Boost C++ Libraries: Ticket #3238: asio, kqueue_reactor, result of kevent() isn't checked for error

status, version changed; resolution set

anonymous — Mon, 29 Nov 2010 05:12:40 GMT

status new → closed
version Boost 1.38.0 → Boost Development Trunk
resolution → fixed

This appears to have been fixed, at least in trunk. Marking as fixed.

Please re-open in case the symptom still exhibits. Unfortunately, I don't think sharing the already initialized io_service across processes is supported (unless I'm missing something). At any rate, the code in question has since been refactored and the implementation handles the case where kevent(...) is -1.

status changed; milestone set; resolution deleted

chris_kohlhoff — Mon, 29 Nov 2010 06:40:10 GMT

status closed → reopened
resolution fixed
milestone → To Be Determined

This is a difficult to fix rainy-day bug. It is not fixed on trunk. Please see:

http://article.gmane.org/gmane.comp.lib.boost.asio.user/3383

The following program will reproduce the issue:

#include <boost/asio/io_service.hpp>
#include <boost/asio/ip/udp.hpp>
#include <iostream>
int main()
{
  boost::asio::io_service io_service;
  boost::asio::io_service::work work(io_service);
  boost::asio::use_service<
    boost::asio::ip::udp::socket::service_type>(
      io_service);
  if (fork()) exit(0);
  io_service.run();
}

On Mac OS X, kevent() failure means the forked child consumes 100% CPU. Compiling with -DBOOST_ASIO_DISABLE_KQUEUE gives the desired behaviour, which is that the forked child consumes no CPU.

devel@… — Mon, 29 Nov 2010 08:34:05 GMT

rfork(RFPROC) (no RFFDG) does a trick on *BSD

chris_kohlhoff — Wed, 02 Mar 2011 08:28:04 GMT

(In [69467]) * Add support for the fork() system call. Programs that use fork must call

io_service.notify_fork() at the appropriate times. Two new examples have been added showing how to use this feature. Refs #3238, #4162.

Clean up the handling of errors reported by the close() system call. In particular, assume that most operating systems won't have close() fail with EWOULDBLOCK, but if it does then set blocking mode and restart the call. If any other error occurs we assume the descriptor is closed. Refs #3307.

EV_ONESHOT seems to cause problems on some versions of Mac OS X, with the io_service destructor getting stuck inside the close() system call. Use EV_CLEAR instead. Refs #5021.

Include function name in exception what() messages.

Fix insufficient initialisers warning with MinGW.

Make the shutdown_service() member functions private.

Add archetypes for testing socket option functions.

Add missing lock in signal_set_service::cancel().

Fix copy/paste error in SignalHandler example.

The signal header needs to be included in signal_set_service.hpp so that we can use constants like NSIG and SIGRTMAX.

Don't use Boost.Thread's convenience header. Use the header file that is specifically for the boost::thread class instead.

status changed; resolution set

chris_kohlhoff — Mon, 06 Jun 2011 01:49:22 GMT

status reopened → closed
resolution → fixed

Merged to release branch in [72428].