IJ58960: ASSERT FROM JIT COMPILER IN JAVA 8

APAR status

• Closed as program error.

Error description

• Error Message: Java 8 terminates unexpectedly with an assert
  from a JIT compilation thread:
  j9jit.19 - * ** ASSERTION FAILED ** at
  c:\temp\bld_108597\bld_win_x86-64_cmprssptrs\compiler\..\compile
  r\env\VMJ9.cpp:5661: ((0 ))
  .
  Stack Trace: 4XENATIVESTACK
  TR_J9VMBase::getVarHandleHandleTableOffset+0x5b (VMJ9.cpp:5664,
  0x00007FFEBA5AF86B <OSB>j9jit29+0xdf86b<CSB>)
  4XENATIVESTACK
  TR_VarHandleTransformer::perform+0x3fc
  (VarHandleTransformer.cpp:256, 0x00007FFEBA840FBC
  <OSB>j9jit29+0x370fbc<CSB>)
  4XENATIVESTACK
  OMR::Optimizer::performOptimization+0x178c
  (OMROptimizer.cpp:1972, 0x00007FFEBAA5348C
  <OSB>j9jit29+0x58348c<CSB>)
  4XENATIVESTACK               OMR::Optimizer::optimize+0x3c5
  (OMROptimizer.cpp:1120, 0x00007FFEBAA4FC75
  <OSB>j9jit29+0x57fc75<CSB>)
  .
  The problem occurred while compiling methods from the Netty
  framework.
  

Local fix

• The problematic methods can be excluded from JIT compilation to
  avoid triggering the assert.
  

Problem summary

• VarHandles are not supported in Java 8 and some of the related
  compiler functions contain assertions to ensure that they are
  not accidentally called in that environment. Usually these
  helpers will never be called since there would not be any Java
  code running on Java 8 that uses VarHandles. However it is
  possible (if unusual) for a Java method to contain conditional
  uses of VarHandles so that it can run optimally on both Java 8
  and later versions that do support VarHandles. The presence of
  such code incorrectly triggered the JIT to perform VarHandle
  related optimizations that fired the assertion.
  

Problem conclusion

• The JIT has been updated to ensure that the VarHandle related
  optimizations are not used on Java 8.
  .
  This APAR will be fixed in the following Releases:
  .
  IBM Semeru Runtimes
  IBM SDK, Java Technology Edition
     8    SR8 FP70  (8.0.8.70)
  .
  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

  JIT

• Fixed component ID

  620700124

Applicable component levels