FULL PRODUCT VERSION :
java version "1.7.0-ea"
Java(TM) SE Runtime Environment (build 1.7.0-ea-b10)
Java HotSpot(TM) 64-Bit Server VM (build 1.7.0-ea-b10, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux tidore 2.6.19-gentoo-r5 #1 SMP Thu Feb 15 12:11:59 CET 2007 x86_64 AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ AuthenticAMD GNU/Linux


A DESCRIPTION OF THE PROBLEM :
My application happened to call RandomAccessFile.close() and FileLock.release() on a lock created from the FileChannel of the RandomAccessFile in two different threads at the same time. This resulted in a Java level deadlock as shown by the jstack output below.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Sorry, no steps. But it is obvious from the jstack output which locks can be acquired in inconsitent order.


ERROR MESSAGES/STACK TRACES THAT OCCUR :
Found one Java-level deadlock:
=============================
"checkpointer":
  waiting to lock monitor 0x00002aaac3b759f0 (object 0x00002aaac2c10958, a java.util.ArrayList),
  which is held by "main"
"main":
  waiting to lock monitor 0x00002aaac3b75600 (object 0x00002aaac2c109a0, a sun.nio.ch.FileLockImpl),
  which is held by "checkpointer"

Java stack information for the threads listed above:
===================================================
"checkpointer":
        at sun.nio.ch.FileChannelImpl$SharedFileLockTable.remove(FileChannelImpl.java:1128)
        - waiting to lock <0x00002aaac2c10958> (a java.util.ArrayList)
        at sun.nio.ch.FileChannelImpl.release(FileChannelImpl.java:925)
        at sun.nio.ch.FileLockImpl.release(FileLockImpl.java:38)
        - locked <0x00002aaac2c109a0> (a sun.nio.ch.FileLockImpl)

"main":
        at sun.nio.ch.FileLockImpl.invalidate(FileLockImpl.java:31)
        - waiting to lock <0x00002aaac2c109a0> (a sun.nio.ch.FileLockImpl)
        at sun.nio.ch.FileChannelImpl$1.release(FileChannelImpl.java:106)
        at sun.nio.ch.FileChannelImpl$SharedFileLockTable.removeAll(FileChannelImpl.java:1155)
        - locked <0x00002aaac2c10958> (a java.util.ArrayList)
        at sun.nio.ch.FileChannelImpl.implCloseChannel(FileChannelImpl.java:104)
        at java.nio.channels.spi.AbstractInterruptibleChannel.close(AbstractInterruptibleChannel.java:97)
        - locked <0x00002aaac2c1f4a8> (a java.lang.Object)
        at java.io.RandomAccessFile.close(RandomAccessFile.java:568)


REPRODUCIBILITY :
This bug can be reproduced occasionally.