IBM Support

IV27286: SELECTOR.SELECT() FIRES REPEATEDLY WITH ZERO EVENTS

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Error Message: AIX Customer is experiencing a high CPU (100%)
    usage as the selector.select() fires repeatedly without
    returning any positive number of events.
    .
    Stack Trace: N/A
    .
    

Local fix

  • N/A
    

Problem summary

  • It is basically a timing issue between adding a channel into
    pollset verses closing the channel (preclose)..the close
    mechanism uses dup2 to dup the file descriptor into a special
    pre-close socket before later releasing the file descriptor.
    consider, When a thread T1 closes a selectable channel at just
    around the same time that T2 registers the channel's file
    descriptor with pollset, then it is possible for the pre-close
    socket to get registered with pollset and the Selector will
    appear to spin as the pre-close socket is always ready.
    

Problem conclusion

  • This defect will be fixed in:
    6.0.0 SR10
    .
    The fix is to remove the temporary cache which holds the
    interestOps & channels and register the channel & interestOps
    immediately.
    

Temporary fix

  • ZE FIX ERROR IV27286 12/10/08
    

Comments

APAR Information

  • APAR number

    IV27286

  • 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

    2012-08-30

  • Closed date

    2012-08-30

  • Last modified date

    2012-11-02

  • 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

[{"Business Unit":{"code":"BU048","label":"IBM Software"},"Product":{"code":"SSCVQ3Y","label":"Java Class Libraries"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.0","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
02 November 2012