<AWT Dev> [OpenJDK 2D-Dev] [9] Review request for 8130136: Swing window sometimes fails to repaint partially when it becomes exposed

[Alexey Ivanov]

Hi Sergey,

Unfortunately I don't have a concise test case which reproduces the 
issue. The issue is seen with a large application running for a long 
period of time.
At the same time, the issue can be seen with additional debug prints in 
AWT functions.

I'll attach “debug prints” patch to the bug as well as a demo app which 
demonstrates this problem exists.

Regards,
Alexey

On 13.10.2015 18:38, Sergey Bylokhov wrote:
> Hi, Alexey.
> Can you attach the test, which can be used to check the fix, to the 
> bugreport?
>
> On 13.10.15 13:15, Alexey Ivanov wrote:
>>> I guess you didn't add the test for a good reason,
>>> could you please comment on that?
>> It's impossible to write a regression test because the failure could be
>> caught only from the native AWT code, no user code could detect it.
>> Additionally, the time it takes to reproduce the issue is indefinite.
>>
>> Regards,
>> Alexey
>>>
>>> Thanks
>>> alexp
>>>
>>> On 10/12/2015 12:11, Alexey Ivanov wrote:
>>>> Hello,
>>>>
>>>> Please review the fix for jdk9:
>>>>     bug: https://bugs.openjdk.java.net/browse/JDK-8130136
>>>>     webrev: 
>>>> http://cr.openjdk.java.net/~aivanov/8130136/jdk9/webrev.00/
>>>>
>>>>
>>>> Problem description:
>>>> Sometimes a window fails to repaint when it becomes exposed.
>>>>
>>>> When repaint failure occurs, SetDIBitsToDevice() in
>>>> GDIBlitLoops_nativeBlit() returns 0 with error 87 ("Parameter
>>>> Error"). It happens because invalid, already released, hDC is passed
>>>> to SetDIBitsToDevice().
>>>>
>>>>
>>>> Root cause:
>>>> When a window is disposed, the DCs associated with it are released.
>>>> The handles can be reused for another window.
>>>>
>>>> A thread disposes the window and releases hDC. At this time, DC
>>>> handle is reused for another window. When Disposer thread cleans up
>>>> for a died thread, it tries to release the cached hDC. But that
>>>> handle is already associated with another window. Thus a valid pair
>>>> hWnd/hDC becomes invalid: painting to released DC fails.
>>>>
>>>>
>>>> The fix:
>>>> Save both hDC and hWnd in the thread local storage, and pair hDC with
>>>> hWnd when removing it to avoid accidentally releasing hDC which is
>>>> already reused for another window.
>>>>
>>>>
>>>> Regards,
>>>> Alexey
>>>
>>
>
>