Re: gdk_threads_enter/leave() in threaded and non threaded situation

[Peter Bloomfield <PeterBloomfield BellSouth net>]

On 2005.02.10 16:20, Stefan Kost wrote:
> hi hi,
>
> I have a gobject property that is set (via g_object_set()) from  
> within a thread and from the main thread.
> Further I have signal handlers that watch this via  
> notify::property.
> These signal handler call gtk functions. Therefore in these  
> signal handlers the gtk part is wrapped with gdk_threads_enter/ 
> leave().
> When the singnal is triggered from the thread it works, but  
> when it gets triggerd from the main thread gdk_threads_enter  
> blocks.
>
> This is quite obvious, as in this thread I am already in  
> gdk_threads_enter(). But how should the signal handler know  
> that (wheter it has been triggered from the main thread or from  
> another thread)?

You *could* store your main thread id on startup, and compare it  
with the current thread id in the handler...but that depends on  
the assumption that the main thread is always locked and a  
subthread is always unlocked, which might be true now but jump up  
and bite you later.

Safer is to use gdk_threads_set_lock_functions to replace the  
standard self-blocking lock with a sensible recursive lock, and  
forget about which thread it is!

Peter