IJ54643: ASSERTION FAILURE AT COPYFORWARDSCHEME.CPP

APAR status

• Closed as program error.

Error description

• Error Message: * ** ASSERTION FAILED ** at
  CopyForwardScheme.cpp:1409: ((false &&
  (static_cast<MM_CycleStateVLHGC*>(env->_cycleState)->_vlhgcIncre
  mentStats._copyForwardStats._ownableSynchronizerCandidates >=
  static_cast<MM_CycleStateVLHGC*>(env->_cycleState)->_vlhgcIncrem
  entStats._copyForwardStats._ownableSynchronizerSurvived)))
  .
  Stack Trace: javaTrace at trcengine.c:1388
  MM_CopyForwardScheme::mainCleanupForCopyForward at
  CopyForwardScheme.cpp:1409
  MM_CopyForwardScheme::copyForwardPostProcess at
  CopyForwardScheme.cpp:1629
  MM_CopyForwardScheme::copyForwardCollectionSet
  CopyForwardScheme.cpp:1696
  MM_CopyForwardDelegate::performCopyForwardForPartialGC at
  CopyForwardDelegate.cpp:75
  MM_IncrementalGenerationalGC::runPartialGarbageCollect at
  IncrementalGenerationalGC.cpp:1045
  MM_IncrementalGenerationalGC::mainThreadGarbageCollect at
  IncrementalGenerationalGC.cpp:369
  MM_MainGCThread::handleSTW at MainGCThread.cpp:178
  .
  

Local fix

• This issue is only applicable to the Balanced GC policy, and it
  can be worked around by using Gencon GC policy.
  

Problem summary

• The problem was caused because some ownable synchronizer objects
  are left behind after a copy forward abort event.  Those objects
  could be discovered by next GC copy forward event, and then
  trigger the assertion failure.
  

Problem conclusion

• The JVM has been updated so that no ownable synchronizer objects
  are left behind after the copy forward abort event.
  .
  This APAR will be fixed in the following Releases:
  .
  IBM Semeru Runtimes
     21              21.0.8.0
     17              17.0.16.0
     11              11.0.28.0
  IBM SDK, Java Technology Edition
     8    SR8 FP50  (8.0.8.50)
  .
  Downloads and supplementary documentation can be found at the
  following locations:
  - For non z/OS operating systems:
    - IBM Semeru Runtimes, Version 11 and later
      https://www.ibm.com/semeru-runtimes/downloads/
    - IBM SDK, Java Technology Edition, Version 8
      https://www.ibm.com/support/pages/java-sdk-downloads/
  - For the z/OS operating system:
    - Java SDK Products on z/OS
      https://www.ibm.com/support/pages/java-sdk-products-zos
  

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