<AWT Dev> [14] Review Request: 8234522 [macos] Crash with use of native file dialog

[Phil Race]

Seems OK.
Although I can't find any Apple documentation on practices to avoid clashes
with someone else's application defined event .. which I expect could 
happen in an application
assembled from independently developer libraries.

-phil.

On 12/11/19 1:35 AM, Dmitry Markov wrote:
> Hi Sergey,
>
> I agree, it would be better to replace NSApplicationDefined with NSEventTypeApplicationDefined under separate task.
>
> The fix still looks good to me.
>
> Thanks,
> Dmitry
>
> PS
> Do not forget to add a summary to the regression test
>
>> On 10 Dec 2019, at 18:20, Sergey Bylokhov <Sergey.Bylokhov at oracle.com> wrote:
>>
>> Hi, Dmitry.
>>
>> We probably can replace NSApplicationDefined by NSEventTypeApplicationDefined, but then we will need
>> to replace NSApplicationDefinedMask by NSEventMaskApplicationDefined, and probably something else.
>> So I leave it for some future deprecation-cleanup.
>>
>> On 12/10/19 4:03 am, Dmitry Markov wrote:
>>> Hi Sergey,
>>> The changes look OK, but I have a few remarks. I would recommend using NSEventTypeApplicationDefined due to deprecation of NSApplicationDefined. Also it would be good to add some kind of summary to the regression test. I do not need a new webrev with suggested changes.
>>> Thanks,
>>> Dmitry
>>>> On 6 Dec 2019, at 23:05, Sergey Bylokhov <sergey.bylokhov at oracle.com> wrote:
>>>>
>>>> Hello.
>>>> Please review the fix for JDK 14.
>>>>
>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8234522
>>>> Fix: http://cr.openjdk.java.net/~serb/8234522/webrev.00
>>>>
>>>> This bug is tricky, we have a special mechanism to postpone deallocation
>>>> of the objects on the Appkit thread.
>>>> It solves the next problem: the native window pointer is disposed in the
>>>> inner AppKit loop, while it is still referenced on the stack in the native
>>>> Cocoa method which caused the mentioned inner loop. When the inner loop is
>>>> exited Cocoa crashes while dereferencing this window pointer.
>>>>
>>>> This mechanism is implemented via posting NSEvent using NSApplicationDefined
>>>> type and filter out this event in the nested event loop.
>>>>
>>>> But for some reason, macOS send us exactly the same event(type+subtype), which
>>>> we try to use for deallocation and of course, this attempt will crashes.
>>>> (probably because all constants of NSEvent we use were deprecated?)
>>>>
>>>> In the fix I have added additional marks(via data fields) to the event to make
>>>> it easy to check it was created by us, also I have bump the initial value of
>>>> subtype to minimize possible collisions.
>>>>
>>>>
>>>> -- 
>>>> Best regards, Sergey.
>>
>> -- 
>> Best regards, Sergey.