IJ17818: RACE CONDITION SETTING AND UNSETTING A STRING INTERN TABLE FLAG

APAR status

• Closed as program error.

Error description

• Error Message: A SIGSEGV is received when updating the shared
  string intern table.
  .
  Stack Trace:
  StringInternTable::updateSharedNodeWeight(J9SharedInvariantInter
  nTable*, J9SharedInternSRPHashTableEntry*) ()
  StringInternTable::markNodeAsUsed(J9InternSearchResult*,
  J9SharedInvariantInternTable*) ()
  ROMClassStringInternManager::visitUTF8(unsigned short, unsigned
  short, unsigned char*, SharedCacheRangeInfo) ()
  ROMClassBuilder::finishPrepareAndLaydown(unsigned char*,
  unsigned char*, unsigned char*,
  ROMClassBuilder::SizeInformation*, unsigned int, unsigned int,
  unsigned int, bool, bool, ClassFileOracle*, SRPOffsetTable*,
  SRPKeyProducer*, ROMClassWriter*, ROMClassCreationContext*,
  ConstantPoolMap*) ()
  ROMClassBuilder::prepareAndLaydown(BufferManager*,
  ClassFileParser*, ROMClassCreationContext*) ()
  ROMClassBuilder::buildROMClass(ROMClassCreationContext*) ()
  j9bcutil_buildRomClass ()
  internalLoadROMClass ()
  internalDefineClass ()
  attemptDynamicClassLoad ()
  internalFindClassInModule ()
  internalFindClassString ()
  .
  The JVM is running with -Xshareclasses
  

Local fix

• Work around the problem by added "mprotect=none" to the
  -Xshareclasses: option on the command line.
  

Problem summary

• The problem is caused by a race condition setting and unsetting
  a string intern table flag.
  

Problem conclusion

• The race condition setting and unsetting the intern string table
  flag is resolved.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR5 FP41  (8.0.5.41)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, information about the available
  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

• R270 PSY

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