IV65397: DTFJ API LOOP GETTING STACK SECTIONS FOR A JAVA THREAD FROM A CO RE DUMP

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: com.ibm.j9ddr.corereaders.memory.MemoryFault:
  Memory Fault reading 0x0106D1F8at
  com.ibm.j9ddr.corereaders.memory.AbstractMemory$CachingMemorySou
  rce.loadBlock(AbstractMemory.java:481)at
  com.ibm.j9ddr.corereaders.memory.AbstractMemory$CachingMemorySou
  rce.getBytes(AbstractMemory.java:441)at
  com.ibm.j9ddr.corereaders.memory.AbstractMemory.getBytesAt(Abstr
  actMemory.java:180)at
  com.ibm.j9ddr.corereaders.memory.AbstractMemory.getBytesAt(Abstr
  actMemory.java:165)at
  com.ibm.j9ddr.corereaders.memory.AbstractMemory.getIntAt(Abstrac
  tMemory.java:215)at
  com.ibm.j9ddr.corereaders.memory.ProcessAddressSpace.getPointerA
  t(ProcessAddressSpace.java:65)at
  com.ibm.j9ddr.vm26.pointer.AbstractPointer.getPointerAtOffset(Ab
  stractPointer.java:364)at
  com.ibm.j9ddr.vm26.pointer.generated.J9JavaStackPointer.previous
  (J9JavaStackPointer.java:180)at
  com.ibm.j9ddr.vm26.j9.J9JavaStackIterator.next(J9JavaStackIterat
  or.java:58)at
  com.ibm.j9ddr.vm26.view.dtfj.java.DTFJJavaThread.walkSections(DT
  FJJavaThread.java:410)at
  com.ibm.j9ddr.vm26.view.dtfj.java.DTFJJavaThread.getStackSection
  s(DTFJJavaThread.java:390)at
  org.eclipse.mat.dtfj.DTFJIndexBuilder.scanJavaThread(DTFJIndexBu
  ilder.java:3817)at
  org.eclipse.mat.dtfj.DTFJIndexBuilder.processConservativeRoots(D
  TFJIndexBuilder.java:2701)at
  org.eclipse.mat.dtfj.DTFJIndexBuilder.fill(DTFJIndexBuilder.java
  :1954)at
  org.eclipse.mat.parser.internal.SnapshotFactoryImpl.parse(Snapsh
  otFactoryImpl.java:231)at
  org.eclipse.mat.parser.internal.SnapshotFactoryImpl.openSnapshot
  (SnapshotFactoryImpl.java:135)at
  org.eclipse.mat.snapshot.SnapshotFactory.openSnapshot(SnapshotFa
  ctory.java:145)at
  org.eclipse.mat.ui.snapshot.ParseHeapDumpJob.run(ParseHeapDumpJo
  b.java:88)at
  org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)
  .
  

Local fix

Problem summary

• The loop is caused when the DTFJ API encounters a file read
  error while traversing the stack sections for a Java thread.
  

Problem conclusion

• The DTFJ API has been updated to handle the dump file read error
  without looping.
  .
  This APAR will be fixed in the following Java Releases:
     7 R1 SR2       (7.1.2.0)
     6 R1 SR8 FP2   (6.1.8.2)
     7    SR8       (7.0.8.0)
  .
  Contact your IBM Product's Service Team for these Service
  Refreshes and Fix Packs.
  For those running stand-alone, Java maintenance is available
  from:
             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

     UP

• R260 PSY

     UP