Several improvements to rmlock(9). Many of these are based on patches

provided by Isilon.
- Add an rm_assert() supporting various lock assertions similar to other
  locking primitives.  Because rmlocks track readers the assertions are
  always fully accurate unlike rw_assert() and sx_assert().
- Flesh out the lock class methods for rmlocks to support sleeping via
  condvars and rm_sleep() (but only while holding write locks), rmlock
  details in 'show lock' in DDB, and the lc_owner method used by
  dtrace.
- Add an internal destroyed cookie so that API functions can assert
  that an rmlock is not destroyed.
- Make use of rm_assert() to add various assertions to the API (e.g.
  to assert locks are held when an unlock routine is called).
- Give RM_SLEEPABLE locks their own lock class and always use the
  rmlock's own lock_object with WITNESS.
- Use THREAD_NO_SLEEPING() / THREAD_SLEEPING_OK() to disallow sleeping
  while holding a read lock on an rmlock.

Submitted by:	andre
Obtained from:	EMC/Isilon

1 files changed, 1 insertions, 0 deletions

diff --git a/sys/sys/lock.h b/sys/sys/lock.h
index 07651eb..40dc16b 100644
--- a/sys/sys/lock.h
+++ b/sys/sys/lock.h
@@ -193,6 +193,7 @@ extern struct lock_class lock_class_mtx_spin;
 extern struct lock_class lock_class_sx;
 extern struct lock_class lock_class_rw;
 extern struct lock_class lock_class_rm;
+extern struct lock_class lock_class_rm_sleepable;
 extern struct lock_class lock_class_lockmgr;
 
 extern struct lock_class *lock_classes[];