;
_Base _M_fixed_helper;
_Parallel_localized_chunk_helper const & operator=(_Parallel_localized_chunk_helper const&); // no assignment operator
};
#pragma warning(pop)
template <typename _Worker_class, typename _Index_type, typename Partitioner>
void _Parallel_chunk_task_group_run(structured_task_group& _Task_group,
task_handle<_Worker_class>* _Chunk_helpers,
const Partitioner&,
_Index_type _I)
{
_Task_group.run(_Chunk_helpers[_I]);
}
template <typename _Worker_class, typename _Index_type>
void _Parallel_chunk_task_group_run(structured_task_group& _Task_group,
task_handle<_Worker_class>* _Chunk_helpers,
affinity_partitioner& _Part,
_Index_type _I)
{
_Task_group.run(_Chunk_helpers[_I], _Part._Get_chunk_location(static_cast<unsigned int>(_I)));
}
// Helper functions that implement parallel_for
template <typename _Worker_class, typename _Random_iterator, typename _Index_type, typename _Function, typename _Partitioner>
void _Parallel_chunk_impl(const _Random_iterator& _First, _Index_type _Range_arg, const _Index_type& _Step, const _Function& _Func, _Partitioner&& _Part)
{
_CONCRT_ASSERT(_Range_arg > 1);
_CONCRT_ASSERT(_Step > 0);
_Index_type _Num_iterations = (_Step == 1) ? _Range_arg : (((_Range_arg - 1) / _Step) + 1);
_CONCRT_ASSERT(_Num_iterations > 1);
_Index_type _Num_chunks = _Part._Get_num_chunks(_Num_iterations);
_CONCRT_ASSERT(_Num_chunks > 0);
// Allocate memory on the stack for task_handles to ensure everything is properly structured.
::Concurrency::details::_MallocaArrayHolder<task_handle<_Worker_class>> _Holder;
task_handle<_Worker_class> * _Chunk_helpers = _Holder._InitOnRawMalloca(_malloca(sizeof(task_handle<_Worker_class>) * static_cast<size_t>(_Num_chunks)));
structured_task_group _Task_group;
_Index_type _Iterations_per_chunk = _Num_iterations / _Num_chunks;
_Index_type _Remaining_iterations = _Num_iterations % _Num_chunks;
// If there are less iterations than desired chunks, set the chunk number
// to be the number of iterations.
if (_Iterations_per_chunk == 0)
{
_Num_chunks = _Remaining_iterations;
}
_Index_type _Work_size = 0;
_Index_type _Start_iteration = 0;
_Index_type _I;
// Split the available work in chunks
for (_I = 0; _I < _Num_chunks - 1; _I++)
{
if (_Remaining_iterations > 0)
{
// Iterations are not divided evenly, so add 1 remainder iteration each time
_Work_size = _Iterations_per_chunk + 1;
_Remaining_iterations--;
}
else
{
_Work_size = _Iterations_per_chunk;
}
// New up a task_handle "in-place", in the array preallocated on the stack
new(&_Chunk_helpers[_I]) task_handle<_Worker_class>(_Worker_class(_I, _First, _Start_iteration, _Start_iteration + _Work_size, _Step, _Func, std::forward<_Partitioner>(_Part)));
_Holder._IncrementConstructedElemsCount();
// Run each of the chunk tasks in parallel
_Parallel_chunk_task_group_run(_Task_group, _Chunk_helpers, std::forward<_Partitioner>(_Part), _I);
// Prepare for the next iteration
_Start_iteration += _Work_size;
}
// Because this is the last iteration, then work size might be different
_CONCRT_ASSERT((_Remaining_iterations == 0) || ((_Iterations_per_chunk == 0) && (_Remaining_iterations == 1)));
_Work_size = _Num_iterations - _Start_iteration;
// New up a task_handle "in-place", in the array preallocated on the stack
new(&_Chunk_helpers[_I]) task_handle<_Worker_class>(_Worker_class(_I, _First, _Start_iteration, _Start_iteration + _Work_size, _Step, _Func, std::forward<_Partitioner>(_Part)));
_Holder._IncrementConstructedElemsCount();
_Task_group.run_and_wait(_Chunk_helpers[_I]);
}
template <typename _Worker_class, typename _Random_iterator, typename _Index_type, typename _Function>
void _Parallel_chunk_impl(const _Random_iterator& _First, _Index_type _Range_arg, const _Index_type& _Step, const _Function& _Func)
{
_Parallel_chunk_impl<_Worker_class>(_First, _Range_arg, _Step, _Func, auto_partitioner());
}
// Helper for the parallel for API with the default dynamic partitioner which implements range-stealing to balance load.
template <typename _Index_type, typename _Diff_type, typename _Function>
void _Parallel_for_partitioned_impl(_Index_type _First, _Diff_type _Range_arg, _Diff_type _Step, const _Function& _Func, const auto_partitioner& _Part)
{
typedef _Parallel_chunk_helper<_Index_type, _Diff_type, _Function, auto_partitioner, false> _Worker_class;
_Parallel_chunk_impl<_Worker_class>(_First, _Range_arg, _Step, _Func, _Part);
}
// Helper for the parallel_for API with a static partitioner - creates a fixed number of chunks up front with no range-stealing enabled.
template <typename _Index_type, typename _Diff_type, typename _Function>
void _Parallel_for_partitioned_impl(_Index_type _First, _Diff_type _Range_arg, _Diff_type _Step, const _Function& _Func, const static_partitioner& _Part)
{
typedef _Parallel_fixed_chunk_helper<_Index_type, _Diff_type, _Function, static_partitioner, false> _Worker_class;
_Parallel_chunk_impl<_Worker_class>(_First, _Range_arg, _Step, _Func, _Part);
}
// Helper for the parallel_for API with a simple partitioner - creates a fixed number of chunks up front with no range-stealing enabled.
template <typename _Index_type, typename _Diff_type, typename _Function>
void _Parallel_for_partitioned_impl(_Index_type _First, _Diff_type _Range_arg, _Diff_type _Step, const _Function& _Func, const simple_partitioner& _Part)
{
typedef _Parallel_fixed_chunk_helper<_Index_type, _Diff_type, _Function, simple_partitioner, false> _Worker_class;
_Parallel_chunk_impl<_Worker_class>(_First, _Range_arg, _Step, _Func, _Part);
}
// Helper for the parallel_for API with an affinity partitioner - creates a fixed number of chunks up front with no range-stealing enabled. subsequent
// calls to parallel_for with the same affinity partitioner (pass in as a non-const reference) are scheduled to the same location they previously ran on
template <typename _Index_type, typename _Diff_type, typename _Function>
void _Parallel_for_partitioned_impl(_Index_type _First, _Diff_type _Range_arg, _Diff_type _Step, const _Function& _Func, affinity_partitioner& _Part)
{
typedef _Parallel_localized_chunk_helper<_Index_type, _Diff_type, _Function, false> _Worker_class;
_Parallel_chunk_impl<_Worker_class>(_First, _Range_arg, _Step, _Func, _Part);
}
template <typename _Index_type, typename _Function, typename _Partitioner>
void _Parallel_for_impl(_Index_type _First, _Index_type _Last, _Index_type _Step, const _Function& _Func, _Partitioner&& _Part)
{
// The step argument must be 1 or greater; otherwise it is an invalid argument
if (_Step < 1)
{
throw std::invalid_argument("_Step");
}
// If there are no elements in this range we just return
if (_First >= _Last)
{
return;
}
// Compute the difference type based on the arguments and avoid signed overflow for int, long, and long long
typedef typename std::tr1::conditional<std::tr1::is_same<_Index_type, int>::value, unsigned int,
typename std::tr1::conditional<std::tr1::is_same<_Index_type, long>::value, unsigned long,
typename std::tr1::conditional<std::tr1::is_same<_Index_type, long long>::value, unsigned long long, decltype(_Last - _First)
>::type
>::type
>::type _Diff_type;
_Diff_type _Range_size = _Diff_type(_Last) - _Diff_type(_First);
_Diff_type _Diff_step = _Step;
if (_Range_size <= _Diff_step)
{
_Func(_First);
}
else
{
_Parallel_for_partitioned_impl<_Index_type, _Diff_type, _Function>(_First, _Range_size, _Step, _Func, std::forward<_Partitioner>(_Part));
}
}
template <typename _Index_type, typename _Function>
void _Parallel_for_impl(_Index_type _First, _Index_type _Last, _Index_type _Step, const _Function& _Func)
{
_Parallel_for_impl(_First, _Last, _Step, _Func, auto_partitioner());
}
/// <summary>
/// <c>parallel_for</c> iterates over a range of indices and executes a user-supplied function at each iteration, in parallel.
/// </summary>
/// <typeparam name="_Index_type">
/// The type of the index being used for the iteration.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the function that will be executed at each iteration.
/// </typeparam>
/// <typeparam name="_Partitioner">
/// The type of the partitioner that is used to partition the supplied range.
/// </typeparam>
/// <param name="_First">
/// The first index to be included in the iteration.
/// </param>
/// <param name="_Last">
/// The index one past the last index to be included in the iteration.
/// </param>
/// <param name="_Step">
/// The value by which to step when iterating from <paramref name="_First"/> to <paramref name="_Last"/>. The step must be positive.
/// <see cref="invalid_argument Class">invalid_argument</see> is thrown if the step is less than 1.
/// </param>
/// <param name="_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
/// <c>void operator()(</c><typeparamref name="_Index_type"/><c>)</c>.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <remarks>
/// For more information, see <see cref="Parallel Algorithms"/>.
/// </remarks>
/**/
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)
{
_Trace_ppl_function(PPLParallelForEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
_Parallel_for_impl(_First, _Last, _Step, _Func, std::forward<_Partitioner>(_Part));
_Trace_ppl_function(PPLParallelForEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
/// <summary>
/// <c>parallel_for</c> iterates over a range of indices and executes a user-supplied function at each iteration, in parallel.
/// </summary>
/// <typeparam name="_Index_type">
/// The type of the index being used for the iteration. <paramref name="_Index_type"/> must be an integral type.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the function that will be executed at each iteration.
/// </typeparam>
/// <param name="_First">
/// The first index to be included in the iteration.
/// </param>
/// <param name="_Last">
/// The index one past the last index to be included in the iteration.
/// </param>
/// <param name="_Step">
/// The value by which to step when iterating from <paramref name="_First"/> to <paramref name="_Last"/>. The step must be positive.
/// <see cref="invalid_argument Class">invalid_argument</see> is thrown if the step is less than 1.
/// </param>
/// <param name="_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
/// <c>void operator()(</c><typeparamref name="_Index_type"/><c>)</c>.
/// </param>
/// <remarks>
/// For more information, see <see cref="Parallel Algorithms"/>.
/// </remarks>
/**/
template <typename _Index_type, typename _Function>
void parallel_for(_Index_type _First, _Index_type _Last, _Index_type _Step, const _Function& _Func)
{
parallel_for(_First, _Last, _Step, _Func, auto_partitioner());
}
/// <summary>
/// <c>parallel_for</c> iterates over a range of indices and executes a user-supplied function at each iteration, in parallel.
/// </summary>
/// <typeparam name="_Index_type">
/// The type of the index being used for the iteration.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the function that will be executed at each iteration.
/// </typeparam>
/// <param name="_First">
/// The first index to be included in the iteration.
/// </param>
/// <param name="_Last">
/// The index one past the last index to be included in the iteration.
/// </param>
/// <param name="_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
/// <c>void operator()(</c><typeparamref name="_Index_type"/><c>)</c>.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <remarks>
/// For more information, see <see cref="Parallel Algorithms"/>.
/// </remarks>
/**/
template <typename _Index_type, typename _Function>
void parallel_for(_Index_type _First, _Index_type _Last, const _Function& _Func, const auto_partitioner& _Part = auto_partitioner())
{
parallel_for(_First, _Last, _Index_type(1), _Func, _Part);
}
/// <summary>
/// <c>parallel_for</c> iterates over a range of indices and executes a user-supplied function at each iteration, in parallel.
/// </summary>
/// <typeparam name="_Index_type">
/// The type of the index being used for the iteration.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the function that will be executed at each iteration.
/// </typeparam>
/// <param name="_First">
/// The first index to be included in the iteration.
/// </param>
/// <param name="_Last">
/// The index one past the last index to be included in the iteration.
/// </param>
/// <param name="_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
/// <c>void operator()(</c><typeparamref name="_Index_type"/><c>)</c>.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <remarks>
/// For more information, see <see cref="Parallel Algorithms"/>.
/// </remarks>
/**/
template <typename _Index_type, typename _Function>
void parallel_for(_Index_type _First, _Index_type _Last, const _Function& _Func, const static_partitioner& _Part)
{
parallel_for(_First, _Last, _Index_type(1), _Func, _Part);
}
/// <summary>
/// <c>parallel_for</c> iterates over a range of indices and executes a user-supplied function at each iteration, in parallel.
/// </summary>
/// <typeparam name="_Index_type">
/// The type of the index being used for the iteration.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the function that will be executed at each iteration.
/// </typeparam>
/// <param name="_First">
/// The first index to be included in the iteration.
/// </param>
/// <param name="_Last">
/// The index one past the last index to be included in the iteration.
/// </param>
/// <param name="_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
/// <c>void operator()(</c><typeparamref name="_Index_type"/><c>)</c>.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <remarks>
/// For more information, see <see cref="Parallel Algorithms"/>.
/// </remarks>
/**/
template <typename _Index_type, typename _Function>
void parallel_for(_Index_type _First, _Index_type _Last, const _Function& _Func, const simple_partitioner& _Part)
{
parallel_for(_First, _Last, _Index_type(1), _Func, _Part);
}
/// <summary>
/// <c>parallel_for</c> iterates over a range of indices and executes a user-supplied function at each iteration, in parallel.
/// </summary>
/// <typeparam name="_Index_type">
/// The type of the index being used for the iteration.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the function that will be executed at each iteration.
/// </typeparam>
/// <param name="_First">
/// The first index to be included in the iteration.
/// </param>
/// <param name="_Last">
/// The index one past the last index to be included in the iteration.
/// </param>
/// <param name="_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
/// <c>void operator()(</c><typeparamref name="_Index_type"/><c>)</c>.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <remarks>
/// For more information, see <see cref="Parallel Algorithms"/>.
/// </remarks>
/**/
template <typename _Index_type, typename _Function>
void parallel_for(_Index_type _First, _Index_type _Last, const _Function& _Func, affinity_partitioner& _Part)
{
parallel_for(_First, _Last, _Index_type(1), _Func, _Part);
}
// parallel_for_each -- This function will iterate over all elements in the iterator's range.
// Closure (binding) classes for invoking parallel_for_each recursively
// A closure class used for packaging chunk of elements in parallel_for_each for parallel invocation
// Forward iterator for_each using unstructured task group
// Disable C4180: qualifier applied to function type has no meaning; ignored
// Warning fires for passing Foo function pointer to parallel_for instead of &Foo.
