check-epoll-level-flag.c

#include "stdio.h"
#include "unistd.h"
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <pthread.h>
#include <sys/epoll.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>

#define MAX_EVENTS 10


int setnonblocking(int fd){
  int flag, ret;
  flag = fcntl(fd, F_GETFL, NULL);
  flag |= O_NONBLOCK;
  ret = fcntl(fd, F_SETFL, flag);
  return ret;
}


int start_listen_server(const char * host, int port){
  int s_sock, flag;
  struct sockaddr_in addr;
  printf("host %s, port %d\n", host, port);
  memset(&addr, 0, sizeof(addr));
  inet_aton(host, &addr.sin_addr);
  addr.sin_family = AF_INET;
  addr.sin_port = htons(port);
  s_sock = socket(AF_INET, SOCK_STREAM, 0);
  flag = 1;
  setsockopt(s_sock, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof(flag));
  setnonblocking(s_sock);
  bind(s_sock, (struct sockaddr *)&addr, sizeof(struct sockaddr));
  listen(s_sock, 5);
  return s_sock;
}


const char * get_instance_name(int thread_mode){
  return thread_mode ? "thread": "process";
}


void * poll_loop(void * args){
  int nfds, conn_sock, listen_sock, addrlen, id, thread_mode;
  struct sockaddr_in addr;
  struct epoll_event ev, events[MAX_EVENTS];
  int epollfd, et_mode;
  
  listen_sock = ((int *)args)[0];
  thread_mode = ((int *)args)[1];
  et_mode = ((int *)args)[2];
  
  printf("sock %d, thread_mode %d, et mode %d.\n", listen_sock, thread_mode, et_mode);
  
  if(thread_mode == 1) id = pthread_self();
  else id = getpid();

  printf("run in %s %d.\n", get_instance_name(thread_mode), id);
  
  epollfd = epoll_create1(0);

  if (epollfd == -1) {
    printf("epoll_create1\n");
    exit(1);
  }

  ev.events = EPOLLIN;
  if(et_mode) ev.events |= EPOLLET;

  ev.data.fd = listen_sock;
  if (epoll_ctl(epollfd, EPOLL_CTL_ADD, listen_sock, &ev) == -1) {
    printf("epoll_ctl: listen_sock\n");
    exit(1);
  }

  while(1){
    printf("epoll wait in %s %u.\n", get_instance_name(thread_mode), id);
    nfds = epoll_wait(epollfd, events, MAX_EVENTS, -1);
    printf("finish waiting with %d fds in %s %u.\n", nfds, get_instance_name(thread_mode), id);
    if (nfds == -1) {
      printf("epoll_wait error\n");
      break;
    }

    while(1){
      conn_sock = accept(listen_sock, (struct sockaddr *) &addr, &addrlen);
      if(conn_sock == -1) {
	if(errno == EAGAIN || errno == EWOULDBLOCK){
	  printf("accept failure in %s %u\n", get_instance_name(thread_mode), id);
	  break;
	}
      }
      else if(conn_sock > 0){
	printf("accept succes %s %u\n", get_instance_name(thread_mode), id);
      }
    }
  }

  printf("run in %s %u.\n", get_instance_name(thread_mode), id);
}


int run_thread_server(int argc, char * argv[]){
  int server_sock, et_mode;
  pthread_t threads[2];
  int args[2];

  if(argc > 4) et_mode = atoi(argv[4]);
  else et_mode = 0;

  server_sock = start_listen_server(argv[2], atoi(argv[3]));

  args[0] = server_sock;
  args[1] = 1;
  args[2] = et_mode;
  
  pthread_create(&threads[0], NULL, poll_loop, &args[0]);
  pthread_create(&threads[1], NULL, poll_loop, &args[0]);

  pthread_join(threads[0], NULL);
  pthread_join(threads[1], NULL);

  return 0;
}


int run_server(int argc, char * argv[]){
  int server_sock, et_mode, pid;
  int args[2];

  if(argc > 4) et_mode = atoi(argv[4]);
  else et_mode = 0;

  server_sock = start_listen_server(argv[2], atoi(argv[3]));
  
  pid = fork();
  if(pid == -1){
    printf("fork error.\n");
    exit(0);
  }

  args[0] = server_sock;
  args[1] = 0;
  args[2] = et_mode;
  
  if(pid == 0){
    poll_loop(&args[0]);
  }
  else{
    poll_loop(&args[0]);
    waitpid(pid, NULL, 0);
  }

  return 0;
}


int main(int argc, char * argv[]){
  if(strcmp(argv[1], "thread") == 0) run_thread_server(argc, argv);
  else run_server(argc, argv);
}