Re: GIOFunc called after a g_io_channel_shutdown

[Tristan Van Berkom <tvb gnome org>]

Renaud Malaval wrote:
> Hello,
>
> I use g_io_channel_unix_new() in a custom dialog to check somes io
> events.
> I close my gioChannel in the foo_dialog_response_cb(), just before
> destroy the custom dialog.
>
> To close the gioChannel I Does :
>
> status = g_io_channel_shutdown(privP->gioChannelP, FALSE, &gerrorP); if
> ( gerrorP) {
>         g_error_free(gerrorP);
> }
> g_io_channel_unref(privP->gioChannelP);
>
> I don't have errors (status is ok and no gerrorP) About 1 or 2 seconds
> after that my GIOFunc callback is called and crash because of bad
> context (user_data pointer is breaked) 
>
> I don't understood why the gioChannel is not closed.
>
> Any idea, please ?

The GIOWatch has a reference to the channel, so unreffing the channel
will not destroy it untill the GIOWatch source has been destroyed...
calling g_io_channel_shutdown(); depending on the file type and what
events you are watching... may trigger an event on the fd (a hangup
detected ? or and EOF maybe ?)

Typicly... in very simple situations I do something like this:
========================================================
channel   = channel_new (probably _unix_new with an fd);
source_id = g_io_add_watch (channel ... args);
g_io_channel_unref (channel); // pass ownership of the channel to the watch

/* ...now later... when shutting down I do: */
g_source_remove (source_id); // this will remove the event source and unreff the channel.
========================================================

Cheers,
                       -Tristan