RFR: 8081474: SwingWorker calls 'done' before the 'doInBackground' is finished [v10]

[Prasanta Sadhukhan]

On Thu, 2 Feb 2023 21:35:06 GMT, Alexey Ivanov <aivanov at openjdk.org> wrote:

>> I haven't verified it, but I think it worked as it's stated: `done` is called first, then listeners are notified. According to the order of calls
>> 
>> https://github.com/openjdk/jdk/blob/b00b70c2400d28070d26630614a010bc52237827/src/java.desktop/share/classes/javax/swing/SwingWorker.java#L310-L313
>> 
>> `SwingWorker.done` gets invoked first followed by `setState` which, in its turn, notifies the listeners.
>> 
>> At this time, as you pointed out, the order is reversed:
>> 
>> https://github.com/openjdk/jdk/blob/76b02ea3a8add954705d6df7f91f5896d141b02d/src/java.desktop/share/classes/javax/swing/SwingWorker.java#L307-L308
>
>> It could be tested by flushing and blocking the EDT in the listener. That will allow us to check the order of events posted from the listener and from the "doneEDT".
> 
> Is flushing required?
> 
> Two `AtomicBoolean`s should do the job. EDT can't process two events simultaneously, one follows the other. So, `done` is expected to be called while both are `false`, and it sets its own flag to `true`; the listener should be called second, so its flag is `false` and `done`'s flag is `true`.
> 
> I'll leave it to Pransanta to figure out the details.

It seems the order of sequence is
listener->State.STARTED->doInBackground->listener->DONE->done

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PR: https://git.openjdk.org/jdk/pull/11940