On Mon, 1 Nov 2021 20:03:42 GMT, Sergey Bylokhov <s...@openjdk.org> wrote:
> Please take a look to one more wagon in this train: > [JDK-8176795](https://bugs.openjdk.java.net/browse/JDK-8176795)->[JDK-8204931](https://bugs.openjdk.java.net/browse/JDK-8204931)->[JDK-8214579](https://bugs.openjdk.java.net/browse/JDK-8214579)->[JDK-8227392](https://bugs.openjdk.java.net/browse/JDK-8227392)->[Current > issue](https://bugs.openjdk.java.net/browse/JDK-8275843). > > #### The short description: > > We have an inconsistent between xrender java code and the x11 window. The > java code thinks that all our windows support only two types of color models: > IntRgbX11 and IntArgbPreX11, but the x11 window supports more types. If such > inconsistency occurs we render some garbage, or just crash since our "blits" > will assume the wrong data layout. This issue was reported and fixed > [before](http://hg.openjdk.java.net/jdk/jdk/rev/c53905e7dc57) but it was not > realized why the rendering was wrong and that it can cause a crash. The fix > is similar to the old one. > > #### The long description: > > * Once upon a time this bug was filed > [JDK-8176795](https://bugs.openjdk.java.net/browse/JDK-8176795) it was about > the rendering of colors to the volatile image, the description can be found > [here](https://bugs.openjdk.java.net/browse/JDK-8176795?focusedCommentId=14138323&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-14138323) > In short: the volatile images in the xrender use intArgbPre color model, it > means that the SunGraphics2D object > [convert](https://github.com/openjdk/jdk/blob/603bba282a089928fd23f8da23a7c1b2d52944ef/src/java.desktop/share/classes/sun/java2d/SunGraphics2D.java#L1753) > the argb value to the argbPre before passing it to the pipeline, and the > xrender pipeline > [convert](http://hg.openjdk.java.net/jdk/jdk/rev/e4b03365ddbf) this value to > the argbPre one more time -> double-conversion-> the bug is reproduced. The > fix for that bug disabled the second conversion in the xrender. but it does > not take into account that this code path is u sed for rendering to the ARGB X11 window where the shared code does not convert the color, so the next bug was filed. > * The second bug is > [JDK-8204931](https://bugs.openjdk.java.net/browse/JDK-8204931), the > description can be found > [here](https://bugs.openjdk.java.net/browse/JDK-8204931?focusedCommentId=14199800&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-14199800). > In short the bug was about rendering directly to the window and missing > color conversion removed previously. The fix for that bug changed the surface > type used by the window, so the shared code start to convert the color from > ARGB to argbPre, but it does not take into account that we do not control the > color model of the window, see how many of them we actually > [support](https://github.com/openjdk/jdk/blob/603bba282a089928fd23f8da23a7c1b2d52944ef/src/java.desktop/unix/classes/sun/java2d/x11/X11SurfaceData.java#L501) > Also note in the link above that if we do not recognize the type we do not > fallback to something but throw InvalidPipeException, this is because the > blits(and other primitives) may use t his type to access the data directly. So the next bug was reported: > * This is the third issue > [JDK-8214579](https://bugs.openjdk.java.net/browse/JDK-8214579). The fix for > that issue tried to roll back the previous one but does not take into account > that the conversion removed by the first issue should be rollback as well, so > the last bug was filed. > * The "last" issue is > [JDK-8227392](https://bugs.openjdk.java.net/browse/JDK-8227392) rollback the > previous one. So the bug reported in the third report come back. > > #### Fix description > > The fix for the current issue contains a few parts: > * Rollback of the > [JDK-8204931](https://bugs.openjdk.java.net/browse/JDK-8204931) so we will > use the proper surface data for the window. > * Return conversion in the xrender pipeline removed by the > [JDK-8176795](https://bugs.openjdk.java.net/browse/JDK-8176795) So we will > convert it when we render to the volatile image(argbPre) and to the > window(argb). We need to convert in both cases since the xrender API which we > use expects the argbPre colors. > * Start to use the > [eargb](https://github.com/openjdk/jdk/blob/603bba282a089928fd23f8da23a7c1b2d52944ef/src/java.desktop/share/classes/sun/java2d/SunGraphics2D.java#L1752) > value( instead of pixel) stored in the SunGraphics2D so we did not get the > double conversion. > > Some tests are updated and one more is added. > > ### Note > I have checked the performance implication of this change and it looks like > after this change the sequence window.setvisible(true)/window.dispose() will > work 30% faster, this may affect the tests which does not wait enough time to > make the window visible. Probably this is the reason why some of our tests > became more stable at some point in jdk11. > > > I have tested this by the jck and jdk_desktop tests. But any additional > verification/testing is welcome. This pull request has now been integrated. Changeset: a9c1acbb Author: Sergey Bylokhov <s...@openjdk.org> URL: https://git.openjdk.java.net/jdk/commit/a9c1acbb8aec46e4a488b7c77bb6318af87747f6 Stats: 141 lines in 6 files changed: 91 ins; 19 del; 31 mod 8275843: Random crashes while the UI code is executed Reviewed-by: azvegint ------------- PR: https://git.openjdk.java.net/jdk/pull/6199
