Add sem_clockwait_np()

This function allows the caller to specify the reference clock
and choose between absolute and relative mode.  In relative mode,
the remaining time can be returned.

The API is similar to clock_nanosleep(3).  Thanks to Ed Schouten
for that suggestion.

While I'm here, reduce the sleep time in the semaphore "child"
test to greatly reduce its runtime.  Also add a reasonable timeout.

Reviewed by:	ed (userland)
MFC after:	2 weeks
Relnotes:	yes
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D9656

This commit is contained in:

Eric van Gyzen

2017-02-23 19:36:38 +00:00

parent af67ca3780

commit b215ceaaec

10 changed files with 299 additions and 43 deletions

									
										include/semaphore.h
									
		+2
		
												View File
												
				@@ -59,6 +59,8 @@ int	 sem_init(sem_t *, int, unsigned int);

				sem_t	*sem_open(const char *, int, ...);

				int	 sem_post(sem_t *);

				int	 sem_timedwait(sem_t * __restrict, const struct timespec * __restrict);

				int	 sem_clockwait_np(sem_t * __restrict, __clockid_t, int,

					    const struct timespec *, struct timespec *);

				int	 sem_trywait(sem_t *);

				int	 sem_unlink(const char *);

				int	 sem_wait(sem_t *);