This bug is green thread JVM specific.

Running both Caffeinemark 2.01 and 2.5. with green thread JVM (Sunsoft build),
Selecting the local button and then the run AGC button causes the VM to hang.

With JDK1.1 Final, It hung on Caffeinemark 2.01 (AGC test), but SEGV and core
dumps with Caffeinemark 2.5 (AGC test). Core can be found at
/net/javavm/space/wesley/CaffeineMarks2.5/jdk11.core

cello% /home/wesley/jdk1.1/bin/appletviewer caffeinemark2.html
SIGSEGV 11* segmentation violation
    si_signo [11]: SIGSEGV 11* segmentation violation
    si_errno [0]: Error 0
    si_code [1]: SEGV_ACCERR [addr: 0x0]

        stackbase=EF0D1000, stackpointer=EF0D0690

Full thread dump:
    "Thread-8" (TID:0xee321838, sys_thread_t:0xede00de0, state:CW) prio=5
        GCFrame.run(GCFrame.java)
        java.lang.Thread.run(Thread.java)
    "Image Fetcher 0" (TID:0xee333038, sys_thread_t:0xede30de0, state:R) prio=3
        java.lang.Thread.setPriority(Thread.java)
        sun.awt.image.InputStreamImageSource.setPixels(InputStreamImageSource.java:463)
        sun.awt.image.GifImageDecoder.sendPixels(GifImageDecoder.java:439)
        sun.awt.image.GifImageDecoder.readImage(GifImageDecoder.java:537)
        sun.awt.image.GifImageDecoder.produceImage(GifImageDecoder.java:223)
        sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.java:219)
        sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:139)
        sun.awt.image.ImageFetcher.run(ImageFetcher.java:116)
    "Thread-6" (TID:0xee30a200, sys_thread_t:0xef040de0, state:R) prio=5
        BenchMark.wait(CaffeineMark.java)
        BenchMark.gcmark(CaffeineMark.java)
        BenchmarkThread.run(CaffeineMark.java)
    "AWT-Finalizer" (TID:0xee30fc48, sys_thread_t:0xef070de0, state:CW) prio=9
        java.lang.Object.wait(Object.java)
        sun.awt.AWTFinalizer.run(AWTFinalizer.java:48)
    "Screen Updater" (TID:0xee30e710, sys_thread_t:0xef0a0de0, state:R) prio=4
        java.lang.Thread.setPriority(Thread.java)
        sun.awt.ScreenUpdater.run(ScreenUpdater.java:97)
    "AWT-Motif" (TID:0xee30dfe8, sys_thread_t:0xef0d0de0, state:R) prio=5 *current thread*
        java.lang.Thread.run(Thread.java)
    "AWT-Input" (TID:0xee30dfc8, sys_thread_t:0xef100de0, state:CW) prio=5
    "AWT-EventQueue-0" (TID:0xee30dfb0, sys_thread_t:0xef130de0, state:CW) prio=5
        java.awt.MediaTracker.waitForID(MediaTracker.java:515)
        java.awt.MediaTracker.waitForID(MediaTracker.java:476)
        GCFrame.GetGIF(GCFrame.java)
        GCFrame.paint(GCFrame.java)
        java.awt.Component.dispatchEventImpl(Component.java)
        java.awt.Container.dispatchEventImpl(Container.java)
        java.awt.Window.dispatchEventImpl(Window.java)
        java.awt.EventDispatchThread.run(EventDispatchThread.java)
    "thread applet-CaffeineMark.class" (TID:0xee30d268, sys_thread_t:0xef2b0de0, state:CW) prio=4
        java.lang.Object.wait(Object.java)
        sun.applet.AppletPanel.getNextEvent(AppletPanel.java:204)
        sun.applet.AppletPanel.run(AppletPanel.java:230)
        java.lang.Thread.run(Thread.java)
    "Finalizer thread" (TID:0xee300220, sys_thread_t:0xef2e0de0, state:R) prio=1
        sun.awt.AWTFinalizer.addFinalizeable(AWTFinalizer.java:65)
        sun.awt.motif.X11Graphics.finalize(X11Graphics.java:99)
    "Async Garbage Collector" (TID:0xee3001d8, sys_thread_t:0xef310de0, state:R) prio=1
    "Idle thread" (TID:0xee300190, sys_thread_t:0xef340de0, state:R) prio=0
    "Clock" (TID:0xee3000d0, sys_thread_t:0xef370de0, state:CW) prio=12
    "main" (TID:0xee3000a8, sys_thread_t:0x38a78, state:CW) prio=5
Monitor Cache Dump:
         java.awt.MediaTracker@EE333240/EE3740A0 (key=0xee333240): unowned
        Waiting to be notified:
            "AWT-EventQueue-0"
         unknown key (key=0xede00de0): monitor owner ede00de0: "Thread-8"
         sun.applet.AppletViewerPanel@EE30CF80/EE364478 (key=0xee30cf80): unowned
        Waiting to be notified:
            "thread applet-CaffeineMark.class"
         sun.awt.AWTFinalizer@EE30FC48/EE370890 (key=0xee30fc48): unowned
        Waiting to be notified:
            "AWT-Finalizer"
         sun.awt.motif.MToolkit@EE30DF50/EE3679A0 (key=0xee30df50): monitor owner ef0d0de0: "AWT-Motif"
        Waiting to be notified:
            "AWT-Input"
Registered Monitor Dump:
    Thread queue lock: unowned
        Waiting to be notified:
            "main"
    Name and type hash table lock: unowned
    String intern lock: unowned
    JNI global reference lock: unowned
    BinClass lock: unowned
    Class loading lock: unowned
    Java stack lock: unowned
    Code rewrite lock: unowned
    Heap lock: unowned
    Has finalization queue lock: unowned
    Finalize me queue lock: unowned
    Monitor IO lock: unowned
    Child death monitor: unowned
    Event monitor: unowned
    I/O monitor: unowned
    Alarm monitor: unowned
        Waiting to be notified:
            "Clock"
    Sbrk lock: unowned
    Monitor cache expansion lock: unowned
    Monitor registry: monitor owner ef0d0de0: "AWT-Motif"
Thread Alarm Q:
Abort (core dumped)


wesley.chen@Eng 1997-02-24

The hang is caused by an bug in the caffeinemark code. The timing thread ends up starving the Image Fetcher thread. If you lower the priority of the timing thread hang goes away. I've been unable to reproduce the crash on anything.
tom.rodriguez@Eng 1997-08-07