How to debug/troubleshoot macOS freezes in OS.objc_msgSendSuper?

[guw]

We have quite a few users struggling with Java debugging in Eclipse.
eclipse-jdt/eclipse.jdt.debug#410

But looking at the jstack dump I have doubts this is really a debugging issue. It looks more like an SWT issue.

2024-03-19 17:34:54
Full thread dump OpenJDK 64-Bit Server VM (17.0.9+9 mixed mode):

Threads class SMR info:
_java_thread_list=0x000060000c9a2c60, length=74, elements={
0x000000015801e400, 0x0000000158919e00, 0x000000015891a400, 0x0000000158012c00,
0x0000000158013200, 0x0000000158052c00, 0x0000000158053200, 0x0000000158053800,
0x0000000158053e00, 0x0000000158938000, 0x000000015a029a00, 0x000000015803d800,
0x00000001582d3400, 0x00000001589aa400, 0x0000000159009600, 0x0000000158d78200,
0x0000000158616a00, 0x00000001595a4600, 0x000000015a0bc600, 0x000000015879d400,
0x0000000159566600, 0x0000000159534a00, 0x000000015952cc00, 0x0000000156525200,
0x0000000159569800, 0x000000015003d200, 0x0000000158aa9a00, 0x00000001503cae00,
0x000000012683d800, 0x000000016823f400, 0x0000000158e03c00, 0x0000000127517400,
0x0000000a74cfd000, 0x0000000107821200, 0x0000000168daec00, 0x0000000126827c00,
0x0000000158abb200, 0x0000000168926600, 0x0000000158659a00, 0x00000001565e7a00,
0x000000015a6d7800, 0x0000000a75ac7400, 0x0000000127041200, 0x0000000156324200,
0x0000000158d67e00, 0x0000000158633600, 0x00000001520b3a00, 0x0000000150b79800,
0x0000000141067800, 0x0000000a73a36400, 0x000000015093f200, 0x0000000158729c00,
0x0000000a73809800, 0x0000000150cde000, 0x0000000a75d88800, 0x000000015a035200,
0x0000000a75dcf000, 0x0000000158a75400, 0x0000000a75dd4e00, 0x0000000158619a00,
0x0000000150216e00, 0x0000000127202800, 0x00000001589a6a00, 0x0000000127329600,
0x0000000151a71600, 0x0000000a73bd7000, 0x000000015079ec00, 0x0000000a75e1f800,
0x0000000151bfec00, 0x0000000158999800, 0x000000015633d600, 0x0000000a7ae5e600,
0x0000000a75b04600, 0x0000000158deae00
}

"main" #1 prio=6 os_prio=31 cpu=233403.76ms elapsed=3345.47s tid=0x000000015801e400 nid=0x103 runnable  [0x000000016d3e7000]
   java.lang.Thread.State: RUNNABLE
	at org.eclipse.swt.internal.cocoa.OS.objc_msgSendSuper(Native Method)
	at org.eclipse.swt.widgets.Widget.callSuper(Widget.java:236)
	at org.eclipse.swt.widgets.Widget.mouseDownSuper(Widget.java:1147)
	at org.eclipse.swt.widgets.Widget.mouseDown(Widget.java:1139)
	at org.eclipse.swt.widgets.Control.mouseDown(Control.java:2642)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:6320)
	at org.eclipse.swt.internal.cocoa.OS.objc_msgSendSuper(Native Method)
	at org.eclipse.swt.widgets.Widget.callSuper(Widget.java:236)
	at org.eclipse.swt.widgets.Widget.windowSendEvent(Widget.java:2264)
	at org.eclipse.swt.widgets.Shell.windowSendEvent(Shell.java:2510)
	at org.eclipse.swt.widgets.Display.windowProc(Display.java:6444)
	at org.eclipse.swt.internal.cocoa.OS.objc_msgSendSuper(Native Method)
	at org.eclipse.swt.widgets.Display.applicationSendEvent(Display.java:5691)
	at org.eclipse.swt.widgets.Display.applicationProc(Display.java:5831)
	at org.eclipse.swt.internal.cocoa.OS.objc_msgSend(Native Method)
	at org.eclipse.swt.internal.cocoa.NSApplication.sendEvent(NSApplication.java:117)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3985)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1155)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:342)
	at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1046)
	at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:155)
	at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:648)
	at org.eclipse.ui.internal.Workbench$$Lambda$200/0x00000070002ab780.run(Unknown Source)
	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:342)
	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:555)
	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:173)
	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:152)
	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:208)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:136)
	at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:402)
	at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(java.base@17.0.9/Native Method)
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(java.base@17.0.9/NativeMethodAccessorImpl.java:77)
	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(java.base@17.0.9/DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(java.base@17.0.9/Method.java:568)
	at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:651)
	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:588)
	at org.eclipse.equinox.launcher.Main.run(Main.java:1459)

Is there any guidance or document how to troubleshoot these freezes?

[guw]

Not an answer yet but some new information. Based on old bugs and their comments in Bugzilla (1, 2) this seems to happen if there is a RuntimeException thrown in the UI code.

Now the million doller question is .... how to detect those exceptions.

@lshanmug in case you have some ideas. 🙏

[laeubi]

Now the million doller question is .... how to detect those exceptions.

@guw if you want to handle exceptions in native code you can do it like this, it is a bit cumbersome but I have already used this in the past: https://docs.oracle.com/en/java/javase/11/docs/specs/jni/design.html#exception-handling

By the way where do I get my $million$ now? :-)

[lshanmug]

Not an answer yet but some new information. Based on old bugs and their comments in Bugzilla (1, 2) this seems to happen if there is a RuntimeException thrown in the UI code.

SWT hanging when RuntimeException occurs was an issue in the past and was fixed in 4.15 (by https://bugs.eclipse.org/bugs/show_bug.cgi?id=562408). I don't remember this issue being reported after that.

Now the million doller question is .... how to detect those exceptions.

Is it reproducible? If yes and in case the problem is caused by any exceptions, may be using Display.setRuntimeExceptionHandler() can help in troubleshooting? (Please see https://bugs.eclipse.org/bugs/show_bug.cgi?id=395381#c25)

[guw]

Thanks @lshanmug Display.setRuntimeExceptionHandler() did not unveil something. Looks like it just freezes on mouse down but only on specific machines. Is there debugging output I can enable or is there a special compiled version with debug output?