/lianghe_work/article/details/46535859
想详细彻底地了解poll或看懂下面的代码请参考《Linux网络编程——I/O复用之poll函数》
代码：
#include <string.h>#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <sys/select.h>#include <sys/time.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <poll.h>#include <errno.h>#define OPEN_MAX 100 int main(int argc, char *argv[]){ //1.创建tcp监听套接字 int sockfd = socket(AF_INET, SOCK_STREAM, 0); //2.绑定sockfd struct sockaddr_in my_addr;bzero(&my_addr, sizeof(my_addr));my_addr.sin_family = AF_INET;my_addr.sin_port = htons(8000);my_addr.sin_addr.s_addr = htonl(INADDR_ANY);bind(sockfd, (struct sockaddr *)&my_addr, sizeof(my_addr)); //3.监听listenlisten(sockfd, 10); //4.poll相应参数准备 struct pollfd client[OPEN_MAX]; int i = 0, maxi = 0; for(;i<OPEN_MAX; i++)client[i].fd = -1;//初始化poll结构中的文件描述符fd client[0].fd = sockfd;//需要监测的描述符client[0].events = POLLIN;//普通或优先级带数据可读 //5.对已连接的客户端的数据处理 while(1){ int ret = poll(client, maxi+1, -1);//对加入poll结构体数组所有元素进行监测 //5.1监测sockfd(监听套接字)是否存在连接 if((client[0].revents & POLLIN) == POLLIN ){ struct sockaddr_in cli_addr; int clilen = sizeof(cli_addr); int connfd = 0; //5.1.1 从tcp完成连接中提取客户端connfd = accept(sockfd, (struct sockaddr *)&cli_addr, &clilen); //5.1.2 将提取到的connfd放入poll结构体数组中，以便于poll函数监测 for(i=1; i<OPEN_MAX; i++){ if(client[i].fd < 0){client[i].fd = connfd;client[i].events = POLLIN; break;}} //5.1.3 maxi更新 if(i > maxi)maxi = i; //5.1.4 如果没有就绪的描述符，就继续poll监测，否则继续向下看 if(--ret <= 0) continue;} //5.2继续响应就绪的描述符 for(i=1; i<=maxi; i++){ if(client[i].fd < 0) continue; if(client[i].revents & (POLLIN | POLLERR)){ int len = 0; char buf[128] = ""; //5.2.1接受客户端数据 if((len = recv(client[i].fd, buf, sizeof(buf), 0)) < 0){ if(errno == ECONNRESET)//tcp连接超时、RST{close(client[i].fd);client[i].fd = -1;} elseperror("read error:"); } else if(len == 0)//客户端关闭连接{close(client[i].fd);client[i].fd = -1;} else//正常接收到服务器的数据send(client[i].fd, buf, len, 0); //5.2.2所有的就绪描述符处理完了，就退出当前的for循环，继续poll监测 if(--ret <= 0) break; }}} return 0;}
运行结果：
