[7u6] Please review my fix for 7148289: [macosx] Deadlock in sun.lwawt.macosx.CWrapper$NSScreen.visibleFrame

[Alexander Zuev]

Anthony,

   sure, the details are:

   the ToolkitThreadBlockerHandler is an interface that is supposed to 
be used
when program has to wait for the event pushed to the EDT finish its task and
he calls like this:
             while (!dispatcher.isDone()) {
                 
DataTransferer.getInstance().getToolkitThreadBlockedHandler().enter();
             }
and the event handler in its unregisterEvent() method calls for 
handler.exit()
The method is supposed to make sure that waiting on the EDT doesn't 
create deadlocks.
The implementation depends on the toolkit architecture - on some 
toolkits it's NoOp since
they don't care if EDT is waiting, but in LWCToolkit our AWT components 
are backed by Swing
delegates so there are a lot of calls from native application thread to 
EDT and vice versa so we
can't afford to stop both threads. Solution is the code that makes 
secondary AppKit event loop
to handle native events so waiting on EDT will leave at least one event 
loop pumping.

   The name is correct because despite the fact that we are in AWT code 
(LWCToolkit) we don't
create nested EDT loop but running nested native (AppKit) loop - hence 
the name: enter/exitNativeEventLoop()

With best regards,
Alex

On 4/27/12 20:54, Anthony Petrov wrote:
> Hi Alexander,
>
> Could you provide some details about the ToolkitThreadBlockedHandler 
> interface? How is it used by the DnD code?
>
> Also, I suggest to replace the word Native with Nested in 
> enter/exitNativeEventLoop() method names.
>
> -- 
> best regards,
> Anthony
>
> On 4/26/2012 7:54 PM, Alexander Zuev wrote:
>> Hello,
>>
>>   please review my fix for the CR 7148289: [macosx] Deadlock in 
>> sun.lwawt.macosx.CWrapper$NSScreen.visibleFrame
>>
>>   Bug description is 
>> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7148289
>>
>>   Fix can be found at 
>> http://cr.openjdk.java.net/~kizune/7148289/webrev.00
>>
>> With best regards,
>> Alex