原文:Linux下C语言多线程,网络通讯简单聊天程序html
功能描述:程序应用多线程技术,但是实现1对N进行网络通讯聊天。但至今没想出合适的退出机制,除了用Ctr+C。出于演示目的,这里采用UNIX域协议(文件系统套接字),程序分为客户端和服务端。应用select函数来实现异步的读写操做。服务器
先说一下服务端:首先先建立套接字,而后绑定,接下进入一个无限循环,用accept函数,接受“链接”请求,而后调用建立线程函数,创造新的线程,进入下一个循环。这样每当有一个新的“链接”被接受都会建立一个新的线程,实现1对N的网络通讯。在服务端程序中线程中用一个buffer读写,为了不错误,这时就要给关键代码加上互斥锁work_mutex,具体见代码。网络
#include<stdio.h> #include<stdlib.h> #include<string.h> #include<pthread.h> #include<sys/socket.h> #include<sys/un.h> #include<unistd.h> #include<semaphore.h> //这里没有用二进制信号量能够删掉 char buffer[1024]; //读写用的区域 sem_t bin_sem; //没用到的二进制信号量,能够删掉 void *pthread_function(void *arg); //线程入口函数声明 pthread_mutex_t work_mutex; //声明互斥锁 int main(){ int result; //整数变量用来储存调用函数的返回值 struct sockaddr_un server_address, client_address; //UNIX域的套接字,server_address用于服务端的监听,client_address用于客户端链接后的套接字 int client_len; //链接后,accept函数会把客户端的地址的长度储存在这 int server_socketfd, client_socketfd;//服务端和客户端的套接字文件描述符 pthread_t a_thread; //线程ID标志 pthread_attr_t thread_attr; //线程的属性,后面能够看的,被我注释掉了,没用到,能够删掉。 result = sem_init(&bin_sem, 0, 1); //初始化二进制信号量,由于用了互斥锁,因此没用到,能够删掉 if(result != 0){ perror("sem_init"); exit(EXIT_FAILURE); } result = pthread_mutex_init(&work_mutex, NULL);//初始化互斥锁 if(result != 0){ perror("pthread_mutex_init"); exit(EXIT_FAILURE); } server_socketfd = socket(AF_UNIX, SOCK_STREAM, 0);//建立套接字,用TCP链接方式,出于演示目的只用UNIX域套接字。 server_address.sun_family = AF_UNIX; strcpy(server_address.sun_path, "server_socket"); unlink("server_socket"); //在绑定以前,把之前存在当前目录下的套接字删除 result = bind(server_socketfd, (struct sockaddr*)&server_address, sizeof(server_address)); //绑定 if(result != 0){ perror("bind"); exit(EXIT_FAILURE); } result = listen(server_socketfd, 5);//监听,最多容许5个链接请求 if(result != 0){ perror("listen"); exit(EXIT_FAILURE); } client_len = sizeof(client_address); while(1){ //开始进入无限循环 /* printf("If you want to quit, please enter 'quit'\n"); printf("Do you want to accept a connectiong\n"); memset(buffer, '\0', sizeof(buffer)); fgets(buffer, sizeof(buffer), stdin); if((strncmp("quit", buffer, 4))==0) break; */ client_socketfd = accept(server_socketfd, (struct sockaddr*)&client_address, &client_len); //接受一个链接请求 /* result = pthread_attr_init(&thread_attr); if(result != 0){ perror("pthread_attr_init"); exit(EXIT_FAILURE); } result = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); if(result != 0){ perror("pthread_attr_setdetachstate"); exit(EXIT_FAILURE); } */ result = pthread_create(&a_thread, NULL, pthread_function, (void *)client_socketfd); //成功接受一个请求后,就会建立一个线程,而后主线程又进入accept函数,若是此时没有链接请求,那么主线程会阻塞 if(result != 0){ perror("pthread_create"); exit(EXIT_FAILURE); } } } void *pthread_function(void *arg){ //线程入口函数,每调用一次pthread_create,都会建立一个新的线程 int fd = (int) arg; //把函数参数,即链接成功后的套接字,赋给fd. int result; fd_set read_fds; //文件描述符集合,用于select函数 int max_fds; //文件描述符集合的最大数 printf("%d id has connected!!