#pragma warning(push)
#pragma warning(disable: 4180)
template <typename _Forward_iterator, typename _Function, unsigned int _Chunk_size>
class _Parallel_for_each_helper
{
public:
typedef typename std::iterator_traits<_Forward_iterator>::value_type _Value_type;
static const unsigned int _Size = _Chunk_size;
_Parallel_for_each_helper(_Forward_iterator& _First, const _Forward_iterator& _Last, const _Function& _Func) :
_M_function(_Func), _M_len(0)
{
static_assert(std::is_lvalue_reference<decltype(*_First)>::value, "lvalue required for forward iterator operator *");
// Add a batch of work items to this functor's array
for (unsigned int _Index=0; (_Index < _Size) && (_First != _Last); _Index++)
{
_M_element[_M_len++] = &(*_First++);
}
}
void operator()() const
{
// Invoke parallel_for on the batched up array of elements
_Parallel_for_impl(0U, _M_len, 1U,
[this] (unsigned int _Index)
{
_M_function(*(_M_element[_Index]));
}
);
}
private:
const _Function& _M_function;
typename std::iterator_traits<_Forward_iterator>::pointer _M_element[_Size];
unsigned int _M_len;
_Parallel_for_each_helper const & operator=(_Parallel_for_each_helper const&); // no assignment operator
};
#pragma warning(pop)
// Helper functions that implement parallel_for_each
template <typename _Forward_iterator, typename _Function>
void _Parallel_for_each_chunk(_Forward_iterator& _First, const _Forward_iterator& _Last, const _Function& _Func, task_group& _Task_group)
{
// The chunk size selection depends more on the internal implementation of parallel_for than
// on the actual input. Also, it does not have to be dynamically computed, but it helps
// parallel_for if it is a power of 2 (easy to divide).
const unsigned int _Chunk_size = 1024;
// This functor will be copied on the heap and will execute the chunk in parallel
_Parallel_for_each_helper<_Forward_iterator, _Function, _Chunk_size> _Functor(_First, _Last, _Func);
// Because this is an unstructured task group, running the task will make a copy of the necessary data
// on the heap, ensuring that it is available at the time of execution.
_Task_group.run(_Functor);
}
template <typename _Forward_iterator, typename _Function>
void _Parallel_for_each_forward_impl(_Forward_iterator& _First, const _Forward_iterator& _Last, const _Function& _Func, task_group& _Task_group)
{
_Parallel_for_each_chunk(_First, _Last, _Func, _Task_group);
// If there is a tail, push the tail
if (_First != _Last)
{
_Task_group.run(
[&_First, &_Last, &_Func, &_Task_group]
{
Concurrency::_Parallel_for_each_forward_impl(_First, _Last, _Func, _Task_group);
}
);
}
}
template <typename _Forward_iterator, typename _Function>
void _Parallel_for_each_impl(_Forward_iterator _First, const _Forward_iterator& _Last, const _Function& _Func, const auto_partitioner&, std::forward_iterator_tag)
{
// Because this is a forward iterator, it is difficult to validate that _First comes before _Last, so
// it is up to the user to provide valid range.
if (_First != _Last)
{
task_group _Task_group;
_Parallel_for_each_forward_impl(_First, _Last, _Func, _Task_group);
_Task_group.wait();
}
}
template <typename _Random_iterator, typename _Index_type, typename _Function>
void _Parallel_for_each_partitioned_impl(const _Random_iterator& _First, _Index_type _Range_arg, _Index_type _Step, const _Function& _Func, const auto_partitioner& _Part)
{
typedef _Parallel_chunk_helper<_Random_iterator, _Index_type, _Function, auto_partitioner, true> _Worker_class;
// Use the same function that schedules work for parallel for
_Parallel_chunk_impl<_Worker_class>(_First, _Range_arg, _Step, _Func, _Part);
}
template <typename _Random_iterator, typename _Index_type, typename _Function>
void _Parallel_for_each_partitioned_impl(const _Random_iterator& _First, _Index_type _Range_arg, _Index_type _Step, const _Function& _Func, const static_partitioner& _Part)
{
typedef _Parallel_fixed_chunk_helper<_Random_iterator, _Index_type, _Function, static_partitioner, true> _Worker_class;
// Use the same function that schedules work for parallel for
_Parallel_chunk_impl<_Worker_class>(_First, _Range_arg, _Step, _Func, _Part);
}
template <typename _Random_iterator, typename _Index_type, typename _Function>
void _Parallel_for_each_partitioned_impl(const _Random_iterator& _First, _Index_type _Range_arg, _Index_type _Step, const _Function& _Func, const simple_partitioner& _Part)
{
typedef _Parallel_fixed_chunk_helper<_Random_iterator, _Index_type, _Function, simple_partitioner, true> _Worker_class;
// Use the same function that schedules work for parallel for
_Parallel_chunk_impl<_Worker_class>(_First, _Range_arg, _Step, _Func, _Part);
}
template <typename _Random_iterator, typename _Index_type, typename _Function>
void _Parallel_for_each_partitioned_impl(const _Random_iterator& _First, _Index_type _Range_arg, _Index_type _Step, const _Function& _Func, affinity_partitioner& _Part)
{
typedef _Parallel_localized_chunk_helper<_Random_iterator, _Index_type, _Function, true> _Worker_class;
// Use the same function that schedules work for parallel for
_Parallel_chunk_impl<_Worker_class>(_First, _Range_arg, _Step, _Func, _Part);
}
template <typename _Random_iterator, typename _Function, typename _Partitioner>
void _Parallel_for_each_impl(const _Random_iterator& _First, const _Random_iterator& _Last, const _Function& _Func, _Partitioner&& _Part, std::random_access_iterator_tag)
{
typedef typename std::iterator_traits<_Random_iterator>::difference_type _Index_type;
// Exit early if there is nothing in the collection
if (_First >= _Last)
{
return;
}
_Index_type _Range_size = _Last - _First;
if (_Range_size == 1)
{
_Func(*_First);
}
else
{
_Index_type _Step = 1;
_Parallel_for_each_partitioned_impl(_First, _Range_size, _Step, _Func, std::forward<_Partitioner>(_Part));
}
}
/// <summary>
/// <c>parallel_for_each</c> applies a specified function to each element within a range, in parallel. It is semantically
/// equivalent to the <c>for_each</c> function in the <c>std</c> namespace, except that iteration over the elements is
/// performed in parallel, and the order of iteration is unspecified. The argument <paramref name="_Func"/> must support
/// a function call operator of the form <c>operator()(T)</c> where the parameter <paramref name="T"/> is the item type
/// of the container being iterated over.
/// </summary>
/// <typeparam name="_Iterator">
/// The type of the iterator being used to iterate over the container.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the function that will be applied to each element within the range.
/// </typeparam>
/// <param name="_First">
/// An iterator addressing the position of the first element to be included in parallel iteration.
/// </param>
/// <param name="_Last">
/// An iterator addressing the position one past the final element to be included in parallel iteration.
/// </param>
/// <param name="_Func">
/// A user-defined function object that is applied to each element in the range.
/// </param>
/// <remarks>
/// <see ref="auto_partitioner Class">auto_partitioner</see> will be used for the overload without an explicit partitioner.
/// <para>For iterators that do not support random access, only <see ref="auto_partitioner Class">auto_partitioner</see> is supported.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
template <typename _Iterator, typename _Function>
void parallel_for_each(_Iterator _First, _Iterator _Last, const _Function& _Func)
{
parallel_for_each(_First, _Last, _Func, auto_partitioner());
}
/// <summary>
/// <c>parallel_for_each</c> applies a specified function to each element within a range, in parallel. It is semantically
/// equivalent to the <c>for_each</c> function in the <c>std</c> namespace, except that iteration over the elements is
/// performed in parallel, and the order of iteration is unspecified. The argument <paramref name="_Func"/> must support
/// a function call operator of the form <c>operator()(T)</c> where the parameter <paramref name="T"/> is the item type
/// of the container being iterated over.
/// </summary>
/// <typeparam name="_Iterator">
/// The type of the iterator being used to iterate over the container.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the function that will be applied to each element within the range.
/// </typeparam>
/// <param name="_First">
/// An iterator addressing the position of the first element to be included in parallel iteration.
/// </param>
/// <param name="_Last">
/// An iterator addressing the position one past the final element to be included in parallel iteration.
/// </param>
/// <param name="_Func">
/// A user-defined function object that is applied to each element in the range.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <remarks>
/// <see ref="auto_partitioner Class">auto_partitioner</see> will be used for the overload without an explicit partitioner.
/// <para>For iterators that do not support random access, only <see ref="auto_partitioner Class">auto_partitioner</see> is supported.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
template <typename _Iterator, typename _Function, typename _Partitioner>
void parallel_for_each(_Iterator _First, _Iterator _Last, const _Function& _Func, _Partitioner&& _Part)
{
_Trace_ppl_function(PPLParallelForeachEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_START);
_Parallel_for_each_impl(_First, _Last, _Func, std::forward<_Partitioner>(_Part), std::_Iter_cat(_First));
_Trace_ppl_function(PPLParallelForeachEventGuid, _TRACE_LEVEL_INFORMATION, CONCRT_EVENT_END);
}
// Disable C4180: qualifier applied to function type has no meaning; ignored
// Warning fires for passing Foo function pointer to parallel_for instead of &Foo.
#pragma warning(push)
#pragma warning(disable: 4180)
/// <summary>
/// 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. <c>parallel_reduce</c> is semantically similar to
/// <c>std::accumulate</c>, except that it requires the binary operation to be associative, and requires an identity value instead of an initial value.
/// </summary>
/// <typeparam name="_Forward_iterator">
/// The iterator type of input range.
/// </typeparam>
/// <param name="_Begin">
/// An input iterator addressing the first element in the range to be reduced.
/// </param>
/// <param name="_End">
/// An input iterator addressing the element that is one position beyond the final element in the range to be reduced.
/// </param>
/// <param name="_Identity">
/// The identity value <paramref name="_Identity"/> is of the same type as the result type of the reduction and also the <c>value_type</c> 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 <c>value_type</c> of the iterator. It must have an appropriate value such that the range reduction operator <paramref name="_Range_fun"/>,
/// when applied to a range of a single element of type <c>value_type</c> and the identity value, behaves like a type cast of the value from type
/// <c>value_type</c> to the identity type.
/// </param>
/// <returns>
/// The result of the reduction.
/// </returns>
/// <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.
/// <para>The first overload requires that the iterator's <c>value_type</c>, <c>T</c>, be the same as the identity value type as well as the reduction
/// result type. The element type T must provide the operator <c>T T::operator + (T)</c> to reduce elements in each chunk. The same operator is
/// used in the second phase as well.</para>
/// <para>The second overload also requires that the iterator's <c>value_type</c> be the same as the identity value type as well as the reduction
/// result type. The supplied binary operator <paramref name="_Sym_fun"/> is used in both reduction phases, with the identity value as the initial
/// value for the first phase.</para>
/// <para>For the third overload, the identity value type must be the same as the reduction result type, but the iterator's <c>value_type</c> may be
/// different from both. The range reduction function <paramref name="_Range_fun"/> is used in the first phase with the identity
/// value as the initial value, and the binary function <paramref name="_Sym_reduce_fun"/> is applied to sub results in the second phase.</para>
/// </remarks>
/**/
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)
{
return parallel_reduce(_Begin, _End, _Identity, std::plus<typename std::iterator_traits<_Forward_iterator>::value_type>());
}
/// <summary>
/// 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. <c>parallel_reduce</c> is semantically similar to
/// <c>std::accumulate</c>, except that it requires the binary operation to be associative, and requires an identity value instead of an initial value.
/// </summary>
/// <typeparam name="_Forward_iterator">
/// The iterator type of input range.
/// </typeparam>
/// <typeparam name="_Sym_reduce_fun">
/// The type of the symmetric reduction function. This must be a function type with signature <c>_Reduce_type _Sym_fun(_Reduce_type, _Reduce_type)</c>, 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 <c>_Range_reduce_fun</c>.
/// </typeparam>
/// <param name="_Begin">
/// An input iterator addressing the first element in the range to be reduced.
/// </param>
/// <param name="_End">
/// An input iterator addressing the element that is one position beyond the final element in the range to be reduced.
/// </param>
/// <param name="_Identity">
/// The identity value <paramref name="_Identity"/> is of the same type as the result type of the reduction and also the <c>value_type</c> 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 <c>value_type</c> of the iterator. It must have an appropriate value such that the range reduction operator <paramref name="_Range_fun"/>,
/// when applied to a range of a single element of type <c>value_type</c> and the identity value, behaves like a type cast of the value from type
/// <c>value_type</c> to the identity type.
/// </param>
/// <param name="_Sym_fun">
/// The symmetric function that will be used in the second of the reduction. Refer to Remarks for more information.
/// </param>
/// <returns>
/// The result of the reduction.
/// </returns>
/// <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.
/// <para>The first overload requires that the iterator's <c>value_type</c>, <c>T</c>, be the same as the identity value type as well as the reduction
/// result type. The element type T must provide the operator <c>T T::operator + (T)</c> to reduce elements in each chunk. The same operator is
/// used in the second phase as well.</para>
/// <para>The second overload also requires that the iterator's <c>value_type</c> be the same as the identity value type as well as the reduction
/// result type. The supplied binary operator <paramref name="_Sym_fun"/> is used in both reduction phases, with the identity value as the initial
/// value for the first phase.</para>
/// <para>For the third overload, the identity value type must be the same as the reduction result type, but the iterator's <c>value_type</c> may be
/// different from both. The range reduction function <paramref name="_Range_fun"/> is used in the first phase with the identity
/// value as the initial value, and the binary function <paramref name="_Sym_reduce_fun"/> is applied to sub results in the second phase.</para>
/// </remarks>
/**/
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)
{
typedef typename std::remove_cv<typename std::iterator_traits<_Forward_iterator>::value_type>::type _Reduce_type;
return parallel_reduce(_Begin, _End, _Identity,
[_Sym_fun](_Forward_iterator _Begin, _Forward_iterator _End, _Reduce_type _Init)->_Reduce_type
{
while (_Begin != _End)
{
_Init = _Sym_fun(_Init, *_Begin++);
}
return _Init;
},
_Sym_fun);
}
template <typename _Reduce_type, typename _Sub_function, typename _Combinable_type>
struct _Reduce_functor_helper;
template<typename _Ty, typename _Sym_fun>
class _Order_combinable;
/// <summary>
/// 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. <c>parallel_reduce</c> is semantically similar to
/// <c>std::accumulate</c>, except that it requires the binary operation to be associative, and requires an identity value instead of an initial value.
/// </summary>
/// <typeparam name="_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.
/// </typeparam>
/// <typeparam name="_Forward_iterator">
/// The iterator type of input range.
/// </typeparam>
/// <typeparam name="_Range_reduce_fun">
/// The type of the range reduction function. This must be a function type with signature <c>_Reduce_type _Range_fun(_Forward_iterator, _Forward_iterator, _Reduce_type)</c>,
/// _Reduce_type is the same as the identity type and the result type of the reduction.
/// </typeparam>
/// <typeparam name="_Sym_reduce_fun">
/// The type of the symmetric reduction function. This must be a function type with signature <c>_Reduce_type _Sym_fun(_Reduce_type, _Reduce_type)</c>, 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 <c>_Range_reduce_fun</c>.
/// </typeparam>
/// <param name="_Begin">
/// An input iterator addressing the first element in the range to be reduced.
/// </param>
/// <param name="_End">
/// An input iterator addressing the element that is one position beyond the final element in the range to be reduced.
/// </param>
/// <param name="_Identity">
/// The identity value <paramref name="_Identity"/> is of the same type as the result type of the reduction and also the <c>value_type</c> 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 <c>value_type</c> of the iterator. It must have an appropriate value such that the range reduction operator <paramref name="_Range_fun"/>,
/// when applied to a range of a single element of type <c>value_type</c> and the identity value, behaves like a type cast of the value from type
/// <c>value_type</c> to the identity type.
/// </param>
/// <param name="_Range_fun">
/// The function that will be used in the first phase of the reduction. Refer to Remarks for more information.
/// </param>
/// <param name="_Sym_fun">
/// The symmetric function that will be used in the second of the reduction. Refer to Remarks for more information.
/// </param>
/// <returns>
/// The result of the reduction.
/// </returns>
/// <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.
