Re: [Libevent-users] Add multiples bufferevents on one base then lead to some errors.

["Michael (Tieying) Zhang" <tieyingz@xxxxxxxxxx>]

ï

Hi Fang,

 

I think you can use the example code from the documentation, and you don't need to set it nonblocking manually in this way.

 

        struct event_base *base;
        struct evconnlistener *listener;
        struct sockaddr_in sin;

        int port = 9876;

        if (argc > 1) {
                port = atoi(argv[1]);
        }
        if (port<=0 || port>65535) {
                puts("Invalid port");
                return 1;
        }

        base = event_base_new();
        if (!base) {
                puts("Couldn't open event base");
                return 1;
        }

        /* Clear the sockaddr before using it, in case there are extra
         * platform-specific fields that can mess us up. */
        memset(&sin, 0, sizeof(sin));
        /* This is an INET address */
        sin.sin_family = AF_INET;
        /* Listen on 0.0.0.0 */
        sin.sin_addr.s_addr = htonl(0);
        /* Listen on the given port. */
        sin.sin_port = htons(port);

        listener = evconnlistener_new_bind(base, accept_conn_cb, NULL,
            LEV_OPT_CLOSE_ON_FREE|LEV_OPT_REUSEABLE, -1,
            (struct sockaddr*)&sin, sizeof(sin));
        if (!listener) {
                perror("Couldn't create listener");
                return 1;
        }
        evconnlistener_set_error_cb(listener, accept_error_cb);

        event_base_dispatch(base);

 

---

tieyingz@xxxxxxxxxx

 

From: Tim Chou

Date: 2016-03-23 18:31

To: libevent-users

Subject: [Libevent-users] Add multiples bufferevents on one base then lead to some errors.

Hi all,

Sorry to disturb you. 

I'm writing a server. I plan to use one thread serving ten connections.

I use bufferevent_setcb to register 10 sockets to one base. I also use a global variable to count the number.

I think I can register the bufferevent on one base before I start a pthread to dispatch().

However, I always get the error: [err] event_queue_insert: 0x146dfc8(fd 32) already on queue 2

If I create one thread for one base with only one bufferevent, then the program works well.

Does anyone help me?

Looking forward to your replies.

Thanks,

Fang

Below is my code. 

on_accept(){

...

  evutil_make_socket_nonblocking(client_fd);

  if (num_dist==0) {

    evbase=event_base_new();

  }

  /* Create a buffer event. */

  bev = malloc(sizeof(struct bufferevent));

  bev = bufferevent_socket_new(evbase, client_fd, BEV_OPT_CLOSE_ON_FREE);

  bufferevent_setcb(bev, buffered_on_read, buffered_on_write, NULL, NULL);

  bufferevent_enable(bev, EV_READ|EV_WRITE|EV_PERSIST);

  num_dist++;

  if (num_dist==10) {

  tid=malloc(sizeof(pthread_t));

  pthread_mutex_lock(&mutex);

  total_thread++;

  printf("%d thread creates.\n",total_thread);

  pthread_mutex_unlock(&mutex);

  pthread_create(&tid, NULL, &server_job_function, (void *) evbase);

  num_dist=0;

  }

}