Socket Freezed on RabbitMq disconnection on windows

[allancomar]

Hi. Looking at the differences between master version and 0.6 we notice that you changed the select to use an infinite time on code:

#elif defined(HAVE_SELECT)
  fd_set fds;
  int res;
  struct timeval tv;
  struct timeval *tvp;

  assert(event == AMQP_SF_POLLIN || event == AMQP_SF_POLLOUT);

start_select:
  FD_ZERO(&fds);
  FD_SET(fd, &fds);

  res = amqp_time_tv_until(deadline, &tv, &tvp);
  if (res != AMQP_STATUS_OK) {
    return res;
  }

  switch (event) {
    case AMQP_SF_POLLIN:
      res = select(fd + 1, &fds, NULL, NULL, tvp);
      break;
    case AMQP_SF_POLLOUT:
      res = select(fd + 1, NULL, &fds, NULL, tvp);
  }

  if (0 < res) {
    return AMQP_STATUS_OK;
  } else if (0 == res) {
    return AMQP_STATUS_TIMEOUT;
  } else {
    switch (amqp_os_socket_error()) {
      case EINTR:
        goto start_select;
      default:
        return AMQP_STATUS_SOCKET_ERROR;
    }
  }
  return AMQP_STATUS_OK;

If we try to connect to a closed port this code in windows stays on the select even if the port got open after ( like when you restart rabbitMq).

Do you have any sugestion to address this behavior?

Thanks, Allan

[alanxz]

The implementation changed from poll() to select() in 0.7 of rabbitmq-c, the effective timeout should not have changed between v0.6 and v0.7. Unfortunately I don't have access to a Win32 machine these days. Could you provide an example that uses this code that reproduces the issue you're seeing here?

[allancomar]

Hi. I just made a simple change on the code using the exception set. I am attaching the patch file here. If you want we can provide some assist to test and / or mantain the windows part of the code.

Left file: E:\Temp\rabbitmq-c-master\librabbitmq\amqp_socket.c
Right file: E:\projetos\rabbitmq-c-master\librabbitmq\amqp_socket.c
305a306
>   fd_set fdexceptset;
314a316,318
>   FD_ZERO(&fdexceptset);
>   FD_SET(fd, &fdexceptset);
>   
323c327
<       res = select(fd + 1, &fds, NULL, NULL, tvp);
---
>       res = select(fd + 1, &fds, NULL, &fdexceptset, tvp);
326c330
<       res = select(fd + 1, NULL, &fds, NULL, tvp);
---
>       res = select(fd + 1, NULL, &fds, &fdexceptset, tvp);
328a333,335
>   if (FD_ISSET(fd, &fdexceptset))
>     return AMQP_STATUS_SOCKET_ERROR;
> 
332c339
<     return AMQP_STATUS_TIMEOUT;
---
>     goto start_select;

Thank you, Allan

[allancomar]

oh my. Can I send you the patch in any other way?

See you!

[alanxz]

If you have a patch, please open a pull-request.

For my own reference, select(), the exceptfds need to be set to detect connection failure. I believe it was this way before, then somehow got lost when we switched from select -> poll -> nonblocking -> select() only on Win32.

[allancomar]

just commited the code. Is anything else I should do?

[alanxz]

Could you open a pull-request with the changed code?

Here's some instructions on how to get this done if you're not familiar:
https://help.github.com/articles/using-pull-requests/

[alanxz]

@allancomar could you try pulling down the branch referenced in #306 and see if it fixes your issue?

[allancomar]

Sry Alan. I just miss that. will do it ASAP ;)

On Wed, Oct 14, 2015 at 12:48 AM, Alan Antonuk notifications@github.com
wrote:

@allancomar https://github.com/allancomar could you try pulling down
the branch referenced in #306
#306 and see if it fixes your
issue?

—
Reply to this email directly or view it on GitHub
#297 (comment).

Allan.

[zengzhenbo]

I met same problem on Linux , when use SimpleAMQPClient to create channel by CreateFromUri, and the version of rabbitmq-c is v0.7.1
The latest release noted that fixed the bug: Connection failure results in hang on Win32
Is this fixed solve the problem on Linux version?