/// <para>The first overload requires that the iterator's <c>value_type</c>, <c>T</c>, be the same as the identity value type as well as the reduction
/// result type. The element type T must provide the operator <c>T T::operator + (T)</c> to reduce elements in each chunk. The same operator is
/// used in the second phase as well.</para>
/// <para>The second overload also requires that the iterator's <c>value_type</c> be the same as the identity value type as well as the reduction
/// result type. The supplied binary operator <paramref name="_Sym_fun"/> is used in both reduction phases, with the identity value as the initial
/// value for the first phase.</para>
/// <para>For the third overload, the identity value type must be the same as the reduction result type, but the iterator's <c>value_type</c> may be
/// different from both. The range reduction function <paramref name="_Range_fun"/> is used in the first phase with the identity
/// value as the initial value, and the binary function <paramref name="_Sym_reduce_fun"/> is applied to sub results in the second phase.</para>
/// </remarks>
/**/
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)
{
typedef typename std::iterator_traits<_Forward_iterator>::value_type _Value_type;
static_assert(!std::tr1::is_same<typename std::iterator_traits<_Forward_iterator>::iterator_category, std::input_iterator_tag>::value
&& !std::tr1::is_same<typename std::iterator_traits<_Forward_iterator>::iterator_category, std::output_iterator_tag>::value,
"iterator can not be input_iterator or output_iterator.");
return _Parallel_reduce_impl(_Begin, _End,
_Reduce_functor_helper<_Reduce_type, _Range_reduce_fun,
_Order_combinable<_Reduce_type, _Sym_reduce_fun>>(_Identity, _Range_fun, _Order_combinable<_Reduce_type, _Sym_reduce_fun>(_Sym_fun)),
typename std::iterator_traits<_Forward_iterator>::iterator_category());
}
// Ordered serial combinable object
template<typename _Ty, typename _Sym_fun>
class _Order_combinable
{
public:
// Only write once, limited contention will be caused
struct _Bucket
{
// Allocate enough space in the Bucket to hold a value
char _Value[(sizeof(_Ty) / sizeof(char))];
_Bucket * _Next;
_Bucket(_Bucket *_N)
{
_Next = _N;
}
void _Insert(_Bucket *_Item)
{
// No need to lock, only one thread will insert
_Item->_Next = _Next;
_Next = _Item;
}
// Construct value in bucket
void _Put(const _Ty &_Cur)
{
new(reinterpret_cast<_Ty *>(&_Value)) _Ty(_Cur);
}
};
private:
const _Sym_fun &_M_fun;
size_t _M_number;
_Bucket *_M_root;
_Order_combinable &operator =(const _Order_combinable &other);
public:
_Bucket *_Construct(_Bucket *_Par = 0)
{
_Bucket * _Ret = static_cast<_Bucket *>(Concurrency::Alloc(sizeof(_Bucket)));
return new(_Ret)_Bucket(_Par);
}
_Order_combinable(const _Sym_fun &_Fun): _M_fun(_Fun)
{
_M_root = 0;
_M_number = 0;
}
~_Order_combinable()
{
while (_M_root)
{
_Bucket *_Cur = _M_root;
_M_root = _M_root->_Next;
reinterpret_cast<_Ty &>(_Cur->_Value).~_Ty();
Concurrency::Free(_Cur);
}
}
// Serially combine and release the list, return result
_Ty _Serial_combine_release()
{
_Ty _Ret(reinterpret_cast<_Ty &>(_M_root->_Value));
_Bucket *_Cur = _M_root;
_M_root = _M_root->_Next;
while (_M_root)
{
reinterpret_cast<_Ty &>(_Cur->_Value).~_Ty();
Concurrency::Free(_Cur);
_Cur = _M_root;
_Ret = _M_fun(reinterpret_cast <_Ty &> (_Cur->_Value), _Ret);
_M_root = _M_root->_Next;
}
reinterpret_cast<_Ty &>(_Cur->_Value).~_Ty();
Concurrency::Free(_Cur);
return _Ret;
}
// allocate a bucket and push back to the list
_Bucket *_Unsafe_push_back()
{
return _M_root = _Construct(_M_root);
}
};
// Implementation for the parallel reduce
template <typename _Forward_iterator, typename _Function>
typename _Function::_Reduce_type _Parallel_reduce_impl(_Forward_iterator _First, const _Forward_iterator& _Last, const _Function& _Func,
std::forward_iterator_tag)
{
// Because this is a forward iterator, it is difficult to validate that _First comes before _Last, so
// it is up to the user to provide valid range.
if (_First != _Last)
{
task_group _Task_group;
_Parallel_reduce_forward_executor(_First, _Last, _Func, _Task_group);
_Task_group.wait();
return _Func._Combinable._Serial_combine_release();
}
else
{
return _Func._Identity_value;
}
}
template<typename _Forward_iterator, typename _Functor>
class _Parallel_reduce_fixed_worker;
template <typename _Worker, typename _Random_iterator, typename _Function>
void _Parallel_reduce_random_executor(_Random_iterator _Begin, _Random_iterator _End, const _Function& _Fun);
template <typename _Random_iterator, typename _Function>
typename _Function::_Reduce_type _Parallel_reduce_impl(_Random_iterator _First, _Random_iterator _Last, const _Function& _Func,
std::random_access_iterator_tag)
{
typedef _Parallel_reduce_fixed_worker<_Random_iterator, _Function> _Worker_class;
// Special case for 0, 1 element
if (_First >= _Last)
{
return _Func._Identity_value;
}
// Directly compute if size is too small
else if (_Last - _First <= 1)
{
_Worker_class(_First, _Last, _Func)();
return _Func._Combinable._Serial_combine_release();
}
else
{
// Use fixed ordered chunk partition to schedule works
_Parallel_reduce_random_executor<_Worker_class>(_First, _Last, _Func);
return _Func._Combinable._Serial_combine_release();
}
}
// Helper function assemble all functors
template <typename _Reduce_type, typename _Sub_function, typename _Combinable_type>
struct _Reduce_functor_helper
{
const _Sub_function &_Sub_fun;
const _Reduce_type &_Identity_value;
mutable _Combinable_type &_Combinable;
typedef _Reduce_type _Reduce_type;
typedef typename _Combinable_type::_Bucket Bucket_type;
_Reduce_functor_helper(const _Reduce_type &_Identity, const _Sub_function &_Sub_fun, _Combinable_type &&comb):
_Sub_fun(_Sub_fun), _Combinable(comb), _Identity_value(_Identity)
{
}
private:
_Reduce_functor_helper &operator =(const _Reduce_functor_helper &other);
};
// All the code below is the worker without range stealing
template<typename _Forward_iterator, typename _Functor>
class _Parallel_reduce_fixed_worker
{
public:
// The bucket allocation order will depend on the worker construction order
_Parallel_reduce_fixed_worker(_Forward_iterator _Begin, _Forward_iterator _End, const _Functor &_Fun):
_M_begin(_Begin), _M_end(_End), _M_fun(_Fun), _M_bucket(_M_fun._Combinable._Unsafe_push_back())
{
}
void operator ()() const
{
_M_bucket->_Put(_M_fun._Sub_fun(_M_begin, _M_end, _M_fun._Identity_value));
}
private:
const _Functor &_M_fun;
const _Forward_iterator _M_begin, _M_end;
typename _Functor::Bucket_type * const _M_bucket;
_Parallel_reduce_fixed_worker &operator =(const _Parallel_reduce_fixed_worker &other);
};
// the parallel worker executor for fixed iterator
// it will divide fixed number of chunks
// almost same as fixed parallel for, except keep the chunk dividing order
template <typename _Worker, typename _Random_iterator, typename _Function>
void _Parallel_reduce_random_executor(_Random_iterator _Begin, _Random_iterator _End, const _Function& _Fun)
{
size_t _Cpu_num = static_cast<size_t>(Concurrency::details::_CurrentScheduler::_GetNumberOfVirtualProcessors()), _Size = _End - _Begin;
structured_task_group _Tg;
Concurrency::details::_MallocaArrayHolder<task_handle<_Worker>> _Holder;
task_handle<_Worker> *_Tasks = _Holder._InitOnRawMalloca(_malloca(sizeof(task_handle<_Worker>) * (_Cpu_num - 1)));
size_t _Begin_index = 0;
size_t _Step = _Size / _Cpu_num;
size_t _NumRemaining = _Size - _Step * _Cpu_num;
for(size_t _I = 0; _I < _Cpu_num - 1; _I++)
{
size_t _Next = _Begin_index + _Step;
// Add remaining to each chunk
if (_NumRemaining)
{
--_NumRemaining;
++_Next;
}
// New up a task_handle "in-place", in the array preallocated on the stack
new (_Tasks + _I) task_handle<_Worker>(_Worker(_Begin + _Begin_index, _Begin + _Next, _Fun));
_Holder._IncrementConstructedElemsCount();
// Run each of the chunk _Tasks in parallel
_Tg.run(_Tasks[_I]);
_Begin_index = _Next;
}
task_handle<_Worker> _Tail(_Worker(_Begin + _Begin_index, _End, _Fun));
_Tg.run_and_wait(_Tail);
}
// The parallel worker executor for forward iterators
// Divide chunks on the fly
template <typename _Forward_iterator, typename _Function, int _Default_worker_size, int _Default_chunk_size>
struct _Parallel_reduce_forward_executor_helper
{
typedef _Parallel_reduce_fixed_worker<_Forward_iterator, _Function> _Worker_class;
mutable std::auto_ptr<task_handle<_Worker_class>> _Workers;
int _Worker_size;
_Parallel_reduce_forward_executor_helper(_Forward_iterator &_First, _Forward_iterator _Last, const _Function& _Func):
_Workers(static_cast<task_handle<_Worker_class> *>(Concurrency::Alloc(sizeof(task_handle<_Worker_class>) * _Default_worker_size)))
{
_Worker_size = 0;
while (_Worker_size < _Default_worker_size && _First != _Last)
{
// Copy the range _Head
_Forward_iterator _Head = _First;
// Read from forward iterator
for (size_t _I = 0; _I < _Default_chunk_size && _First != _Last; ++_I, ++_First)
{
// Body is empty
}
// _First will be the end of current chunk
new (_Workers.get() + _Worker_size++) task_handle<_Worker_class>(_Worker_class(_Head, _First, _Func));
}
}
_Parallel_reduce_forward_executor_helper(const _Parallel_reduce_forward_executor_helper &_Other):
_Workers(_Other._Workers), _Worker_size(_Other._Worker_size)
{
}
void operator ()() const
{
structured_task_group _Tg;
for(int _I = 0; _I < _Worker_size; _I++)
{
_Tg.run(_Workers.get()[_I]);
}
_Tg.wait();
}
~_Parallel_reduce_forward_executor_helper()
{
if (_Workers.get())
{
for (int _I = 0; _I < _Worker_size; _I++)
{
_Workers.get()[_I].~task_handle<_Worker_class>();
}
Concurrency::Free(_Workers.release());
}
}
};
template <typename _Forward_iterator, typename _Function>
void _Parallel_reduce_forward_executor(_Forward_iterator _First, _Forward_iterator _Last, const _Function& _Func, task_group& _Task_group)
{
const static int _Internal_worker_number = 1024, _Default_chunk_size = 512;
typedef _Parallel_reduce_fixed_worker<_Forward_iterator, _Function> _Worker_class;
structured_task_group _Worker_group;
Concurrency::details::_MallocaArrayHolder<task_handle<_Worker_class>> _Holder;
task_handle<_Worker_class>* _Workers = _Holder._InitOnRawMalloca(_malloca(_Internal_worker_number * sizeof(task_handle<_Worker_class>)));
// Start execution first
int _Index = 0;
while (_Index < _Internal_worker_number && _First != _Last)
{
// Copy the range _Head
_Forward_iterator _Head = _First;
// Read from forward iterator
for (size_t _I = 0; _I < _Default_chunk_size && _First != _Last; ++_I, ++_First)
{
// Body is empty
};
// Create a new task, _First is range _End
new (_Workers + _Index) task_handle<_Worker_class>(_Worker_class(_Head, _First, _Func));
_Holder._IncrementConstructedElemsCount();
_Worker_group.run(_Workers[_Index]);
++_Index;
}
// Divide and append the left
while (_First != _Last)
{
_Task_group.run(_Parallel_reduce_forward_executor_helper<_Forward_iterator, _Function, _Internal_worker_number, _Default_chunk_size>(_First, _Last, _Func));
}
_Worker_group.wait();
}
#pragma warning(pop)
// Disable C4180: qualifier applied to function type has no meaning; ignored
// Warning fires for passing Foo function pointer to parallel_for instead of &Foo.
