poll实现echo服务器的并发

代码实现

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <sys/time.h>
#include <unistd.h>
#include <sys/poll.h>#define MAX_CLI 50int clients[MAX_CLI];
struct sockaddr_in clientaddr;
socklen_t len = sizeof(clientaddr);int socket_create(int port) {//创建并绑定网络监听的socket套接字int fd;if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {perror("socket");exit(EXIT_FAILURE);}struct sockaddr_in addr;bzero(&addr, sizeof(addr));addr.sin_family = AF_INET;addr.sin_addr.s_addr = INADDR_ANY;addr.sin_port = htons(port);if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {perror("bind");exit(EXIT_FAILURE);}if (listen(fd, 20) < 0) {perror("listen");exit(EXIT_FAILURE);}return fd;
}
int recv_msg(int fd, char *buff, int size) { int rsize = recv(fd, buff, sizeof(char ) * size, 0);if (rsize <= 0) {if (rsize == 0) return 0;return -1;}printf("Recv : %s\n", buff);return 1;
}int send_msg(int fd, char *buff, int size) {int ssize = send(fd, buff, sizeof(char ) * size, 0);if (ssize <= 0) {if (ssize == 0) return 0;return -1;}printf("Send success!\n");return 1;
}void echo_work(int server_listen) {struct pollfd fds[MAX_CLI + 1];fds[0].fd = server_listen;fds[0].events = POLLIN;int max_fd = server_listen;while (1) {int ret = poll(fds, MAX_CLI + 1, -1);if (ret == -1) {perror("poll");exit(EXIT_FAILURE);}//接受连接请求if (fds[0].revents & POLLIN) {int client_fd;if ((client_fd = accept(server_listen, (struct sockaddr *)&clientaddr, &len)) < 0) {perror("accept");exit(EXIT_FAILURE);}printf("one client connect success!\n");for (int i = 0; i < MAX_CLI; i++) {if (clients[i] == -1) {clients[i] = client_fd;break;}}//更新pollfd数组for (int i = 1; i  <= MAX_CLI; i++) {if (clients[i - 1] != -1) {fds[i].fd = clients[i - 1];fds[i].events = POLLIN;max_fd = fds[i].fd > max_fd ? fds[i].fd : max_fd;}}}//检查客户端套接字是否有数据可读for (int i = 1; i <= MAX_CLI; i++) {if (fds[i].revents & POLLIN) {char buff[1024] = {0};if (recv_msg(fds[i].fd, buff, 1024) <= 0) {printf("disconnect one client  OR error!\n");close(fds[i].fd);clients[i - 1] = -1;continue;} if (send_msg(fds[i].fd, buff, 1024) <= 0) {printf("disconnect one client  OR error!\n");close(fds[i].fd);clients[i - 1] = -1;continue;} }}} return ;
}int main() {int server_listen;if ((server_listen = socket_create(8080)) < 0) {perror("socket_create");exit(EXIT_FAILURE);}for(int i = 0; i < MAX_CLI; i++) clients[i] = -1;echo_work(server_listen);return 0;
}

运行效果