> This picks up fixing the issue of > [JDK-8276809](https://bugs.openjdk.org/browse/JDK-8276809) again. A fix had > been integrated with #17224 but @prrace had concerns and so it was backed out. > > I have now spent quite some thoughts into the problem and end up with the > [initial > commit](https://github.com/openjdk/jdk/pull/6306/commits/5d18a76cb967e9ede6394cbd6c28bb61facf785c) > of #6306 as the most elegant and least intrusive solution. > > Why is this? > > The JNI warning we observe in the test is: > `[WARNING in native method: JNI call made without checking exceptions when > required to from CallStaticVoidMethodV > at > sun.awt.Win32GraphicsEnvironment.initDisplay(java.desktop@22.0.1-internal/Native > Method) > at > sun.awt.Win32GraphicsEnvironment.initDisplayWrapper(java.desktop@22.0.1-internal/Win32GraphicsEnvironment.java:95) > at > sun.awt.Win32GraphicsEnvironment.<clinit>(java.desktop@22.0.1-internal/Win32GraphicsEnvironment.java:63) > ... > at FreeTypeScalerJNICheck.runTest(FreeTypeScalerJNICheck.java:53) > at FreeTypeScalerJNICheck.main(FreeTypeScalerJNICheck.java:44)` > > This happens because obviously the test FreeTypeScalerJNICheck runs with > `-Xcheck:jni` and in the scenario where we're observing the warning, a > missing exception check for the JNI call to > `sun.awt.Win32GraphicsEnvironment::dwmCompositionChanged` at > awt_Win32GraphicsEnv.cpp#L129 > https://github.com/openjdk/jdk/blob/c5e72450966ad50d57a8d22e9d634bfcb319aee9/src/java.desktop/windows/native/libawt/windows/awt_Win32GraphicsEnv.cpp#L129 > is airing up. Omitting the exception check would not be a problem if it > could be guaranteed that after this call no other JNI->Java call was being > made. But seemingly in this very particular configuration on some of our > Windows servers, there must be JNI->Java calls that follow the call to > `sun.awt.Win32GraphicsEnvironment::dwmCompositionChanged`, likely from the > subsequent call to > [initScreens](https://github.com/openjdk/jdk/blob/c5e72450966ad50d57a8d22e9d634bfcb319aee9/src/java.desktop/windows/native/libawt/windows/awt_Win32GraphicsEnv.cpp#L149) > in `sun.awt.Win32GraphicsEnvironment::initDisplay`. > https://github.com/openjdk/jdk/blob/8b6293f6bfb7b7628c6604e6c44401fc96d85cf4/src/java.desktop/windows/native/libawt/windows/awt_Win32GraphicsEnv.cpp#L141 > Maybe the usual control flow would call the wrapping native method > `DWMIsCompositi onEnabled()` from somewhere else initially such that the initialization of `Win32GraphicsEnvironment` would not go through `initScreens` or similar. > ...
Christoph Langer has updated the pull request incrementally with one additional commit since the last revision: Add formatting suggestions ------------- Changes: - all: https://git.openjdk.org/jdk/pull/17404/files - new: https://git.openjdk.org/jdk/pull/17404/files/528f25bf..24dd7541 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=17404&range=03 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17404&range=02-03 Stats: 4 lines in 1 file changed: 3 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/17404.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/17404/head:pull/17404 PR: https://git.openjdk.org/jdk/pull/17404
