IV70545: DEADLOCK IN CLASS THREADGROUP

APAR status

• Closed as program error.

Error description

• Error Message: A Javacore file generated at the time of the
  deadlock shows the following:1LKDEADLOCK    Deadlock detected
  !!!NULL           ---------------------NULL2LKDEADLOCKTHR
  Thread "<Thread-1>" (0x0000010014E29A00)3LKDEADLOCKWTR    is
  waiting for:4LKDEADLOCKMON      sys_mon_t:0x0000010016705930
  infl_mon_t: 0x0000010016705970:4LKDEADLOCKOBJ
  java/lang/ThreadGroup$ChildrenThreadsLock@0x0A00000003C2EC98/0x0
  A00000003C2ECB0:3LKDEADLOCKOWN    which is owned
  by:2LKDEADLOCKTHR  Thread "<Thread-2>"
  (0x0000010014B48A00)3LKDEADLOCKWTR    which is waiting
  for:4LKDEADLOCKMON      sys_mon_t:0x00000100167059B8 infl_mon_t:
  0x00000100167059F8:4LKDEADLOCKOBJ
  java/lang/ThreadGroup@0x0A00000003C2EBA8/0x0A00000003C2EBC0:3LKD
  EADLOCKOWN    which is owned by:2LKDEADLOCKTHR  Thread
  "<Thread-1>" (0x0000010014E29A00)NULL
  .
  Stack Trace: N/A
  .
  

Local fix

Problem summary

• The problem occurs when a thread holding the ThreadGroup lock
  tries to create a new thread while a second thread tries to
  remove a thread from the same ThreadGroup.
  

Problem conclusion

• The JVM has been updated to prevent deadlock between user code
  and ThreadGroup internals.
  .
  This APAR will be fixed in the following Java Releases:
     6    SR16 FP4  (6.0.16.4)
     7    SR9       (7.0.9.0)
     7 R1 SR3       (7.1.3.0)
     8    SR1       (8.0.1.0)
     6 R1 SR8 FP4   (6.1.8.4)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the Service
  Refreshes and Fix Packs can be found at:
             https://www.ibm.com/developerworks/java/jdk/
  

Temporary fix

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

  J9 COMMON CODE

• Fixed component ID

  620700127

Applicable component levels

• R600 PSY

     UP

• R260 PSY

     UP

• R270 PSY

     UP