6 files changed, 97 insertions, 25 deletions

diff --git a/lib/libc/gen/Makefile.inc b/lib/libc/gen/Makefile.inc
index a75a0d1..f1d1378 100644
--- a/lib/libc/gen/Makefile.inc
+++ b/lib/libc/gen/Makefile.inc
@@ -461,6 +461,7 @@ MLINKS+=scandir.3 alphasort.3
 MLINKS+=sem_open.3 sem_close.3 \
 	sem_open.3 sem_unlink.3
 MLINKS+=sem_wait.3 sem_trywait.3
+MLINKS+=sem_timedwait.3 sem_clockwait_np.3
 MLINKS+=send.2 sendmmsg.2
 MLINKS+=setjmp.3 _longjmp.3 \
 	setjmp.3 _setjmp.3 \
diff --git a/lib/libc/gen/Symbol.map b/lib/libc/gen/Symbol.map
index 0d5dfec..f452297 100644
--- a/lib/libc/gen/Symbol.map
+++ b/lib/libc/gen/Symbol.map
@@ -418,6 +418,10 @@ FBSD_1.4 {
 	stravis;
 };
 
+FBSD_1.5 {
+	sem_clockwait_np;
+};
+
 FBSDprivate_1.0 {
 	/* needed by thread libraries */
 	__thr_jtable;
diff --git a/lib/libc/gen/sem_new.c b/lib/libc/gen/sem_new.c
index 8fe027f..d36d1e2 100644
--- a/lib/libc/gen/sem_new.c
+++ b/lib/libc/gen/sem_new.c
@@ -56,6 +56,7 @@ __weak_reference(_sem_init, sem_init);
 __weak_reference(_sem_open, sem_open);
 __weak_reference(_sem_post, sem_post);
 __weak_reference(_sem_timedwait, sem_timedwait);
+__weak_reference(_sem_clockwait_np, sem_clockwait_np);
 __weak_reference(_sem_trywait, sem_trywait);
 __weak_reference(_sem_unlink, sem_unlink);
 __weak_reference(_sem_wait, sem_wait);
@@ -345,23 +346,34 @@ usem_wake(struct _usem2 *sem)
 }
 
 static __inline int
-usem_wait(struct _usem2 *sem, const struct timespec *abstime)
+usem_wait(struct _usem2 *sem, clockid_t clock_id, int flags,
+    const struct timespec *rqtp, struct timespec *rmtp)
 {
-	struct _umtx_time *tm_p, timeout;
+	struct {
+		struct _umtx_time timeout;
+		struct timespec remain;
+	} tms;
+	void *tm_p;
 	size_t tm_size;
+	int retval;
 
-	if (abstime == NULL) {
+	if (rqtp == NULL) {
 		tm_p = NULL;
 		tm_size = 0;
 	} else {
-		timeout._clockid = CLOCK_REALTIME;
-		timeout._flags = UMTX_ABSTIME;
-		timeout._timeout = *abstime;
-		tm_p = &timeout;
-		tm_size = sizeof(timeout);
+		tms.timeout._clockid = clock_id;
+		tms.timeout._flags = (flags & TIMER_ABSTIME) ? UMTX_ABSTIME : 0;
+		tms.timeout._timeout = *rqtp;
+		tm_p = &tms;
+		tm_size = sizeof(tms);
 	}
-	return _umtx_op(sem, UMTX_OP_SEM2_WAIT, 0, 
-		    (void *)tm_size, __DECONST(void*, tm_p));
+	retval = _umtx_op(sem, UMTX_OP_SEM2_WAIT, 0, (void *)tm_size, tm_p);
+	if (retval == -1 && errno == EINTR && (flags & TIMER_ABSTIME) == 0 &&
+	    rqtp != NULL && rmtp != NULL) {
+		*rmtp = tms.remain;
+	}
+
+	return (retval);
 }
 
 int
@@ -381,8 +393,8 @@ _sem_trywait(sem_t *sem)
 }
 
 int
-_sem_timedwait(sem_t * __restrict sem,
-	const struct timespec * __restrict abstime)
+_sem_clockwait_np(sem_t * __restrict sem, clockid_t clock_id, int flags,
+	const struct timespec *rqtp, struct timespec *rmtp)
 {
 	int val, retval;
 
@@ -393,7 +405,8 @@ _sem_timedwait(sem_t * __restrict sem,
 	_pthread_testcancel();
 	for (;;) {
 		while (USEM_COUNT(val = sem->_kern._count) > 0) {
-			if (atomic_cmpset_acq_int(&sem->_kern._count, val, val - 1))
+			if (atomic_cmpset_acq_int(&sem->_kern._count, val,
+			    val - 1))
 				return (0);
 		}
 