#pragma warning(push)
#pragma warning(disable: 4180)
//
// Dispatch the execution and handle the condition that all of the iterators are random access
//
template<typename _Any_input_traits, typename _Any_output_traits>
struct _Unary_transform_impl_helper
{
template<typename _Input_iterator, typename _Output_iterator, typename _Unary_operator>
static void _Parallel_transform_unary_impl(_Input_iterator _Begin, _Input_iterator _End, _Output_iterator& _Result, const _Unary_operator& _Unary_op, const auto_partitioner&)
{
task_group _Tg;
_Parallel_transform_unary_impl2(_Begin, _End, _Result, _Unary_op, _Tg);
_Tg.wait();
}
};
template<>
struct _Unary_transform_impl_helper<std::random_access_iterator_tag, std::random_access_iterator_tag>
{
template<typename _Random_input_iterator, typename _Random_output_iterator, typename _Unary_operator, typename _Partitioner>
static void _Parallel_transform_unary_impl(_Random_input_iterator _Begin, _Random_input_iterator _End,
_Random_output_iterator& _Result, const _Unary_operator& _Unary_op, _Partitioner&& _Part)
{
if (_Begin < _End)
{
Concurrency::_Parallel_for_impl(static_cast<size_t>(0), static_cast<size_t>(_End - _Begin), static_cast<size_t>(1),
[_Begin, &_Result, &_Unary_op](size_t _Index)
{
_Result[_Index] = _Unary_op(_Begin[_Index]);
},
std::forward<_Partitioner>(_Part));
_Result += _End - _Begin;
}
}
};
template<typename _Any_input_traits1, typename _Any_input_traits2, typename _Any_output_traits>
struct _Binary_transform_impl_helper
{
template<typename _Input_iterator1, typename _Input_iterator2, typename _Output_iterator, typename _Binary_operator>
static void _Parallel_transform_binary_impl(_Input_iterator1 _Begin1, _Input_iterator1 _End1, _Input_iterator2 _Begin2,
_Output_iterator& _Result, const _Binary_operator& _Binary_op, const auto_partitioner&)
{
task_group _Tg;
_Parallel_transform_binary_impl2(_Begin1, _End1, _Begin2, _Result, _Binary_op, _Tg);
_Tg.wait();
}
};
template<>
struct _Binary_transform_impl_helper<std::random_access_iterator_tag, std::random_access_iterator_tag, std::random_access_iterator_tag>
{
template<typename _Random_input_iterator1, typename _Random_input_iterator2, typename _Random_output_iterator, typename _Binary_operator, typename _Partitioner>
static void _Parallel_transform_binary_impl(_Random_input_iterator1 _Begin1, _Random_input_iterator1 _End1,
_Random_input_iterator2 _Begin2, _Random_output_iterator& _Result, const _Binary_operator& _Binary_op, _Partitioner&& _Part)
{
if (_Begin1 < _End1)
{
Concurrency::_Parallel_for_impl(static_cast<size_t>(0), static_cast<size_t>(_End1 - _Begin1), static_cast<size_t>(1),
[_Begin1, _Begin2, &_Result, &_Binary_op](size_t _Index)
{
_Result[_Index] = _Binary_op(_Begin1[_Index], _Begin2[_Index]);
},
std::forward<_Partitioner>(_Part));
_Result += _End1 - _Begin1;
}
}
};
//
// The implementation for at least one of the iterator is forward iterator
//
template <typename _Forward_iterator, typename _Iterator_kind>
class _Iterator_helper
{
public:
static const size_t _Size = 1024;
typedef typename std::iterator_traits<_Forward_iterator>::value_type value_type;
_Iterator_helper()
{
static_assert(!std::is_same<_Iterator_kind, std::input_iterator_tag>::value
&& !std::is_same<_Iterator_kind, std::output_iterator_tag>::value,
"iterator can not be input_iterator or output_iterator.");
}
size_t _Populate(_Forward_iterator& _First, _Forward_iterator _Last)
{
size_t _Length = 0;
static_assert(std::is_lvalue_reference<decltype(*_First)>::value, "lvalue required for forward iterator operator *");
for (size_t _Index=0; (_Index < _Size) && (_First != _Last); _Index++)
{
// We only support l-value here, so it's safe
_M_element_array[_Length++] = &(*_First++);
}
return _Length;
}
void _Populate(_Forward_iterator& _First, size_t _Length)
{
for (size_t _Index=0; _Index < _Length; _Index++)
{
_M_element_array[_Index] = &(*_First++);
}
}
void _Store(const value_type& _Elem, size_t _Index) const
{
*(_M_element_array[_Index]) = _Elem;
}
typename std::iterator_traits<_Forward_iterator>::reference _Load(size_t _Index) const
{
return *(_M_element_array[_Index]);
}
private:
typename std::iterator_traits<_Forward_iterator>::pointer _M_element_array[_Size];
};
template <typename _Random_iterator>
class _Iterator_helper<_Random_iterator, std::random_access_iterator_tag>
{
public:
static const size_t _Size = 1024;
typedef typename std::iterator_traits<_Random_iterator>::value_type value_type;
_Iterator_helper()
{
}
size_t _Populate(_Random_iterator& _First, _Random_iterator _Last)
{
typename std::iterator_traits<_Random_iterator>::difference_type _Range_size = _Last - _First;
typename std::iterator_traits<_Random_iterator>::difference_type _Sized = _Size;
_M_first = _First;
if (_Range_size > _Sized)
{
_First += _Size;
return _Size;
}
else
{
_First += _Range_size;
return static_cast<size_t>(_Range_size);
}
}
void _Populate(_Random_iterator& _First, size_t _Length)
{
_M_first = _First;
_First += _Length;
}
void _Store(const value_type& _Elem, size_t _Index) const
{
_M_first[_Index] = _Elem;
}
typename std::iterator_traits<_Random_iterator>::reference _Load(size_t _Index) const
{
// We only support l-value here
return _M_first[_Index];
}
private:
_Random_iterator _M_first;
};
template <typename _Input_iterator1, typename _Input_iterator2, typename _Output_iterator, typename _Binary_operator>
class _Parallel_transform_binary_helper
{
public:
_Parallel_transform_binary_helper(_Input_iterator1& _First1, _Input_iterator1 _Last1, _Input_iterator2& _First2,
_Output_iterator& _Result, const _Binary_operator& _Binary_op) :
_M_binary_op(_Binary_op), _M_len(0)
{
_M_len = _M_input_helper1._Populate(_First1, _Last1);
_M_input_helper2._Populate(_First2, _M_len);
_M_output_helper._Populate(_Result, _M_len);
}
void operator()() const
{
// Invoke parallel_for on the batched up array of elements
Concurrency::_Parallel_for_impl(static_cast<size_t>(0), _M_len, static_cast<size_t>(1),
[this] (size_t _Index)
{
_M_output_helper._Store(_M_binary_op(_M_input_helper1._Load(_Index), _M_input_helper2._Load(_Index)), _Index);
});
}
private:
_Iterator_helper<_Input_iterator1, typename std::iterator_traits<_Input_iterator1>::iterator_category> _M_input_helper1;
_Iterator_helper<_Input_iterator2, typename std::iterator_traits<_Input_iterator2>::iterator_category> _M_input_helper2;
_Iterator_helper<_Output_iterator, typename std::iterator_traits<_Output_iterator>::iterator_category> _M_output_helper;
const _Binary_operator& _M_binary_op;
size_t _M_len;
_Parallel_transform_binary_helper const & operator=(_Parallel_transform_binary_helper const&); // no assignment operator
};
template <typename _Input_iterator1, typename _Input_iterator2, typename _Output_iterator, typename _Binary_operator>
void _Parallel_transform_binary_impl2(_Input_iterator1 _First1, _Input_iterator1 _Last1, _Input_iterator2 _First2, _Output_iterator &_Result,
const _Binary_operator& _Binary_op, task_group& _Tg)
{
// This functor will be copied on the heap and will execute the chunk in parallel
{
_Parallel_transform_binary_helper<_Input_iterator1, _Input_iterator2, _Output_iterator, _Binary_operator> functor(_First1, _Last1, _First2, _Result, _Binary_op);
_Tg.run(functor);
}
// If there is a tail, push the tail
if (_First1 != _Last1)
{
_Tg.run(
[=, &_Result, &_Binary_op, &_Tg]
{
_Parallel_transform_binary_impl2(_First1, _Last1, _First2, _Result, _Binary_op, _Tg);
});
}
}
template <typename _Input_iterator, typename _Output_iterator, typename _Unary_operator>
class _Parallel_transform_unary_helper
{
public:
_Parallel_transform_unary_helper(_Input_iterator& _First, _Input_iterator _Last, _Output_iterator &_Result, const _Unary_operator& _Unary_op) :
_M_unary_op(_Unary_op), _M_len(0)
{
_M_len = _M_input_helper._Populate(_First, _Last);
_M_output_helper._Populate(_Result, _M_len);
}
void operator()() const
{
// Invoke parallel_for on the batched up array of elements
Concurrency::_Parallel_for_impl(static_cast<size_t>(0), _M_len, static_cast<size_t>(1),
[this] (size_t _Index)
{
_M_output_helper._Store(_M_unary_op(_M_input_helper._Load(_Index)), _Index);
});
}
private:
_Iterator_helper<_Input_iterator, typename std::iterator_traits<_Input_iterator>::iterator_category> _M_input_helper;
_Iterator_helper<_Output_iterator, typename std::iterator_traits<_Output_iterator>::iterator_category> _M_output_helper;
const _Unary_operator& _M_unary_op;
size_t _M_len;
_Parallel_transform_unary_helper const & operator=(_Parallel_transform_unary_helper const&); // no assignment operator
};
template <typename _Input_iterator, typename _Output_iterator, typename _Unary_operator>
void _Parallel_transform_unary_impl2(_Input_iterator _First, _Input_iterator _Last, _Output_iterator &_Result,
const _Unary_operator& _Unary_op, task_group& _Tg)
{
// This functor will be copied on the heap and will execute the chunk in parallel
{
_Parallel_transform_unary_helper<_Input_iterator, _Output_iterator, _Unary_operator> functor(_First, _Last, _Result, _Unary_op);
_Tg.run(functor);
}
// If there is a tail, push the tail
if (_First != _Last)
{
_Tg.run(
[=, &_Result, &_Unary_op, &_Tg]
{
_Parallel_transform_unary_impl2(_First, _Last, _Result, _Unary_op, _Tg);
});
}
}
template <typename _Input_iterator, typename _Output_iterator, typename _Unary_operator, typename _Partitioner>
_Output_iterator _Parallel_transform_unary_impl(_Input_iterator _First, _Input_iterator _Last, _Output_iterator _Result, const _Unary_operator& _Unary_op, _Partitioner&& _Part)
{
typedef typename std::iterator_traits<_Input_iterator>::iterator_category _Input_iterator_type;
typedef typename std::iterator_traits<_Output_iterator>::iterator_category _Output_iterator_type;
if (_First != _Last)
{
_Unary_transform_impl_helper<_Input_iterator_type, _Output_iterator_type>
::_Parallel_transform_unary_impl(_First, _Last, _Result, _Unary_op, std::forward<_Partitioner>(_Part));
}
return _Result;
}
/// <summary>
/// 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 <c>std::transform</c>.
/// </summary>
/// <typeparam name="_Input_iterator1">
/// The type of the first or only input iterator.
/// </typeparam>
/// <typeparam name="_Output_iterator">
/// The type of the output iterator.
/// </typeparam>
/// <typeparam name="_Unary_operator">
/// The type of the unary functor to be executed on each element in the input range.
/// </typeparam>
/// <param name="_First1">
/// An input iterator addressing the position of the first element in the first or only source range to be operated on.
/// </param>
/// <param name="_Last1">
/// An input iterator addressing the position one past the final element in the first or only source range to be operated on.
/// </param>
/// <param name="_Result">
/// An output iterator addressing the position of the first element in the destination range.
/// </param>
/// <param name="_Unary_op">
/// A user-defined unary function object that is applied to each element in the source range.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <returns>
/// 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.
/// </returns>
/// <remarks>
/// <see ref="auto_partitioner Class">auto_partitioner</see> will be used for the overloads without an explicit partitioner argument.
/// <para>For iterators that do not support random access, only <see ref="auto_partitioner Class">auto_partitioner</see> is supported.</para>
/// <para>The overloads that take the argument <paramref name="_Unary_op"/> transform the input range into the output range by applying
/// the unary functor to each element in the input range. <paramref name="_Unary_op"/> must support the function call operator with signature
/// <c>operator()(T)</c> where <c>T</c> is the value type of the range being iterated over.</para>
/// <para>The overloads that take the argument <paramref name="_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. <paramref name="_Binary_op"/> must support
/// the function call operator with signature <c>operator()(T, U)</c> where <c>T</c>, <c>U</c> are value types of the two input iterators.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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())
{
return _Parallel_transform_unary_impl(_First1, _Last1, _Result, _Unary_op, _Part);
}
/// <summary>
/// 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 <c>std::transform</c>.
/// </summary>
/// <typeparam name="_Input_iterator1">
/// The type of the first or only input iterator.
/// </typeparam>
/// <typeparam name="_Output_iterator">
/// The type of the output iterator.
/// </typeparam>
/// <typeparam name="_Unary_operator">
/// The type of the unary functor to be executed on each element in the input range.
/// </typeparam>
/// <param name="_First1">
/// An input iterator addressing the position of the first element in the first or only source range to be operated on.
/// </param>
/// <param name="_Last1">
/// An input iterator addressing the position one past the final element in the first or only source range to be operated on.
/// </param>
/// <param name="_Result">
/// An output iterator addressing the position of the first element in the destination range.
/// </param>
/// <param name="_Unary_op">
/// A user-defined unary function object that is applied to each element in the source range.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <returns>
/// 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.
/// </returns>
/// <remarks>
/// <see ref="auto_partitioner Class">auto_partitioner</see> will be used for the overloads without an explicit partitioner argument.
/// <para>For iterators that do not support random access, only <see ref="auto_partitioner Class">auto_partitioner</see> is supported.</para>
/// <para>The overloads that take the argument <paramref name="_Unary_op"/> transform the input range into the output range by applying
/// the unary functor to each element in the input range. <paramref name="_Unary_op"/> must support the function call operator with signature
/// <c>operator()(T)</c> where <c>T</c> is the value type of the range being iterated over.</para>
/// <para>The overloads that take the argument <paramref name="_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. <paramref name="_Binary_op"/> must support
/// the function call operator with signature <c>operator()(T, U)</c> where <c>T</c>, <c>U</c> are value types of the two input iterators.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
return _Parallel_transform_unary_impl(_First1, _Last1, _Result, _Unary_op, _Part);
}
/// <summary>
/// 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 <c>std::transform</c>.
/// </summary>
/// <typeparam name="_Input_iterator1">
/// The type of the first or only input iterator.
/// </typeparam>
/// <typeparam name="_Output_iterator">
/// The type of the output iterator.
/// </typeparam>
/// <typeparam name="_Unary_operator">
/// The type of the unary functor to be executed on each element in the input range.
/// </typeparam>
/// <param name="_First1">
/// An input iterator addressing the position of the first element in the first or only source range to be operated on.
/// </param>
/// <param name="_Last1">
/// An input iterator addressing the position one past the final element in the first or only source range to be operated on.
/// </param>
/// <param name="_Result">
/// An output iterator addressing the position of the first element in the destination range.
/// </param>
/// <param name="_Unary_op">
/// A user-defined unary function object that is applied to each element in the source range.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <returns>
/// 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.
/// </returns>
/// <remarks>
/// <see ref="auto_partitioner Class">auto_partitioner</see> will be used for the overloads without an explicit partitioner argument.
/// <para>For iterators that do not support random access, only <see ref="auto_partitioner Class">auto_partitioner</see> is supported.</para>
/// <para>The overloads that take the argument <paramref name="_Unary_op"/> transform the input range into the output range by applying
/// the unary functor to each element in the input range. <paramref name="_Unary_op"/> must support the function call operator with signature
/// <c>operator()(T)</c> where <c>T</c> is the value type of the range being iterated over.</para>
/// <para>The overloads that take the argument <paramref name="_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. <paramref name="_Binary_op"/> must support
/// the function call operator with signature <c>operator()(T, U)</c> where <c>T</c>, <c>U</c> are value types of the two input iterators.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
return _Parallel_transform_unary_impl(_First1, _Last1, _Result, _Unary_op, _Part);
}
/// <summary>
/// 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 <c>std::transform</c>.
/// </summary>
/// <typeparam name="_Input_iterator1">
/// The type of the first or only input iterator.
/// </typeparam>
/// <typeparam name="_Output_iterator">
/// The type of the output iterator.
/// </typeparam>
/// <typeparam name="_Unary_operator">
/// The type of the unary functor to be executed on each element in the input range.
/// </typeparam>
/// <param name="_First1">
/// An input iterator addressing the position of the first element in the first or only source range to be operated on.
/// </param>
/// <param name="_Last1">
/// An input iterator addressing the position one past the final element in the first or only source range to be operated on.
/// </param>
/// <param name="_Result">
/// An output iterator addressing the position of the first element in the destination range.
/// </param>
/// <param name="_Unary_op">
/// A user-defined unary function object that is applied to each element in the source range.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <returns>
/// 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.
/// </returns>
/// <remarks>
/// <see ref="auto_partitioner Class">auto_partitioner</see> will be used for the overloads without an explicit partitioner argument.
/// <para>For iterators that do not support random access, only <see ref="auto_partitioner Class">auto_partitioner</see> is supported.</para>
/// <para>The overloads that take the argument <paramref name="_Unary_op"/> transform the input range into the output range by applying
/// the unary functor to each element in the input range. <paramref name="_Unary_op"/> must support the function call operator with signature
/// <c>operator()(T)</c> where <c>T</c> is the value type of the range being iterated over.</para>
/// <para>The overloads that take the argument <paramref name="_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. <paramref name="_Binary_op"/> must support
/// the function call operator with signature <c>operator()(T, U)</c> where <c>T</c>, <c>U</c> are value types of the two input iterators.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
return _Parallel_transform_unary_impl(_First1, _Last1, _Result, _Unary_op, _Part);
}
/// <summary>
/// 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 <c>std::transform</c>.
/// </summary>
/// <typeparam name="_Input_iterator1">
/// The type of the first or only input iterator.
/// </typeparam>
/// <typeparam name="_Input_iterator2">
/// The type of second input iterator.
/// </typeparam>
/// <typeparam name="_Output_iterator">
/// The type of the output iterator.
/// </typeparam>
/// <typeparam name="_Binary_operator">
/// The type of the binary functor executed pairwise on elements from the two source ranges.
/// </typeparam>
/// <param name="_First1">
/// An input iterator addressing the position of the first element in the first or only source range to be operated on.
/// </param>
/// <param name="_Last1">
/// An input iterator addressing the position one past the final element in the first or only source range to be operated on.
/// </param>
/// <param name="_First2">
/// An input iterator addressing the position of the first element in the second source range to be operated on.
