2 files changed, 32 insertions, 29 deletions

diff --git a/lib/libpthread/sys/lock.c b/lib/libpthread/sys/lock.c
index 12ce1a0..d005baa 100644
--- a/lib/libpthread/sys/lock.c
+++ b/lib/libpthread/sys/lock.c
@@ -65,7 +65,7 @@ _lock_init(struct lock *lck, enum lock_type ltype,
 		lck->l_head->lr_watcher = NULL;
 		lck->l_head->lr_owner = NULL;
 		lck->l_head->lr_waiting = 0;
-		lck->l_head->lr_handshake = 0;
+		lck->l_head->lr_active = 1;
 		lck->l_tail = lck->l_head;
 	}
 	return (0);
@@ -85,7 +85,7 @@ _lockuser_init(struct lockuser *lu, void *priv)
 		lu->lu_myreq->lr_watcher = NULL;
 		lu->lu_myreq->lr_owner = lu;
 		lu->lu_myreq->lr_waiting = 0;
-		lu->lu_myreq->lr_handshake = 0;
+		lu->lu_myreq->lr_active = 0;
 		lu->lu_watchreq = NULL;
 		lu->lu_priority = 0;
 		lu->lu_private = priv;
@@ -166,19 +166,16 @@ _lock_acquire(struct lock *lck, struct lockuser *lu, int prio)
 			for (i = 0; i < MAX_SPINS; i++) {
 				if (lu->lu_watchreq->lr_locked == 0)
 					return;
+				if (lu->lu_watchreq->lr_active == 0)
+					break;
 			}
 			atomic_store_rel_long(&lu->lu_watchreq->lr_waiting, 1);
 			while (lu->lu_watchreq->lr_locked != 0)
 				lck->l_wait(lck, lu);
 			atomic_store_rel_long(&lu->lu_watchreq->lr_waiting, 0);
-			/*
-			 * Wait for original owner to stop accessing the
-			 * lockreq object.
-			 */
-			while (lu->lu_watchreq->lr_handshake)
-				;
 		}
 	}
+	lu->lu_myreq->lr_active = 1;
 }
 
 /*
@@ -240,24 +237,21 @@ _lock_release(struct lock *lck, struct lockuser *lu)
 			}
 		}
 		if (lu_h != NULL) {
-			lu_h->lu_watchreq->lr_handshake = 1;
 			/* Give the lock to the highest priority user. */
-			atomic_store_rel_long(&lu_h->lu_watchreq->lr_locked, 0);
 			if ((lu_h->lu_watchreq->lr_waiting != 0) &&
 			    (lck->l_wakeup != NULL))
 				/* Notify the sleeper */
 				lck->l_wakeup(lck, lu_h->lu_myreq->lr_watcher);
-			atomic_store_rel_long(&lu_h->lu_watchreq->lr_handshake,
-				 0);
+			else
+				atomic_store_rel_long(&lu_h->lu_watchreq->lr_locked, 0);
 		} else {
-			myreq->lr_handshake = 1;
-			/* Give the lock to the previous request. */
-			atomic_store_rel_long(&myreq->lr_locked, 0);
 			if ((myreq->lr_waiting != 0) &&
 			    (lck->l_wakeup != NULL))
 				/* Notify the sleeper */
 				lck->l_wakeup(lck, myreq->lr_watcher);
-			atomic_store_rel_long(&myreq->lr_handshake, 0);
+			else
+				/* Give the lock to the previous request. */
+				atomic_store_rel_long(&myreq->lr_locked, 0);
 		}
 	} else {
 		/*
@@ -270,19 +264,25 @@ _lock_release(struct lock *lck, struct lockuser *lu)
 		lu->lu_watchreq = NULL;
 		lu->lu_myreq->lr_locked = 1;
 		lu->lu_myreq->lr_waiting = 0;
-		if (lck->l_wakeup) {
-			/* Start wakeup */
-			myreq->lr_handshake = 1;
+		if (myreq->lr_waiting != 0 && lck->l_wakeup) 
+			/* Notify the sleeper */
+			lck->l_wakeup(lck, myreq->lr_watcher);
+		else
 			/* Give the lock to the previous request. */
 			atomic_store_rel_long(&myreq->lr_locked, 0);
-			if (myreq->lr_waiting != 0) {
-				/* Notify the sleeper */
-				lck->l_wakeup(lck, myreq->lr_watcher);
-			}
-			/* Stop wakeup */
-			atomic_store_rel_long(&myreq->lr_handshake, 0);
-		} else {
-			atomic_store_rel_long(&myreq->lr_locked, 0);
-		}
 	}
+	lu->lu_myreq->lr_active = 0;
 }
+
+void
+_lock_grant(struct lock *lck /* unused */, struct lockuser *lu)
+{
+	atomic_store_rel_long(&lu->lu_watchreq->lr_locked, 0);
+}
+
+void
+_lockuser_setactive(struct lockuser *lu, int active)
+{
+	lu->lu_myreq->lr_active = active;
+}
+
diff --git a/lib/libpthread/sys/lock.h b/lib/libpthread/sys/lock.h
index e397111..6fa23e2 100644
--- a/lib/libpthread/sys/lock.h
+++ b/lib/libpthread/sys/lock.h
@@ -55,7 +55,7 @@ struct lockreq {
 	struct lockuser	*lr_watcher;	/* only used for priority locks */
 	struct lockuser	*lr_owner;	/* only used for priority locks */
 	long		lr_waiting;	/* non-zero when wakeup needed */
-	volatile long	lr_handshake;	/* non-zero when wakeup in progress */
+	volatile int	lr_active;	/* non-zero if the lock is last lock for thread */
 };
 
 struct lockuser {
@@ -72,6 +72,7 @@ struct lockuser {
 #define	_LCK_REQUEST_INITIALIZER	{ 0, NULL, NULL, 0 }
 
 #define	_LCK_BUSY(lu)			((lu)->lu_watchreq->lr_locked != 0)
+#define	_LCK_ACTIVE(lu)			((lu)->lu_watchreq->lr_active != 0)
 #define	_LCK_GRANTED(lu)		((lu)->lu_watchreq->lr_locked == 0)
 
 #define	_LCK_SET_PRIVATE(lu, p)		(lu)->lu_private = (void *)(p)
@@ -84,7 +85,9 @@ int	_lock_init(struct lock *, enum lock_type,
 	    lock_handler_t *, lock_handler_t *);
 int	_lockuser_init(struct lockuser *lu, void *priv);
 void	_lockuser_destroy(struct lockuser *lu);
+void	_lockuser_setactive(struct lockuser *lu, int active);
 void	_lock_acquire(struct lock *, struct lockuser *, int);
 void	_lock_release(struct lock *, struct lockuser *);
+void	_lock_grant(struct lock *, struct lockuser *);
 
 #endif