socket 事件模型

相关函数

1. WSACreateEvent
2. WSAEventSelect
3. WSAWaitForMultipleEvents
4. WSAWaitForMultipleEvents
5. WSAEnumNetworkEvents

代码

//////////////////////////////////////////////////
// WSAEventSelect文件

#include "initsock.h"
#include <stdio.h>
#include <iostream>
#include <windows.h>

// 初始化Winsock库
CInitSock theSock;

int main()
{
    // 事件句柄和套节字句柄表
    WSAEVENT    eventArray[WSA_MAXIMUM_WAIT_EVENTS];
    SOCKET        sockArray[WSA_MAXIMUM_WAIT_EVENTS];
    int nEventTotal = 0;

    USHORT nPort = 4567;    // 此服务器监听的端口号

    // 创建监听套节字
    SOCKET sListen = ::socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);    
    sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(nPort);
    sin.sin_addr.S_un.S_addr = INADDR_ANY;
    if(::bind(sListen, (sockaddr*)&sin, sizeof(sin)) == SOCKET_ERROR)
    {
        printf(" Failed bind() \n");
        return -1;
    }
    ::listen(sListen, 5);

    // 创建事件对象，并关联到新的套节字
    WSAEVENT event = ::WSACreateEvent();
    
    ::WSAEventSelect(sListen, event, FD_ACCEPT|FD_CLOSE);
    // 添加到表中
    eventArray[nEventTotal] = event;
    sockArray[nEventTotal] = sListen;    
    nEventTotal++;

    // 处理网络事件
    while(TRUE)
    {
        // 在所有事件对象上等待
        int nIndex = ::WSAWaitForMultipleEvents(nEventTotal, eventArray, FALSE, WSA_INFINITE, FALSE);
        // 对每个事件调用WSAWaitForMultipleEvents函数，以便确定它的状态
        nIndex = nIndex - WSA_WAIT_EVENT_0;
        for(int i=nIndex; i<nEventTotal; i++)
        {
            nIndex = ::WSAWaitForMultipleEvents(1, &eventArray[i], TRUE, 10, FALSE);
            if(nIndex == WSA_WAIT_FAILED || nIndex == WSA_WAIT_TIMEOUT)
            {
                continue;
            }
            else
            {
                // 获取到来的通知消息，WSAEnumNetworkEvents函数会自动重置受信事件
                WSANETWORKEVENTS event;
                ::WSAEnumNetworkEvents(sockArray[i], eventArray[i], &event);
                if(event.lNetworkEvents & FD_ACCEPT)                // 处理FD_ACCEPT通知消息
                {
                    if(event.iErrorCode[FD_ACCEPT_BIT] == 0)
                    {
                        if(nEventTotal > WSA_MAXIMUM_WAIT_EVENTS)
                        {
                            printf(" Too many connections! \n");
                            continue;
                        }
                        SOCKET sNew = ::accept(sockArray[i], NULL, NULL);
                        WSAEVENT event = ::WSACreateEvent();
                        ::WSAEventSelect(sNew, event, FD_READ|FD_CLOSE|FD_WRITE);
                        // 添加到表中
                        eventArray[nEventTotal] = event;
                        sockArray[nEventTotal] = sNew;    
                        nEventTotal++;
                    }
                }
                else if(event.lNetworkEvents & FD_READ)            // 处理FD_READ通知消息
                {
                    if(event.iErrorCode[FD_READ_BIT] == 0)
                    {
                        char szText[256];
                        int nRecv = ::recv(sockArray[i], szText, strlen(szText), 0);
                        if(nRecv > 0)                
                        {
                            szText[nRecv] = '\0';
                            printf("接收到数据：%s \n", szText);
                        }
                    }
                }
                else if(event.lNetworkEvents & FD_CLOSE)        // 处理FD_CLOSE通知消息
                {
                    if(event.iErrorCode[FD_CLOSE_BIT] == 0)
                    {
                        ::closesocket(sockArray[i]);
                        for(int j=i; j<nEventTotal-1; j++)
                        {
                            sockArray[j] = sockArray[j+1];
                            sockArray[j] = sockArray[j+1];    
                        }
                        nEventTotal--;
                    }
                }
                else if(event.lNetworkEvents & FD_WRITE)        // 处理FD_WRITE通知消息
                {
                }
            }
        }
    }
    return 0;
}

事件相关函数:

WSACloseEvent

The WSACloseEvent function closes an open event object handle.

WSASetEvent

The WSASetEvent function sets the state of the specified event object to signaled.

手动将事件设置为有信号,那么WSAWaitForMultipleEvents将不会再等待

WSAResetEvent

The WSAResetEvent function resets the state of the specified event object to nonsignaled.

WSAResetEvent和WSASetEvent是作用是相对的