Re: handlers for g_timeout_add and g_idle_add different threads?

[Al Hooton <al hootons org>]

        Tim, and all:

        Thanks for the several replies I got to this question, the information
was exactly what I needed.  This one simple detail seems to be left out
of the otherwise good documentation on main loops and idel/timeout
handlers in the GTK+ doc, hopefully this thread will get archived and
help some other folks.

-Al


On Wed, 2004-12-08 at 10:12 +1300, Tim Evans wrote:
> Al Hooton wrote:
> >     Quick question:  I've read through all the stuff I can find on the glib
> > main loop support for timeout handlers and idle handlers, but there's a
> > simple question I have:
> >
> > - Do either, or both. of these types of handlers get run in a different
> > thread, or are they run out of the mainloop/GMainContext the
> > g_timeout_add and g_idle_add routines were called in to add them?
>
> They are both run inside the mainloop, so in the same thread that called 
> gtk_main().  This means that you shouldn't spend too much time in an 
> idle or timeout handler because it will block your gui.
>
> Note that adding idle and timeout handlers is thread safe and can be 
> done from any thread without needing to acquire any locks first.  I find 
> g_idle_add to be the best way for a worker thread to communicate with 
> the gui thread.
>
> If you have called gdk_threads_init then idle and timeout handlers will 
> be run *without* the gdk thread lock and you will have to add 
> gdk_threads_enter/leave calls yourself if you are doing gui stuff.