RFR: 8316931: [macos14] Test "java/awt/TrayIcon/ShowAfterDisposeTest/ShowAfterDisposeTest.html" throws and exception on Mac OS 14(x64, aarch64) [v4]

[Sergey Bylokhov]

On Fri, 19 Jan 2024 01:43:48 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

>> Somehow we have null passed in.
>> So something looked up appcontext and got null.
>> Likely because some other code removed the app context from a map or similar. 
>> First step is to find exactly where that happened, then we can start to reason about how we managed to still post an event.
>
> Note that it does not fail with NPE but instead this code trigger the bug:
> 
>         AppContext eventContext = targetToAppContext(event.getSource());
>         if (eventContext != null && !eventContext.equals(appContext)) {
>             throw new RuntimeException("Event posted on wrong app context : " + event);
>         }
> 
> The source of the event is TrayIcon, and the appconteext for it is non-null as well.
> 
> This is the code where we post an event:
> 
>     @Override
>     public void dispose() {
>         dummyFrame.dispose();
> 
>         if (popup != null) {
>             popup.removeNotify();
>         }
> 
>         LWCToolkit.targetDisposedPeer(target, this);
>         target = null;
> 
>         super.dispose();
>     }
> 
>     private void postEvent(final AWTEvent event) {
>         SunToolkit.executeOnEventHandlerThread(target, new Runnable() {
>             public void run() {
>                 SunToolkit.postEvent(SunToolkit.targetToAppContext(target), event);
>             }
>         });
>     }
> 
> 
> Note that we also call SunToolkit.targetToAppContext(target), and the target should be a TrayIcon and have a non-null appcontext, because later we successfully fetch it.
> 
> 
> So the problem here is not in the null appcontext, but that we set target to null in the peer in dispose(), at the time we still processing the events.
>  - So we should check how all this should be synchronized, to prevent such race
>  - Or we should not set target to null as on Windows
>  - Or call dispose on EDT like on Linux.

I think we should set the target once and use it forever.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/17329#discussion_r1458186579