IZ99243: USE OF JVMTI AGENT PREVENTS OBJECT FINALIZATION AFTER APPLYING APAR IV11135

PM49617: SHIP SDK APAR IZ99243 AS A WSAS IFIX
PM52687: SHIP SDK APAR IV06580 and defect 184227 as WSAS IFIX
PM53783: SHIP several SDK apars as WSAS iFix on top of 1.6 SR9 FP2

APAR status

• Closed as program error.

Error description

• Error Message: The IBM Java 6 JVM fails to perform finalization
  of objects when the following conditions are met:
  .
  1. The Just-In-Time compiler is enabled.
  .
  2. A JVMTI agent is in use.
  .
  Not finalizing objects can cause allocated resources (such as
  file descriptors) to never be freed, leading to possible "Too
  many open files" exceptions or OutOfMemoryErrors.
  .
  Stack Trace: N/A
  .
  

Local fix

• This issue can be circumvented with the JVM option
  -Xjit:forceFullSpeedDebug. Note that this may cause severe
  performance degradation. Another workaround is to prevent the
  compilation of Object constructors with this option:
  .
  -Xjit:dontInline={java/lang/Object.<init>*},exclude={java/lang/O
  bject.<init>*}
  

Problem summary

• When a JVMTI agent is attached to the JVM, the JIT compiler is
  forced to disable certain optimizations to ensure correctness.
  In this restricted mode ("HCR mode"), the JIT compiler was
  unable to recognize that certain classes of objects needed to be
  finalized.
  

Problem conclusion

• This defect will be fixed in:
  6.0.0 SR9 FP3
  6.0.1 GA FP1
  .
  The JIT compiler has been updated to generate correct code for
  object finalization under HCR mode.
  .
  To obtain the fix:
  Install build 20110405 or later
  

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

  JIT

• Fixed component ID

  620700124

Applicable component levels

• R600 PSY

     UP