IV20921: HANG IN A SINGLE APPLICATION THREAD WHILE ALL OTHER THREADS HAVE YIELDED

APAR status

• Closed as program error.

Error description

• Error Message: The application hangs, i.e., no progress is made
  by the application, with no error message.
  .
  Stack Trace: N/A
  .
  

Local fix

• -Xjit:disableAsyncCheckRemoval works around this problem but it
  may cause slight performance degradation.
  

Problem summary

• This problem may occur when a trusted method (i.e., a method in
  String, HashMap, or TreeMap classes) that contains a loop is
  inlined in user code.  With low probability, the JIT generates a
  code for the user loop that doesn't have a GC point.
  Now if other threads are waiting for GC to happen, and the user
  code doesn't progress until something happens in the other
  threads, there will be a deadlock. In other words, GC is waiting
  for user loop which is waiting for other threads which are
  waiting for GC.
  

Problem conclusion

• This defect will be fixed in:
  7.0.0 SR2
  6.0.0 SR11
  6.0.1 SR3
  5.0.0 SR14
  .
  The check that JIT uses to detect whether a loop has come from a
  trusted method has been made more accurate.
  

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:

  IV20922

Fix information

• Fixed component name

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R260 PSY

     UP

• R600 PSY

     UP