| 1 |  |  | /*	$OpenBSD: synch.h,v 1.2 2017/09/05 02:40:54 guenther Exp $ */ | 
    
    | 2 |  |  | /* | 
    
    | 3 |  |  |  * Copyright (c) 2017 Martin Pieuchot | 
    
    | 4 |  |  |  * | 
    
    | 5 |  |  |  * Permission to use, copy, modify, and distribute this software for any | 
    
    | 6 |  |  |  * purpose with or without fee is hereby granted, provided that the above | 
    
    | 7 |  |  |  * copyright notice and this permission notice appear in all copies. | 
    
    | 8 |  |  |  * | 
    
    | 9 |  |  |  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | 
    
    | 10 |  |  |  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | 
    
    | 11 |  |  |  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | 
    
    | 12 |  |  |  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | 
    
    | 13 |  |  |  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | 
    
    | 14 |  |  |  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | 
    
    | 15 |  |  |  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | 
    
    | 16 |  |  |  */ | 
    
    | 17 |  |  |  | 
    
    | 18 |  |  | #include <sys/atomic.h> | 
    
    | 19 |  |  | #include <sys/time.h> | 
    
    | 20 |  |  | #include <sys/futex.h> | 
    
    | 21 |  |  |  | 
    
    | 22 |  |  | static inline int | 
    
    | 23 |  |  | _wake(volatile uint32_t *p, int n) | 
    
    | 24 |  |  | { | 
    
    | 25 |  |  | 	return futex(p, FUTEX_WAKE, n, NULL, NULL); | 
    
    | 26 |  |  | } | 
    
    | 27 |  |  |  | 
    
    | 28 |  |  | static inline void | 
    
    | 29 |  |  | _wait(volatile uint32_t *p, int val) | 
    
    | 30 |  |  | { | 
    
    | 31 |  |  | 	while (*p != (uint32_t)val) | 
    
    | 32 |  |  | 		futex(p, FUTEX_WAIT, val, NULL, NULL); | 
    
    | 33 |  |  | } | 
    
    | 34 |  |  |  | 
    
    | 35 |  |  | static inline int | 
    
    | 36 |  |  | _twait(volatile uint32_t *p, int val, clockid_t clockid, const struct timespec *abs) | 
    
    | 37 |  |  | { | 
    
    | 38 |  |  | 	struct timespec rel; | 
    
    | 39 |  |  |  | 
    
    | 40 |  |  | 	if (abs == NULL) | 
    
    | 41 |  |  | 		return futex(p, FUTEX_WAIT, val, NULL, NULL); | 
    
    | 42 |  |  |  | 
    
    | 43 |  |  | 	if (abs->tv_nsec >= 1000000000 || clock_gettime(clockid, &rel)) | 
    
    | 44 |  |  | 		return (EINVAL); | 
    
    | 45 |  |  |  | 
    
    | 46 |  |  | 	rel.tv_sec = abs->tv_sec - rel.tv_sec; | 
    
    | 47 |  |  | 	if ((rel.tv_nsec = abs->tv_nsec - rel.tv_nsec) < 0) { | 
    
    | 48 |  |  | 		rel.tv_sec--; | 
    
    | 49 |  |  | 		rel.tv_nsec += 1000000000; | 
    
    | 50 |  |  | 	} | 
    
    | 51 |  |  | 	if (rel.tv_sec < 0) | 
    
    | 52 |  |  | 		return (ETIMEDOUT); | 
    
    | 53 |  |  |  | 
    
    | 54 |  |  | 	return futex(p, FUTEX_WAIT, val, &rel, NULL); | 
    
    | 55 |  |  | } | 
    
    | 56 |  |  |  | 
    
    | 57 |  |  | static inline int | 
    
    | 58 |  |  | _requeue(volatile uint32_t *p, int n, int m, volatile uint32_t *q) | 
    
    | 59 |  |  | { | 
    
    | 60 |  |  | 	return futex(p, FUTEX_REQUEUE, n, (void *)(long)m, q); | 
    
    | 61 |  |  | } |