I have the following thread dump from a hung java swing application. It hung after a button is clicked and the GUI changed to blank. Other threads in socket communication and task management are still working (from the log file I can tell). I have removed some non-relevant output.
The #13 AW-EventQueue-0 should send out a command through the socket but it seems failed there. The #20 and #21 are AW-EventQueue-0-SharedResourceRunner which is not the same as the #13? It seems there is no deadlock but the GUI is not responsive and became blank.
do you see any useful information about the cause of the hanging?
Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.20-b23 mixed mode):
"DestroyJavaVM" #32 prio=5 os_prio=0 tid=0x00007f286c009800 nid=0xa41 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"TimerQueue" #22 daemon prio=5 os_prio=0 tid=0x00007f28002a8800 nid=0xa65 waiting on condition [0x00007f284c56f000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x0000000088a8f5c0> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
at java.util.concurrent.DelayQueue.take(DelayQueue.java:211)
at javax.swing.TimerQueue.run(TimerQueue.java:171)
at java.lang.Thread.run(Thread.java:745)
"AWT-EventQueue-0-SharedResourceRunner" #21 daemon prio=6 os_prio=0 tid=0x00007f280021d000 nid=0xa64 in Object.wait() [0x00007f284d434000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x0000000088aec748> (a jogamp.opengl.SharedResourceRunner)
at java.lang.Object.wait(Object.java:502)
at jogamp.opengl.SharedResourceRunner.run(SharedResourceRunner.java:276)
- locked <0x0000000088aec748> (a jogamp.opengl.SharedResourceRunner)
at java.lang.Thread.run(Thread.java:745)
"AWT-EventQueue-0-SharedResourceRunner" #20 daemon prio=6 os_prio=0 tid=0x00007f28001f3000 nid=0xa63 in Object.wait() [0x00007f284f7f5000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x0000000088aed588> (a jogamp.opengl.SharedResourceRunner)
at java.lang.Object.wait(Object.java:502)
at jogamp.opengl.SharedResourceRunner.run(SharedResourceRunner.java:276)
- locked <0x0000000088aed588> (a jogamp.opengl.SharedResourceRunner)
at java.lang.Thread.run(Thread.java:745)
"AWT-EventQueue-0" #13 prio=6 os_prio=0 tid=0x00007f286c444800 nid=0xa59 in Object.wait() [0x00007f2858913000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x00000000dc467018> (a java.lang.Object)
at java.lang.Object.wait(Object.java:502)
at com.mycp.common.task.BMBTaskBase.startTask(BMBTaskBase.java:551)
- locked <0x00000000dc467018> (a java.lang.Object)
at com.mycp.uiapp.workmgmt.WorkMgmtMgr.sendBegCmd(WorkMgmtMgr.java:334)
at com.mycp.uiapp.workmgmt.WorkMgmtPanelBase.prepareAndSendBegWork(WorkMgmtPanelBase.java:559)
at com.mycp.uiapp.workmmgmt.WorkMgmtPanel.prepareAndSendBegWork(WorkMgmtPanel.java:1479)
at com.mycp.uiapp.workmgmt.WorkMgmtPanelBase.btnPrepareClicked(WorkMgmtPanelBase.java:363)
at com.mycp.uiapp.workmgmt.WorkMgmtPanel.btnPrepareClicked(WorkMgmtPanel.java:1412)
at com.mycp.uiapp.workmgmt.WorkMgmtPanel.actionPerformed(WorkMgmtPanel.java:1336)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2346)
"AWT-Shutdown" #14 prio=5 os_prio=0 tid=0x00007f286c443000 nid=0xa58 in Object.wait() [0x00007f2858a17000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x0000000088ae8c28> (a java.lang.Object)
at java.lang.Object.wait(Object.java:502)
at sun.awt.AWTAutoShutdown.run(AWTAutoShutdown.java:295)
- locked <0x0000000088ae8c28> (a java.lang.Object)
at java.lang.Thread.run(Thread.java:745)
"AWT-XAWT" #12 daemon prio=6 os_prio=0 tid=0x00007f286c384000 nid=0xa51 runnable [0x00007f285914f000]
java.lang.Thread.State: RUNNABLE
at sun.awt.X11.XToolkit.waitForEvents(Native Method)
at sun.awt.X11.XToolkit.run(XToolkit.java:559)
at sun.awt.X11.XToolkit.run(XToolkit.java:523)
at java.lang.Thread.run(Thread.java:745)
