IZ66091: JAVA HANG WHILE THE JIT IS COMPILING A METHOD

APAR status

• Closed as program error.

Error description

• Error Message: The Java JIT compiler hangs and consumes 100%
  CPU during the compilation of a method.
  .
  Stack Trace:
  {libj9jit24.so}{walker__22TR_ByteCodeIlGeneratorFP8TR_Block}
  {libj9jit24.so}{genExceptionHandlers__22TR_ByteCodeIlGeneratorFP
  8TR_Block}
  {libj9jit24.so}{genILFromByteCodes__22TR_ByteCodeIlGeneratorFv}
  {libj9jit24.so}{internalGenIL__22TR_ByteCodeIlGeneratorFv}
  {libj9jit24.so}{genIL__22TR_ByteCodeIlGeneratorFv}
  {libj9jit24.so}{genIL__23TR_ResolvedMethodSymbolFP11TR_FrontEndP
  14TR_CompilationP23TR_SymbolReferenceTablebP8TR_ArrayXTP18TR_Sym
  bolReference_}
  .
  A JVMTI agent or some kind of bytecode manipulation software
  may be in use, to log or profile exceptions, or to instrument
  exception handling behaviour in some fashion.
  

Local fix

• Disable any JVMTI agent or bytecode manipulation sofwtare that
  may be modifying the Java bytecodes. If the problem persists,
  the issues can be avoided by using the -Xjit:exclude={...}
  option to prevent the JIT compiler from compiling the offending
  method.
  

Problem summary

• The JIT failed to handle a rare kind of method
  in which all the code reachable only by an exception handler
  was not contiguous in the bytecode stream. Normally, javac does
  not produce such methods; they are typically products of
  bytecode manipulation.
  

Problem conclusion

• This defect will be fixed in:
  6.0.0 SR6
  5.0.0 SR11
  .
  The JIT was modified to handle this case correctly.
  .
  To obtain the fix:
  Install build 20090806 or later
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

  IZ55337

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  JAVA 5 JIT

• Fixed component ID

  620500124

Applicable component levels

• R500 PSN

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