IZ75061: ZIPFILE.CLOSE() DOESN'T CLOSE INPUTSTREAMS OPENED WITH ZIPFILE.GETINPUTSTREAM()

APAR status

• Closed as program error.

Error description

• Error Message: Native OutOfMemoryError caused by exhaustion of
  virtual address space, particularly on Windows 32-bit.  Many
  small leaking allocations observed in the native C/C++ runtime
  heap, particularly 56-byte allocations.
  
  These allocations cause fragmentation of the native C/C++
  runtime heap.  The total amount of leaked memory is relatively
  small, but the amount of memory reserved for heap extensions is
  large (typified by large jumps in the amount of virtual address
  space in the memory map for the process).
  .
  Stack Trace: java/lang/OutOfMemoryError
  Stack trace varies.
  .
  The first pointer in leaking 56-byte allocation should point to
  an ANSI string representing a zip file entry name.  Many
  duplicates of the same entry names may be seen (these entry
  names may correspond to resources loaded using
  ClassLoader.getResourceAsStream(), particularly when the
  classloader is a WebSphere Application Server classloader).
  

Local fix

• Ensure that your application calls ZipFileInputStream.close()
  explicitly.  This includes Middleware code.
  

Problem summary

• ZipFile.close() does not close streams that have been opened
  using
  ZipFile.getInputStream(), as the JavaDoc describes it should.
  When the pattern of use for ZipFile is to:
  1. Open ZipFile
  2. Call ZipFile.getInputStream() without subsequently calling
  close() direcly on the
  InputStreams
  3. Call ZipFile.close()
  Then native memory associated with the returned InputStreams is
  not freed as it
  should be.  Note, the above pattern of use is perfectly valid
  according to the
  JavaDoc, and appears to be in use by some WebSphere Application
  Server's
  classloaders in response to ClassLoader.getResourceAsStream().
  

Problem conclusion

• This defect will be fixed in:
  6.0.0 SR9
  .
  ZipFile.close() can now call close() on any InputStreams that
  have
  been opened using ZipFile.getInputStream(), but have not yet
  been closed explicitly
  by application.
  A new Java option is introduced to turn on this behaviour as
  there may be performance
  impact to add this support.
  Solution is either application closes the InpustStreams
  explicitly or run your Java
  applications with "-Dcom.ibm.zipfile.closeinputstreams=true".
  .
  To obtain the fix:
  Install build 20100531_04 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:

  PM15938

Fix information

• Fixed component name

  JAVA CLASS LIBS

• Fixed component ID

  620700130

Applicable component levels

• R600 PSY

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