IV16934: DEADLOCK MAY HAPPEN WHEN A THREAD FAILS TO START

APAR status

• Closed as program error.

Error description

• Error Message: The following message shows up in the Java core
  file:
  
                  Deadlock detected !!!
                  ---------------------
                   Thread "T1" (0x4AA98600)
                     is waiting for:
                       sys_mon_t:0x6DBD39E0 infl_mon_t:
  0x6DBD3A18:
  
  java/lang/ThreadGroup$ChildrenThreadsLock@0x1EFEDD60/0x1EFEDD6C:
                     which is owned by:
                   Thread "T2" (0x51D78900)
                     which is waiting for:
                       sys_mon_t:0x6CD150F8 infl_mon_t:
  0x6CD15130:
  
  java/lang/Thread$ThreadLock@0x3D7AD6C0/0x3D7AD6CC:
                     which is owned by:
                   Thread "T1" (0x4AA98600)
  .
  Stack Trace: Thread "T1" has the following Java callstack:
                          at
  java/lang/ThreadGroup.remove(ThreadGroup.java)
                          at java/lang/Thread.start(Thread.java)
                          ......
                  Thread "T2" has the following Java callstack:
                          at java/lang/Thread.isAlive(Thread.java)
                          at
  java/lang/ThreadGroup.activeCount(ThreadGroup.java)
                          at
  java/lang/Thread.activeCount(Thread.java)
                          ......
  .
  

Local fix

Problem summary

• Deadlock may happen if a thread fails to start and at the same
  time another thread is enumerating the thread group of the
  starting thread.
  

Problem conclusion

• This defect will be fixed in:
  6.0.0 SR11
  6.0.1 SR3
  7.0.0 SR2
  .
                         The JVM has been updated to prevent the
  dead lock from occurring when a thread fails to start.
  

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