/// </param>
/// <param name="_Result">
/// An output iterator addressing the position of the first element in the destination range.
/// </param>
/// <param name="_Binary_op">
/// A user-defined binary function object that is applied pairwise, in a forward order, to the two source ranges.
/// </param>
/// <param name="_Part">
/// A reference to the partitioner object. The argument can be one of
/// <c>const</c> <see ref="auto_partitioner Class">auto_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="static_partitioner Class">static_partitioner</see><c>&</c>,
/// <c>const</c> <see ref="simple_partitioner Class">simple_partitioner</see><c>&</c> or
/// <see ref="affinity_partitioner Class">affinity_partitioner</see><c>&</c>
/// If an <see ref="affinity_partitioner Class">affinity_partitioner</see> 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.
/// </param>
/// <returns>
/// 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.
/// </returns>
/// <remarks>
/// <see ref="auto_partitioner Class">auto_partitioner</see> will be used for the overloads without an explicit partitioner argument.
/// <para>For iterators that do not support random access, only <see ref="auto_partitioner Class">auto_partitioner</see> is supported.</para>
/// <para>The overloads that take the argument <paramref name="_Unary_op"/> transform the input range into the output range by applying
/// the unary functor to each element in the input range. <paramref name="_Unary_op"/> must support the function call operator with signature
/// <c>operator()(T)</c> where <c>T</c> is the value type of the range being iterated over.</para>
/// <para>The overloads that take the argument <paramref name="_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. <paramref name="_Binary_op"/> must support
/// the function call operator with signature <c>operator()(T, U)</c> where <c>T</c>, <c>U</c> are value types of the two input iterators.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
typedef typename std::iterator_traits<_Input_iterator1>::iterator_category _Input_iterator_type1;
typedef typename std::iterator_traits<_Input_iterator2>::iterator_category _Input_iterator_type2;
typedef typename std::iterator_traits<_Output_iterator>::iterator_category _Output_iterator_type;
if (_First1 != _Last1)
{
_Binary_transform_impl_helper<_Input_iterator_type1, _Input_iterator_type2, _Output_iterator_type>
::_Parallel_transform_binary_impl(_First1, _Last1, _First2, _Result, _Binary_op, std::forward<_Partitioner>(_Part));
}
return _Result;
}
/// <summary>
/// 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 <c>std::transform</c>.
/// </summary>
/// <typeparam name="_Input_iterator1">
/// The type of the first or only input iterator.
/// </typeparam>
/// <typeparam name="_Input_iterator2">
/// The type of second input iterator.
/// </typeparam>
/// <typeparam name="_Output_iterator">
/// The type of the output iterator.
/// </typeparam>
/// <typeparam name="_Binary_operator">
/// The type of the binary functor executed pairwise on elements from the two source ranges.
/// </typeparam>
/// <param name="_First1">
/// An input iterator addressing the position of the first element in the first or only source range to be operated on.
/// </param>
/// <param name="_Last1">
/// An input iterator addressing the position one past the final element in the first or only source range to be operated on.
/// </param>
/// <param name="_First2">
/// An input iterator addressing the position of the first element in the second source range to be operated on.
/// </param>
/// <param name="_Result">
/// An output iterator addressing the position of the first element in the destination range.
/// </param>
/// <param name="_Binary_op">
/// A user-defined binary function object that is applied pairwise, in a forward order, to the two source ranges.
/// </param>
/// <returns>
/// 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.
/// </returns>
/// <remarks>
/// <see ref="auto_partitioner Class">auto_partitioner</see> will be used for the overloads without an explicit partitioner argument.
/// <para>For iterators that do not support random access, only <see ref="auto_partitioner Class">auto_partitioner</see> is supported.</para>
/// <para>The overloads that take the argument <paramref name="_Unary_op"/> transform the input range into the output range by applying
/// the unary functor to each element in the input range. <paramref name="_Unary_op"/> must support the function call operator with signature
/// <c>operator()(T)</c> where <c>T</c> is the value type of the range being iterated over.</para>
/// <para>The overloads that take the argument <paramref name="_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. <paramref name="_Binary_op"/> must support
/// the function call operator with signature <c>operator()(T, U)</c> where <c>T</c>, <c>U</c> are value types of the two input iterators.</para>
/// <para>For more information, see <see cref="Parallel Algorithms"/>.</para>
/// </remarks>
/**/
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)
{
return parallel_transform(_First1, _Last1, _First2, _Result, _Binary_op, auto_partitioner());
}
#pragma warning(pop)
#pragma warning(push)
// object allocated on the heap may not be aligned 64
#pragma warning(disable: 4316)
/// <summary>
/// The <c>combinable<T></c> object is intended to provide thread-private copies of data, to perform lock-free
/// thread-local sub-computations during parallel algorithms. At the end of the parallel operation, the
/// thread-private sub-computations can then be merged into a final result. This class can be used instead of
/// a shared variable, and can result in a performance improvement if there would otherwise be a lot of
/// contention on that shared variable.
/// </summary>
/// <typeparam name="_Ty">
/// The data type of the final merged result. The type must have a copy constructor and a default constructor.
/// </typeparam>
/// <remarks>
/// For more information, see <see cref="Parallel Containers and Objects"/>.
/// </remarks>
/**/
template<typename _Ty>
class combinable
{
private:
// Disable warning C4324: structure was padded due to __declspec(align())
// This padding is expected and necessary.
#pragma warning(push)
#pragma warning(disable: 4324)
__declspec(align(64))
struct _Node
{
unsigned long _M_key;
_Ty _M_value;
_Node* _M_chain;
_Node(unsigned long _Key, _Ty _InitialValue)
: _M_key(_Key), _M_value(_InitialValue), _M_chain(NULL)
{
}
};
#pragma warning(pop)
static _Ty _DefaultInit()
{
return _Ty();
}
public:
/// <summary>
/// Constructs a new <c>combinable</c> object.
/// </summary>
/// <remarks>
/// <para>The first constructor initializes new elements with the default constructor for the type <paramref name="_Ty"/>.</para>
/// <para>The second constructor initializes new elements using the initialization functor supplied as the
/// <paramref name="_FnInitialize"/> parameter.</para>
/// <para>The third constructor is the copy constructor.</para>
/// </remarks>
/// <seealso cref="Parallel Containers and Objects"/>
/**/
combinable()
: _M_fnInitialize(_DefaultInit)
{
_InitNew();
}
/// <summary>
/// Constructs a new <c>combinable</c> object.
/// </summary>
/// <typeparam name="_Function">
/// The type of the initialization functor object.
/// </typeparam>
/// <param name="_FnInitialize">
/// A function which will be called to initialize each new thread-private value of the type <paramref name="_Ty"/>.
/// It must support a function call operator with the signature <c>_Ty ()</c>.
/// </param>
/// <remarks>
/// <para>The first constructor initializes new elements with the default constructor for the type <paramref name="_Ty"/>.</para>
/// <para>The second constructor initializes new elements using the initialization functor supplied as the
/// <paramref name="_FnInitialize"/> parameter.</para>
/// <para>The third constructor is the copy constructor.</para>
/// </remarks>
/// <seealso cref="Parallel Containers and Objects"/>
/**/
template <typename _Function>
explicit combinable(_Function _FnInitialize)
: _M_fnInitialize(_FnInitialize)
{
_InitNew();
}
/// <summary>
/// Constructs a new <c>combinable</c> object.
/// </summary>
/// <param name="_Copy">
/// An existing <c>combinable</c> object to be copied into this one.
/// </param>
/// <remarks>
/// <para>The first constructor initializes new elements with the default constructor for the type <paramref name="_Ty"/>.</para>
/// <para>The second constructor initializes new elements using the initialization functor supplied as the
/// <paramref name="_FnInitialize"/> parameter.</para>
/// <para>The third constructor is the copy constructor.</para>
/// </remarks>
/// <seealso cref="Parallel Containers and Objects"/>
/**/
combinable(const combinable& _Copy)
: _M_size(_Copy._M_size), _M_fnInitialize(_Copy._M_fnInitialize)
{
_InitCopy(_Copy);
}
/// <summary>
/// Assigns to a <c>combinable</c> object from another <c>combinable</c> object.
/// </summary>
/// <param name="_Copy">
/// An existing <c>combinable</c> object to be copied into this one.
/// </param>
/// <returns>
/// A reference to this <c>combinable</c> object.
/// </returns>
/**/
combinable& operator=(const combinable& _Copy)
{
clear();
delete [] _M_buckets;
_M_fnInitialize = _Copy._M_fnInitialize;
_M_size = _Copy._M_size;
_InitCopy(_Copy);
return *this;
}
/// <summary>
/// Destroys a <c>combinable</c> object.
/// </summary>
/**/
~combinable()
{
clear();
delete [] _M_buckets;
}
/// <summary>
/// Returns a reference to the thread-private sub-computation.
/// </summary>
/// <returns>
/// A reference to the thread-private sub-computation.
/// </returns>
/// <seealso cref="Parallel Containers and Objects"/>
/**/
_Ty& local()
{
unsigned long _Key = Concurrency::details::platform::GetCurrentThreadId();
size_t _Index;
_Node* _ExistingNode = _FindLocalItem(_Key, &_Index);
if (_ExistingNode == NULL)
{
_ExistingNode = _AddLocalItem(_Key, _Index);
}
_CONCRT_ASSERT(_ExistingNode != NULL);
return _ExistingNode->_M_value;
}
/// <summary>
/// Returns a reference to the thread-private sub-computation.
/// </summary>
/// <param name="_Exists">
/// A reference to a boolean. The boolean value referenced by this argument will be
/// set to <c>true</c> if the sub-computation already existed on this thread, and set to
/// <c>false</c> if this was the first sub-computation on this thread.
/// </param>
/// <returns>
/// A reference to the thread-private sub-computation.
/// </returns>
/// <seealso cref="Parallel Containers and Objects"/>
/**/
_Ty& local(bool& _Exists)
{
unsigned long _Key = Concurrency::details::platform::GetCurrentThreadId();
size_t _Index;
_Node* _ExistingNode = _FindLocalItem(_Key, &_Index);
if (_ExistingNode == NULL)
{
_Exists = false;
_ExistingNode = _AddLocalItem(_Key, _Index);
}
else
{
_Exists = true;
}
_CONCRT_ASSERT(_ExistingNode != NULL);
return _ExistingNode->_M_value;
}
/// <summary>
/// Clears any intermediate computational results from a previous usage.
/// </summary>
/**/
void clear()
{
for (size_t _Index = 0; _Index < _M_size; ++_Index)
{
_Node* _CurrentNode = _M_buckets[_Index];
while (_CurrentNode != NULL)
{
_Node* _NextNode = _CurrentNode->_M_chain;
delete _CurrentNode;
_CurrentNode = _NextNode;
}
}
memset((void*)_M_buckets, 0, _M_size * sizeof _M_buckets[0]);
}
/// <summary>
/// Computes a final value from the set of thread-local sub-computations by calling the supplied combine functor.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to combine two thread-local sub-computations.
/// </typeparam>
/// <param name="_FnCombine">
/// The functor that is used to combine the sub-computations. Its signature is <c>T (T, T)</c> or
/// <c>T (const T&, const T&)</c>, and it must be associative and commutative.
/// </param>
/// <returns>
/// The final result of combining all the thread-private sub-computations.
/// </returns>
/// <seealso cref="Parallel Containers and Objects"/>
/**/
template<typename _Function>
_Ty combine(_Function _FnCombine) const
{
_Node* _CurrentNode = NULL;
size_t _Index;
// Look for the first value in the set, and use (a copy of) that as the result.
// This eliminates a single call (of unknown cost) to _M_fnInitialize.
for (_Index = 0; _Index < _M_size; ++_Index)
{
_CurrentNode = _M_buckets[_Index];
if (_CurrentNode != NULL)
{
break;
}
}
// No values... return the initializer value.
if (_CurrentNode == NULL)
{
return _M_fnInitialize();
}
// Accumulate the rest of the items in the current bucket.
_Ty _Result = _CurrentNode->_M_value;
for (_CurrentNode = _CurrentNode->_M_chain; _CurrentNode != NULL; _CurrentNode = _CurrentNode->_M_chain)
{
_Result = _FnCombine(_Result, _CurrentNode->_M_value);
}
// Accumulate values from the rest of the buckets.
_CONCRT_ASSERT(_Index < _M_size);
for (++_Index; _Index < _M_size; ++_Index)
{
for (_CurrentNode = _M_buckets[_Index]; _CurrentNode != NULL; _CurrentNode = _CurrentNode->_M_chain)
{
_Result = _FnCombine(_Result, _CurrentNode->_M_value);
}
}
return _Result;
}
/// <summary>
/// Computes a final value from the set of thread-local sub-computations by calling the supplied combine functor
/// once per thread-local sub-computation. The final result is accumulated by the function object.
/// </summary>
/// <typeparam name="_Function">
/// The type of the function object that will be invoked to combine a single thread-local sub-computation.
/// </typeparam>
/// <param name="_FnCombine">
/// The functor that is used to combine one sub-computation. Its signature is <c>void (T)</c> or
/// <c>void (const T&)</c>, and must be associative and commutative.
/// </param>
/// <seealso cref="Parallel Containers and Objects"/>
/**/
template<typename _Function>
void combine_each(_Function _FnCombine) const
{
for (size_t _Index = 0; _Index < _M_size; ++_Index)
{
for (_Node* _CurrentNode = _M_buckets[_Index]; _CurrentNode != NULL; _CurrentNode = _CurrentNode->_M_chain)
{
_FnCombine(_CurrentNode->_M_value);
}
}
}
private:
void _InitNew()
{
_M_size = Concurrency::details::_GetCombinableSize();
_M_buckets = new _Node*[_M_size];
memset((void*)_M_buckets, 0, _M_size * sizeof _M_buckets[0]);
}
void _InitCopy(const combinable& _Copy)
{
_M_buckets = new _Node*[_M_size];
for (size_t _Index = 0; _Index < _M_size; ++_Index)
{
_M_buckets[_Index] = NULL;
for (_Node* _CurrentNode = _Copy._M_buckets[_Index]; _CurrentNode != NULL; _CurrentNode = _CurrentNode->_M_chain)
{
_Node* _NewNode = new _Node(_CurrentNode->_M_key, _CurrentNode->_M_value);
_NewNode->_M_chain = _M_buckets[_Index];
_M_buckets[_Index] = _NewNode;
}
}
}
_Node* _FindLocalItem(unsigned long _Key, size_t* _PIndex)
{
_CONCRT_ASSERT(_PIndex != NULL);
*_PIndex = _Key % _M_size;
// Search at this index for an existing value.
_Node* _CurrentNode = _M_buckets[*_PIndex];
while (_CurrentNode != NULL)
{
if (_CurrentNode->_M_key == _Key)
{
return _CurrentNode;
}
_CurrentNode = _CurrentNode->_M_chain;
}
return NULL;
}
_Node* _AddLocalItem(unsigned long _Key, size_t _Index)
{
_Node* _NewNode = new _Node(_Key, _M_fnInitialize());
_Node* _TopNode;
do
{
_TopNode = _M_buckets[_Index];
_NewNode->_M_chain = _TopNode;
} while (_InterlockedCompareExchangePointer(reinterpret_cast<void * volatile *>(&_M_buckets[_Index]), _NewNode, _TopNode) != _TopNode);
return _NewNode;
}
private:
_Node *volatile * _M_buckets;
size_t _M_size;
std::tr1::function<_Ty ()> _M_fnInitialize;
};
#pragma warning(pop) // C4316
#pragma push_macro("_MAX_NUM_TASKS_PER_CORE")
#pragma push_macro("_FINE_GRAIN_CHUNK_SIZE")
#pragma push_macro("_SORT_MAX_RECURSION_DEPTH")
// This number is used to control dynamic task splitting
// The ideal chunk (task) division is that the number of cores is equal to the number of tasks, but it will
// perform very poorly when tasks are not balanced. The simple solution is to allocate more tasks than number
// of cores. _MAX_NUM_TASKS_PER_CORE provides a maximum number of tasks that will be allocated per core.
