[Gtk-sharp-list] Threading problem on Windows

[D. Dobrev]

Thank you very much, Michael, this works perfectly on both Windows and Linux.


Michael Hutchinson wrote:
> 
> On Mon, Dec 1, 2008 at 4:54 PM, D. Dobrev <dpldobrev at yahoo.com> wrote:
>>
>> Hello.
>> I have the following code:
>> protected virtual void OnButtonOneDieClicked(object sender, EventArgs e)
>>        {
>>                if (this.isDieRolling)
>>                {
>>                        this.isDieRolling = false;
>>                }
>>                else
>>                {
>>                        this.isDieRolling = true;
>>                        Thread thread = new Thread(() =>
>>                                                   {
>>                                                                while
>> (this.isDieRolling)
>>                                                                {
>>                                                                       
>> Thread.Sleep(1);
>>                                                                       
>> Application.Invoke((image, args) =>
>>                                                                                                          
>> {
>>
>> this.imageOneDie.Pixbuf = this.RollDie();
>>                                                                                                          
>> });
>>                                                                }
>>                                                   });
>>                        thread.Start();
>>                }
>>        }
>>
>> Its purpose is: when the button is first clicked, a few pictures (the
>> sides
>> of a die) begin rapidly changing. The second click stops the changes
>> (this
>> simulates the rolling of a die). In Linux this works perfectly, but in
>> Windows the rolling rate is variable: it begins fast, then it slows down,
>> then again fast, etc., with random intervals. Does anyone have an idea
>> what
>> the problem might be? If this helps, the source of my application can be
>> found attached at the bottom of my
>> http://www.nabble.com/forum/ViewPost.jtp?post=20758097&framed=y previous
>> thread .
> 
> You don't need a thread here -- all it's giving you is semi-random
> intervals of calling this.imageOneDie.Pixbuf = this.RollDie().
> Thread.Sleep causes a context switch, so the thread's rate depends on
> the OS' scheduler. The Application.Invoke is run on another thread
> (the GTK# thread), so this also depends on the scheduler.
> 
> I recommend a GLib.Timeout: see
> http://www.mono-project.com/Responsive_Applications#Timeouts and
> http://www.go-mono.com/docs/monodoc.ashx?link=T%3aGLib.Timeout
> 
> It runs directly on the GTK thread at a specified rate, e.g. 30FPS
> (33ms / frame):
> 
> protected virtual void OnButtonOneDieClicked(object sender, EventArgs e)
> {
>     if (this.isDieRolling) {
>         this.isDieRolling = false;
>     } else {
>         this.isDieRolling = true;
>         GLib.Timeout.Add (33, delegate {
>             this.imageOneDie.Pixbuf = this.RollDie();
>             return this.isDieRolling;
>         });
>     }
> }
> 
> There may be other factors involved, but the thread certainly isn't
> doing any good.
> 
> -- 
> Michael Hutchinson
> http://mjhutchinson.com
> _______________________________________________
> Gtk-sharp-list maillist  -  Gtk-sharp-list at lists.ximian.com
> http://lists.ximian.com/mailman/listinfo/gtk-sharp-list
> 
> 

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