Date: Tue, 31 Oct 2006 08:45:39 +0900 (JST)
Message-Id: <20061031.084539.74749515.garrigue at math.nagoya-u.ac.jp>
To: matthieu.dubuget at laposte.net
Cc: lablgtk at math.nagoya-u.ac.jp
Subject: Re: Callbacks and threads
From: Jacques Garrigue <garrigue at math.nagoya-u.ac.jp>
In-Reply-To: <4545E762.9010000 at laposte.net>
References: <4545E762.9010000 at laposte.net>
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From: Matthieu Dubuget <matthieu.dubuget at laposte.net>

> I tried:
> b#connect#clicked ~callback:(
>   fun () ->
>     active false;
>     f ();
>     active true;
> )
> 
> f is called ok, except that:
> - cursor change is not displayed during computation (seems like I have
> to give control back to the main loop for this to happen?)
> - if another button is clicked during the computation, the corresponding
> callback is called after f has returned.

This is the expected beahavior.

> I then tried:
> b#connect#clicked ~callback:(
> (fun () ->
>   active false ;
>   ignore (Thread.create (fun () ->
>     f ();
>     active true) ())
> )
> 
> Unfortunately, this way, f is nether executed?

This should work. However, you must link with gtkThread.cmo, otherwise
the GTK main loop will not allow threads to be executed. (OCaml cannot
switch threads during callbacks, so a thread-aware main loop is needed
to allow thread-switching.)

Jacques