IZ86326: JDWP THREAD HANGS WAITING FOR A MONITOR HELD BY A SUSPENDED CLAS SLOADER THREAD

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: jdwp thread:
  0:006> kp
  ChildEBP RetAddr
  0920fc18 7c90e9c0 ntdll!KiFastSystemCallRet
  0920fc1c 7c8025db ntdll!ZwWaitForSingleObject+0xc
  0920fc80 7c802542 kernel32!WaitForSingleObjectEx+0xa8
  0920fc94 7f0a1efa kernel32!WaitForSingleObject+0x12
  0920fcac 7f0a2c1a j9thr23!monitor_enter_three_tier(struct
  J9Thread * self = 0x00000000, struct J9ThreadMonitor * monitor =
  0x00000023)+0x9a
  0920fcb8 7f110a76 j9thr23!j9thread_monitor_enter(struct
  J9ThreadMonitor * monitor = 0x10ce9048)+0x3a
  0920fccc 7ee7d567 j9jvmti23!jvmtiRawMonitorEnter(struct
  JVMTINativeInterface_ ** env = 0x10ce9048, struct _jrawMonitorID
  * monitor = 0x10ce904c)+0x96
  WARNING: Stack unwind information not available. Following
  frames may be wrong.
  0920fce0 7ee79737 jdwp!Agent_OnUnload+0x1c2dd
  00000000 00000000 jdwp!Agent_OnUnload+0x184ad
  Class loading thread:
  0:079> kp
  ChildEBP RetAddr
  0cd7f474 7c90e9c0 ntdll!KiFastSystemCallRet
  0cd7f478 7c8025db ntdll!ZwWaitForSingleObject+0xc
  0cd7f4dc 7c802542 kernel32!WaitForSingleObjectEx+0xa8
  0cd7f4f0 7f0a22d0 kernel32!WaitForSingleObject+0x12
  0cd7f528 7f0a2ce2 j9thr23!monitor_wait(struct J9ThreadMonitor *
  monitor = 0x4affc033, int64 millis = -4490119718996728, int
  nanos = 58524746, int interruptable = 1375732930)+0x210
  0cd7f540 7f051ead j9thr23!j9thread_monitor_wait(struct
  J9ThreadMonitor * monitor = 0x7f03014b)+0x12
  0cd7f550 7f051eef
  j9vm23!internalAcquireVMAccessNoMutexWithMask(struct J9VMThread
  * vmThread = 0x7f03014b, unsigned int haltMask = 0xd57af00)+0x1d
  0cd7f55c 7f021047 j9vm23!internalAcquireVMAccessNoMutex(struct
  J9VMThread * vmThread = 0x7f03014b)+0xf
  0cd7f5ac 7f03014b j9vm23!internalAcquireVMAccess(void)+0x47
  0cd7f60c 7ee7dbec j9vm23!isSameObject(void)+0x8b
  WARNING: Stack unwind information not available. Following
  frames may be wrong.
  0cd7f620 7ee784da jdwp!Agent_OnUnload+0x1c962
  0cd7f634 7ee797db jdwp!Agent_OnUnload+0x17250
  0cd7f63c 7ee79c38 jdwp!Agent_OnUnload+0x18551
  0cd7f644 7ee7af24 jdwp!Agent_OnUnload+0x189ae
  0cd7f670 7ee704c2 jdwp!Agent_OnUnload+0x19c9a
  00000000 00000000 jdwp!Agent_OnUnload+0xf238
  .
  N/A
  

Local fix

• N/A
  

Problem summary

• Application hangs while one of its thread(jdwp) is trying to
  acquire a monitor lock which is held by another thread(Class
  loader in this case). Since the class loading thread is found to
  be in suspended state, the thread cannot release the lock until
  it resumes. It's not just the loader that is suspended and all
  other threads except the few jdwp threads are found to be in
  suspended state. This explains that the jdwp thread has
  suspended all the threads and trying to acquire a lock before
  resuming the threads. Since the monitor lock being requested is
  held by a suspended thread, this goes to a deadlock kind of
  situation that cannot be recovered until the lock is released by
  the loader thread.
  

Problem conclusion

• This defect will be fixed in:
  5.0.0 SR13
  .
  JVM has been updated to overcome this deadlock situation that
  happens with the JDWP thread.
  .
  To obtain the fix:
  Install build 20101015 or later
  

Temporary fix

• N/A
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  JAVA 5 J9 COMMO

• Fixed component ID

  620500127

Applicable component levels

• R500 PSN

     UP