Re: Threads and idle functions

[David Buchan <pdbuchan yahoo com>]

yep. Seems to be working.

Thanks!

Dave



________________________________
 From: James Morris <jwm art net gmail com>
To: David Buchan <pdbuchan yahoo com> 
Sent: Monday, July 2, 2012 9:10 PM
Subject: Re: Threads and idle functions
 
On 3 July 2012 01:50, David Buchan <pdbuchan yahoo com> wrote:
> My understanding is that child threads must never alter the UI in any way.
>
> If I have a program which spawns a child thread to download some data and I want to be able to have a 
> dialog pop up should an error occur, is it correct to say that I need an idle function to be running 
> concurrently to monitor some global variable which would contain the status (set by the download thread), 
> and then the idle function would create the dialog pop-up?
>
> Put another way, if only the GTK+ main iteration is allowed to alter the GUI, then how does someone get 
> information out of a child thread and to the UI?

Well from what I hear, g_idle_add offers some form of thread safety so
a child thread can communicate some item of data via a callback
executed in the GUI thread.

The documentation also seems to support this view:
http://developer.gnome.org/glib/2.31/glib-The-Main-Event-Loop.html#glib-The-Main-Event-Loop.description

your child/download thread does the monitoring of the error status and
when an error is found, use g_idle_add to wait some moments and then
communicate the error to a callback.

HTH,
James.
> Dave
> _______________________________________________
> gtk-app-devel-list mailing list
> gtk-app-devel-list gnome org
> https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list