求助：read from socket:0

【 在 jackybupt 的大作中提到: 】 : read from socket:0 : 结果返回0 : 对方没有执行断开，怎么会读到0，难道自动断开吗？ : ................... 缓冲区中没有数据可读了，就可以返回零。

【 在 jackybupt 的大作中提到: 】 : read from socket:0 : 结果返回0 : 对方没有执行断开，怎么会读到0，难道自动断开吗？ : ................... 最好把你的代码贴出来。

是这样的： 我一个服务器连3个客户端，因为要发送文件给这3个客户端，所以我在服务器端手动起了一个客户端，这个客户端会和服务器连接，然后发送文件，大概过程就是这样 有些时候发送文件成功，有些时候却是这个手动起的客户端自动和服务器断开，结果显示read from socket:0 都不知道是啥原因？

贴代码

代码

【 在 jackybupt 的大作中提到: 】 : 是这样的： : 我一个服务器连3个客户端，因为要发送文件给这3个客户端，所以我在服务器端手动起了一个客户端，这个客户端会和服务器连接，然后发送文件，大概过程就是这样 : 有些时候发送文件成功，有些时候却是这个手动起的客户端自动和服务器断开，结果显示read from socket:0 都不知道是啥原因 如果读到文件末尾会有这样情况的。 你的客户端应该判断是否读到文件末尾，如果是，应该，close掉。服务器端回受到一个返回为0的数据报。然后服务器close。完成这次socket通信。

因为都没发送文件，所以确定不是读到文件末尾的问题 一般什么情况下TCP SOCKET会自动断开呢？

【 在 jackybupt 的大作中提到: 】 : 因为都没发送文件，所以确定不是读到文件末尾的问题 : 一般什么情况下TCP SOCKET会自动断开呢？ 还是贴你的代码吧。 socket断的情况挺复杂的，你不贴出代码，谁也不知道是你的逻辑问题还是网络问题。

