On 1/11/2013 3:57 PM, Anthony Petrov wrote:
On 1/10/2013 20:23, Petr Pchelko wrote:
Sergey wrote:
As far as I understand from the discussion SWT doesn't survive
situation, when we open 2 window(SWT and AWT) and close SWT window
first. Since in this case SWT stops appkit run loop. This fix works
in this case and this means that we should apply the same patch to SWT.
Petr, can you clarify this? Thanks
I have applied the patch and tried a little example with SWT Window
and AWT Frame. The app still hangs in case the SWT Frame is closed
first. The problem is that in SWT the common pattern is to put such
code to the end of main:
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) display.sleep();
}
display.dispose();
//end of main function
(It is so common that it is in the first helloworld example in the SWT
documentation)
So, SWT does not care about the native events, it shuts down as soon
as Shell gets disposed. The main thread finishes and AWT hangs.
I don't think we could fix the issue in AWT, but there is a simple
workaround to add a dispose listener to the shell which would spin the
runloop until AWTAutoShutdown.isReadyToShutdown, so it could be fixed
in SWT. However, the case when AWT and SWT windows are opened
simultaneously is so likely to produce deadlocks that I am not sure we
want to support this case at all. JDK6 does not.
OK. So let me get it straight: it didn't work before with SWT, and for
now it's not going to work even with my fix? But my fix itself does not
worsen things up when running with SWT anyway, right? Is this all correct?
The described scenario, when we have an SWT shell and an AWT frame and
then close the shell, didn't work before your fix and won't work with
the fix applied. Therefore I don't think this workaround with
AWTKeepAlive daemon thread should be applied. It looks like a hack (and
is a hack) and doesn't add any value.
When we eventually decide to support this scenario, and if SWT team is
ready to listen to AWT "is alive" status, then we'll implement it in a
clearer way, for example by making AWTAutoShutdown public.
Thanks,
Artem
As for the embedded case, the issue with shutdown is fixed on the SWT
side, however, making the AWTAutoShutdown method public would allow to
make the solution better.
No, why? We don't want to export AWTAutoShutdown. Now that AWT will send
keep alive pings after my fix, SWT, if they want to, could simply listen
to these pings (using the run loop observers), and return false from the
shell.isDisposed() at least for 1 second after the last keep-alive ping.
This will enable both SWT and AWT to co-exist, prevent any hangs, and
allow both of them to terminate w/o problems when both are finished.
But this is unrelated to the AWT side of things. This is a possible
enhancement for the SWT itself.
--
best regards,
Anthony
With best regards. Petr.
This fix actually does not help in the case when SWT On Jan 10, 2013,
at 6:24 PM, Petr Pchelko wrote:
Yes. SWT did not survive in such a situation. A will try to apply the
fix and test if it helps with the SWT.
With best regards. Petr.
On Jan 10, 2013, at 6:13 PM, Sergey Bylokhov wrote:
10.01.2013 17:55, Anthony Petrov wrote:
Thanks Petr. I think we don't want to do the same in FX because we
don't even want to call any AWT APIs from there in the first place.
Instead, my current solution offers a way to terminate both
toolkits graciously.
As far as I understand from the discussion SWT doesn't survive
situation, when we open 2 window(SWT and AWT) and close SWT window
first. Since in this case SWT stops appkit run loop. This fix works
in this case and this means that we should apply the same patch to SWT.
Petr, can you clarify this? Thanks
Sergey, does this resolve your concern?
--
best regards,
Anthony
On 12/28/12 23:06, Petr Pchelko wrote:
Hello.
As I understood while implementing the EmbeddedFrame, when we
embed AWT into SWT, SWT did not care if AWT is OK to terminate,
SWT just called dispose() for a frame and terminated without
looking at AWT. This resulted in issues when AWT was still
terminating but the main SWT thread was already finished. When AWT
was calling something to synchronously perform selectors on the
main thread deadlocks occurred. So we had to add a dispose
listener to the SWT container, which spinned the main runloop
until AWT frame finished disposing.
However, I may have misunderstood something.
With best regards, Petr.
28.12.2012, в 20:58, Anthony Petrov<[email protected]>
написал(а):
On 12/28/2012 20:36, Sergey Bylokhov wrote:
http://cr.openjdk.java.net/~anthony/8-52-startOnFirstThreadCheck-8005465.0/
2. Introducing an AWTKeepAlive thread activated in the embedded
mode only. This thread will send an event to the native event
queue every 500ms as long as there are active AWT objects
present. This activity will notify the embedder toolkit that
the Java application as a whole is still alive and needs not
exit yet.
Why it wasn't necessary for awt-swt bridge?
I don't know. Perhaps we should ask someone who's familiar with
SWT? Steve? How does SWT determine that AWT is dead and therefore
it's OK to terminate the native event loop and exit on the Mac?
--
best regards,
Anthony
--
Best regards, Sergey.