\n", fd); while (1){ FD_ZERO(&read_fds);//清空集合 FD_SET(0, &read_fds);//将标准输入放入监听的文件描述符集合, 这个用于读取标准输入,即键盘的输入 FD_SET(fd, &read_fds);//将链接后的客户文件描述符放入监听的文件描述符集合, 这个用于向客户端读取数据 max_fds = fd + 1; // sem_wait(&bin_sem); pthread_mutex_lock(&work_mutex); //对关键区域上锁 printf("%d has get the lock\n", fd); result = select(max_fds, &read_fds, (fd_set *)NULL, (fd_set *)NULL, (struct timeval*)NULL); //开始监听那些文件描述符出于可读状态 if(result < 1){ printf("select"); } if(FD_ISSET(0, &read_fds)){ //若是标准输入处于可读状态,说明键盘有所输入,将输入的数据存放在buffer中,而后向客户端写回,若是输入“quit”将会退出一个聊天线程 memset(buffer, '\0', sizeof(buffer)); //保险起见,清零 fgets(buffer, sizeof(buffer), stdin); if((strncmp("quit", buffer, 4))==0){ printf("You have terminaled the chat\n"); // sem_post(&bin_sem); pthread_mutex_unlock(&work_mutex); break; } else{ result=write(fd, buffer, sizeof(buffer)); if(result==-1){ perror("write"); exit(EXIT_FAILURE); } } } if(FD_ISSET(fd, &read_fds)){ //若是客户套接字符可读,那么读取存放在buffer中,而后显示出来,若是对方中断聊天,那么result==0 memset(buffer, '\0', sizeof(buffer)); result = read(fd, buffer, sizeof(buffer)); if(result == -1){ perror("read"); exit(EXIT_FAILURE); } else if(result == 0){ printf("The other side has terminal the chat\n"); // sem_post(&bin_sem); pthread_mutex_unlock(&work_mutex); break; } else{ printf("receive message: %s", buffer); } } pthread_mutex_unlock(&work_mutex); //解锁 sleep (1); //若是没有这一行,当前线程会一直占据buffer.让当前线程暂停一秒能够实现1对N的功能。 // sem_post(&bin_sem); // sleep (1); } // printf("I am here\n"); close(fd); pthread_exit(NULL); }
读者能够对比一下http://blog.csdn.net/hwz119/archive/2007/03/19/1534233.aspx多线程
读者能够发现,连接网络中的程序须要结束当前一个聊天才能进行下一个聊天,而这个服务端能够同时对N我的进行聊天,尽管有些bug(若是客户端对方回复太快太频繁,服务端的锁就会切换来切换去,没法回复到正确的客户端)。异步
客户端跟服务端很像,但比较简单。这里面就不注释了。这两个程序我都运行过。。。没什么基本大的问题。。可是功能很不完善。。。还需改进。。。。。socket
#include<stdio.h> #include<stdlib.h> #include<sys/socket.h> #include<sys/un.h> #include<string.h> #include<sys/types.h> #include<sys/time.h> int main() { int result; int socketfd; int len; struct sockaddr_un address; fd_set read_fds, test_fds; int fd; int max_fds; char buffer[1024]; socketfd = socket(AF_UNIX, SOCK_STREAM, 0); address.sun_family = AF_UNIX; strcpy(address.sun_path, "server_socket"); len = sizeof(address); result = connect(socketfd, (struct sockaddr*)&address, len); if(result == -1) { perror("connect"); exit(EXIT_FAILURE); } FD_ZERO(&read_fds); FD_SET(0, &read_fds); FD_SET(socketfd, &read_fds); max_fds = socketfd +1; printf("Chat now!!\n"); while(1) { test_fds = read_fds; result = select(max_fds, &test_fds, (fd_set *)NULL, (fd_set *)NULL, (struct timeval*)NULL); if(result < 1) { perror("select"); exit(EXIT_FAILURE); } if(FD_ISSET(0, &test_fds)) { memset(buffer, '\0', sizeof(buffer)); // printf("send:"); fgets(buffer, sizeof(buffer), stdin); if((strncmp("quit", buffer, 4))== 0) { printf("\nYou are going to quit\n"); break; } result = write(socketfd, buffer, sizeof(buffer)); if(result == -1) { perror("write"); exit(EXIT_FAILURE); } } if(FD_ISSET(socketfd, &test_fds)) { memset(buffer, '\0', sizeof(buffer)); result = read(socketfd, buffer, sizeof(buffer)); if(result == -1) { perror("read"); exit(EXIT_FAILURE); } else if(result == 0) { printf("The other side has termianl chat!\n"); break; } else { printf("recieve: %s", buffer); } } } close(socketfd); exit(EXIT_SUCCESS); }