Re: Strange GObject warning, crashes GUI

[John Coppens <john jcoppens com>]

On Sat, 15 Jan 2011 12:38:03 +0200
Mohammed Sameer <msameer foolab org> wrote:

> > GLib-GObject-WARNING **: gsignal.c:3081: signal name `depressed' is
> > invalid for instance `0x8a0900'
> >
> > messages.
>
> I've seen this error only once when I was writing a C++ wrapper for a GObject and
> the GObject instance was being unref'ed thus destroyed without the C++ wrapper
> being informed. The C++ wrapper later on tried to call an "action signal" on
> the invalid instance it had and Glib printed that error.
>
> So it was the C++ wrapper trying to use some garbage memory as the GObject.

Hello Mohamed...

Thanks for the reply. I'm programming in C, and the code for the
ComboBox is very uncomplicated. Also, there is no way for anything to
have been unref'd, as far as I can detect.

Interesting would be to be able to identify what is at "instance
`0x8a0900'"

> I think this also explains the hang because of the invalid memory reference.

The hang, according to a suggestion from Johannes on the Anjuta list:

<quote>
"That hang happens when you have a breakpoint in a signal handler
that processes some kind of synchronous X event. Possible solution is to
start anjuta from a different terminal like this:

DISPLAY=:0 gdb anjuta

and switch back to that terminal when X hangs and look at the debug
output."
</quote>

This explains why most of the window manager hangs. I have yet to try
this out.

John