前几篇文章介绍了集中linux epoll的封装方式，本篇回归windows，介绍一个IOCP的封装。

首先介绍要达到的目的:

1) 导出基本接口，作为一个更高层跨平台网络库的基础组件

2) 导出的接口用法与epoll版本大致相当，以方便日后的跨平台封装

3) 默认的使用方式是单线程的，与epoll一致。

 

下面是接口文件:

/*        Copyright (C) <2012>  
     
          This program is free software: you can redistribute it and/or modify    it under the terms of the GNU General Public License as published by    the Free Software Foundation, either version 3 of the License, or    (at your option) any later version.    This program is distributed in the hope that it will be useful,    but WITHOUT ANY WARRANTY; without even the implied warranty of    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    GNU General Public License for more details.    You should have received a copy of the GNU General Public License    along with this program.  If not, see 
      .*/    #ifndef _KENDYNET_H#define _KENDYNET_H//重叠结构struct OverLapContext{    OVERLAPPED    m_overLapped;    WSABUF*       wbuf;    DWORD         buf_count;    unsigned char m_Type;};struct Socket;//socket的简单封装typedef struct Socket{    SOCKET sock;    HANDLE complete_port;    void (*RecvFinish)(struct Socket*,struct OverLapContext*,DWORD);    void (*SendFinish)(struct Socket*,struct OverLapContext*,DWORD);}*Socket_t;int    InitNetSystem();void   CleanNetSystem();HANDLE CreateNetEngine(DWORD NumberOfConcurrentThreads);void   CloseNetEngine(HANDLE);int    RunEngine(HANDLE,DWORD timeout);int    Bind2Engine(HANDLE,Socket_t);//now表示是否立即发起操作int    WSA_Send(Socket_t,struct OverLapContext*,int now,DWORD *lastErrno);int    WSA_Recv(Socket_t,struct OverLapContext*,int now,DWORD *lastErrno);#endif
     

 

其中的Engine就是IOCP,使用方式就是RunEngine,在函数内部调用GetQueuedCompletionStatus以处理事件.事件处理完成后，

回调RecvFinish/SendFinish.在简单的单线程程序中，只需要创建一个engine,并在主线程调用RunEngine即可.当然，因为完成

队列其实是线程安全的，所以多个线程同时对一个IOCP调用engine也是可以的。但我不建议这么做，如果需要多线程，可以创建

N个engine和工作线程，各工作线程在自己的engine上执行RunEngine即可(与epoll版本一致).

下面贴出实现:

