windows重叠I/O模型

重叠I/O就相当于异步I/O。

一、重叠I/O的I/O完成确认

1、使用事件对象

接收端：

 #include <stdio.h>
 #include <stdlib.h>
 #include <WinSock2.h>

 #define BUF_SIZE 1024
 void ErrorHandling(char *message);

 int main(int argc, char *argv[])
 {
     if (argc != ) {
         printf("Usage : %s <port>\n", argv[]);
         exit();
     }

     WSADATA wsaData;
     SOCKET hLinSock, hCRecvSock;
     SOCKADDR_IN lisnAdr, recvAdr;
     int recvAdrSz;

     WSABUF dataBuf;
     WSAEVENT evObj;
     WSAOVERLAPPED overlapped;

     char buf[BUF_SIZE];
     int recvBytes = , flags = ;

     if (WSAStartup(MAKEWORD(, ), &wsaData) != )
         ErrorHandling("WSAStartup() error.");

     hLinSock = socket(PF_INET, SOCK_STREAM, );
     memset(&lisnAdr, , sizeof(lisnAdr));
     lisnAdr.sin_family = AF_INET;
     lisnAdr.sin_addr.s_addr = htonl(INADDR_ANY);
     lisnAdr.sin_port = htons(atoi(argv[]));

     if (bind(hLinSock, (SOCKADDR*)&lisnAdr, sizeof(lisnAdr)) == SOCKET_ERROR)
         ErrorHandling("bind() error.");
     if (listen(hLinSock, ) == SOCKET_ERROR)
         ErrorHandling("listen() error.");

     recvAdrSz = sizeof(recvAdr);
     hCRecvSock = accept(hLinSock, (SOCKADDR*)&recvAdr, &recvAdrSz);

     evObj = WSACreateEvent();
     memset(&overlapped, , sizeof(overlapped));
     overlapped.hEvent = evObj;
     dataBuf.len = BUF_SIZE;
     dataBuf.buf = buf;

     if (WSARecv(hCRecvSock, &dataBuf, , (LPDWORD)&recvBytes, (LPDWORD)&flags, &overlapped, NULL) == SOCKET_ERROR)
     {
         if (WSAGetLastError() == WSA_IO_PENDING)
         {
             puts("Background data receive");
             WSAWaitForMultipleEvents(, &evObj, TRUE, WSA_INFINITE, FALSE);
             WSAGetOverlappedResult(hCRecvSock, &overlapped, (LPDWORD)&recvBytes, FALSE, NULL);
         }
         else{
             ErrorHandling("WSARECV() error");
         }
     }

     printf("Received message: %s\n", buf);
     WSACloseEvent(evObj);
     closesocket(hCRecvSock);
     closesocket(hLinSock);
     WSACleanup();
     return ;
 }

 void ErrorHandling(char *message) {
     fputs(message, stderr);
     fputc('\n', stderr);
 }

 void CompressSockets(SOCKET hSockArr[], int idx, int total){
     for (int i = idx; i < total; i++)
         hSockArr[i] = hSockArr[i + ];
 }

 void CompressEvents(WSAEVENT hEventArr[], int idx, int total){
     for (int i = idx; i < total; i++)
         hEventArr[i] = hEventArr[i + ];
 }

发送端：

 #pragma warning(disable:4996)
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <winsock2.h>

 void ErrorHandling(char *message);

 int main(int argc, char* argv[]) {
     if (argc != ) {
         printf("Usage : %s <IP> <port>\n", argv[]);
         exit();
     }

     WSADATA wsaData;
     SOCKET hSocket;
     SOCKADDR_IN sendAdr;

     WSABUF dataBuf;
     char msg[] = "Network is Computer!";
     int sendBytes = ;

     WSAEVENT evObj;
     WSAOVERLAPPED overlapped;

     if (WSAStartup(MAKEWORD(, ), &wsaData) != )
         ErrorHandling("WSAStartup() error");

     hSocket = WSASocket(PF_INET, SOCK_STREAM, , NULL, , WSA_FLAG_OVERLAPPED);
     memset(&sendAdr, , sizeof(sendAdr));
     sendAdr.sin_family = AF_INET;
     sendAdr.sin_addr.s_addr = inet_addr(argv[]);
     sendAdr.sin_port = htons(atoi(argv[]));

     if (connect(hSocket, (SOCKADDR*)&sendAdr, sizeof(sendAdr)) == SOCKET_ERROR)
         ErrorHandling("connect() error");
     else
         printf("Connected.......\n");

