o Implement pthread_mutex_timedlock(), which does not block indefinitely on

  a mutex locked by another thread.
o document it: pthread_mutex_timedlock(3)

1 files changed, 32 insertions, 0 deletions

diff --git a/lib/libthr/thread/thr_mutex.c b/lib/libthr/thread/thr_mutex.c
index 33958b7..3567a34 100644
--- a/lib/libthr/thread/thr_mutex.c
+++ b/lib/libthr/thread/thr_mutex.c
@@ -93,6 +93,7 @@ __weak_reference(__pthread_mutex_unlock, pthread_mutex_unlock);
 /* No difference between libc and application usage of these: */
 __weak_reference(_pthread_mutex_init, pthread_mutex_init);
 __weak_reference(_pthread_mutex_destroy, pthread_mutex_destroy);
+__weak_reference(_pthread_mutex_timedlock, pthread_mutex_timedlock);
 
 
 /*
@@ -556,6 +557,28 @@ _pthread_mutex_lock(pthread_mutex_t *mutex)
 }
 
 int
+_pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *abstime)
+{
+	int error;
+
+	error = 0;
+	if (_thread_initial == NULL)
+		_thread_init();
+
+	/*
+	 * Initialize it if it's a valid statically inited mutex.
+	 */
+	if (mutex == NULL)
+		error = EINVAL;
+	else if ((*mutex != PTHREAD_MUTEX_INITIALIZER) ||
+	    ((error = mutex_init(mutex, 0)) == 0))
+		error = mutex_lock_common(mutex, 0, abstime);
+
+	PTHREAD_ASSERT(error != EINTR, "According to SUSv3 this function shall not return an error code of EINTR");
+	return (error);
+}
+
+int
 __pthread_mutex_unlock(pthread_mutex_t * mutex)
 {
 	return (mutex_unlock_common(mutex, /* add reference */ 0));
@@ -1418,6 +1441,15 @@ get_mcontested(pthread_mutex_t mutexp, const struct timespec *abstime)
 	int error;
 
 	/*
+	 * If the timeout is invalid this thread is not allowed
+	 * to block;
+	 */
+	if (abstime != NULL) {
+		if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+			return (EINVAL);
+	}
+
+	/*
 	 * Put this thread on the mutex's list of waiting threads.
 	 * The lock on the thread ensures atomic (as far as other
 	 * threads are concerned) setting of the thread state with