#include 
     
      #include 
      
       #include 
       
        #include "KendyNet.h"#include "stdio.h"enum{    IO_RECVREQUEST = 1<<1,   //应用层接收请求    IO_SENDREQUEST = 1<<3,   //应用层发送请求    IO_RECVFINISH =  1<<2,//接收完成    IO_SENDFINISH =  1<<4,   //发送完成};enum{    IO_RECV = (1<<1) + (1<<2),    IO_SEND = (1<<3) + (1<<4),    IO_REQUEST = (1<<1) + (1<<3),};int    InitNetSystem(){    int nResult;    WSADATA wsaData;    nResult = WSAStartup(MAKEWORD(2,2), &wsaData);    if (NO_ERROR != nResult)    {        printf("\nError occurred while executing WSAStartup().");        return -1; //error    }    return 0;}void   CleanNetSystem(){     WSACleanup();}HANDLE CreateNetEngine(DWORD NumberOfConcurrentThreads){    HANDLE CompletePort = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, NumberOfConcurrentThreads);    if(NULL == CompletePort)    {        printf("\nError occurred while creating IOCP: %d.", WSAGetLastError());    }    return CompletePort;}void   CloseNetEngine(HANDLE CompletePort){    CloseHandle(CompletePort);}static int raw_Send(Socket_t s,struct OverLapContext *overLapped,DWORD *lastErrno){    DWORD dwFlags = 0;    DWORD dwBytes = 0;    int nBytesSend = WSASend(s->sock, overLapped->wbuf, overLapped->buf_count,         &dwBytes, dwFlags, (OVERLAPPED*)overLapped, NULL);    if(SOCKET_ERROR == nBytesSend)        *lastErrno = WSAGetLastError();    return dwBytes;}static int raw_Recv(Socket_t s,struct OverLapContext *overLapped,DWORD *lastErrno){    DWORD dwFlags = 0;    DWORD dwBytes = 0;    int nBytesSend = WSARecv(s->sock, overLapped->wbuf, overLapped->buf_count,         &dwBytes, &dwFlags, (OVERLAPPED*)overLapped, NULL);    if(SOCKET_ERROR == nBytesSend)        *lastErrno = WSAGetLastError();    return dwBytes;}typedef void (*CallBack)(struct Socket*,struct OverLapContext*,DWORD);int    RunEngine(HANDLE CompletePort,DWORD timeout){    DWORD bytesTransfer;    Socket_t       socket;    struct OverLapContext *overLapped = 0;    DWORD lastErrno = 0;    BOOL bReturn;    CallBack call_back;    for( ; ; )    {        call_back = 0;        bReturn = GetQueuedCompletionStatus(            CompletePort,&bytesTransfer,            (LPDWORD)&socket,            (OVERLAPPED**)&overLapped,timeout);                if(FALSE == bReturn || socket == NULL || overLapped == NULL)        {            break;        }        if(0 == bytesTransfer)        {            //连接中断            if(overLapped->m_Type & IO_RECV)                call_back = socket->RecvFinish;                else                call_back = socket->SendFinish;            bytesTransfer = 0;        }        else        {            if(overLapped->m_Type & IO_REQUEST)            {                overLapped->m_Type = overLapped->m_Type << 1;                if(overLapped->m_Type  & IO_RECVFINISH)                    bytesTransfer = raw_Recv(socket,overLapped,&lastErrno);                else if(overLapped->m_Type  & IO_SENDFINISH)                    bytesTransfer = raw_Send(socket,overLapped,&lastErrno);                else                {                    //出错                    continue;                }                if(bytesTransfer <= 0 && lastErrno != 0 && lastErrno != WSA_IO_PENDING)                    bytesTransfer = 0;                else                    continue;            }                    if(overLapped->m_Type & IO_RECVFINISH)                call_back = socket->RecvFinish;            else if(overLapped->m_Type & IO_SENDFINISH)                call_back = socket->SendFinish;            else            {                //出错                continue;            }        }        if(call_back)            call_back(socket,overLapped,bytesTransfer);    }    return 0;}int    Bind2Engine(HANDLE CompletePort,Socket_t socket){    HANDLE hTemp;    if(!socket->RecvFinish || !socket->SendFinish)        return -1;    hTemp = CreateIoCompletionPort((HANDLE)socket->sock, CompletePort,(ULONG_PTR)socket, 0);    if (NULL == hTemp)        return -1;    socket->complete_port = CompletePort;    return 0;}int    WSA_Send(Socket_t socket,struct OverLapContext *OverLap,int now,DWORD *lastErrno){    if(!socket->complete_port)        return -1;    ZeroMemory(&OverLap->m_overLapped, sizeof(OVERLAPPED));    if(!now)    {        OverLap->m_Type = IO_SENDREQUEST;        PostQueuedCompletionStatus(socket->complete_port,1,(ULONG_PTR)socket,(OVERLAPPED*)OverLap);    }    else    {        OverLap->m_Type = IO_SENDFINISH;        return raw_Send(socket,overLapped,lastErrno);    }    return 0;}int    WSA_Recv(Socket_t socket,struct OverLapContext *OverLap,int now,DWORD *lastErrno){    if(!socket->complete_port)        return -1;    ZeroMemory(&OverLap->m_overLapped, sizeof(OVERLAPPED));    if(!now)    {        OverLap->m_Type = IO_RECVREQUEST;        PostQueuedCompletionStatus(socket->complete_port,1,(ULONG_PTR)socket,(OVERLAPPED*)OverLap);        return 0;    }    else    {            OverLap->m_Type = IO_RECVFINISH;        return raw_Recv(socket,overLapped,lastErrno);    }}
       
      
     

 

