PK64874: HITTING OOM WHILE LOADING HUGE FILES IN JTEXTAREA.

APAR status

• Closed as program error.

Error description

• Error Message: Hitting OOM while loading huge files in
  JTextArea.
  .
  Stack Trace: java.lang.OutOfMemoryError:
  
  at
  javax.swing.text.GapContent.allocateArray(GapContent.java:106)
  
  at javax.swing.text.GapVector.resize(GapVector.java:226)
  
  at javax.swing.text.GapVector.shiftEnd(GapVector.java:241)
  
  at javax.swing.text.GapContent.shiftEnd(GapContent.java:355)
  
  at javax.swing.text.GapVector.open(GapVector.java(Compiled
  Code))
  at javax.swing.text.GapVector.replace(GapVector.java(Compiled
  Code))
  at
  javax.swing.text.GapContent.insertString(GapContent.java(Inlined
  Compiled Code))
  at
  javax.swing.text.AbstractDocument.handleInsertString(AbstractDoc
  ument.java(Compiled Code))
  at
  javax.swing.text.AbstractDocument.insertString(AbstractDocument.
  java(Compiled Code))
  at
  javax.swing.text.PlainDocument.insertString(PlainDocument.java(C
  ompiled Code))
  at
  javax.swing.text.DefaultEditorKit.read(DefaultEditorKit.java(Com
  piled Code))
  at
  javax.swing.text.JTextComponent.read(JTextComponent.java:1350)
  
  at MyThread.readin(MyThread.java:81)
  at MyThread.run(MyThread.java:115)
  .
  No
  

Local fix

• No
  

Problem summary

• 1. Launch the application, select the option to load a file.
  2. Load a huge file of size 20MB into JTextArea. Once the file
  contents are observed, close the window.
  3. Repeat step 2 five or six times on a machine with 1G RAM and
  we should be able to observe the OutofMemory Error.
  

Problem conclusion

• This defect will be fixed in:
  1.4.2 SR12
  .
  After investigating the issue we figured out the IBM 5.0 and
  onwards are behaving much better in comparison of IBM142. The
  reason of IBM 5.0 Java behaving better than IBM 142 Java is due
  to the storage array resize policy in GapContent class got
  changed in the earlier one.
  In IBM 142 Java the memory consumed by JTextArea appears to
  require 4 bytes per character. Although, 2 bytes is
  understandable in that as Java is unicode internally. But the
  extra 2 bytes was wastage of memory.
  5. So, under this defect we are backporting the 5.0 changes in
  the 142 codebase which was addressing the same issue i.e. high
  memory usage while loading huge files in JTextArea. By inclusion
  of this we can reduce the memory usage upto 50%.
  .
  To obtain the fix:
  Install build 20080713 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

• R42A PSN

     UP

• R42L PSN

     UP

• R42W PSN

     UP

• R420 PSN

     UP