IV02756: A 'FINAL' FIELD IS NOT INITIALIZED INSIDE AN OBJECT

APAR status

• Closed as program error.

Error description

• Error Message: Could be any syndrom (NPE, incorrect output etc)
  related to an uninitialized Final field in a multi-threaded
  environment.
  e.g.
  j> 06:00:02 java.lang.NullPointerException
  j> 06:00:02  at java.util.Random.next(Random.java:181)
  j> 06:00:02  at java.util.Random.nextInt(Random.java:301)
  j> 06:00:02  at
  tests.com.ibm.jtc.concurrent.locks.ReentrantLockTest.testStress(
  ReentrantLockTest.java:346)
  .
  Stack Trace: N/A
  .
  seen on z/OS and Linux on Z
  

Local fix

• -Xjit:disableScheduling turns off the instruction scheduler and
  provides a workaround. However this might impact performance of
  some programs significantly.
  

Problem summary

• The 390 instruction scheduler incorrectly reordered two Store
  instructions and as a result we exposed an object (to other
  threads) before finish initializing its Final field. This is
  visible in a multi-threaded environment only.
  

Problem conclusion

• This defect will be fixed in:
  5.0.0 SR13
  6.0.0 SR10
  6.0.1 SR1
  .
  The JVM has been updated to prevent scheduler from reordering
  the stores instructions.
  .
  To obtain the fix:
  Install build 20110628 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:

  IV02757

Fix information

• Fixed component name

  JAVA 5 JIT

• Fixed component ID

  620500124

Applicable component levels

• R500 PSY

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