IV47606: DEADLOCK IN RANDOMACCESSFILE/FILEINPUTSTREAM/FILEOUTPUTSTREAM IN MULTI-THREAD ENV

APAR status

• Closed as program error.

Error description

• Error Message: There is deadlock found between
  java.nio.channels.spi.AbstractInterruptibleChannel and
  RandomAccessFile/FileInputStream/FileOutputStream when in multi
  thread environment
  .
  Stack Trace: There is a deadlock in the classes code:
  3XMTHREADBLOCK Blocked on: java/lang/Object@0x00000000FFF51D58
  Owned by: "Attach API initializer"
  (J9VMThread:0x0000000000F02D00,
  java/lang/Thread:0x00000000FFF479F8)
  3XMHEAPALLOC Heap bytes allocated since last GC cycle=3768
  (0xEB8)
  3XMTHREADINFO3 Java callstack:
  4XESTACKTRACE at
  java/nio/channels/spi/AbstractInterruptibleChannel.close(Abstrac
  tInterruptibleChannel.java:111)
  4XESTACKTRACE at
  java/io/RandomAccessFile.close(RandomAccessFile.java:586)
  5XESTACKTRACE (entered lock:
  java/lang/Object@0x00000000FFF515B0, entry count: 1)
  3XMTHREADBLOCK Blocked on: java/lang/Object@0x00000000FFF515B0
  Owned by: "Attach API teardown" (J9VMThread:0x0000000000F07E00,
  java/lang/Thread:0x00000000FFF48098)
  3XMHEAPALLOC Heap bytes allocated since last GC cycle=19584
  (0x4C80)
  3XMTHREADINFO3 Java callstack:
  4XESTACKTRACE at
  java/io/RandomAccessFile.close(RandomAccessFile.java:575)
  4XESTACKTRACE at
  sun/nio/ch/FileChannelImpl.implCloseChannel(FileChannelImpl.java
  :123)
  4XESTACKTRACE at
  java/nio/channels/spi/AbstractInterruptibleChannel$1.interrupt(A
  bstractInterruptibleChannel.java:165)
  5XESTACKTRACE (entered lock:
  java/lang/Object@0x00000000FFF51D58, entry count: 1)
  4XESTACKTRACE at
  java/nio/channels/spi/AbstractInterruptibleChannel.begin(Abstrac
  tInterruptibleChannel.java:180)
  4XESTACKTRACE at
  sun/nio/ch/FileChannelImpl.lock(FileChannelImpl.java:1007)
  4XESTACKTRACE at
  java/nio/channels/FileChannel.lock(FileChannel.java:1052)
  .
  N/A
  

Local fix

• Do not close RandomAccessFile/FileInputStream/FileOutputStream
  and its channel in different thread at same time.
  

Problem summary

• There is a wrong patch in
  java.io.RandomAccessFile/FileInputStream/FileOutputStream which
  synchronizes too much code and it cause the deadlock.
  

Problem conclusion

• This defect will be fixed in:
  7.0.0 SR6
  .
  Modify the code to synchronize the really needed code to solve
  the deadlock
  

Temporary fix

• N/A
  

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 CLASS LIBS

• Fixed component ID

  620700130

Applicable component levels

• R700 PSY

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