IO多路轉接之epoll
阿新 • • 發佈：2019-02-13
#include <stdio.h> #include <string.h> #include <stdlib.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <sys/epoll.h> #include <unistd.h> #include <fcntl.h> int start_up(char* ip, short port) { int listen_sock = socket(AF_INET, SOCK_STREAM, 0); if (listen_sock < 0) { perror("socket"); exit(2); } struct sockaddr_in local; local.sin_family = AF_INET; local.sin_port = htons(port); local.sin_addr.s_addr = inet_addr(ip); if (bind(listen_sock, (struct sockaddr*)&local, sizeof(local))) { perror("bind"); exit(3); } if (listen(listen_sock, 5) < 0) { perror("listen"); exit(4); } return listen_sock; } void Usage(const char* proc) { printf("Usage: %s [ip] [port]\n", proc); } static int set_nonblock(int fd) { int fl = fcntl(fd, F_GETFL); fcntl(fd, F_SETFL, fl|O_NONBLOCK); } int main(int argc, char* argv[]) { if (argc != 3) { Usage(argv[0]); exit(1); } int listen_sock = start_up(argv[1], atoi(argv[2])); int epfd = epoll_create(256); if (epfd < 0) { perror("epoll_create"); exit(5); } struct epoll_event ev; ev.events = EPOLLIN; ev.data.fd = listen_sock; // 註冊唯一檔案描述符：關注讀事件 epoll_ctl(epfd, EPOLL_CTL_ADD, listen_sock, &ev); struct epoll_event ready_events[64]; int timeout = -1; while (1) { int num = epoll_wait(epfd, ready_events, 64, timeout); if (num < 0) { perror("epoll_wait"); } else if (num == 0) { printf("timeout...\n"); } else { int i = 0; for (; i < num; i++) { // listen_sock 就緒 int new_fd = ready_events[i].data.fd; if (new_fd == listen_sock && (ready_events[i].events & EPOLLIN)) { struct sockaddr_in client; socklen_t len = sizeof(client); int new_fd = accept(listen_sock, (struct sockaddr*)&client, &len); if (new_fd < 0) { perror("accept"); } else { printf("get a new connect: %s:%d\n", inet_ntoa(client.sin_addr), ntohs(client.sin_port)); ev.events = EPOLLIN; ev.data.fd = new_fd; epoll_ctl(epfd, EPOLL_CTL_ADD, new_fd, &ev); } } else if (ready_events[i].events & EPOLLIN) // normal events { char buf[1024]; ssize_t s = read(new_fd, buf, sizeof(buf)-1); if (s < 0) { perror("read"); } else if (s == 0) { printf("client closed...\n"); epoll_ctl(epfd, EPOLL_CTL_DEL, new_fd, NULL); close(new_fd); } else { buf[s] = 0; printf("clinet# %s\n", buf); ev.events = EPOLLOUT | EPOLLET; ev.data.fd = new_fd; epoll_ctl(epfd, EPOLL_CTL_MOD, new_fd, &ev); } } else if (ready_events[i].events & EPOLLOUT) { char buf[1024]; strcpy(buf, "HTTP/1.0 200 OK\r\n\r\n<html><h1>hello world ! =_=||</h1></html>"); write(new_fd, buf, strlen(buf)); epoll_ctl(epfd, EPOLL_CTL_DEL, new_fd, NULL); close(new_fd); } } } } // while return 0; }