agents.h

C语言库函数的原型,有用的拿去

/***
* ==++==
*
* Copyright (c) Microsoft Corporation.  All rights reserved.
*
* ==--==
* =+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*
* agents.h
*
* Main public header file for ConcRT's asynchronous agents layer. This is the only header file a
* C++ program should have to include in order to avail itself of asynchronous agents.
*
* The core runtime, PPL, and resource manager are in separate headers.
* =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
****/

#pragma once

#include <crtdefs.h>
#include <concrt.h>
#include <stdexcept>
#include <functional>
#include <tuple>
#include <type_traits>
#include <vector>

#pragma pack(push,_CRT_PACKING)

// Forward declarations

/// <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
{
/// <summary>
///     Each message instance has an identity that follows it as it is
///     cloned and passed between messaging components. This cannot be the
///     address of the message object.
/// </summary>
/**/
typedef __int32 runtime_object_identity;

/// <summary>
///     A lock holder that acquires a non-reentrant lock on instantiation and releases
///     it on destruction.
/// </summary>
/**/
typedef ::Concurrency::details::_NonReentrantPPLLock::_Scoped_lock _NR_lock;

/// <summary>
///     A lock holder that acquires a reentrant lock on instantiation and releases
///     it on destruction
/// </summary>
/**/
typedef ::Concurrency::details::_ReentrantPPLLock::_Scoped_lock _R_lock;


//***************************************************************************
// Internal namespace:
//
// Concurrency::details contains definitions to support routines in the public namespaces and macros.
// Clients should not directly interact with this namespace.
//***************************************************************************

namespace details
{
    //**************************************************************************
    // Core Messaging Support:
    //**************************************************************************

    //
    // A base class to derive from that keeps unique ids on its derived classes
    //
    class _Runtime_object : public _AllocBase
    {
    public:
        // Creates a new runtime object.
        _CRTIMP2 _Runtime_object();

        // Creates a runtime object from an identity.
        _CRTIMP2 _Runtime_object(::Concurrency::runtime_object_identity _Id);

        // Gets the runtime object identity.
        virtual ::Concurrency::runtime_object_identity _GetId() const
        {
            return _M_id;
        }

    protected:
        // The runtime object identity.
        ::Concurrency::runtime_object_identity _M_id;
    };

    // A queue used to hold the messages for the messaging blocks
    template<class _Message>
    class _Queue : public _AllocBase
    {
    protected:
        // A pointer to the head of the queue.
        _Message * _M_pHead;

        // A pointer to a pointer to the tail of the queue.
        _Message ** _M_ppTail;

        // The number of elements presently stored in the queue.
        size_t _M_count;

    public:
        typedef typename _Message type;

        // Create a Queue
        _Queue() : _M_pHead(NULL), _M_ppTail(&_M_pHead), _M_count(0)
        {
        }

        // Destroy the queue
        ~_Queue()
        {
            // Delete any messages that may be remaining in the queue
            _Message * _Msg = _Dequeue();
            while (_Msg != NULL)
            {
                delete _Msg;
                _Msg = _Dequeue();
            }
        }

        // Returns the count of items in the queue
        size_t _Count() const
        {
            return _M_count;
        }

        // Add an item to the tail of the queue
        //
        // Returns a Boolean indicating whether the operation succeeded.
        bool _Enqueue(_Message *_Element)
        {
            _ASSERTE(_Element->_M_pNext == NULL);
            _ASSERTE(*_M_ppTail == NULL);

            *_M_ppTail = _Element;
            _Element->_M_pNext = NULL;
            _M_ppTail = &(_Element->_M_pNext);
            _M_count++;

            return true;
        }

        // Remove the specified element from the queue
        //
        // Returns a Boolean indicating whether the operation succeeded, i.e. that the message was found in the queue.
        bool _Remove(_Message * _OldElement)
        {
            bool _Result = false;

            _ASSERTE(_OldElement != NULL);

            if (_M_pHead == _OldElement)
            {
                _M_pHead = _OldElement->_M_pNext;
                if (_M_pHead == NULL)
                {
                    _M_ppTail = &_M_pHead;
                }

                _OldElement->_M_pNext = NULL;
                _M_count--;
                _Result = true;
            }
            else
            {
                _Message * _Next = NULL;
                for (_Message * _Node = _M_pHead; _Node != NULL; _Node = _Next)
                {
                    _Next = _Node->_M_pNext;

                    if (_Node->_M_pNext == _OldElement)
                    {
                        _Node->_M_pNext = _OldElement->_M_pNext;
                        // if this is the last element of the _Queue
                        if (_Node->_M_pNext == NULL && _M_count == 1)
                        {
                            _M_ppTail = &_M_pHead;
                        }

                        _OldElement->_M_pNext = NULL;
                        _M_count--;
                        _Result = true;
                        break;
                    }
                }
            }

            return _Result;
        }

        // Dequeue an item from the head of queue
        //
        // Returns a pointer to the message found at the head of the queue.
        _Message * _Dequeue()
        {
            if (_M_pHead == NULL)
            {
                return NULL;
            }

            _Message * _Result = _M_pHead;

