用select的时候 设置超时时间 就有一些数据收不到，当设置为轮询就可以啦。
这不科学啊！为毛？
#include <winsock.h> #include <stdio.h> #include <string> #pragma comment(lib, "ws2_32.lib") #define MYPORT 1234 // the port users will be connecting to #define BACKLOG 5 // how many pending connections queue will hold #define BUF_SIZE 200 int fd_A[BACKLOG]; // accepted connection fd int conn_amount; // current connection amount void showclient() { int i; printf("client amount: %d ", conn_amount); for (i = 0; i < BACKLOG; i++) { printf("[%d]:%d ", i, fd_A[i]); } printf(" "); } int main(void) { WSADATA wsaData; WSAStartup(0x0202, &wsaData); int sock_fd, new_fd; // listen on sock_fd, new connection on new_fd struct sockaddr_in server_addr; // server address information struct sockaddr_in client_addr; // connector's address information int sin_size; int yes = 1; char buf[BUF_SIZE]; int ret; int i; if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) { perror("socket"); exit(1); } //if (setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, NULL, sizeof(int)) == -1) { // perror("setsockopt"); // exit(1); //} server_addr.sin_family = AF_INET; // host byte order server_addr.sin_port = htons(MYPORT); // short, network byte order server_addr.sin_addr.s_addr = INADDR_ANY; // automatically fill with my IP memset(server_addr.sin_zero, ' ', sizeof(server_addr.sin_zero)); if (bind(sock_fd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) { perror("bind"); exit(1); } if (listen(sock_fd, BACKLOG) == -1) { perror("listen"); exit(1); } printf("listen port %d ", MYPORT); fd_set fdsr; int maxsock; struct timeval tv; conn_amount = 0; sin_size = sizeof(client_addr); maxsock = sock_fd; while (1) { // initialize file descriptor set FD_ZERO(&fdsr); FD_SET(sock_fd, &fdsr); // timeout setting tv.tv_sec = 0; tv.tv_usec = 0; // add active connection to fd set for (i = 0; i < BACKLOG; i++) { if (fd_A[i] != 0) { FD_SET(fd_A[i], &fdsr); } } ret = select(maxsock + 1, &fdsr, NULL, NULL, &tv); if (ret < 0) { perror("select"); break; } /*else if (ret == 0) { printf("timeout "); continue; }*/ // check every fd in the set for (i = 0; i < conn_amount; i++) { if (FD_ISSET(fd_A[i], &fdsr)) { ret = recv(fd_A[i], buf, sizeof(buf), 0); if (ret <= 0) { // client close printf("client[%d] close ", i); closesocket(fd_A[i]); FD_CLR(fd_A[i], &fdsr); fd_A[i] = 0; } else { // receive data if (ret < BUF_SIZE) memset(&buf[ret], ' ', 1); printf("client[%d] send:%s ", i, buf); } } } // check whether a new connection comes if (FD_ISSET(sock_fd, &fdsr)) { new_fd = accept(sock_fd, (struct sockaddr *)&client_addr, &sin_size); if (new_fd <= 0) { perror("accept"); continue; } // add to fd queue if (conn_amount < BACKLOG) { fd_A[conn_amount++] = new_fd; printf("new connection client[%d] %s:%d ", conn_amount, inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port)); if (new_fd > maxsock) maxsock = new_fd; } else { printf("max connections arrive, exit "); send(new_fd, "bye", 4, 0); closesocket(new_fd); break; } } //showclient(); } // close other connections for (i = 0; i < BACKLOG; i++) { if (fd_A[i] != 0) { closesocket(fd_A[i]); } } exit(0); }
/** * main.c * socket client * @date : 2011/11/27 * @author : MJN */ #include <stdio.h> #include <WinSock2.h> #pragma comment(lib, "ws2_32") #define MYPORT 1234 // the port users will be connecting to void CleanUpSocket( SOCKET clientSocket ) { printf("SocketError:%d ",WSAGetLastError()); closesocket(clientSocket); WSACleanup(); } int BytesSum = 0; int main() { int iResult; WORD wVersionRequested; WSADATA wsaData; SOCKET clientSocket; struct sockaddr_in clientService; wVersionRequested = MAKEWORD(2, 2); /* initialize windows socket */ iResult = WSAStartup(wVersionRequested, &wsaData); if (iResult != 0) { printf("WSAStartup failed with error: %d ", iResult); return -1; } else { printf("WSAStartup succeeded! "); } /* create client tcp socket */ clientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (clientSocket == INVALID_SOCKET) { printf("create socket failed with error: %d ", WSAGetLastError()); WSACleanup(); return -1; } else { printf("create socket(%d) succeeded! ", clientSocket); } //u_long mode = 0; //ioctlsocket(clientSocket,FIONBIO,&mode); /* connect to server */ clientService.sin_family = AF_INET; clientService.sin_port = htons(MYPORT); clientService.sin_addr.s_addr = inet_addr("127.0.0.1"); iResult = connect(clientSocket, (SOCKADDR *) &clientService, sizeof(clientService)); if (iResult == SOCKET_ERROR) { CleanUpSocket(clientSocket); return -1; } else { printf("connect succeed! "); } char lBuf[100] = "Hello Kitty!"; int i = 0; char lrecvbyf[1024]; while(++i < 20) { int lResult = send(clientSocket, lBuf, strlen(lBuf)+1,0); if (SOCKET_ERROR == lResult) { CleanUpSocket(clientSocket); return 0; } else { BytesSum += lResult; printf("BytesSum(%d) Bytes Send:%d ",BytesSum,lResult); } //lResult = recv(clientSocket, lrecvbyf, strlen(lrecvbyf)+1,0); //if (SOCKET_ERROR == lResult) //{ // CleanUpSocket(clientSocket); // return 0; //} //else //{ // lrecvbyf[lResult] = ' '; // printf("recv:%s ",lrecvbyf); // printf("BytesSum(%d) Bytes Send:%d ",BytesSum,lResult); //} } closesocket(clientSocket); WSACleanup(); return 0; }