// If this number is too small, the load balancing problem will affect efficiency very seriously, especially
// when the compare operation is expensive.
//
// Note that this number is a maximum number -- the dynamic partition system will reduce the number of partitions
// per core based on the dynamic load. If all cores are very busy, the number of partitions will shrink to
// reduce the scheduler overhead.
//
// Initially, the total tasks(chunks) number of partitions "_Div_num" will be: core number * _MAX_NUM_TASKS_PER_CORE.
// The _Div_num will be divided by 2 after each task splitting. There are two special numbers for _Div_num:
// 1. When _Div_num reaches the point that _Div_num < _MAX_NUM_TASKS_PER_CORE, it means we have split more tasks than cores.
// 2. When _Div_num reaches the point that _Div_num <= 1, it means stop splitting more tasks and begin sorting serially.
#define _MAX_NUM_TASKS_PER_CORE 1024
// This is a number mainly is used to control the sampling and dynamic task splitting strategies.
// If the user configurable minimal divisible chunk size (default is 2048) is smaller than FINE_GRAIN_CHUNK_SIZE,
// the random sampling algorithm for quicksort will enter fine-grained mode, and take a strategy that reduces the sampling
// overhead. Also, the dynamic task splitting will enter fine-grained mode, which will split as many tasks as possible.
#define _FINE_GRAIN_CHUNK_SIZE 512
// This is the maximum depth that the quicksort will be called recursively. If we allow too far, a stack overflow may occur.
#define _SORT_MAX_RECURSION_DEPTH 64
template<typename _Random_iterator, typename _Function>
inline size_t _Median_of_three(const _Random_iterator &_Begin, size_t _A, size_t _B, size_t _C, const _Function &_Func, bool &_Potentially_equal)
{
_Potentially_equal = false;
if (_Func(_Begin[_A], _Begin[_B]))
{
if (_Func(_Begin[_A], _Begin[_C]))
{
return _Func(_Begin[_B], _Begin[_C]) ? _B : _C;
}
else
{
return _A;
}
}
else
{
if (_Func(_Begin[_B], _Begin[_C]))
{
return _Func(_Begin[_A], _Begin[_C]) ? _A : _C;
}
else
{
_Potentially_equal = true;
return _B;
}
}
}
template<typename _Random_iterator, typename _Function>
inline size_t _Median_of_nine(const _Random_iterator &_Begin, size_t _Size, const _Function &_Func, bool &_Potentially_equal)
{
size_t _Offset = _Size / 8;
size_t _A = _Median_of_three(_Begin, 0, _Offset, _Offset * 2, _Func, _Potentially_equal),
_B = _Median_of_three(_Begin, _Offset * 3, _Offset * 4, _Offset * 5, _Func, _Potentially_equal),
_C = _Median_of_three(_Begin, _Offset * 6, _Offset * 7, _Size - 1, _Func, _Potentially_equal);
_B = _Median_of_three(_Begin, _A, _B, _C, _Func, _Potentially_equal);
if (_Potentially_equal)
{
_Potentially_equal = !_Func(_Begin[_C], _Begin[_A]);
}
return _B;
}
// _Potentially_equal means that potentially all the values in the buffer are equal to the pivot value
template<typename _Random_iterator, typename _Function>
inline size_t _Select_median_pivot(const _Random_iterator &_Begin, size_t _Size, const _Function &_Func, const size_t _Chunk_size, bool &_Potentially_equal)
{
// Base on different chunk size, apply different sampling optimization
if (_Chunk_size < _FINE_GRAIN_CHUNK_SIZE && _Size <= std::max<size_t>(_Chunk_size * 4, static_cast<size_t>(15)))
{
bool _Never_care_equal;
return _Median_of_three(_Begin, 0, _Size / 2, _Size - 1, _Func, _Never_care_equal);
}
else
{
return _Median_of_nine(_Begin, _Size, _Func, _Potentially_equal);
}
}
// Find out two middle points for two sorted arrays by binary search so that the number of total elements on the left part of two middle points is equal
// to the number of total elements on the right part of two sorted arrays and all elements on the left part is smaller than right part.
template<typename _Random_iterator, typename _Random_buffer_iterator, typename _Function>
size_t _Search_mid_point(const _Random_iterator &_Begin1, size_t &_Len1, const _Random_buffer_iterator &_Begin2, size_t &_Len2, const _Function &_Func)
{
size_t _Len = (_Len1 + _Len2) / 2, _Index1 = 0, _Index2 = 0;
while (_Index1 < _Len1 && _Index2 < _Len2)
{
size_t _Mid1 = (_Index1 + _Len1) / 2, _Mid2 = (_Index2 + _Len2) / 2;
if (_Func(_Begin1[_Mid1], _Begin2[_Mid2]))
{
if (_Mid1 + _Mid2 < _Len)
{
_Index1 = _Mid1 + 1;
}
else
{
_Len2 = _Mid2;
}
}
else
{
if (_Mid1 + _Mid2 < _Len)
{
_Index2 = _Mid2 + 1;
}
else
{
_Len1 = _Mid1;
}
}
}
if (_Index1 == _Len1)
{
_Len2 = _Len - _Len1;
}
else
{
_Len1 = _Len - _Len2;
}
return _Len;
}
// "move" operation is applied between buffers
template<typename _Random_iterator, typename _Random_buffer_iterator, typename _Random_output_iterator, typename _Function>
void _Merge_chunks(_Random_iterator _Begin1, const _Random_iterator &_End1, _Random_buffer_iterator _Begin2, const _Random_buffer_iterator &_End2,
_Random_output_iterator _Output, const _Function &_Func)
{
while (_Begin1 != _End1 && _Begin2 != _End2)
{
if (_Func(*_Begin1, *_Begin2))
{
*_Output++ = std::move(*_Begin1++);
}
else
{
*_Output++ = std::move(*_Begin2++);
}
}
if (_Begin1 != _End1)
{
std::_Move(_Begin1, _End1, _Output);
}
else if (_Begin2 != _End2)
{
std::_Move(_Begin2, _End2, _Output);
}
}
// _Div_num of threads(tasks) merge two chunks in parallel, _Div_num should be power of 2, if not, the largest power of 2 that is
// smaller than _Div_num will be used
template<typename _Random_iterator, typename _Random_buffer_iterator, typename _Random_output_iterator, typename _Function>
void _Parallel_merge(_Random_iterator _Begin1, size_t _Len1, _Random_buffer_iterator _Begin2, size_t _Len2, _Random_output_iterator _Output,
const _Function &_Func, size_t _Div_num)
{
// Turn to serial merge or continue splitting chunks base on "_Div_num"
if (_Div_num <= 1 || (_Len1 <= 1 && _Len2 <= 1))
{
_Merge_chunks(_Begin1, _Begin1 + _Len1, _Begin2, _Begin2 + _Len2, _Output, _Func);
}
else
{
size_t _Mid_len1 = _Len1, _Mid_len2 = _Len2;
size_t _Mid = _Search_mid_point(_Begin1, _Mid_len1, _Begin2, _Mid_len2, _Func);
structured_task_group _Tg;
auto _Handle = make_task([&]
{
_Parallel_merge(_Begin1, _Mid_len1, _Begin2, _Mid_len2, _Output, _Func, _Div_num / 2);
});
_Tg.run(_Handle);
_Parallel_merge(_Begin1 + _Mid_len1, _Len1 - _Mid_len1, _Begin2 + _Mid_len2, _Len2 - _Mid_len2, _Output + _Mid, _Func, _Div_num / 2);
_Tg.wait();
}
}
// Return current sorting byte from key
template<typename _Ty, typename _Function>
inline size_t _Radix_key(const _Ty& _Val, size_t _Radix, _Function _Proj_func)
{
return static_cast<size_t>(_Proj_func(_Val) >> static_cast<int>(8 * _Radix) & 255);
}
// One pass of radix sort
template<typename _Random_iterator, typename _Random_buffer_iterator, typename _Function>
void _Integer_radix_pass(const _Random_iterator &_Begin, size_t _Size, const _Random_buffer_iterator &_Output, size_t _Radix, _Function _Proj_func)
{
if (!_Size)
{
return;
}
size_t _Pos[256] = {0};
for (size_t _I = 0; _I < _Size; _I++)
{
++_Pos[_Radix_key(_Begin[_I], _Radix, _Proj_func)];
}
for (size_t _I = 1; _I < 256; _I++)
{
_Pos[_I] += _Pos[_I - 1];
}
// _Size > 0
for (size_t _I = _Size - 1; _I != 0; _I--)
{
_Output[--_Pos[_Radix_key(_Begin[_I], _Radix, _Proj_func)]] = std::move(_Begin[_I]);
}
_Output[--_Pos[_Radix_key(_Begin[0], _Radix, _Proj_func)]] = std::move(_Begin[0]);
}
// Serial least-significant-byte radix sort, it will sort base on last "_Radix" number of bytes
template<typename _Random_iterator, typename _Random_buffer_iterator, typename _Function>
void _Integer_radix_sort(const _Random_iterator &_Begin, size_t _Size, const _Random_buffer_iterator &_Output,
size_t _Radix, _Function _Proj_func, size_t _Deep = 0)
{
size_t _Cur_radix = 0;
if (_Size == 0)
{
return;
}
while (_Cur_radix < _Radix)
{
_Integer_radix_pass(_Begin, _Size, _Output, _Cur_radix++, _Proj_func);
_Integer_radix_pass(_Output, _Size, _Begin, _Cur_radix++, _Proj_func);
}
if (_Cur_radix == _Radix)
{
_Integer_radix_pass(_Begin, _Size, _Output, _Cur_radix++, _Proj_func);
}
// if odd round is passed, then move result back to input buffer
if (_Deep + _Radix + 1 & 1)
{
if (_Radix + 1 & 1)
{
std::_Move(_Output, _Output + _Size, _Begin);
}
else
{
std::_Move(_Begin, _Begin + _Size, _Output);
}
}
}
// Parallel most-significant-byte _Radix sort.
// In the end, it will turn to serial least-significant-byte radix sort
template<typename _Random_iterator, typename _Random_buffer_iterator, typename _Function>
void _Parallel_integer_radix_sort(const _Random_iterator &_Begin, size_t _Size, const _Random_buffer_iterator &_Output,
size_t _Radix, _Function _Proj_func, const size_t _Chunk_size, size_t _Deep = 0)
{
// If the chunk _Size is too small, then turn to serial least-significant-byte radix sort
if (_Size <= _Chunk_size || _Radix < 1)
{
return _Integer_radix_sort(_Begin, _Size, _Output, _Radix, _Proj_func, _Deep);
}
size_t _Threads_num = Concurrency::details::_CurrentScheduler::_GetNumberOfVirtualProcessors();
size_t _Buffer_size = sizeof(size_t) * 256 * _Threads_num;
size_t _Step = _Size / _Threads_num;
size_t _Remain = _Size % _Threads_num;
Concurrency::details::_MallocaArrayHolder<size_t [256]> _Holder;
size_t (*_Chunks)[256] = _Holder._InitOnRawMalloca(_malloca(_Buffer_size));
memset(_Chunks, 0, _Buffer_size);
// Our purpose is to map unsorted data in buffer "_Begin" to buffer "_Output" so that all elements who have the same
// byte value in the "_Radix" position will be grouped together in the buffer "_Output"
//
// Serial version:
// To understand this algorithm, first consider a serial version. In following example, we treat 1 digit as 1 byte, so we have a
// total of 10 elements for each digit instead of 256 elements in each byte. Let's suppose "_Radix" == 1 (right most is 0), and:
//
// begin: [ 32 | 62 | 21 | 43 | 55 | 43 | 23 | 44 ]
//
// We want to divide the output buffer "_Output" into 10 chunks, and each the element in the "_Begin" buffer should be mapped into
// the proper destination chunk based on its current digit (byte) indicated by "_Radix"
//
// Because "_Radix" == 1, after a pass of this function, the chunks in the "_Output" should look like:
//
// buffer: [ | | 21 23 | 32 | 43 43 44 | 55 | 62 | | | ]
// 0 1 2 3 4 5 6 7 8 9
//
// The difficulty is determining where to insert values into the "_Output" to get the above result. The way to get the
// start position of each chunk of the buffer is:
// 1. Count the number of elements for each chunk (in above example, chunk0 is 0, chunk1 is 0, chunk2 is 2, chunk3 is 1 ...
// 2. Make a partial sum for these chunks( in above example, we will get chunk0=chunk0=0, chunk1=chunk0+chunk1=0,
// chunk2=chunk0+chunk1+chunk2=2, chunk3=chunk0+chunk1+chunk2+chunk3=3
//
// After these steps, we will get the end position of each chunk in the "_Output". The begin position of each chunk will be the end
// point of last chunk (begin point is close but the end point is open). After that, we can scan the original array again and directly
// put elements from original buffer "_Begin" into specified chunk on buffer "_Output".
// Finally, we invoke _parallel_integer_radix_sort in parallel for each chunk and sort them in parallel based on the next digit (byte).
// Because this is a STABLE sort algorithm, if two numbers has same key value on this byte (digit), their original order should be kept.
//
// Parallel version:
// Almost the same as the serial version, the differences are:
// 1. The count for each chunk is executed in parallel, and each thread will count one segment of the input buffer "_Begin".
// The count result will be separately stored in their own chunk size counting arrays so we have a total of threads-number
// of chunk count arrays.
// For example, we may have chunk00, chunk01, ..., chunk09 for first thread, chunk10, chunk11, ..., chunk19 for second thread, ...
// 2. The partial sum should be executed across these chunk counting arrays that belong to different threads, instead of just
// making a partial sum in one counting array.
// This is because we need to put values from different segments into one final buffer, and the absolute buffer position for
// each chunkXX is needed.
// 3. Make a parallel scan for original buffer again, and move numbers in parallel into the corresponding chunk on each buffer based
// on these threads' chunk size counters.
