CIOCPServer data structure definitions and program memory pool

2019 Unicorn Enterprises heavily recruiting engineers Python standard >>>

In order to avoid frequent application release the memory , using memory pool to manage buffer objects and client context object memory use.

Using the pointer to save all free memory blocks , forming the free list .

When the application memory, this pointer is not NULL, from the free list to remove a used , if take complete, on a real application memory .

---

                  1 buffer objects               

Using the procedure described CIOCPBuffer per-IO data, comprising the necessary information IO operations, when submitted, the object is CIOCPBuffer

Here is the application buffer object code:

CIOCPBuffer *CIOCPServer::AllocateBuffer(int nLen){
    CIOCPBuffer *pBuffer = NULL;
    if(nLen>BUFFER_SIZE)
        return NULL;

    ::EnterCriticalSection(&m_FreeBufferListLock);
    if(m_pFreeBufferList == NULL)
    {
        pBuffer=(CIOCPBuffer*)::HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,sizeof(CIOCPBuffer)+BUFFER_SIZE);
    }
    else
    {
        pBuffer = m_pFreeBufferList;
        m_pFreeBufferList = m_pFreeBufferList->pNext;
        pBuffer->pNext = NULL;
        m_nFreeBufferCount--;
    }
    ::LeaveCriticalSection(&m_FreeBufferListLock);
    if(pBuffer!=NULL)
    {
        pBuffer->buff = (char*)(pBuffer+1);
        pBuffer->nLen = nLen;
    }
    return pBuffer;
}

Here is the code to release the buffer object:

void CIOCPServer::ReleaseBuffer(CIOCPBuffer *pBuffer)
{
    ::EnterCriticalSection(&m_pFreeBufferListLock);
    if(m_nFreeBufferCount<=m_nMaxFreeBuffers)
    {
        memset(pBuffer,0,sizeof(CIOCPBuffer)+BUFFERSIZE);
        pBuffer->pNext = m_pFreeBufferList;
        m_pFreeBufferList = pBuffer;
        m_pFreeBufferCount++;
    }
    else
    {
        ::HeapFree(::GetProcessHeap(),0,pBuffer);
    }
    ::LeaveCriticalSection(&m_pFreeBufferListLock);
}

                  2 client area context object                    

Client context object is the per-Handle data, including information about the sockets, the server program receives a new connection, you create a client context object for the new connection, to record customer information.

Code buffer context object with almost the same, the release code is as follows:

void CIOCPServer::RealeaseContext(CIOCPContext *pContext)
{
    if(pContext->s != INVALID_SOCKET)
        ::closesocket(pContext->s);
    CIOCPBuffer *pNext;
    while(pContext->pOutOfOrderReads !=NULL)
    {
        pNext = pContext->pOutOfOrderReads->pNext;
        ReleaseBuffer(pContext->pOutOfOrderReads);
        pContext->pOutOfOrderReads = pNext;
    }
    ::EnterCriticalSection(&m_pFreeBufferListLock);
    if(m_nFreeBufferCount<=m_nMaxFreeBuffers)
    {
        CRITICAL_SECTION cstmp = pContext->Lock;
        memset(pContext,0,sizeof(CIOCPContext));
        pContext->Lock = cstmp;
        pContext->pNext = m_pFreeContextList;
        m_pFreeContextList = pContext;
        m_nFreeContextCount++;
    }
    else
    {
        ::DeleteCriticalSection(&pContext->Lock);
        ::HeapFree(::GetProcessHeap(),0,pBuffer);
    }
    ::LeaveCriticalSection(&m_pFreeBufferListLock);
}

Reproduced in: https: //my.oschina.net/u/204616/blog/545039