On Wed, 30 Jun 2021 11:36:18 GMT, Ajit Ghaisas <aghai...@openjdk.org> wrote:
>> Final blit operation in MTLLayer.blitTexture() is driven by CVDisplayLink in
>> Metal.
>> In this test case we are hitting an invalid condition because of which we
>> exit from MTLLayer.blitTexture(), but we are not stopping the CVDisplayLink.
>> This is causing the CVDisplayLink callback to run in loop. Fix is to stop
>> CVDisplayLink when we return without completing final blit operation in
>> MTLLayer.blitTexture().
>>
>> Sanity and performance analysis is green. More details in JBS.
>
> src/java.desktop/macosx/native/libawt_lwawt/java2d/metal/MTLLayer.m line 88:
>
>> 86:
>> 87: if (self.nextDrawableCount != 0) {
>> 88: [self stopDisplayLink];
>
> Please check invoking stopDisplayLink at this place. If a Drawable is not
> available, we should return from here but recheck after 16ms. A drawable
> might be made available on subsequent attempts.
>
> Stopping DisplayLink at other invalid cases makes sense.
@aghaisas Thanks for the review. Redraw of static content is driven by
setNeedsDisplay, because we stop CVDisplayLink once final blit is done. Also
with preliminary testing i see that we are not hitting this condition at all
after CVDisplayLink is enabled. We still have a verification task under
https://bugs.openjdk.java.net/browse/JDK-8258583 . Stopping or not stopping
CVDisplayLink at this place is not causing any change. I will go ahead and
remove stopDisplayLink at this place, in future if we hit this code because of
some boundary condition we can enable it and verify.
-------------
PR: https://git.openjdk.java.net/jdk17/pull/175