// Count in parallel and separately save their local results without reducing
Concurrency::parallel_for(static_cast<size_t>(0), _Threads_num, [=](size_t _Index)
{
size_t _Beg_index, _End_index;
// Calculate the segment position
if (_Index < _Remain)
{
_Beg_index = _Index * (_Step + 1);
_End_index = _Beg_index + (_Step + 1);
}
else
{
_Beg_index = _Remain * (_Step + 1) + (_Index - _Remain) * _Step;
_End_index = _Beg_index + _Step;
}
// Do a counting
while (_Beg_index != _End_index)
{
++_Chunks[_Index][_Radix_key(_Begin[_Beg_index++], _Radix, _Proj_func)];
}
});
int _Index = -1, _Count = 0;
// Partial sum cross different threads' chunk counters
for (int _I = 0; _I < 256; _I++)
{
size_t _Last = _I ? _Chunks[_Threads_num - 1][_I - 1] : 0;
_Chunks[0][_I] += _Last;
for (size_t _J = 1; _J < _Threads_num; _J++)
{
_Chunks[_J][_I] += _Chunks[_J - 1][_I];
}
// "_Chunks[_Threads_num - 1][_I] - _Last" will get the global _Size for chunk _I(including all threads local _Size for chunk _I)
// this will chunk whether the chunk _I is empty or not. If it's not empty, it will be recorded.
if (_Chunks[_Threads_num - 1][_I] - _Last)
{
++_Count;
_Index = _I;
}
}
// If there is more than 1 chunk that has content, then continue the original algorithm
if (_Count > 1)
{
// Move the elements in parallel into each chunk
Concurrency::parallel_for(static_cast<size_t>(0), _Threads_num, [=](size_t _Index)
{
size_t _Beg_index, _End_index;
// Calculate the segment position
if (_Index < _Remain)
{
_Beg_index = _Index * (_Step + 1);
_End_index = _Beg_index + (_Step + 1);
}
else
{
_Beg_index = _Remain * (_Step + 1) + (_Index - _Remain) * _Step;
_End_index = _Beg_index + _Step;
}
// Do a move operation to directly put each value into its destination chunk
// Chunk pointer is moved after each put operation.
if (_Beg_index != _End_index--)
{
while (_Beg_index != _End_index)
{
_Output[--_Chunks[_Index][_Radix_key(_Begin[_End_index], _Radix, _Proj_func)]] = std::move(_Begin[_End_index]);
--_End_index;
}
_Output[--_Chunks[_Index][_Radix_key(_Begin[_End_index], _Radix, _Proj_func)]] = std::move(_Begin[_End_index]);
}
});
// Invoke _parallel_integer_radix_sort in parallel for each chunk
Concurrency::parallel_for(static_cast<size_t>(0), static_cast<size_t>(256), [=](size_t _Index)
{
if (_Index < 256 - 1)
{
_Parallel_integer_radix_sort(_Output + _Chunks[0][_Index], _Chunks[0][_Index + 1] - _Chunks[0][_Index],
_Begin + _Chunks[0][_Index], _Radix - 1, _Proj_func, _Chunk_size, _Deep + 1);
}
else
{
_Parallel_integer_radix_sort(_Output + _Chunks[0][_Index], _Size - _Chunks[0][_Index],
_Begin + _Chunks[0][_Index], _Radix - 1, _Proj_func, _Chunk_size, _Deep + 1);
}
});
}
else
{
// Only one chunk has content
// A special optimization is applied because one chunk means all numbers have a same value on this particular byte (digit).
// Because we cannot sort them at all (they are all equal at this point), directly call _parallel_integer_radix_sort to
// sort next byte (digit)
_Parallel_integer_radix_sort(_Begin, _Size, _Output, _Radix - 1, _Proj_func, _Chunk_size, _Deep);
}
}
template<typename _Random_iterator, typename _Random_buffer_iterator, typename _Function>
void _Parallel_integer_sort_asc(const _Random_iterator &_Begin, size_t _Size, const _Random_buffer_iterator &_Output,
_Function _Proj_func, const size_t _Chunk_size)
{
typedef typename std::iterator_traits<_Random_iterator>::value_type _Value_type;
// The key type of the radix sort, this must be an "unsigned integer-like" type, that is, it needs support:
// operator>> (int), operator>>= (int), operator& (int), operator <, operator size_t ()
typedef typename std::remove_const<typename std::remove_reference<decltype(_Proj_func(*_Begin))>::type>::type _Integer_type;
// Find out the max value, which will be used to determine the highest differing byte (the radix position)
_Integer_type _Max_val = Concurrency::parallel_reduce(_Begin, _Begin + _Size, _Proj_func(*_Begin),
[=](_Random_iterator _Begin, _Random_iterator _End, _Integer_type _Init) -> _Integer_type
{
while (_Begin != _End)
{
_Integer_type _Ret = _Proj_func(*_Begin++);
if (_Init < _Ret)
{
_Init = _Ret;
}
}
return _Init;
}, [](const _Integer_type &a, const _Integer_type &b) -> const _Integer_type& {return (a < b)? b : a;});
size_t _Radix = 0;
// Find out highest differing byte
while (_Max_val >>= 8)
{
++_Radix;
}
_Parallel_integer_radix_sort(_Begin, _Size, _Output, _Radix, _Proj_func, _Chunk_size);
}
template<typename _Random_iterator, typename _Function>
void _Parallel_quicksort_impl(const _Random_iterator &_Begin, size_t _Size, const _Function &_Func, size_t _Div_num, const size_t _Chunk_size, int _Depth)
{
if (_Depth >= _SORT_MAX_RECURSION_DEPTH || _Size <= _Chunk_size || _Size <= static_cast<size_t>(3) || _Chunk_size >= _FINE_GRAIN_CHUNK_SIZE && _Div_num <= 1)
{
return std::sort(_Begin, _Begin + _Size, _Func);
}
// Determine whether we need to do a three-way quick sort
// We benefit from three-way merge if there are a lot of elements that are EQUAL to the median value,
// _Select_median_pivot function will test redundant density by sampling
bool _Is_three_way_split = false;
size_t _Mid_index = _Select_median_pivot(_Begin, _Size, _Func, _Chunk_size, _Is_three_way_split);
// Move the median value to the _Begin position.
if (_Mid_index)
{
std::swap(*_Begin, _Begin[_Mid_index]);
}
size_t _I = 1, _J = _Size - 1;
// Three-way or two-way partition
// _Div_num < _MAX_NUM_TASKS_PER_CORE is checked to make sure it will never do three-way split before splitting enough tasks
if (_Is_three_way_split && _Div_num < _MAX_NUM_TASKS_PER_CORE)
{
while (_Func(*_Begin, _Begin[_J]))
{
--_J;
}
while (_Func(_Begin[_I], *_Begin))
{
++_I;
}
// Starting from this point, left side of _I will less than median value, right side of _J will be greater than median value,
// and the middle part will be equal to median. _K is used to scan between _I and _J
size_t _K = _J;
while (_I <= _K)
{
if (_Func(_Begin[_K], *_Begin))
{
std::swap(_Begin[_I++], _Begin[_K]);
}
else
{
--_K;
}
while (_Func(*_Begin, _Begin[_K]))
{
std::swap(_Begin[_K--], _Begin[_J--]);
}
}
++_J;
}
else
{
while (_I <= _J)
{
// Will stop before _Begin
while (_Func(*_Begin, _Begin[_J]))
{
--_J;
}
// There must be another element equal or greater than *_Begin
while (_Func(_Begin[_I], *_Begin))
{
++_I;
}
if (_I < _J)
{
std::swap(_Begin[_I++], _Begin[_J--]);
}
else
{
break;
}
}
_I = ++_J;
}
std::swap(*_Begin, _Begin[--_I]);
structured_task_group _Tg;
volatile size_t _Next_div = _Div_num / 2;
auto _Handle = make_task([&]
{
_Parallel_quicksort_impl(_Begin + _J, _Size - _J, _Func, _Next_div, _Chunk_size, _Depth+1);
});
_Tg.run(_Handle);
_Parallel_quicksort_impl(_Begin, _I, _Func, _Next_div, _Chunk_size, _Depth+1);
// If at this point, the work hasn't been scheduled, then slow down creating new tasks
if (_Div_num < _MAX_NUM_TASKS_PER_CORE)
{
_Next_div /= 2;
}
_Tg.wait();
}
// This function will be called to sort the elements in the "_Begin" buffer. However, we can't tell whether the result will end up in buffer
// "_Begin", or buffer "_Output" when it returned. The return value is designed to indicate which buffer holds the sorted result.
// Return true if the merge result is in the "_Begin" buffer; return false if the result is in the "_Output" buffer.
// We can't always put the result into one assigned buffer because that may cause frequent buffer copies at return time.
template<typename _Random_iterator, typename _Random_buffer_iterator, typename _Function>
inline bool _Parallel_buffered_sort_impl(const _Random_iterator &_Begin, size_t _Size, _Random_buffer_iterator _Output, const _Function &_Func,
int _Div_num, const size_t _Chunk_size)
{
static_assert(std::is_same<typename std::iterator_traits<_Random_iterator>::value_type, typename std::iterator_traits<_Random_buffer_iterator>::value_type>::value,
"same value type expected");
if (_Div_num <= 1 || _Size <= _Chunk_size)
{
_Parallel_quicksort_impl(_Begin, _Size, _Func, _MAX_NUM_TASKS_PER_CORE, _Chunk_size, 0);
// In case _Size <= _Chunk_size happened BEFORE the planned stop time (when _Div_num == 1) we need to calculate how many turns of
// binary divisions are left. If there are an odd number of turns left, then the buffer move is necessary to make sure the final
// merge result will be in the original input array.
int _Left_div_turns = 0;
while (_Div_num >>= 1)
{
_Left_div_turns++;
}
if (_Left_div_turns & 1)
{
std::move(_Begin, _Begin + _Size, _Output);
return true;
}
else
{
return false;
}
}
else
{
size_t _Mid = _Size / 2;
structured_task_group _Tg;
auto _Handle = make_task([&, _Chunk_size]
{
_Parallel_buffered_sort_impl(_Begin, _Mid, _Output, _Func, _Div_num / 2, _Chunk_size);
});
_Tg.run(_Handle);
bool _Is_buffer_swap = _Parallel_buffered_sort_impl(_Begin + _Mid, _Size - _Mid, _Output + _Mid, _Func, _Div_num / 2, _Chunk_size);
_Tg.wait();
if (_Is_buffer_swap)
{
_Parallel_merge(_Output, _Mid, _Output + _Mid, _Size - _Mid, _Begin, _Func, _Div_num);
}
else
{
_Parallel_merge(_Begin, _Mid, _Begin + _Mid, _Size - _Mid, _Output, _Func, _Div_num);
}
return !_Is_buffer_swap;
}
}
// Disable the warning saying constant value in condition expression.
// This is by design that lets the compiler optimize the trivial constructor.
#pragma warning (push)
#pragma warning (disable: 4127)
// Allocate and construct a buffer
template<typename _Allocator>
inline typename _Allocator::pointer _Construct_buffer(size_t _N, _Allocator &_Alloc)
{
typename _Allocator::pointer _P = _Alloc.allocate(_N);
// If the objects being sorted have trivial default constructors, they do not need to be
// constructed here. This can benefit performance.
if (!std::has_trivial_default_constructor<typename _Allocator::value_type>::value)
{
for (size_t _I = 0; _I < _N; _I++)
{
// Objects being sorted must have a default constructor
typename _Allocator::value_type _T;
_Alloc.construct(_P + _I, std::forward<typename _Allocator::value_type>(_T));
}
}
return _P;
}
// Destroy and deallocate a buffer
template<typename _Allocator>
inline void _Destroy_buffer(typename _Allocator::pointer _P, size_t _N, _Allocator &_Alloc)
{
// If the objects being sorted have trivial default destructors, they do not need to be
// destructed here. This can benefit performance.
if (!std::has_trivial_destructor<typename _Allocator::value_type>::value)
{
for (size_t _I = 0; _I < _N; _I++)
{
_Alloc.destroy(_P + _I);
}
}
_Alloc.deallocate(_P, _N);
}
//
// Exception safe RAII wrapper for the allocated buffers
//
template<typename _Allocator>
class _AllocatedBufferHolder
{
public:
_AllocatedBufferHolder(size_t _Size, const _Allocator & _Alloc): _M_alloc(_Alloc)
{
_M_size = _Size;
_M_buffer = _Construct_buffer(_Size, _M_alloc);
}
~_AllocatedBufferHolder()
{
_Destroy_buffer(_M_buffer, _M_size, _M_alloc);
}
typename _Allocator::pointer _Get_buffer()
{
return _M_buffer;
}
private:
size_t _M_size;
_Allocator _M_alloc;
typename _Allocator::pointer _M_buffer;
};
#pragma warning (pop)
/// <summary>
/// Arranges the elements in a specified range into a nondescending order, or according to an ordering criterion specified by a binary predicate,
/// in parallel. This function is semantically similar to <c>std::sort</c> in that it is a compare-based, unstable, in-place sort.
/// </summary>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <remarks>
/// The first overload uses the the binary comparator <c>std::less</c>.
/// <para>The second overloaded uses the supplied binary comparator that should have the signature <c>bool _Func(T, T)</c> where <c>T</c>
/// is the type of the elements in the input range.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
template<typename _Random_iterator>
inline void parallel_sort(const _Random_iterator &_Begin, const _Random_iterator &_End)
{
parallel_sort(_Begin, _End, std::less<typename std::iterator_traits<_Random_iterator>::value_type>());
}
/// <summary>
/// Arranges the elements in a specified range into a nondescending order, or according to an ordering criterion specified by a binary predicate,
/// in parallel. This function is semantically similar to <c>std::sort</c> in that it is a compare-based, unstable, in-place sort.
/// </summary>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the binary comparison functor.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <param name="_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 <c>true</c> when satisfied and <c>false</c> when not satisfied. This comparator function
/// must impose a strict weak ordering on pairs of elements from the sequence.
/// </param>
/// <param name="_Chunk_size">
/// The mimimum size of a chunk that will be split into two for parallel execution.
/// </param>
/// <remarks>
/// The first overload uses the the binary comparator <c>std::less</c>.
/// <para>The second overloaded uses the supplied binary comparator that should have the signature <c>bool _Func(T, T)</c> where <c>T</c>
/// is the type of the elements in the input range.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
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)
{
_CONCRT_ASSERT(_Chunk_size > 0);
// Check for cancellation before the algorithm starts.
interruption_point();
size_t _Size = _End - _Begin;
size_t _Core_num = Concurrency::details::_CurrentScheduler::_GetNumberOfVirtualProcessors();
if (_Size <= _Chunk_size || _Core_num < 2)
{
return std::sort(_Begin, _End, _Func);
}
_Parallel_quicksort_impl(_Begin, _Size, _Func, _Core_num * _MAX_NUM_TASKS_PER_CORE, _Chunk_size, 0);
}
/// <summary>
/// Arranges the elements in a specified range into a nondescending order, or according to an ordering criterion specified by a binary predicate,
/// in parallel. This function is semantically similar to <c>std::sort</c> in that it is a compare-based, unstable, in-place sort except that
/// it needs <c>O(n)</c> additional space, and requires default initialization for the elements being sorted.
/// </summary>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// In most cases parallel_buffered_sort will show an improvement in performance over <see cref="parallel_sort Function">parallel_sort</see>, and you should
/// use it over parallel_sort if you have the memory available.
/// <para>If you do not supply a binary comparator <c>std::less</c> is used as the default, which requires the element type to provide the
/// operator <c>operator<()</c>.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
template<typename _Random_iterator>
inline void parallel_buffered_sort(const _Random_iterator &_Begin, const _Random_iterator &_End)
{
parallel_buffered_sort<std::allocator<typename std::iterator_traits<_Random_iterator>::value_type>>(_Begin, _End,
std::less<typename std::iterator_traits<_Random_iterator>::value_type>());
}
/// <summary>
/// Arranges the elements in a specified range into a nondescending order, or according to an ordering criterion specified by a binary predicate,
/// in parallel. This function is semantically similar to <c>std::sort</c> in that it is a compare-based, unstable, in-place sort except that
/// it needs <c>O(n)</c> additional space, and requires default initialization for the elements being sorted.
/// </summary>
/// <typeparam name="_Allocator">
/// The type of an STL compatible memory allocator.
/// </typeparam>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// In most cases parallel_buffered_sort will show an improvement in performance over <see cref="parallel_sort Function">parallel_sort</see>, and you should
/// use it over parallel_sort if you have the memory available.
/// <para>If you do not supply a binary comparator <c>std::less</c> is used as the default, which requires the element type to provide the
/// operator <c>operator<()</c>.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
template<typename _Allocator, typename _Random_iterator>
inline void parallel_buffered_sort(const _Random_iterator &_Begin, const _Random_iterator &_End)
{
parallel_buffered_sort<_Allocator>(_Begin, _End,
std::less<typename std::iterator_traits<_Random_iterator>::value_type>());
}
/// <summary>
/// Arranges the elements in a specified range into a nondescending order, or according to an ordering criterion specified by a binary predicate,
/// in parallel. This function is semantically similar to <c>std::sort</c> in that it is a compare-based, unstable, in-place sort except that
/// it needs <c>O(n)</c> additional space, and requires default initialization for the elements being sorted.
