This test doesn't print "OK" like I think it should, it just prints "ctor called".  It seems that timerExec doesn't work when called from other threads than the GUI thread.  The SWT docs seem to say that this should work.  Am I doing something wrong?

When doing the same thing in my real DWT app, I get an "Invalid thread access" exception, but I haven't put an exception handler into the secondary thread in this sample.

---
module timertest2;

import dwt.DWT;
import dwt.dwthelper.Runnable;
import dwt.widgets.Display;
import dwt.widgets.Shell;
import dwt.widgets.Button;
import dwt.widgets.Text;

import tango.core.Thread;
import dwt.events.SelectionListener;
import dwt.events.SelectionEvent;
import tango.util.log.Trace;


void main()
{
    try {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setSize(300, 200);
        shell.setText(__FILE__);
        auto btn = new Button( shell, DWT.PUSH );
        btn.setBounds(40, 50, 100, 50);
        btn.setText( "test timerExec" );

        auto txt = new Text(shell, DWT.BORDER);
        txt.setBounds(170, 50, 100, 40);

        auto t = new Thread({Display.getDefault.timerExec(500, new class Runnable {
            this() { Trace.formatln("ctor called").flush; }
            void run() { Trace.formatln("OK").flush; txt.setText("timerExec OK"); }
        });});

        btn.addSelectionListener(new class () SelectionListener {
            void widgetSelected(SelectionEvent event) { t.start(); }
            void widgetDefaultSelected(SelectionEvent event) { }
        });

        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch()) {
                display.sleep();
                Trace.format(".").flush;
            }
        }
    }
    catch (Exception e) {
        Trace.formatln(e.toString);
    }
}
---

torhu wrote:
> This test doesn't print "OK" like I think it should, it just prints "ctor called".  It seems that timerExec doesn't work when called from other threads than the GUI thread.  The SWT docs seem to say that this should work.  Am I doing something wrong?
> 
> When doing the same thing in my real DWT app, I get an "Invalid thread access" exception, but I haven't put an exception handler into the secondary thread in this sample.
> 

I made a version for the old DWT and phobos too.  It behaves the same way, except that it actually prints "Invalid thread access".  That's interesting, because the with new dwt and Tango, exceptions in secondary threads don't propagate to the main thread.  They just seem to vanish.

torhu schrieb:
> This test doesn't print "OK" like I think it should, it just prints "ctor called".  It seems that timerExec doesn't work when called from other threads than the GUI thread.  The SWT docs seem to say that this should work.  Am I doing something wrong?
> 
> When doing the same thing in my real DWT app, I get an "Invalid thread access" exception, but I haven't put an exception handler into the secondary thread in this sample.

You get the same exception also in your example code, but it is not catched, so the message got lost.

You need to wrap your code in the Thread into another
display.asyncExec( dgRunnable({}));

Frank Benoit wrote:
> torhu schrieb:
>> This test doesn't print "OK" like I think it should, it just prints
>> "ctor called".  It seems that timerExec doesn't work when called from
>> other threads than the GUI thread.  The SWT docs seem to say that this
>> should work.  Am I doing something wrong?
>> 
>> When doing the same thing in my real DWT app, I get an "Invalid thread
>> access" exception, but I haven't put an exception handler into the
>> secondary thread in this sample.
> 
> You get the same exception also in your example code, but it is not
> catched, so the message got lost.
> 

I wonder why it's not caught, since it happens automatically with the old DWT.  I think I tested this a while ago, but I can't quite remember if it was a DWT-specific problem, or if it happens with Tango without DWT too.


> You need to wrap your code in the Thread into another
> display.asyncExec( dgRunnable({}));
> 

Yeah, I was hoping I could just fire off timerExecs without blocking the current thread by using syncExec, or having to use asyncExec which is more complicated.  But from rereading the SWT docs, timerExec does behave correctly in DWT.  I'll have to do this another way, then.