IJ02541: ASSERTIONS IN GC WHEN JVMTI RUNS WITH CONCURRENT SCAVENGER

APAR status

• Closed as program error.

Error description

• Error Message: 14:30:00.734642317                 0x0
  j9mm.621  Event       GC Assertion message: readObject
  503fd3a558 in Evacuate
  14:30:00.735437029       *0x50420a7200       j9mm.141  Assert
  * ** ASSERTION FAILED ** at ./StandardAccessBarrier.cpp:655:
  ((false))
  .
  Stack Trace: #14 0x00007f80abb02aae in
  MM_StandardAccessBarrier::preObjectRead (this=0x7f80ac0366d0,
  vmThread=<value optimized out>, srcObject=<value optimized out>,
      srcAddress=<value optimized out>) at
  StandardAccessBarrier.cpp:655
  #15 0x00007f80ab9561ae in
  MM_ObjectAccessBarrier::mixedObjectReadObject
  (this=0x7f80ac0366d0, vmThread=0x99ed00, srcObject=0x2fe050e8,
  srcOffset=<value optimized out>,
      isVolatile=false) at ObjectAccessBarrier.cpp:562
  #16 0x00007f80ab1d9b3d in jvmtiGetThreadInfo (env=<value
  optimized out>, thread=<value optimized out>,
  info_ptr=0x7f80a95769f0) at jvmtiThread.c:487
  #17 0x00007f80aad03210 in
  jdwp::ThreadReference::NameHandler::Execute(JNIEnv_*) () from
  /team/Dmitri/136058/sdk/jre/lib/amd64/libjdwp.so
  #18 0x00007f80aad0ee7e in
  jdwp::SyncCommandHandler::Run(JNIEnv_*, jdwp::CommandParser*) ()
  from /team/Dmitri/136058/sdk/jre/lib/amd64/libjdwp.so
  #19 0x00007f80aad0e582 in
  jdwp::CommandDispatcher::ExecCommand(JNIEnv_*,
  jdwp::CommandParser*) () from
  /team/Dmitri/136058/sdk/jre/lib/amd64/libjdwp.so
  #20 0x00007f80aad19503 in jdwp::PacketDispatcher::Run(JNIEnv_*)
  () from /team/Dmitri/136058/sdk/jre/lib/amd64/libjdwp.so
  #21 0x00007f80aad19d88 in
  jdwp::PacketDispatcher::StartFunction(_jvmtiEnv*, JNIEnv_*,
  void*) () from /team/Dmitri/136058/sdk/jre/lib/amd64/libjdwp.so
  #22 0x00007f80ab1d928a in wrappedAgentThreadStart
  (portLib=0x7f80b1cc4840, entryArg=<value optimized out>) at
  jvmtiThread.c:968
  #23 0x00007f80b0eb1475 in omrsig_protect
  (portLibrary=0x7f80b1cc4840, fn=0x7f80ab1d91d0
  <wrappedAgentThreadStart>, fn_arg=0x7f80ac35a910,
      handler=0x7f80b15a6440 <structuredSignalHandler>,
  handler_arg=0x99ed00, flags=126, result=0x7f80a9576ef8) at
  ../../omr/port/unix/omrsignal.c:397
  #24 0x00007f80ab1d890f in agentThreadStart (entryArg=<value
  optimized out>) at jvmtiThread.c:930
  #25 0x00007f80b131738e in thread_wrapper () from
  /team/Dmitri/136058/sdk/jre/lib/amd64/compressedrefs/libj9thr29.
  so
  .
  

Local fix

• Do not use Concurrent Scavenger by excluding
  -Xgc:concurrentScavenge option
  

Problem summary

• The elements of JNI Weak Global References Table were not
  handled properly in Concurrent Scavenger
  

Problem conclusion

• Handling of JNI Weak Global References Table elements has been
  fixed for case of Concurrent Scavenger
  .
  This APAR will be fixed in the following Java Releases:
     8    SR5 FP7   (8.0.5.7)
  .
  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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