#26 Can't interrupt when blocked on network
It's not possible to gracefully exit mpg321 on BSD systems when it
gets blocked on network input. This happens because
read_from_fd calls read(), which by default gets restarted after a
signal. This may be a BSD specific phenomenon - I think that Linux
signals default to non-restarting.
The fix for this on systems with sigaction() is to unset
SA_RESTART to prevent auto-restarting of the read system call.
Replacing the calls to
signal(SIGINT, handler)
with
sigemptyset (&sa.sa_mask);
sa.sa_flags = 0;
sa.sa_handler = handle_signals;
if (sigaction(SIGINT, &sa, NULL) == -1) {
perror("sigaction");
}
(and a declaration at the start of struct sigaction sa, of course).
corrects the problem and makes it possible to do graceful cleanup
when killed during a network hang.
Not submitted as a patch since it's so tiny (only three spots to fix -
one at the start of main, and the two calls to signal(sigint)) and since
it needs to be tested on Linux before I'd call it happy.
