id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
3238	asio, kqueue_reactor, result of kevent() isn't checked for error	devel@…	chris_kohlhoff	"No kevent() result checking.
{{{
asio/detail/kqueue_reactor.hpp:438
...
    wait_in_progress_ = true;
    lock.unlock();

    // Block on the kqueue descriptor.
    struct kevent events[128];
    int num_events = (block || need_kqueue_wait_)
      ? kevent(kqueue_fd_, 0, 0, events, 128, timeout)
      : 0;

    lock.lock();
    wait_in_progress_ = false;

    // Block signals while performing operations.
    boost::asio::detail::signal_blocker sb;

    // Dispatch the waiting events.
    for (int i = 0; i < num_events; ++i)
    {
            // processing events
...
}}}
Here is '''int num_events = kevent(kqueue_fd_, ...''', then '''for (int i = 0; i < num_events''' but '''num_events''' can be -1 here, and all this code makes no sense then.

Suppose we have such code:
{{{
smtp_queue q(""/var/spool/smtpq"");
asio::io_service io_service;
smtp_server s(io_service, 25, q);
smtp_client c(io_service, ""target.host"", ""smtp"", q);
if(fork()) exit(0); // daemonize
io_service.run();
}}}
Here we call '''fork()''' then '''io_service.run()'''.
fork doesn't copy kqueue descriptor and subsequent kevent(fd,...) calls return -1 with errno = 9 (EBADFD, ""Bad file descriptor"").
This case makes asio's kqueue reactor hangup.
Probably, kevent() result should be checked for error and exception thrown if any.
"	Bugs	closed	To Be Determined	asio	Boost Development Trunk	Problem	fixed	asio kqueue