PH27989: USE OF NON-ASYNC-SIGNAL-SAFE CALL INSIDE SIGNAL HANDLER MAY CAUSE CLEARMAKE TO HANG ON EXIT

APAR status

• Closed as program error.

Error description

• When performing builds on large multiprocessor systems (> 64
  cores), clearmake may hang on exit if an incoming signal arrives
  immediately before the signal handler thread is shut down...
  Attaching the a debugger to the stuck process reveals that the
  signal handler thread is attempting to allocate memory:
   #0  0x00006e3ff2b60dce in _lll_lock_wait_private () from
  /lib64/libc.so.6
   #1  0x00006e3ff2aec138 in _L_lock_9164 () from /lib64/libc.so.6
   #2  0x00006e3ff2ae9a32 in malloc () from /lib64/libc.so.6
  ...
  <Signal handler called>
  ...
  The main thread of the program is attempting to free memory as
  part of shutting down the signal handler thread, and the
  __int_free() call and the malloc() call are apparently
  deadlocked.
  
  According to the POSIX standard, malloc() is not
  async-signal-safe and should not be called from within a signal
  handler.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Users of ClearCase / clearmake.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * ClearCase was not properly handling events received during   *
  * shutdown.                                                    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  

Problem conclusion

• A fix is available in ClearCase versions 9.0.1.12   9.0.2.4
  and 9.1.0.1
  

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

  CLEARCASE WIN

• Fixed component ID

  5724G2900

Applicable component levels