APAR status
Closed as program error.
Error description
Error Message: N/A . Stack Trace: N/A . The JIT might propagate final field initialization values to future uses of the final field. This means that modification of the final field's value might not be visible to code executed after the modification occurs. Final fields can be modified using JNI and Unsafe APIs which breaks the java language guarantee that final fields cannot have their values changed after an initial value is assigned.
Local fix
With this APAR we are introducing an java command line option that can be used to prevent the JIT from assuming that primitive box class final fields are immutable. -Xjit:disableImmutableFieldAliasing This option is added to avoid problem while developers modify there code such that they avoid modifying primitive box class final fields.
Problem summary
When applications use JNI or Unsafe code to modify a primitive box classes final field the JIT might prevent that change from being visible by Java code. This is the result of the JIT optimizing the Java code to avoid unnecessary memory operations based the Java specification definition of the "final" keyword causing fields to be immutable after initial assignment.
Problem conclusion
A Java command line option was added that is used by the JIT to disable aliasing of primitive box class final fields. . This APAR will be fixed in the following Java Releases: 8 SR6 FP7 (8.0.6.7) . 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 number
IJ22300
Reported component name
JIT
Reported component ID
620700124
Reported release
130
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-01-24
Closed date
2020-01-30
Last modified date
2020-01-30
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
[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSC9HBA","label":"Just In Time (JIT) Compiler"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"130","Edition":"","Line of Business":{"code":"","label":""}}]
Document Information
Modified date:
30 January 2020