/// </summary>
/// <typeparam name="_Allocator">
/// The type of an STL compatible memory allocator.
/// </typeparam>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <param name="_Alloc">
/// An instance of an STL compatible memory allocator.
/// </param>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// In most cases parallel_buffered_sort will show an improvement in performance over <see cref="parallel_sort Function">parallel_sort</see>, and you should
/// use it over parallel_sort if you have the memory available.
/// <para>If you do not supply a binary comparator <c>std::less</c> is used as the default, which requires the element type to provide the
/// operator <c>operator<()</c>.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
template<typename _Allocator, typename _Random_iterator>
inline void parallel_buffered_sort(const _Allocator& _Alloc, const _Random_iterator &_Begin, const _Random_iterator &_End)
{
parallel_buffered_sort<_Allocator>(_Alloc, _Begin, _End, std::less<typename std::iterator_traits<_Random_iterator>::value_type>());
}
/// <summary>
/// Arranges the elements in a specified range into a nondescending order, or according to an ordering criterion specified by a binary predicate,
/// in parallel. This function is semantically similar to <c>std::sort</c> in that it is a compare-based, unstable, in-place sort except that
/// it needs <c>O(n)</c> additional space, and requires default initialization for the elements being sorted.
/// </summary>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the binary comparator.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <param name="_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 <c>true</c> when satisfied and <c>false</c> when not satisfied. This comparator function
/// must impose a strict weak ordering on pairs of elements from the sequence.
/// </param>
/// <param name="_Chunk_size">
/// The mimimum size of a chunk that will be split into two for parallel execution.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// In most cases parallel_buffered_sort will show an improvement in performance over <see cref="parallel_sort Function">parallel_sort</see>, and you should
/// use it over parallel_sort if you have the memory available.
/// <para>If you do not supply a binary comparator <c>std::less</c> is used as the default, which requires the element type to provide the
/// operator <c>operator<()</c>.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
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)
{
parallel_buffered_sort<std::allocator<typename std::iterator_traits<_Random_iterator>::value_type>>(_Begin, _End, _Func, _Chunk_size);
}
/// <summary>
/// Arranges the elements in a specified range into a nondescending order, or according to an ordering criterion specified by a binary predicate,
/// in parallel. This function is semantically similar to <c>std::sort</c> in that it is a compare-based, unstable, in-place sort except that
/// it needs <c>O(n)</c> additional space, and requires default initialization for the elements being sorted.
/// </summary>
/// <typeparam name="_Allocator">
/// The type of an STL compatible memory allocator.
/// </typeparam>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the binary comparator.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <param name="_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 <c>true</c> when satisfied and <c>false</c> when not satisfied. This comparator function
/// must impose a strict weak ordering on pairs of elements from the sequence.
/// </param>
/// <param name="_Chunk_size">
/// The mimimum size of a chunk that will be split into two for parallel execution.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// In most cases parallel_buffered_sort will show an improvement in performance over <see cref="parallel_sort Function">parallel_sort</see>, and you should
/// use it over parallel_sort if you have the memory available.
/// <para>If you do not supply a binary comparator <c>std::less</c> is used as the default, which requires the element type to provide the
/// operator <c>operator<()</c>.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
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)
{
_Allocator _Alloc;
return parallel_buffered_sort<_Allocator, _Random_iterator, _Function>(_Alloc, _Begin, _End, _Func, _Chunk_size);
}
/// <summary>
/// Arranges the elements in a specified range into a nondescending order, or according to an ordering criterion specified by a binary predicate,
/// in parallel. This function is semantically similar to <c>std::sort</c> in that it is a compare-based, unstable, in-place sort except that
/// it needs <c>O(n)</c> additional space, and requires default initialization for the elements being sorted.
/// </summary>
/// <typeparam name="_Allocator">
/// The type of an STL compatible memory allocator.
/// </typeparam>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the binary comparator.
/// </typeparam>
/// <param name="_Alloc">
/// An instance of an STL compatible memory allocator.
/// </param>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <param name="_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 <c>true</c> when satisfied and <c>false</c> when not satisfied. This comparator function
/// must impose a strict weak ordering on pairs of elements from the sequence.
/// </param>
/// <param name="_Chunk_size">
/// The mimimum size of a chunk that will be split into two for parallel execution.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// In most cases parallel_buffered_sort will show an improvement in performance over <see cref="parallel_sort Function">parallel_sort</see>, and you should
/// use it over parallel_sort if you have the memory available.
/// <para>If you do not supply a binary comparator <c>std::less</c> is used as the default, which requires the element type to provide the
/// operator <c>operator<()</c>.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
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)
{
_CONCRT_ASSERT(_Chunk_size > 0);
// Check cancellation before the algorithm starts.
interruption_point();
size_t _Size = _End - _Begin;
size_t _Core_num = Concurrency::details::_CurrentScheduler::_GetNumberOfVirtualProcessors();
if (_Size <= _Chunk_size || _Core_num < 2)
{
return std::sort(_Begin, _End, _Func);
}
const static size_t CORE_NUM_MASK = 0x55555555;
_AllocatedBufferHolder<_Allocator> _Holder(_Size, _Alloc);
// Prevent cancellation from happening during the algorithm in case it leaves buffers in unknown state.
run_with_cancellation_token([&]() {
// This buffered sort algorithm will divide chunks and apply parallel quicksort on each chunk. In the end, it will
// apply parallel merge to these sorted chunks.
//
// We need to decide on the number of chunks to divide the input buffer into. If we divide it into n chunks, log(n)
// merges will be needed to get the final sorted result. In this algorithm, we have two buffers for each merge
// operation, let's say buffer A and B. Buffer A is the original input array, buffer B is the additional allocated
// buffer. Each turn's merge will put the merge result into the other buffer; for example, if we decided to split
// into 8 chunks in buffer A at very beginning, after one pass of merging, there will be 4 chunks in buffer B.
// If we apply one more pass of merging, there will be 2 chunks in buffer A again.
//
// The problem is we want to the final merge pass to put the result back in buffer A, so that we don't need
// one extra copy to put the sorted data back to buffer A.
// To make sure the final result is in buffer A (original input array), we need an even number of merge passes,
// which means log(n) must be an even number. Thus n must be a number power(2, even number). For example, when the
// even number is 2, n is power(2, 2) = 4, when even number is 4, n is power(2, 4) = 16. When we divide chunks
// into these numbers, the final merge result will be in the original input array. Now we need to decide the chunk(split)
// number based on this property and the number of cores.
//
// We want to get a chunk (split) number close to the core number (or a little more than the number of cores),
// and it also needs to satisfy above property. For a 8 core machine, the best chunk number should be 16, because it's
// the smallest number that satisfies the above property and is bigger than the core number (so that we can utilize all
// cores, a little more than core number is OK, we need to split more tasks anyway).
//
// In this algorithm, we will make this alignment by bit operations (it's easy and clear). For a binary representation,
// all the numbers that satisfy power(2, even number) will be 1, 100, 10000, 1000000, 100000000 ...
// After OR-ing these numbers together, we will get a mask (... 0101 0101 0101) which is all possible combinations of
// power(2, even number). We use _Core_num & CORE_NUM_MASK | _Core_num << 1 & CORE_NUM_MASK, a bit-wise operation to align
// _Core_num's highest bit into a power(2, even number).
//
// It means if _Core_num = 8, the highest bit in binary is bin(1000) which is not power(2, even number). After this
// bit-wise operation, it will align to bin(10000) = 16 which is power(2, even number). If the _Core_num = 16, after
// alignment it still returns 16. The trick is to make sure the highest bit of _Core_num will align to the "1" bit of the
// mask bin(... 0101 0101 0101) We don't care about the other bits on the aligned result except the highest bit, because they
// will be ignored in the function.
_Parallel_buffered_sort_impl(_Begin, _Size, stdext::make_unchecked_array_iterator(_Holder._Get_buffer()),
_Func, _Core_num & CORE_NUM_MASK | _Core_num << 1 & CORE_NUM_MASK, _Chunk_size);
}, cancellation_token::none());
}
#pragma warning(push)
#pragma warning (disable: 4127)
//
// This is a default function used for parallel_radixsort which will return just the value.
// It also performs compile-time checks to ensure that the data type is integral.
//
template <typename _DataType>
struct _Radix_sort_default_function
{
size_t operator()(const _DataType& val) const
{
// An instance of the type predicate returns the value if the type _DataType is one of the integral types, otherwise it
// statically asserts.
// An integral type is one of: bool, char, unsigned char, signed char, wchar_t, short, unsigned short, int, unsigned int, long,
// and unsigned long.
// In addition, with compilers that provide them, an integral type can be one of long long, unsigned long long, __int64, and
// unsigned __int64
static_assert(std::is_integral<_DataType>::value,
"Type should be integral to use default radix function. For more information on integral types, please refer to http://msdn.microsoft.com/en-us/library/bb983099.aspx.");
static_assert((sizeof(_DataType) <= sizeof(size_t)), "Passed Type is bigger than size_t.");
if (std::is_unsigned<_DataType>::value)
{
return val;
}
else
{
// The default function needs to take the signed integer-like representation and map it to an unsigned one. The
// following code will take the midpoint of the unsigned representable range (SIZE_MAX/2)+1 and does an unsigned
// add of the value. Thus, it maps a [-signed_min,+signed_max] range into a [0, unsigned_max] range.
return (((SIZE_MAX/2) + 1) + static_cast<size_t>(val));
}
}
};
#pragma warning (pop)
/// <summary>
/// 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.
/// </summary>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// An unary projection functor with the signature<c>I _Proj_func(T)</c> is required to return a key when given an element, where <c>T</c> is the element
/// type and <c>I</c> is an unsigned integer-like type.
/// <para>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.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
template<typename _Random_iterator>
inline void parallel_radixsort(const _Random_iterator &_Begin, const _Random_iterator &_End)
{
typedef typename std::iterator_traits<_Random_iterator>::value_type _DataType;
_Radix_sort_default_function<_DataType> _Proj_func;
parallel_radixsort<std::allocator<_DataType>>(_Begin, _End, _Proj_func, 256 * 256);
}
/// <summary>
/// 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.
/// </summary>
/// <typeparam name="_Allocator">
/// The type of an STL compatible memory allocator.
/// </typeparam>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// An unary projection functor with the signature<c>I _Proj_func(T)</c> is required to return a key when given an element, where <c>T</c> is the element
/// type and <c>I</c> is an unsigned integer-like type.
/// <para>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.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
template<typename _Allocator, typename _Random_iterator>
inline void parallel_radixsort(const _Random_iterator &_Begin, const _Random_iterator &_End)
{
_Allocator _Alloc;
return parallel_radixsort<_Allocator, _Random_iterator>(_Alloc, _Begin, _End);
}
/// <summary>
/// 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.
/// </summary>
/// <typeparam name="_Allocator">
/// The type of an STL compatible memory allocator.
/// </typeparam>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <param name="_Alloc">
/// An instance of an STL compatible memory allocator.
/// </param>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// An unary projection functor with the signature<c>I _Proj_func(T)</c> is required to return a key when given an element, where <c>T</c> is the element
/// type and <c>I</c> is an unsigned integer-like type.
/// <para>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.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
template<typename _Allocator, typename _Random_iterator>
inline void parallel_radixsort(const _Allocator& _Alloc, const _Random_iterator &_Begin, const _Random_iterator &_End)
{
typedef typename std::iterator_traits<_Random_iterator>::value_type _DataType;
_Radix_sort_default_function<_DataType> _Proj_func;
parallel_radixsort<_Allocator>(_Alloc, _Begin, _End, _Proj_func);
}
/// <summary>
/// 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.
/// </summary>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the projection function.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <param name="_Proj_func">
/// A user-defined projection function object that converts an element into an integral value.
/// </param>
/// <param name="_Chunk_size">
/// The mimimum size of a chunk that will be split into two for parallel execution.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// An unary projection functor with the signature<c>I _Proj_func(T)</c> is required to return a key when given an element, where <c>T</c> is the element
/// type and <c>I</c> is an unsigned integer-like type.
/// <para>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.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
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)
{
parallel_radixsort<std::allocator<typename std::iterator_traits<_Random_iterator>::value_type>>(
_Begin, _End, _Proj_func, _Chunk_size);
}
/// <summary>
/// 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.
/// </summary>
/// <typeparam name="_Allocator">
/// The type of an STL compatible memory allocator.
/// </typeparam>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the projection function.
/// </typeparam>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <param name="_Proj_func">
/// A user-defined projection function object that converts an element into an integral value.
/// </param>
/// <param name="_Chunk_size">
/// The mimimum size of a chunk that will be split into two for parallel execution.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// An unary projection functor with the signature<c>I _Proj_func(T)</c> is required to return a key when given an element, where <c>T</c> is the element
/// type and <c>I</c> is an unsigned integer-like type.
/// <para>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.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
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)
{
_Allocator _Alloc;
return parallel_radixsort<_Allocator, _Random_iterator, _Function>(_Alloc, _Begin, _End, _Proj_func, _Chunk_size);
}
/// <summary>
/// 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.
/// </summary>
/// <typeparam name="_Allocator">
/// The type of an STL compatible memory allocator.
/// </typeparam>
/// <typeparam name="_Random_iterator">
/// The iterator type of the input range.
/// </typeparam>
/// <typeparam name="_Function">
/// The type of the projection function.
/// </typeparam>
/// <param name="_Alloc">
/// An instance of an STL compatible memory allocator.
/// </param>
/// <param name="_Begin">
/// A random-access iterator addressing the position of the first element in the range to be sorted.
/// </param>
/// <param name="_End">
/// A random-access iterator addressing the position one past the final element in the range to be sorted.
/// </param>
/// <param name="_Proj_func">
/// A user-defined projection function object that converts an element into an integral value.
/// </param>
/// <param name="_Chunk_size">
/// The mimimum size of a chunk that will be split into two for parallel execution.
/// </param>
/// <remarks>
/// All overloads require <c>n * sizeof(T)</c> additional space, where <c>n</c> is the number of elements to be sorted, and <c>T</c> is the element type.
/// An unary projection functor with the signature<c>I _Proj_func(T)</c> is required to return a key when given an element, where <c>T</c> is the element
/// type and <c>I</c> is an unsigned integer-like type.
/// <para>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.</para>
/// <para>If you do not supply an allocator type or instance, the STL memory allocator <c>std::allocator<T></c> is used to allocate the buffer.</para>
/// <para>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 <paramref name="_Chunk_size"/> can be used to indicate to the algorithm that it should handles chunks of size < <paramref name="_Chunk_size"/>
/// serially.</para>
/// </remarks>
/**/
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)
{
_CONCRT_ASSERT(_Chunk_size > 0);
// Check for cancellation before the algorithm starts.
interruption_point();
size_t _Size = _End - _Begin;
// If _Size <= 1, no more sorting needs to be done.
if (_Size <= 1)
{
return;
}
_AllocatedBufferHolder<_Allocator> _Holder(_Size, _Alloc);
// Prevent cancellation from happening during the algorithm in case it leaves the buffers in unknown state.
run_with_cancellation_token([&]() {
_Parallel_integer_sort_asc(_Begin, _Size, stdext::make_unchecked_array_iterator(_Holder._Get_buffer()), _Proj_func, _Chunk_size);
}, cancellation_token::none());
}
#pragma pop_macro("_SORT_MAX_RECURSION_DEPTH")
#pragma pop_macro("_MAX_NUM_TASKS_PER_CORE")
#pragma pop_macro("_FINE_GRAIN_CHUNK_SIZE")
}
namespace concurrency = Concurrency;
#pragma pop_macro("new")
#pragma pack(pop)