Answer to: What causes GLib I/O Channels operations to use up 100% CPU in GTK+ app.?

[Daniel Yek <dyek real com>]

[Moving gtk-app-devel-list gnome org to BCC. See earlier post for test code.]

At 02:41 AM 10/12/2006, Daniel Yek wrote:
> At 02:36 AM 10/12/2006, Daniel Yek wrote:
> > Could somebody enlighten me why after an I/O Channel operation 
> > (g_io_channel_shutdown() here), the GTK+ program started to use up 100% CPU?
> >
> > Is it monitoring something? Do I need to undo g_io_add_watch() somehow? 
> > What operation is needed to not get into such situation?

Figured that out myself.

1. Closing the write-end of the pipe caused GIOConditoin of G_IO_HUP being 
generated when being polled. Failing to intercept and react to it by 
removing the Channel watch causes infinite GIOConditoin of G_IO_HUP 
"notification attempt" and hence 100% CPU usage. There should be an assert 
to guard this infinite loop in channel monitoring.

2. Closing the read-end of the pipe caused GIOConditoin of G_IO_NVAL when 
being polled. Failing to intercept and react to it by removing the Channel 
watch causes infinite GIOConditoin of G_IO_NVAL "notification attempt".

3. Shutting down the I/O Channel without removing Channel Watch again 
causes condition #2 above.

These seem like rough edges to me; (or was that simply my fault of not 
programming it right earlier?)

Is there any developer willing to insert asserts or implement default 
handling where appropriate?

Thanks.


--
Daniel Yek