I just wanted to follow up with this in case someone comes across this thread later.
After thoroughly exploring the landscape, I found that the issue on Ubuntu was caused by a conflict between the webkit2gtk-4.0 library (which I was using to show a progress dialog in the case that the JRE or app needs to download an update). Additionally it seemed to have a problem with just the general gtk+-3.0 dependency, if GTK was initialized before JavaFX was loaded. I worked around the gtk+-3.0 issue by breaking the GTK stuff into a separate process (calling itself with different args). This workaround was not sufficient to resolve the webkit2gtk-4.0 conflict as, even if it wasn't used at runtime, it would still conflict with JavaFX's webview - resulting in a segfault. The only solution was to remove the webkit2gtk-4.0 dependency entirely from my app, and do the progress dialog differently (I ended up just using basic GTK widgets). Best regards Steve On Wed, Jan 19, 2022 at 9:40 AM Steve Hannah <st...@weblite.ca> wrote: > The following issue only seems to occur on Linux (Ubuntu 20.04.1), and > only when I try to launch the JVM from a custom C launcher using JNI. It > does not occur when launching the JVM as a separate process using the > "java" binary. It also does not occur on MacOS when using the same C > launcher using JNI. > > When I call MyApplication.launch(args). (where MyApplication extends the > JavaFX Application class), I get the following stack trace: > > Jan. 19, 2022 8:54:27 A.M. com.sun.javafx.application.PlatformImpl startup > Exception in thread "Thread-5" java.lang.IllegalStateException: This > operation is permitted on the event thread only; currentThread = Thread-5 > at com.sun.glass.ui.Application.checkEventThread(Application.java:447) > at com.sun.glass.ui.Application.setName(Application.java:200) > at > com.sun.javafx.application.PlatformImpl.lambda$setApplicationName$2(PlatformImpl.java:142) > at > com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:457) > at java.base/java.security.AccessController.doPrivileged(Native > Method) > at > com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:456) > at > com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96) > Exception in Application start method > Exception in thread "Thread-31" Failed to show docs > java.lang.IllegalStateException: Not on FX application thread; currentThread > = Thread-31 > at com.sun.javafx.tk.Toolkit.checkFxUserThread(Toolkit.java:295) > at > com.sun.javafx.tk.quantum.QuantumToolkit.checkFxUserThread(QuantumToolkit.java:458) > at > com.sun.javafx.tk.quantum.QuantumToolkit.exit(QuantumToolkit.java:828) > at > com.sun.javafx.application.PlatformImpl.lambda$tkExit$16(PlatformImpl.java:624) > at > com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:484) > at > com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:457) > at java.base/java.security.AccessController.doPrivileged(Native > Method) > at > com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:456) > at > com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96) > java.lang.RuntimeException: Exception in Application start method > at > com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:901) > at > com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:196) > at java.base/java.lang.Thread.run(Thread.java:829) > Caused by: java.lang.IllegalStateException: Not on FX application thread; > currentThread = Thread-6 > at com.sun.javafx.tk.Toolkit.checkFxUserThread(Toolkit.java:295) > at > com.sun.javafx.tk.quantum.QuantumToolkit.checkFxUserThread(QuantumToolkit.java:458) > at javafx.stage.Stage.<init>(Stage.java:254) > at javafx.stage.Stage.<init>(Stage.java:240) > at > com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:845) > at > com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:484) > at > com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:457) > at java.base/java.security.AccessController.doPrivileged(Native > Method) > at > com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:456) > at > com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96) > > > I have tried a few different versions of JavaFX (11, 11.0.2, 17.0.1), > running on a few different JDK installs (all JDK11). Above stacktrace is > from 17.0.1. > > From the C application that launches the JVM, I have tried running > directly on the main thread, and also launching it in a fresh thread using > pthreads - but same issue. I am running this inside an application written > in Go but the JNI code is all in C. > > It appears as though JavaFX is unable to create its application thread for > some reason. Does anyone have any suggestions on reasons why this would be > the case? Are there some system properties that need to be there which > would have been bootstrapped by the "java" binary, but would not when the > JVM is launched via JNI? > > Any suggestions appreciated. I've been banging my head on this for a > while now. > > Best regards > > Steve > -- Steve Hannah Web Lite Solutions Corp.
