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