PK18936: MEMORY LEAK IN LINKEDHASHMAP.JAVA: LINKEDHASHMAP$ENTRY

APAR status

• Closed as program error.

Error description

• Java program throws an OutOfMemory exception and generates
  a heapdump in the process. The heapdump indicates a huge
  number of objects of type java/util/LinkedHashMap$Entry.
  

Local fix

Problem summary

• A Java application using LinkedHashMap, might run out of
  Java heap space due to a memory leak that exists in the
  LinkedHashMap$Entry code. The heapdump thus generated due
  to OutOfMemory condition points to large number of objects
  of type LinkedHashMap$Entry active on the heap.
  

Problem conclusion

• 123456789-123456789-123456789-123456789-123456789-123456789
  A programming error existed in a private method used for
  deletion of objects of LinkedHashMap$Entry type in
  LinkedHashMap$Entry class. Due to this error, the strong
  references existing between the entry that is supposed to
  get removed and the previous and next entries don't get
  cleared. This causes the 'removed' entry objects to hold
  on to other referenced entries even after removal from the
  LinkedHashMap preventing them from getting garbage
  collected during GC. This causes a continuous increase in
  heap usage and thus an OutofMemory condition.
  .
  To obtain the fix:
  Install build 20060208 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:

Fix information

• Fixed component name

  JAVA(1.3/1.4 CO

• Fixed component ID

  5648C9800

Applicable component levels

• R420 PSN

     UP

• R42A PSN

     UP

• R42L PSN

     UP

• R42W PSN

     UP