IBM Support

IV68216: DEADLOCK WHEN A FILEWRITER IS WORKED ON CONCURRENTLY BY MORE THA N ONE WRITER INSTANCES

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APAR status

  • Closed as program error.

Error description

  • Error Message: Application hangs when two threads work on 2
    Writer instances with the same underlying FileWriter. An example
    scenario, one thread is working on a FileWriter while another
    thread is working on a PrintWriter instance which uses same
    FileWriter instance as the former thread.
    .
    Stack Trace: Blocked on: java/io/FileOutputStream@0x23144B88
    Owned by: "Thread-5"Java callstack:at
    java/io/OutputStreamWriter.write(OutputStreamWriter.java:212)at
    java/io/PrintWriter.write(PrintWriter.java:416)(entered lock:
    java/io/FileWriter@0x23144B60, entry count: 1)at
    testcase$bar.run(testcase.java:28)at
    java/lang/Thread.run(Thread.java:785)Blocked on:
    java/io/FileWriter@0x23144B60 Owned by: "Thread-6"Java
    callstack:at
    sun/nio/cs/StreamEncoder.write(StreamEncoder.java:129)at
    java/io/OutputStreamWriter.emptyBuffer(OutputStreamWriter.java:3
    02)(entered lock: java/io/FileOutputStream@0x23144B88, entry
    count: 2)at
    java/io/OutputStreamWriter.write(OutputStreamWriter.java:215)(en
    tered lock: java/io/FileOutputStream@0x23144B88, entry count:
    1)at testcase$bar.run(testcase.java:28)at
    java/lang/Thread.run(Thread.java:785)
    .
    

Local fix

Problem summary

  • The hang arises due to threads acquiring multiple locks related
    to Writer class in different order.
    

Problem conclusion

  • The locking sequences are streamlined to prevent the deadlocks
    in multi-threaded scenarios.
    .
    This APAR will be fixed in the following Java Releases:
       6    SR16 FP4  (6.0.16.4)
       8    SR1       (8.0.1.0)
       7 R1 SR3       (7.1.3.0)
       6 R1 SR8 FP4   (6.1.8.4)
       7    SR9       (7.0.9.0)
    .
    Contact your IBM Product's Service Team for these Service
    Refreshes and Fix Packs.
    For those running stand-alone, information about the available
    Service Refreshes and Fix Packs can be found at:
               https://www.ibm.com/developerworks/java/jdk/
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV68216

  • Reported component name

    JAVA CLASS LIBS

  • Reported component ID

    620700130

  • Reported release

    600

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2015-01-05

  • Closed date

    2015-04-08

  • Last modified date

    2015-04-08

  • 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

  • R600 PSY

       UP

  • R800 PSY

       UP

  • R700 PSY

       UP



Document information

More support for: Runtimes for Java Technology
Java Class Libraries

Software version: 6.0

Reference #: IV68216

Modified date: 08 April 2015