Add an implementation of pthread_rwlock_timed{rd,wr}lock() to libthr with

attendant documentation.

1 files changed, 54 insertions, 11 deletions

diff --git a/lib/libthr/thread/thr_rwlock.c b/lib/libthr/thread/thr_rwlock.c
index f819a80..afd2fa5 100644
--- a/lib/libthr/thread/thr_rwlock.c
+++ b/lib/libthr/thread/thr_rwlock.c
@@ -40,13 +40,17 @@
 __weak_reference(_pthread_rwlock_destroy, pthread_rwlock_destroy);
 __weak_reference(_pthread_rwlock_init, pthread_rwlock_init);
 __weak_reference(_pthread_rwlock_rdlock, pthread_rwlock_rdlock);
+__weak_reference(_pthread_rwlock_timedrdlock, pthread_rwlock_timedrdlock);
+__weak_reference(_pthread_rwlock_timedwrlock, pthread_rwlock_timedwrlock);
 __weak_reference(_pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock);
 __weak_reference(_pthread_rwlock_trywrlock, pthread_rwlock_trywrlock);
 __weak_reference(_pthread_rwlock_unlock, pthread_rwlock_unlock);
 __weak_reference(_pthread_rwlock_wrlock, pthread_rwlock_wrlock);
 
-static int	rwlock_rdlock_common(pthread_rwlock_t *, int);
-static int	rwlock_wrlock_common(pthread_rwlock_t *, int);
+static int	rwlock_rdlock_common(pthread_rwlock_t *, int,
+		    const struct timespec *);
+static int	rwlock_wrlock_common(pthread_rwlock_t *, int,
+		    const struct timespec *);
 
 int
 _pthread_rwlock_destroy (pthread_rwlock_t *rwlock)
@@ -116,7 +120,8 @@ out_mutex:
  * it is greater than 0 it will return immediately with EBUSY.
  */
 static int
-rwlock_rdlock_common(pthread_rwlock_t *rwlock, int nonblocking)
+rwlock_rdlock_common(pthread_rwlock_t *rwlock, int nonblocking,
+    const struct timespec *timeout)
 {
 	pthread_rwlock_t 	prwlock;
 	int			ret;
@@ -124,6 +129,13 @@ rwlock_rdlock_common(pthread_rwlock_t *rwlock, int nonblocking)
 	if (rwlock == NULL || *rwlock == NULL)
 		return(EINVAL);
 
+	/*
+	 * Check for validity of the timeout parameter.
+	 */
+	if (timeout != NULL &&
+	    (timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000))
+		return (EINVAL);
+
 	prwlock = *rwlock;
 
 	/* grab the monitor lock */
@@ -143,7 +155,12 @@ rwlock_rdlock_common(pthread_rwlock_t *rwlock, int nonblocking)
 			return (EBUSY);
 		}
 
-		ret = pthread_cond_wait(&prwlock->read_signal, &prwlock->lock);
+		if (timeout == NULL)
+			ret = pthread_cond_wait(&prwlock->read_signal,
+			    &prwlock->lock);
+		else
+			ret = pthread_cond_timedwait(&prwlock->read_signal,
+			    &prwlock->lock, timeout);
 
 		if (ret != 0 && ret != EINTR) {
 			/* can't do a whole lot if this fails */
@@ -168,13 +185,20 @@ rwlock_rdlock_common(pthread_rwlock_t *rwlock, int nonblocking)
 int
 _pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
 {
-	return (rwlock_rdlock_common(rwlock, 0));
+	return (rwlock_rdlock_common(rwlock, 0, NULL));
+}
+
+int
+_pthread_rwlock_timedrdlock(pthread_rwlock_t *rwlock,
+    const struct timespec *timeout)
+{
+	return (rwlock_rdlock_common(rwlock, 0, timeout));
 }
 
 int
 _pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
 {
-	return (rwlock_rdlock_common(rwlock, 1));
+	return (rwlock_rdlock_common(rwlock, 1, NULL));
 }
 
 int
@@ -215,13 +239,20 @@ _pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
 int
 _pthread_rwlock_wrlock (pthread_rwlock_t *rwlock)
 {
-	return (rwlock_wrlock_common(rwlock, 0));
+	return (rwlock_wrlock_common(rwlock, 0, NULL));
+}
+
+int
+_pthread_rwlock_timedwrlock (pthread_rwlock_t *rwlock,
+    const struct timespec *timeout)
+{
+	return (rwlock_wrlock_common(rwlock, 0, timeout));
 }
 
 int
 _pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
 {
-	return (rwlock_wrlock_common(rwlock, 1));
+	return (rwlock_wrlock_common(rwlock, 1, NULL));
 }
 
 /*
@@ -229,7 +260,8 @@ _pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
  * it is greater than 0 it will return immediately with EBUSY.
  */
 static int
-rwlock_wrlock_common(pthread_rwlock_t *rwlock, int nonblocking)
+rwlock_wrlock_common(pthread_rwlock_t *rwlock, int nonblocking,
+    const struct timespec *timeout)
 {
 	pthread_rwlock_t 	prwlock;
 	int			ret;
@@ -237,6 +269,13 @@ rwlock_wrlock_common(pthread_rwlock_t *rwlock, int nonblocking)
 	if (rwlock == NULL || *rwlock == NULL)
 		return(EINVAL);
 
+	/*
+	 * Check the timeout value for validity.
+	 */
+	if (timeout != NULL &&
+	    (timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000))
+		return (EINVAL);
+
 	prwlock = *rwlock;
 
 	/* grab the monitor lock */
@@ -251,8 +290,12 @@ rwlock_wrlock_common(pthread_rwlock_t *rwlock, int nonblocking)
 
 		++prwlock->blocked_writers;
 
-		ret = pthread_cond_wait(&prwlock->write_signal,
-		    &prwlock->lock);
+		if (timeout == NULL)
+			ret = pthread_cond_wait(&prwlock->write_signal,
+			    &prwlock->lock);
+		else
+			ret = pthread_cond_timedwait(&prwlock->write_signal,
+			    &prwlock->lock, timeout);
 
 		if (ret != 0 && ret != EINTR) {
 			--prwlock->blocked_writers;