On Tue, 26 Nov 2024 15:11:58 GMT, Karm Michal Babacek <d...@openjdk.org> wrote:
>> If there is a problem with finding and calling e.g. >> `java/awt/GraphicsEnvironment` in `AWTIsHeadless`, the env' Exception >> remains set and it is not cleared. Later, that manifests as: >> >> Fatal error reported via JNI: Could not allocate library name >> >> Which is misleading. The code path is perhaps rare in a normal JDK usage, >> but it has been complicating our users' bug reports in the >> GraalVM/native-image ecosystem for quite some time. >> >> Instead of failing later indicating that the user has incorrectly configured >> JNI, it bails out very soon with a message that seems as if a jstring could >> not have been allocated. It sends users on wild goose chases where it >> appears `JNU_NewStringPlatform` calls failed, e.g. >> >> * https://github.com/oracle/graal/issues/9138 >> * https://github.com/oracle/graal/issues/8475 >> * https://github.com/oracle/graal/issues/9300 >> * https://github.com/quarkusio/quarkus/issues/31596 >> * https://github.com/graalvm/mandrel/issues/292 >> * https://github.com/Karm/mandrel-integration-tests/issues/262 >> >> This commit fixes the error reporting in the AWTIsHeadless. >> >> Furthermore, when AOT compiled, there is little sense for having a >> JAVA_HOME, yet some parts of AWT code look for it to search fonts. In such >> case, an empty directory structure is enough to accommodate it, e.g. >> >> /tmp/JAVA_HOME/ >> /tmp/JAVA_HOME/conf >> /tmp/JAVA_HOME/conf/fonts >> /tmp/JAVA_HOME/lib >> >> The exception is somewhat cryptic for users again, merely stating: >> >> Exception in thread "main" java.io.IOException: Problem reading font >> data. >> at java.desktop@22.0.1/java.awt.Font.createFont0(Font.java:1205) >> at java.desktop@22.0.1/java.awt.Font.createFont(Font.java:1076) >> at imageio.Main.loadFonts(Main.java:139 >> >> Adding the cause there makes it clearer, i.e. that JAVA_HOME might be >> missing: >> >> Exception in thread "main" java.io.IOException: Problem reading font >> data. >> at java.desktop@23-internal/java.awt.Font.createFont0(Font.java:1206) >> at java.desktop@23-internal/java.awt.Font.createFont(Font.java:1076) >> at imageio.Main.loadFonts(Main.java:139) >> at imageio.Main.paintRectangles(Main.java:97) >> at imageio.Main.main(Main.java:195) >> at >> java.base@23-internal/java.lang.invoke.LambdaForm$DMH/sa346b79c.invokeStaticInit(LambdaForm$DMH) >> Caused by: java.lang.Error: java.home property not set >> at >> java.desktop@23-internal/sun.awt.FontConfiguration.findFontConfigF... > > Karm Michal Babacek has updated the pull request incrementally with one > additional commit since the last revision: > > Amended error message, doesn't clear exception src/java.desktop/unix/native/libawt/awt/awt_LoadLibrary.c line 70: > 68: graphicsEnvClass = (*env)->FindClass(env, > 69: > "java/awt/GraphicsEnvironment"); > 70: CHECK_EXCEPTION_FATAL(env, "FindClass > java/awt/GraphicsEnvironment failed"); If `FindClass` fails to find the class, a `NoClassDefFoundError` should be raised. This function returns immediately (a value of `true`). The caller of this function should check if there's a pending exception and perform an appropriate action. In this case, the function is called from https://github.com/openjdk/jdk/blob/955bf185c38ec0fcedb0a549461fc85367b37fbb/src/java.desktop/unix/native/libawt/awt/awt_LoadLibrary.c#L130-L132 If there's a pending exception, it should bail out and let the exception be thrown on the Java side. If it doesn't, the pending exception makes `JNU_NewStringPlatform` fail at https://github.com/openjdk/jdk/blob/955bf185c38ec0fcedb0a549461fc85367b37fbb/src/java.desktop/unix/native/libawt/awt/awt_LoadLibrary.c#L149-L150 --- Ah! There's no Java code to catch the exception… `AWT_OnLoad` is essentially `JNI_OnLoad`. In this case, `CHECK_EXCEPTION_FATAL` seems right. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/20169#discussion_r1922849674
