From 8330d43435f37955b5a44318bc10652bac376e68 Mon Sep 17 00:00:00 2001
From: mtm <mtm@FreeBSD.org>
Date: Wed, 18 Feb 2004 15:22:52 +0000
Subject: o Style o Instead of checking both the passed in pointer and its
 value   for NULL, only check the latter. Any caller that passes in   a NULL
 pointer is obviously wrong.

---
 lib/libthr/thread/thr_mutex_prioceiling.c | 58 +++++++++++++++----------------
 lib/libthr/thread/thr_mutex_protocol.c    | 29 ++++++----------
 2 files changed, 39 insertions(+), 48 deletions(-)

diff --git a/lib/libthr/thread/thr_mutex_prioceiling.c b/lib/libthr/thread/thr_mutex_prioceiling.c
index 7701378..c7396a4 100644
--- a/lib/libthr/thread/thr_mutex_prioceiling.c
+++ b/lib/libthr/thread/thr_mutex_prioceiling.c
@@ -47,9 +47,7 @@ _pthread_mutexattr_getprioceiling(pthread_mutexattr_t *mattr, int *prioceiling)
 {
 	int ret = 0;
 
-	if ((mattr == NULL) || (*mattr == NULL))
-		ret = EINVAL;
-	else if ((*mattr)->m_protocol != PTHREAD_PRIO_PROTECT)
+	if (*mattr == NULL)
 		ret = EINVAL;
 	else
 		*prioceiling = (*mattr)->m_ceiling;
@@ -62,12 +60,13 @@ _pthread_mutexattr_setprioceiling(pthread_mutexattr_t *mattr, int prioceiling)
 {
 	int ret = 0;
 
-	if ((mattr == NULL) || (*mattr == NULL))
-		ret = EINVAL;
-	else if ((*mattr)->m_protocol != PTHREAD_PRIO_PROTECT)
+	if (*mattr == NULL)
 		ret = EINVAL;
-	else
+	else if (prioceiling <= PTHREAD_MAX_PRIORITY &&
+	    prioceiling >= PTHREAD_MIN_PRIORITY)
 		(*mattr)->m_ceiling = prioceiling;
+	else
+		ret = EINVAL;
 
 	return (ret);
 }
@@ -76,16 +75,11 @@ int
 _pthread_mutex_getprioceiling(pthread_mutex_t *mutex,
 			      int *prioceiling)
 {
-	int ret;
-
-	if ((mutex == NULL) || (*mutex == NULL))
-		ret = EINVAL;
-	else if ((*mutex)->m_protocol != PTHREAD_PRIO_PROTECT)
-		ret = EINVAL;
+	if (*mutex == NULL)
+		return (EINVAL);
 	else
-		ret = (*mutex)->m_prio;
-
-	return (ret);
+		*prioceiling = (*mutex)->m_prio;
+	return (0);
 }
 
 int
@@ -94,20 +88,26 @@ _pthread_mutex_setprioceiling(pthread_mutex_t *mutex,
 {
 	int ret = 0;
 
-	if ((mutex == NULL) || (*mutex == NULL))
-		ret = EINVAL;
-	else if ((*mutex)->m_protocol != PTHREAD_PRIO_PROTECT)
-		ret = EINVAL;
-	else {
-		/* Lock the mutex: */
-		if ((ret = pthread_mutex_lock(mutex)) == 0) {
-			/* Return the old ceiling and set the new ceiling: */
-			*old_ceiling = (*mutex)->m_prio;
-			(*mutex)->m_prio = prioceiling;
+	if (*mutex == NULL)
+		return (EINVAL);
+	else if (prioceiling > PTHREAD_MAX_PRIORITY ||
+	    prioceiling < PTHREAD_MIN_PRIORITY)
+		return (EINVAL);
+
+	/*
+	 * Because of the use of pthread_mutex_unlock(), the
+	 * priority ceiling of a mutex cannot be changed
+	 * while the mutex is held by another thread. It also,
+	 * means that the the thread trying to change the
+	 * priority ceiling must adhere to prio protection rules.
+	 */
+	if ((ret = pthread_mutex_lock(mutex)) == 0) {
+		/* Return the old ceiling and set the new ceiling: */
+		*old_ceiling = (*mutex)->m_prio;
+		(*mutex)->m_prio = prioceiling;
 
-			/* Unlock the mutex: */
-			ret = pthread_mutex_unlock(mutex);
-		}
+		/* Unlock the mutex: */
+		ret = pthread_mutex_unlock(mutex);
 	}
 	return(ret);
 }
diff --git a/lib/libthr/thread/thr_mutex_protocol.c b/lib/libthr/thread/thr_mutex_protocol.c
index f7be5a6..56c8622 100644
--- a/lib/libthr/thread/thr_mutex_protocol.c
+++ b/lib/libthr/thread/thr_mutex_protocol.c
@@ -43,28 +43,19 @@ __weak_reference(_pthread_mutexattr_setprotocol, pthread_mutexattr_setprotocol);
 int
 _pthread_mutexattr_getprotocol(pthread_mutexattr_t *mattr, int *protocol)
 {
-	int ret = 0;
-
-	if ((mattr == NULL) || (*mattr == NULL))
-		ret = EINVAL;
-	else
-		*protocol = (*mattr)->m_protocol;
-
-	return(ret);
+	if (*mattr == NULL)
+		return (EINVAL);
+	*protocol = (*mattr)->m_protocol;
+	return(0);
 }
 
 int
 _pthread_mutexattr_setprotocol(pthread_mutexattr_t *mattr, int protocol)
 {
-	int ret = 0;
-
-	if ((mattr == NULL) || (*mattr == NULL) ||
-	    (protocol < PTHREAD_PRIO_NONE) || (protocol > PTHREAD_PRIO_PROTECT))
-		ret = EINVAL;
-	else {
-		(*mattr)->m_protocol = protocol;
-		(*mattr)->m_ceiling = PTHREAD_MAX_PRIORITY;
-	}
-	return(ret);
+	if (*mattr == NULL || protocol < PTHREAD_PRIO_NONE ||
+	    protocol > PTHREAD_PRIO_PROTECT)
+		return (EINVAL);
+	(*mattr)->m_protocol = protocol;
+	(*mattr)->m_ceiling = PTHREAD_MAX_PRIORITY;
+	return(0);
 }
-
-- 
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