@@ -406,20 +419,28 @@ _sem_timedwait(sem_t * __restrict sem,
 		 * The timeout argument is only supposed to
 		 * be checked if the thread would have blocked.
 		 */
-		if (abstime != NULL) {
-			if (abstime->tv_nsec >= 1000000000 || abstime->tv_nsec < 0) {
+		if (rqtp != NULL) {
+			if (rqtp->tv_nsec >= 1000000000 || rqtp->tv_nsec < 0) {
 				errno = EINVAL;
 				return (-1);
 			}
 		}
 		_pthread_cancel_enter(1);
-		retval = usem_wait(&sem->_kern, abstime);
+		retval = usem_wait(&sem->_kern, clock_id, flags, rqtp, rmtp);
 		_pthread_cancel_leave(0);
 	}
 	return (retval);
 }
 
 int
+_sem_timedwait(sem_t * __restrict sem,
+	const struct timespec * __restrict abstime)
+{
+	return (_sem_clockwait_np(sem, CLOCK_REALTIME, TIMER_ABSTIME, abstime,
+	    NULL));
+};
+
+int
 _sem_wait(sem_t *sem)
 {
 	return _sem_timedwait(sem, NULL);
diff --git a/lib/libc/gen/sem_timedwait.3 b/lib/libc/gen/sem_timedwait.3
index 254af60..1623ebe 100644
--- a/lib/libc/gen/sem_timedwait.3
+++ b/lib/libc/gen/sem_timedwait.3
@@ -34,18 +34,22 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 3, 2008
+.Dd March 10, 2017
 .Dt SEM_TIMEDWAIT 3
 .Os
 .Sh NAME
-.Nm sem_timedwait
+.Nm sem_timedwait ,
+.Nm sem_clockwait_np
 .Nd "lock a semaphore"
 .Sh LIBRARY
 .Lb libpthread
 .Sh SYNOPSIS
 .In semaphore.h
+.In time.h
 .Ft int
 .Fn sem_timedwait "sem_t *sem" "const struct timespec *abs_timeout"
+.Ft int
+.Fn sem_clockwait_np "sem_t * restrict sem" "clockid_t clock_id" "int flags" "const struct timespec * rqtp" "struct timespec * rmtp"
 .Sh DESCRIPTION
 The
 .Fn sem_timedwait
@@ -77,10 +81,40 @@ clock.
 The validity of the
 .Fa abs_timeout
 is not checked if the semaphore can be locked immediately.
-.Sh RETURN VALUES
+.Pp
 The
-.Fn sem_timedwait
-function returns zero if the calling process successfully performed the
+.Fn sem_clockwait_np
+function is a more flexible variant of
+.Fn sem_timedwait .
+The
+.Fa clock_id
+parameter specifies the reference clock.
+If the
+.Fa flags
+parameter contains
+.Dv TIMER_ABSTIME ,
+then the requested timeout
+.Pq Fa rqtp
+is an absolute timeout; otherwise,
+the timeout is relative.
+If this function fails with
+.Er EINTR
+and the timeout is relative,
+a non-NULL
+.Fa rmtp
+will be updated to contain the amount of time remaining in the interval
+.Po
+the requested time minus the time actually slept
+.Pc .
+An absolute timeout has no effect on
+.Fa rmtp .
+A single structure can be used for both
+.Fa rqtp
+and
+.Fa rmtp .
+.Sh RETURN VALUES
+These
+functions return zero if the calling process successfully performed the
 semaphore lock operation on the semaphore designated by
 .Fa sem .
 If the call was unsuccessful, the state of the semaphore is unchanged,
@@ -88,9 +122,7 @@ and the function returns a value of \-1 and sets the global variable
 .Va errno
 to indicate the error.
 .Sh ERRORS
-The
-.Fn sem_timedwait
-function will fail if:
+These functions will fail if:
 .Bl -tag -width Er
 .It Bq Er EINVAL
 The
@@ -114,6 +146,18 @@ The
 .Fn sem_timedwait
 function conforms to
 .St -p1003.1-2004 .
+The
+.Fn sem_clockwait_np
+function is not specified by any standard;
+it exists only on
+.Fx
+at the time of this writing.
 .Sh HISTORY
-The function first appeared in
+The
+.Fn sem_timedwait
+function first appeared in
 .Fx 5.0 .
+The
+.Fn sem_clockwait_np
+function first appeared in
+.Fx 12.0 .
diff --git a/lib/libc/include/namespace.h b/lib/libc/include/namespace.h
index c95829e..52e9b25 100644
--- a/lib/libc/include/namespace.h
+++ b/lib/libc/include/namespace.h
@@ -217,6 +217,7 @@
 #define		sem_open			_sem_open
 #define		sem_post			_sem_post
 #define		sem_timedwait			_sem_timedwait
+#define		sem_clockwait_np		_sem_clockwait_np
 #define		sem_trywait			_sem_trywait
 #define		sem_unlink			_sem_unlink
 #define		sem_wait			_sem_wait
diff --git a/lib/libc/include/un-namespace.h b/lib/libc/include/un-namespace.h
index 0233348..e40e6fd 100644
--- a/lib/libc/include/un-namespace.h
+++ b/lib/libc/include/un-namespace.h
@@ -198,6 +198,7 @@
 #undef		sem_open
 #undef		sem_post
 #undef		sem_timedwait
+#undef		sem_clockwait_np
 #undef		sem_trywait
 #undef		sem_unlink
 #undef		sem_wait