代码一点点，不做介绍了，下面是一个简单的echo测试

#include 
     
      #include 
      
       #include 
       
        #include 
        
         #include "KendyNet.h"struct connection{    struct Socket socket;    WSABUF wsendbuf;    WSABUF wrecvbuf;    char   sendbuf[128];    char   recvbuf[128];    struct OverLapContext send_overlap;    struct OverLapContext recv_overlap;};void RecvFinish(struct Socket *s,struct OverLapContext *overLap,DWORD bytestransfer){    struct connection *c = (struct connection*)s;    if(bytestransfer <= 0)        free(c);    else    {        DWORD lastErrno = 0;        memcpy(c->sendbuf,c->recvbuf,bytestransfer);        c->wsendbuf.len = bytestransfer;        WSA_Send(s,&c->send_overlap,1,&lastErrno);    }}void SendFinish(struct Socket *s,struct OverLapContext *overLap,DWORD bytestransfer){    struct connection *c = (struct connection*)s;    if(bytestransfer <= 0)        free(c);    else    {        DWORD lastErrno = 0;        WSA_Recv((Socket_t)c,&c->recv_overlap,1,&lastErrno);    }}struct connection* CreateConnection(SOCKET s){    struct connection *c;    c = malloc(sizeof(*c));    ZeroMemory(c, sizeof(*c));    c->socket.sock = s;    c->socket.RecvFinish = &RecvFinish;    c->socket.SendFinish = &SendFinish;    c->wrecvbuf.buf = c->recvbuf;    c->wrecvbuf.len = 128;    c->recv_overlap.buf_count = 1;    c->recv_overlap.wbuf = &c->wrecvbuf;    c->wsendbuf.buf = c->sendbuf;    c->wsendbuf.len = 0;    c->send_overlap.buf_count = 1;    c->send_overlap.wbuf = &c->wsendbuf;    return c;}DWORD WINAPI Listen(void *arg){    HANDLE *iocp = (HANDLE*)arg;    HANDLE complete_port = *iocp;    struct sockaddr_in    addr;    int                         optval=1;                        //Socket属性值    unsigned long               ul=1;    struct linger lng;    struct sockaddr_in ClientAddress;    int nClientLength = sizeof(ClientAddress);    struct connection *c;            SOCKET ListenSocket;    ListenSocket = WSASocket(AF_INET, SOCK_STREAM, 0, NULL, 0, WSA_FLAG_OVERLAPPED);        if (INVALID_SOCKET == ListenSocket)     {        printf("\nError occurred while opening socket: %d.", WSAGetLastError());        return 0;    }        addr.sin_family        = AF_INET;    addr.sin_port        = htons(8010);    addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");    setsockopt(ListenSocket,SOL_SOCKET,SO_EXCLUSIVEADDRUSE,(char*)&optval,sizeof(optval));  //禁止端口多用    setsockopt(ListenSocket,IPPROTO_TCP,TCP_NODELAY,(char*)&optval,sizeof(optval));         //不采用延时算法     setsockopt(ListenSocket,SOL_SOCKET,SO_DONTLINGER,(char*)&optval,sizeof(optval));        //执行立即关闭        lng.l_linger=0;    lng.l_onoff=1;    setsockopt(ListenSocket,SOL_SOCKET,SO_LINGER,(char*)&lng,sizeof(lng));    //禁止重用本地端口    if ((bind(ListenSocket, (struct sockaddr *)&addr, sizeof( struct sockaddr_in))) == SOCKET_ERROR)    {        closesocket(ListenSocket);        return 0;    }    if((listen(ListenSocket, 5)) == SOCKET_ERROR)    {        closesocket(ListenSocket);        return 0;    }    printf("listener 启动\n");    while(1)    {        SOCKET client = accept(ListenSocket, (struct sockaddr*)&ClientAddress, &nClientLength);        if (INVALID_SOCKET == client)        {            continue;        }        if(ioctlsocket(client,FIONBIO,(unsigned long*)&ul)==SOCKET_ERROR)        {            closesocket(client);            continue;        }        c = CreateConnection(client);        Bind2Engine(complete_port,(Socket_t)c);        //发出第一个读请求        WSA_Recv((Socket_t)c,&c->recv_overlap,0,0);    }    return 0;}int main(){    HANDLE iocp;    DWORD dwThread;    InitNetSystem();    iocp = CreateNetEngine(0);            CreateThread(NULL,0,Listen,&iocp,0,&dwThread);        while(1)        RunEngine(iocp,10);    return 0;}