epoll.c

#include <unistd.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/epoll.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>

typedef struct {
  int fd;
  int msg_len;
  char *msg;
} EchoEvent;

int make_non_blocking(int fd) {
  int flags;
  flags = fcntl(fd, F_GETFL, 0);
  flags |= O_NONBLOCK;
  fcntl(fd, F_SETFL, flags);
  return 0;
}

int main(int argc, char *argv[]) {
  int efd, sfd;
  struct sockaddr_in addr = { 0 };
  sfd = socket(AF_INET, SOCK_STREAM, 0);
  addr.sin_family = AF_INET;
  addr.sin_addr.s_addr = INADDR_ANY;
  addr.sin_port = htons(8080);
  int r = bind(sfd, (struct sockaddr*)&addr, sizeof(addr));
  printf("%d\n", r);
  make_non_blocking(sfd);
  listen(sfd, 10);
  char msg[] = "listen at 8080\n";
  write(1, msg, sizeof(msg));

  efd = epoll_create1(0);
  int evs_n = 10;
  struct epoll_event ev;
  struct epoll_event evs[10];
  ev.data.fd = sfd;
  ev.events = EPOLLIN | EPOLLET;
  epoll_ctl(efd, EPOLL_CTL_ADD, sfd, &ev);

  int buff_size = 300;
  char buff[310];
  while (1) {
    int n, i;
    n = epoll_wait(efd, evs, evs_n, -1);
    printf("%d\n", n);
    for (i=0; i<n; i++) {
      if (evs[i].data.fd == sfd) {
        char *msg = "get a connection\n";
        printf("%s", msg);
        int len = sizeof(addr);
        int cli_fd = accept(sfd, (struct sockaddr*)&addr, &len);
        make_non_blocking(cli_fd);
        ev.data.fd = cli_fd;
        ev.events = EPOLLIN | EPOLLET;
        epoll_ctl(efd, EPOLL_CTL_ADD, cli_fd, &ev);
      }
      else if (evs[i].events & EPOLLIN) {
        int c;
        c = read(evs[i].data.fd, buff, buff_size);
        if (c == 0) {
          char *msg = "remote close";
          printf("%s\n", msg);
          close(evs[i].data.fd);
          continue;
        }
        write(1, buff, c);
        //ev.data.fd = evs[i].data.fd;
        //ev.events = EPOLLOUT | EPOLLET;
        //epoll_ctl(efd, EPOLL_CTL_MOD, ev.data.fd, &ev);
      }
    }
  }
  return 0;
}