     evObj = WSACreateEvent();
     memset(&overlapped, , sizeof(overlapped));
     overlapped.hEvent = evObj;
     dataBuf.len = strlen(msg) + ;
     dataBuf.buf = msg;

     if (WSASend(hSocket, &dataBuf, , (LPDWORD)&sendBytes, , &overlapped, NULL) == SOCKET_ERROR){
         if (WSAGetLastError() == WSA_IO_PENDING){
             puts("Background data send");
             WSAWaitForMultipleEvents(, &evObj, TRUE, WSA_INFINITE, FALSE);
             WSAGetOverlappedResult(hSocket, &overlapped, (LPDWORD)&sendBytes, FALSE, NULL);
         }
         else{
             ErrorHandling("WSASend() error");
         }
     }
     printf("Send data size:%d\n", sendBytes);
     WSACloseEvent(evObj);
     closesocket(hSocket);
     WSACleanup();
     return ;
 }

 void ErrorHandling(char *message) {
     fputs(message, stderr);
     fputc('\n', stderr);
 }

2、基于Completion Routine

接收端：

 #include <stdio.h>
 #include <stdlib.h>
 #include <WinSock2.h>

 #define BUF_SIZE 1024
 void ErrorHandling(char *message);
 void CALLBACK CompRoutine(DWORD, DWORD, LPWSAOVERLAPPED, DWORD);

 WSABUF dataBuf;
 char buf[BUF_SIZE];
 int recvBytes = ;

 int main(int argc, char *argv[])
 {
     if (argc != ) {
         printf("Usage : %s <port>\n", argv[]);
         exit();
     }

     WSADATA wsaData;
     SOCKET hLinSock, hRecvSock;
     SOCKADDR_IN lisnAdr, recvAdr;

     WSAEVENT evObj;
     WSAOVERLAPPED overlapped;

     int idx, recvAdrSz, flags = ;

     if (WSAStartup(MAKEWORD(, ), &wsaData) != )
         ErrorHandling("WSAStartup() error.");

     hLinSock = socket(PF_INET, SOCK_STREAM, );
     memset(&lisnAdr, , sizeof(lisnAdr));
     lisnAdr.sin_family = AF_INET;
     lisnAdr.sin_addr.s_addr = htonl(INADDR_ANY);
     lisnAdr.sin_port = htons(atoi(argv[]));

     if (bind(hLinSock, (SOCKADDR*)&lisnAdr, sizeof(lisnAdr)) == SOCKET_ERROR)
         ErrorHandling("bind() error.");
     if (listen(hLinSock, ) == SOCKET_ERROR)
         ErrorHandling("listen() error.");

     recvAdrSz = sizeof(recvAdr);
     hRecvSock = accept(hLinSock, (SOCKADDR*)&recvAdr, &recvAdrSz);
     if (hRecvSock == INVALID_SOCKET)
         ErrorHandling("accept() error");

     memset(&overlapped, , sizeof(overlapped));

     dataBuf.len = BUF_SIZE;
     dataBuf.buf = buf;

     evObj = WSACreateEvent();

     if (WSARecv(hRecvSock, &dataBuf, , (LPDWORD)&recvBytes, (LPDWORD)&flags, &overlapped, CompRoutine) == SOCKET_ERROR)
     {
         if (WSAGetLastError() == WSA_IO_PENDING)
         {
             puts("Background data receive");
         }
         else{
             ErrorHandling("WSARECV() error");
         }
     }

     idx = WSAWaitForMultipleEvents(, &evObj, FALSE, WSA_INFINITE, TRUE);
     if (idx == WAIT_IO_COMPLETION)
         puts("Overlapped I/O Completed");
     else
         ErrorHandling("WSARecv() error");
     WSACloseEvent(evObj);
     closesocket(hRecvSock);
     closesocket(hLinSock);
     WSACleanup();
     return ;
 }

 void CALLBACK CompRoutine(DWORD dwError, DWORD szRecvBytes, LPWSAOVERLAPPED lpOverlapped, DWORD flags){

     if (dwError != ){
         ErrorHandling("CompRoutine error");
     }
     else{
         recvBytes = szRecvBytes;
         printf("Received message: %s\n", buf);
     }
 }

 void ErrorHandling(char *message) {
     fputs(message, stderr);
     fputc('\n', stderr);
 }

发送端：同上