Skip to main content

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
Re: [rap-dev] ModalContext

mail.apptech.nichost.ru wrote:
Hello

One way to solve these problems could be to take the Synchronizer class
from SWT
It is a good way, I think.

What I would appreciate most, are JUnit test cases that demonstrate the
use case and currently fail
I'll try to do this. But is there a special project for rap jface tests? Or
I have to create new one?
Just a note, there are RWT (SWT) tests but no JFace tests.
Anyway, there are two test suites: org.eclipse.rap.rwt.test and org.eclipse.rap.rwt.q07.test. The first test suite tests server-side functionality, the latter mostly lifecycle-adapter code.

The split was introduced in an effort to separate the client-independent functionality from the client-specific (qooxdoo) code. During this, priorities shifted and we had to stop somewhere in between... That's why there are still some open ends.

To actually run the tests you need two more projects:
* org.eclipse.rap.rwt.test.mockup
* org.eclipse.rap.rwt.testfixture
All that can be found under /cvsroot/rt/org.eclipse.rap/runtime.rwt.test
The test suites are called org.eclipse.RWTHostTestSuite and
org.eclipse.RWTQ07TestSuite



Thank you,
Igor

-----Original Message-----
From: rap-dev-bounces@xxxxxxxxxxx [mailto:rap-dev-bounces@xxxxxxxxxxx] On
Behalf Of Rudiger Herrmann
Sent: Friday, June 19, 2009 3:55 PM
To: RAP project development-related communication
Subject: Re: [rap-dev] ModalContext

Hi Igor,

as a rule of thumb, if RAP works differently than RCP, it is a bug. To fix the bug, it should be fixed in RWT and not in the upper layers
(Workbench, JFace, etc).

I filed this bug for the issues with calling (a)syncExec( null ):
   280829: [Display] calling syncExec/asyncExec(null) behaves
   differently in SWT
   https://bugs.eclipse.org/bugs/show_bug.cgi?id=280829
It should be relatively easy to fix this.

As far as I understand, the second and third remark are related to
synchronization. Your follow-up posting also describes synchronization
issues. Please correct me if I'm wrong.

One way to solve these problems could be to take the Synchronizer class from
SWT and use it instead of the code in UICallBackManager. Some additions to the Synchronizer class would be necessary like calling
UICallBackManager#sendUICallBack() from synchExec, etc.
Also sleep/readAndDispatch would need to be reworked to make use of the
Synchronizer methods/lock objects.
Then timerExec() would to need be reworked to fit into the Synchronizer
mechanism. Plus whatever I overlooked so far...
The positive aspect of this way is that we re-use the SWT synchronization
code. The downside is that a lot of the existing code would have to be
changed, which is probably more time-consuming than just fixing the issues
at hand.

What I would appreciate most, are JUnit test cases that demonstrate the use
case and currently fail. With these test cases we could then address one
issue after another.

Cheers,
Rüdiger


mail.apptech.nichost.ru wrote:
Hello

It seems that the ModalContext functionality should be reimplemented on RAP (it is ported from RCP now).

First remark: look at the
org.eclipse.jface.operation.ModalContext.ModalContextThread.run(). There is a call: "display.asyncExec(null);". On RCP such call have a
special meaning.
This call causes display thread to wake up.

Maybe this call ("display.asyncExec(null);") should be removed from the
org.eclipse.jface.operation.ModalContext.ModalContextThread.run() ?
Alternative maybe Display#asyncExec should be reimplemented (and also
syncExec) for the case where runnable is null?

Second remark:

There is another part of code in the
org.eclipse.jface.operation.ModalContext.ModalContextThread.run():

display.syncExec(new Runnable() {
  public void run() {
    // do nothing
  }
});

On RAP this code causes deadlocks with
org.eclipse.jface.operation.ModalContext.ModalContextThread.block()
method.
Moreover, there is a problem with
org.eclipse.rwt.internal.lifecycle.UICallBackManager.SyncRunnable and ModalContext. As you know, SyncRunnable has a block() method, wich blocks the thread that called org.eclipse.rwt.internal.lifecycle.UICallBackManager.addSync(Display, Runnable) method. The blocked thread will wait on special lock object until the notification from other thread (with should call SyncRunnable#run method). But when you are using ModalContext the other thread will blocked on runnablesLock.

I think the problem in the
org.eclipse.rwt.internal.lifecycle.UICallBackManager.addSync(Display,
Runnable) method.

Third remark:

// Make sure that all events in the asynchronous event queue // are dispatched.
display.syncExec(new Runnable() {
  public void run() {
    // do nothing
  }
});

This code do not the things that declared in comments.

Last remark: "display.asyncExec(null);" can be implemented correctly, but you have to place additional synchronization string in org.eclipse.jface.operation.ModalContext.ModalContextThread.run() to prevent ending of execution org.eclipse.jface.operation.ModalContext.ModalContextThread.run() before
display.sleep() occures in
org.eclipse.jface.operation.ModalContext.ModalContextThread.block()
method.
Place

synchronized (display.getThread()) {
}

before

// Stop event dispatching
continueEventDispatching = false;

The display.getThread() returns UIThread instance. So it will be locked until the switchThread notification from display.sleap() method.

Thank you, Igor


_______________________________________________
rap-dev mailing list
rap-dev@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/rap-dev
_______________________________________________
rap-dev mailing list
rap-dev@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/rap-dev


_______________________________________________
rap-dev mailing list
rap-dev@xxxxxxxxxxx
https://dev.eclipse.org/mailman/listinfo/rap-dev


Back to the top