IV86616: HANG IN CERTAIN SCENARIO WITH JAVA.NIO.CHANNELS.FILECHANNEL.LOCK() AFTER APPLYING APAR IV78039

APAR status

• Closed as program error.

Error description

• Error Message: N/A
  .
  Stack Trace: Java callstack:
     at sun/nio/ch/FileDispatcherImpl.lock0(Native Method)
     at
  sun/nio/ch/FileDispatcherImpl.lock(FileDispatcherImpl.java:119)
     at sun/nio/ch/FileChannelImpl.lock(FileChannelImpl.java:1095)
     at java/nio/channels/FileChannel.lock(FileChannel.java:1064)
     .
     .
     .
  
  Native callstack:
     nsleep+0xe4 (0x09000000000397E8 <OSB>libc.a+0x388e8<CSB>)
     sleep+0x88 (0x090000000015D88C <OSB>libc.a+0x15c98c<CSB>)
     Java_sun_nio_ch_FileDispatcherImpl_lock0+0xe0
  (0x0900000007B339A4 <OSB>libnio.so+0x99a4<CSB>)
     (0x0900000006249B50 <OSB>libj9vm28.so+0xdcb50<CSB>)
     (0x090000000616FAFC <OSB>libj9vm28.so+0x2afc<CSB>)
     (0x09000000062D5C80 <OSB>libj9prt28.so+0x2c80<CSB>)
     (0x090000000616F8D4 <OSB>libj9vm28.so+0x28d4<CSB>)
     (0x09000000062B887C <OSB>libj9thr28.so+0x387c<CSB>)
     _pthread_body+0xf0 (0x0900000000542E14
  <OSB>libpthreads.a+0x3e14<CSB>)
  .
  

Local fix

Problem summary

• Problem is caused because system api 'fcntl' fails with error
  EDEADLK and APAR IV78039 retry indefinitely as EDEADLK normally
  is a temporary situation when multiple process/threads attempt
  to lock same file.
  

Problem conclusion

• java.nio.channels.FileChannel.lock() has been updated to retry
  for limited number of times. If situation is not changed in this
  time, an IOException with message 'Deadlock condition if locked'
  is thrown and should be handled at application level.
  .
  This APAR will be fixed in the following Java Releases:
     8    SR3 FP10  (8.0.3.10)
     7 R1 SR3 FP50  (7.1.3.50)
     6 R1 SR8 FP30  (6.1.8.30)
     7    SR9 FP50  (7.0.9.50)
     6    SR16 FP30 (6.0.16.30)
  .
  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 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

• R800 PSY

     UP

• R700 PSY

     UP

• R600 PSY

     UP