IV26972: MULTIPLE THREADS STUCK IN PARKED STATE

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APAR status

  • Closed as program error.

Error description

  • Error Message: The JVM hangs while multiple threads are parked
    on the same lock (e.g. a
    java/util/concurrent/locks/ReentrantLock$NonfairSync object).
    The thread that is supposed to wake all the parked threads is
    also incorrectly stuck in the parked state so all the threads
    remain parked and never wake up.
    .
    Stack Trace: sun/misc/Unsafe.park
    java/util/concurrent/locks/LockSupport.park
    java/util/concurrent/locks/AbstractQueuedSynchronizer.parkAndChe
    ckInterrupt
    java/util/concurrent/locks/AbstractQueuedSynchronizer.acquireQue
    ued
    java/util/concurrent/locks/AbstractQueuedSynchronizer.acquire
    java/util/concurrent/locks/ReentrantLock$NonfairSync.lock
    java/util/concurrent/locks/ReentrantLock.lock
    java/util/concurrent/ArrayBlockingQueue.offer
    .
    

Local fix

Problem summary

  • The problem occurs when the Java code depends on volatile
    semantics to ensure that the volatile field updates are seen in
    different threads. The problem is caused by incorrect volatile
    field handling in JIT-compiled code. A memory fence for a
    volatile field is missing after a write operation due to
    incorrect JIT code generation. This issue affects z/OS and
    z/Linux, running on z9 or older hardware.
    

Problem conclusion

  • This defect will be fixed in:
    5.0 SR15
    6.0 SR12
    
    6.0.1 SR3
    7.0.0 SR2
    .
    The JIT compiler has been updated to generate the memory fence
    if the field is found to be a volatile.
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV26972

  • Reported component name

    JIT

  • Reported component ID

    620700124

  • Reported release

    260

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2012-08-24

  • Closed date

    2012-08-24

  • Last modified date

    2012-10-10

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

    IV29907

Fix information

  • Fixed component name

    JIT

  • Fixed component ID

    620700124

Applicable component levels

  • R260 PSY

       UP



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Document information


More support for:

Runtimes for Java Technology
Just In Time (JIT) Compiler

Software version:

260

Reference #:

IV26972

Modified date:

2012-10-10

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