"Java2D Disposer" #10 daemon prio=10 os_prio=0 tid=0x00007f286c35e000 nid=0xa50 in Object.wait() [0x00007f2859250000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x0000000087ab7ec0> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:142)
- locked <0x0000000087ab7ec0> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:158)
at sun.java2d.Disposer.run(Disposer.java:148)
at java.lang.Thread.run(Thread.java:745)
"Thread-0" #9 prio=5 os_prio=0 tid=0x00007f286c234800 nid=0xa4f waiting on condition [0x00007f2859af5000]
java.lang.Thread.State: TIMED_WAITING (sleeping)
at java.lang.Thread.sleep(Native Method)
at com.mycp.logging.BMBLogging$Task.run(BMBLogging.java:1072)
at java.lang.Thread.run(Thread.java:745)
"Service Thread" #8 daemon prio=9 os_prio=0 tid=0x00007f286c0cf800 nid=0xa4d runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"C1 CompilerThread2" #7 daemon prio=9 os_prio=0 tid=0x00007f286c0b2000 nid=0xa4c waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"C2 CompilerThread1" #6 daemon prio=9 os_prio=0 tid=0x00007f286c0b0000 nid=0xa4b waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"C2 CompilerThread0" #5 daemon prio=9 os_prio=0 tid=0x00007f286c0ad800 nid=0xa4a waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"Signal Dispatcher" #4 daemon prio=9 os_prio=0 tid=0x00007f286c0ab000 nid=0xa49 waiting on condition [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"Finalizer" #3 daemon prio=8 os_prio=0 tid=0x00007f286c07c000 nid=0xa48 in Object.wait() [0x00007f285a2dd000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x0000000087a7e6c8> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:142)
- locked <0x0000000087a7e6c8> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:158)
at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:209)
"Reference Handler" #2 daemon prio=10 os_prio=0 tid=0x00007f286c07a000 nid=0xa47 in Object.wait() [0x00007f285a3de000]
java.lang.Thread.State: WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
- waiting on <0x0000000087a7e708> (a java.lang.ref.Reference$Lock)
at java.lang.Object.wait(Object.java:502)
at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:157)
- locked <0x0000000087a7e708> (a java.lang.ref.Reference$Lock)
"VM Thread" os_prio=0 tid=0x00007f286c072800 nid=0xa46 runnable
"GC task thread#0 (ParallelGC)" os_prio=0 tid=0x00007f286c01e800 nid=0xa42 runnable
"GC task thread#1 (ParallelGC)" os_prio=0 tid=0x00007f286c020800 nid=0xa43 runnable
"GC task thread#2 (ParallelGC)" os_prio=0 tid=0x00007f286c022000 nid=0xa44 runnable
"GC task thread#3 (ParallelGC)" os_prio=0 tid=0x00007f286c024000 nid=0xa45 runnable
"VM Periodic Task Thread" os_prio=0 tid=0x00007f286c0d2000 nid=0xa4e waiting on condition
JNI global references: 485
Heap
PSYoungGen total 118272K, used 98176K [0x00000000d6e00000, 0x00000000de700000, 0x0000000100000000)
eden space 113152K, 82% used [0x00000000d6e00000,0x00000000dc8e00c8,0x00000000ddc80000)
from space 5120K, 100% used [0x00000000de180000,0x00000000de680000,0x00000000de680000)
to space 5120K, 0% used [0x00000000ddc80000,0x00000000ddc80000,0x00000000de180000)
ParOldGen total 159744K, used 76671K [0x0000000084a00000, 0x000000008e600000, 0x00000000d6e00000)
object space 159744K, 47% used [0x0000000084a00000,0x00000000894dfc50,0x000000008e600000)
Metaspace used 30027K, capacity 30212K, committed 30464K, reserved 1077248K
class space used 3528K, capacity 3582K, committed 3584K, reserved 1048576K
The thread dump shows stack traces from about 22 different threads. Many of them look like application threads (as opposed to JVM internal threads). Most of the application threads are waiting for something. Which of those threads should not be waiting?
I'd start by looking at thread 13: Looks like the Swing EDT, and it's waiting inside a call to a button's actionPerformed(...) handler. That can't be good.