            _M_pHead = _Result->_M_pNext;
            if (_M_pHead == NULL)
            {
                _M_ppTail = &_M_pHead;
            }

            _Result->_M_pNext = NULL;
            _M_count--;
            return _Result;
        }

        // Return the item at the head of the queue, without dequeuing
        //
        // Returns a pointer to the message found at the head of the queue.
        _Message * _Peek()
        {
            return _M_pHead;
        }

        // Return true if the id matches the message at the head of the queue
        bool _Is_head(runtime_object_identity _MsgId)
        {
            // Peek at the next message in the message buffer.  Use it to
            // check if the ids match
            _Message * _Msg = _M_pHead;

            if (_Msg == NULL || _Msg->msg_id() != _MsgId)
            {
                return false;
            }

            return true;
        }
    };

    //
    // The async_send_queue class puts a lock around the Enqueue/Dequeue operations on
    // a Queue.  This class is here mainly to support the message propagation queue
    // It holds incoming messages and will be written to on async_send(). Messages in
    // this queue will be moved to the internal storage of the block within an LWT.
    //
    template<class _Message>
    class _Async_send_queue
    {
    public:
        // Create an async send queue
        _Async_send_queue()
        {
        }

        // Return the count of items in the async send queue
        size_t _Count() const
        {
            return _M_queue._Count();
        }

        // Add an item to the back of the async send queue
        //
        // Returns a Boolean indicating whether the operation succeeded.
        bool _Enqueue(_Message * _Element)
        {
            _NR_lock _Lock(_M_lock);

            return (_M_queue._Enqueue(_Element));
        }

        // Remove an item from the async send queue
        //
        // Returns a Boolean indicating whether the operation succeeded, i.e. that the message was found in the async send queue.
        bool _Remove(_Message * _OldElement)
        {
            _NR_lock _Lock(_M_lock);

            return (_M_queue._Remove(_OldElement));
        }

        // Remove an item from the head of the async send queue
        //
        // Returns a pointer to the message found at the head of the async send queue.
        _Message * _Dequeue()
        {
            _NR_lock _Lock(_M_lock);

            return (_M_queue._Dequeue());
        }

        // Return the item at the head of the async send queue, without dequeuing
        //
        // Returns a pointer to the message found at the head of the async send queue.
        _Message * _Peek()
        {
            return _M_queue._Peek();
        }

    private:
        // A lock to guard the queue
        ::Concurrency::details::_NonReentrantPPLLock _M_lock;

        // Underlying queue
        _Queue<_Message> _M_queue;
    };


    //
    // _Dynamic_array implements a container very similar to std::vector.
    // However, it exposes a reduced subset of functionality that is
    // geared towards use in network_link_registry. The array acess is not
    // thread-safe.
    //
    template<class _Type>
    class _Dynamic_array
    {
    public:

        typedef _Dynamic_array<_Type> _Myt;

        typedef _Type& reference;
        typedef _Type const& const_reference;

        //
        // Construct a dynamic array
        //
        _Dynamic_array()
        {
            _Init();
        }

        //
        // Release any resources used by dynamic array
        //
        ~_Dynamic_array()
        {
            _Clear();
        }

        //
        // Assignment operator. Copy the contents of _Right
        //
        _Myt& operator=(const _Myt& _Right)
        {
            if (this != &_Right)
            {
                // Remove all the elements
                _Clear();

                // Allocate space for the new elements
                size_t _Size = _Right._Size();
                _Grow(_Size);

                // Copy over the new elements
                for (size_t _I=0; _I < _Size; _I++)
                {
                    _Push_back(_Right[_I]);
                }
            }

            return *this;
        }

        //
        // Clear all the elements in the array
        //
        void _Clear()
        {
            if (_M_array != NULL)
            {
                delete [] _M_array;
                _Init();
            }
        }

        //
        // Add an element to the end of the array
        //
        void _Push_back(_Type const& _Element)
        {
            if (_M_index >= _M_size)
            {
                // Not enough space. Grow the array
                size_t _NewSize = (_M_index + 1) * _S_growthFactor;
                _Grow(_NewSize);
            }

            _ASSERTE(_M_index < _M_size);
            _M_array[_M_index] = _Element;
            _M_index++;
        }

        //
        // Index operation. Retrieve an element at the specified index. No bounds check is done.
        //
        reference operator[](size_t _Pos)
        {
            _ASSERTE(_Pos < _M_size);
            return _M_array[_Pos];
        }

        //
        // Index operation. Retrieve an element at the specified index. No bounds check is done.
        //
        const_reference operator[](size_t _Pos) const
        {
            _ASSERTE(_Pos < _M_size);
            return _M_array[_Pos];
        }

        //
        // Returns the count of elements in the array
        //
        size_t _Size() const
        {
            return _M_index;
        }

        //
        // Swap the contents of this array with _Right
        //
        void _Swap(_Myt& _Right)
        {
            if (this != &_Right)
            {
                // Swap the details.
                _Type * _Array = _M_array;
                size_t _Index = _M_index;
                size_t _Size = _M_size;

                _M_array = _Right._M_array;
                _M_index = _Right._M_index;
                _M_size = _Right._M_size;

                _Right._M_array = _Array;