cvs commit: src/sys/kern kern_mutex.c

[John Baldwin]

jhb         2003/07/02 09:14:09 PDT

  FreeBSD src repository

  Modified files:
    sys/kern             kern_mutex.c 
  Log:
  - Add comments about the maintenance of the per-thread list of contested
    locks held by each thread.
  - Fix a bug in the original BSD/OS code where a contested lock was not
    properly handed off from the old thread to the new thread when a
    contested lock with more than one blocked thread was transferred from
    one thread to another.
  - Don't use an atomic operation to write the MTX_CONTESTED value to
    mtx_lock in the aforementioned special case.  The memory barriers and
    exclusion provided by sched_lock are sufficient.
  
  Spotted by:     alc (2)
  
  Revision  Changes    Path
  1.129     +9 -4      src/sys/kern/kern_mutex.c