Allow threads to atomically release rw and sx locks while waiting for an

event.  Locking primitives that support this (mtx, rw, and sx) now each
include their own foo_sleep() routine.
- Rename msleep() to _sleep() and change it's 'struct mtx' object to a
  'struct lock_object' pointer.  _sleep() uses the recently added
  lc_unlock() and lc_lock() function pointers for the lock class of the
  specified lock to release the lock while the thread is suspended.
- Add wrappers around _sleep() for mutexes (mtx_sleep()), rw locks
  (rw_sleep()), and sx locks (sx_sleep()).  msleep() still exists and
  is now identical to mtx_sleep(), but it is deprecated.
- Rename SLEEPQ_MSLEEP to SLEEPQ_SLEEP.
- Rewrite much of sleep.9 to not be msleep(9) centric.
- Flesh out the 'RETURN VALUES' section in sleep.9 and add an 'ERRORS'
  section.
- Add __nonnull(1) to _sleep() and msleep_spin() so that the compiler will
  warn if you try to pass a NULL wait channel.  The functions already have
  a KASSERT to that effect.

1 files changed, 3 insertions, 0 deletions

diff --git a/sys/sys/mutex.h b/sys/sys/mutex.h
index cde6e44..a8d349f 100644
--- a/sys/sys/mutex.h
+++ b/sys/sys/mutex.h
@@ -339,6 +339,9 @@ extern struct mtx_pool *mtxpool_sleep;
 #define mtx_trylock_flags(m, opts)					\
 	_mtx_trylock((m), (opts), LOCK_FILE, LOCK_LINE)
 
+#define	mtx_sleep(chan, mtx, pri, wmesg, timo)				\
+	_sleep((chan), &(mtx)->mtx_object, (pri), (wmesg), (timo))
+
 #define	mtx_initialized(m)	lock_initalized(&(m)->mtx_object)
 
 #define mtx_owned(m)	(((m)->mtx_lock & ~MTX_FLAGMASK) == (uintptr_t)curthread)