Re: Correct way to deallocate an unix signal source

[Philip Withnall <withnall endlessm com>]

Hi,

On Thu, 2019-03-14 at 00:09 +0100, Enrico Mioso wrote:
> I am facing an issue, where it seems I am not deallocating correctly
> an UNIX signal source. I use
> my_state->unix_signals_src = g_unix_signal_source_new(SIGINT);
> g_source_set_callback(my_state->unix_signals_src, my_unix_signals_cb,
> my_state, NULL);
> my_state->unix_signals_src_tag = g_source_attach(my_state-
> > unix_signals_src, my_state->ctx);
> g_source_unref(my_state->unix_signals_src);
>
> then, on the exit path of my program, I have something like:
>
> if (!my_state->sigint_received)
>    g_source_destroy(my_state->unix_signals_src);
>
> my_state->unix_signals_src_tag = 0;

This code seems fine to me, within the context you’ve provided. I
assume you’re also correctly unreffing the GMainContext at the end of
your program.

> This output can be obtained even using the glib.supp file as found in
> glib repository.
> Looking at the file specified by valgrind, glib-unix.c, line 222, I
> can see:
> return _g_main_create_unix_signal_watch (signum);

That valgrind trace looks like an intentional one-time leak, since the
allocation is within pthread_create().

I’d be very happy to accept a patch to GLib to add this to glib.supp. ☺

Philip