[OpenJDK 2D-Dev]  Review Request: 8158072 Need a test for JDK-7172749
Sergey.Bylokhov at oracle.com
Fri May 27 19:36:28 UTC 2016
On 27.05.16 22:17, Phil Race wrote:
> I suppose this will pass on the various platforms and pipelines since
> we've only seen the bug reported against xrender ? ....
Long time ago we had the similar issues on other platforms:
So I assume that it should not fail on all configurations(tested
ogl/xrender+linux/osx). But I intentionally added more draw operations
and didn't restrict the test on Xrender pipeline, on each platform
default will be selected and tested.
> 41 * @bug 8158072
> I think you should also include 7172749 on this line.
> On 05/27/2016 11:47 AM, Sergey Bylokhov wrote:
>> Please review the new test for jdk9.
>> To me the reason of JDK-7172749  falling was curious. So I decided
>> to dig into it.
>> To reproduce the bug the next sequence is necessary:
>> Thread A
>> - create the surface
>> - SG2D is created for the surface
>> - SG2D.drawLine is called
>> - XRRenderer(Pipe).drawLine is called
>> - ========= STOP "THREAD A" for a nanoseconds=========
>> Thread B
>> - SG2D is created for the surface create in Thread A
>> - SG2D.drawLine is called or any other draw operations.
>> - The surface is flushed.
>> Thread A
>> - ========= RUN "THREAD A" again=========
>> - (we still inside XRRenderer(Pipe).drawLine)
>> - SG2D.getCompClip() is called, and this caused revalidation of SG2D,
>> because it was already flushed. This means that the surface/pipes etc
>> are changed, but note we still in the old XRRenderer(PixelDrawPipe)
>> which actually should be disposed as well
>> - we try to use the new surface and got ClassCastException.
>> - After the fix we will start to draw the line again from
>> "SG2D.drawLine" above, using new surface and the new PixelDrawPipe.
>> The interesting thing is how we will work if revalidation will replace
>> the surface to the same type(so ClassCastException will not occurred)
>> but the pipe will be changed to the new? I cannot prove it but it
>> seems that we will draw something to the new surface using the old
>> PixelDrawPipe. (But this is only for the record if someone will work
>> on this/or similar issues).
>> And the test which reproduce the bug.
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8158072
>> Webrev can be found at:
>>  https://bugs.openjdk.java.net/browse/JDK-7172749
Best regards, Sergey.
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