我是调用协议栈的 没法帖啊 下面这个是协议栈监听的线程代码： #include "msrp_network.h" /* Receiving thread */ void *msrp_recv_thread(void *data) { char buffer[2600]; local_events(MSRP_LOG, "Thread created"); int err = 0, fd = 0, client = 0; struct sockaddr_in client_address; unsigned int addrlen = sizeof(struct sockaddr); fd_set tempfds; FD_ZERO(&recv_fds); /* Create a secret socket pair to unblock select, needed to update recv_fds */ if(socketpair(AF_UNIX, SOCK_STREAM, 0, recv_pair) < 0) local_events(MSRP_ERROR, "Error setting Socket pair..."); FD_SET(recv_pair[0], &recv_fds); if(recv_pair[0] > recv_fdmax) recv_fdmax = recv_pair[0]; while(msrp_exists) { tempfds = recv_fds; err = select(recv_fdmax+1, &tempfds, NULL, NULL, (struct timeval *)NULL); local_events(MSRP_LOG, "Select unblocked (err = %d)", err); if(err < 0) break; else { /* Check which descriptor has data here ... */ for(fd = 0; fd <= recv_fdmax; fd++) { if(FD_ISSET(fd, &tempfds)) { local_events(MSRP_LOG, "File descriptor %d is set", fd); if(fd == recv_pair[0]) { local_events(MSRP_LOG, "Unblocking select to refresh fdset"); /* Unblock select to refresh fds */ recv(fd, buffer, 2277, 0); continue; } /* TODO check if incoming message is for session or conference */ /* Get the session associated with this fd */ msrp_session *session = msrp_session_get(fd); if(session) { /* It's a valid session */ if(!session->from) { /* Drop the buffer */ local_events(MSRP_LOG, "No session associated to file descriptor %d, dropping buffer", fd); err = recv(fd, buffer, 2600, 0); if(err < -1) local_events(MSRP_LOG, "Read error on file descriptor %d", fd); else if(err == 0) local_events(MSRP_LOG, "File descriptor %d disconnected", fd); else local_events(MSRP_LOG, "Dropped %d bytes (file descriptor %d)", fd); if(session->type == MSRP_ENDPOINT) local_ep_callback(MSRP_ENDPOINT_DUMPED, session->session, 0, NULL, 0); msrp_recv_del_fd(fd); continue; } if((session->from->flags & MSRP_PASSIVE) && (fd == session->from->fd)) { /* It's a 'connect', accept */ client = accept(fd, (struct sockaddr *)(&client_address), &addrlen); if(client < 0) continue; if(session->type == MSRP_SWITCH) { // /* This session belongs to a conference, check the sender's address to match it */ if(msrp_conference_match_user((msrp_conference *)session->session, client, &client_address) < 0) { local_events(MSRP_LOG, "Unexpected connection to switch from %s:%hu (fd %d)", inet_ntoa(client_address.sin_addr) ? inet_ntoa(client_address.sin_addr) : "???.???.???.???", ntohs(client_address.sin_port), client); close(client); } else { local_events(MSRP_LOG, "Conference user connected from %s:%hu (fd %d)", inet_ntoa(client_address.sin_addr) ? inet_ntoa(client_address.sin_addr) : "???.???.???.???", ntohs(client_address.sin_port), client); msrp_recv_add_fd(client); } } else { /* Normal session (TODO handle relays) */ msrp_recv_del_fd(session->from->fd); /* Stop accepting connections */ if(session->to) { local_events(MSRP_LOG, "Peer '%s' connected from %s:%hu (fd %d)", session->to->sessionid ? session->to->sessionid : "??", inet_ntoa(client_address.sin_addr) ? inet_ntoa(client_address.sin_addr) : "???.???.???.???", ntohs(client_address.sin_port), client); msrp_recv_add_fd(client); session->to->fd = client; if(session->type == MSRP_ENDPOINT) local_ep_callback(MSRP_REMOTE_CONNECT, session->session, 0, NULL, 0); } else { local_events(MSRP_LOG, "Unexpected connection from from %s:%hu (fd %d)", inet_ntoa(client_address.sin_addr) ? inet_ntoa(client_address.sin_addr) : "???.???.???.???", ntohs(client_address.sin_port), client); close(client); } } } else { /* There's data to read from our peer in this session */ err = read(fd, buffer, 2600); printf("Read from socket:%d\n",err); if(err < 1) { /* This client disconnected */ local_events(MSRP_LOG, "Peer (fd %d) disconnected", fd); /* FIXME remove session */ if(session->to && (fd == session->to->fd)) { if(session->type == MSRP_ENDPOINT) { local_ep_callback(MSRP_REMOTE_DISCONNECT, session->session, 0, NULL, 0); msrp_session_destroy(session); } else if(session->type == MSRP_SWITCH) { msrp_conf_user *user = (msrp_conf_user *)session->to->opaque; if(user) msrp_conference_remove_user((msrp_conference *)session->session, user->ID); } } else if(session->from && (fd == session->from->fd)) { if(session->type == MSRP_ENDPOINT) local_ep_callback(MSRP_LOCAL_DISCONNECT, session->session, 0, NULL, 0); msrp_session_destroy(session); } msrp_recv_del_fd(fd); } else { /* Read chunk */ local_events(MSRP_LOG, "Incoming buffer (%d bytes), parse it", err); msrp_buffer_parse(fd, session, buffer, err); } } } else { local_events(MSRP_LOG, "No session/relay/conference associated to file descriptor %d yet", fd); err = recv(fd, buffer, 2600, 0); if(err < -1) local_events(MSRP_LOG, "Read error on file descriptor %d", fd); else if(err == 0) local_events(MSRP_LOG, "File descriptor %d disconnected", fd); else { /* Drop the buffer */ local_events(MSRP_LOG, "Dropped %d bytes (file descriptor %d)", fd); msrp_recv_del_fd(fd); } continue; } } } } } pthread_exit(0); } /* Add a new file descriptor to the receiving set for select */ void msrp_recv_add_fd(int fd) { if(fd < 0) return; local_events(MSRP_LOG, "File descriptor %d added to fdset", fd); pthread_mutex_lock(&recv_lock); /* Add the new file descriptor to the receiving fds */ FD_SET(fd, &recv_fds); if(fd > recv_fdmax) recv_fdmax = fd; /* Unblock the select by writing a byte onto one end of the socket pair */ char ch = '\0'; int err = send(recv_pair[1], &ch, 1, 0); if(err < 1) local_events(MSRP_ERROR, "Error unblocking select"); pthread_mutex_unlock(&recv_lock); } /* Remove a new file descriptor from the receiving set for select */ void msrp_recv_del_fd(int fd) { if(fd < 0) return; local_events(MSRP_LOG, "File descriptor %d removed from fdset", fd); pthread_mutex_lock(&recv_lock); /* Remove the file descriptor from the receiving fds */ int deleted_fd = fd; FD_CLR(fd, &recv_fds); /* Unblock the select by writing a byte onto one end of the socket pair */ send(recv_pair[1], '\0', 1, 0); pthread_mutex_unlock(&recv_lock); close(deleted_fd); shutdown(deleted_fd, SHUT_RDWR); }