1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 * Copyright 2016 Joyent, Inc.
26 */
27
28 #include <sys/types.h>
29 #include <time.h>
30 #include <errno.h>
31
32 /*
33 * This function is blatently stolen from the kernel.
34 * See the dissertation in the comments preceding the
35 * hrt2ts() function in:
36 * uts/common/os/timers.c
37 */
38 void
hrt2ts(hrtime_t hrt,timespec_t * tsp)39 hrt2ts(hrtime_t hrt, timespec_t *tsp)
40 {
41 #if defined(__amd64)
42 tsp->tv_sec = hrt / NANOSEC;
43 tsp->tv_nsec = hrt % NANOSEC;
44 #else
45 uint32_t sec, nsec, tmp;
46
47 tmp = (uint32_t)(hrt >> 30);
48 sec = tmp - (tmp >> 2);
49 sec = tmp - (sec >> 5);
50 sec = tmp + (sec >> 1);
51 sec = tmp - (sec >> 6) + 7;
52 sec = tmp - (sec >> 3);
53 sec = tmp + (sec >> 1);
54 sec = tmp + (sec >> 3);
55 sec = tmp + (sec >> 4);
56 tmp = (sec << 7) - sec - sec - sec;
57 tmp = (tmp << 7) - tmp - tmp - tmp;
58 tmp = (tmp << 7) - tmp - tmp - tmp;
59 nsec = (uint32_t)hrt - (tmp << 9);
60 while (nsec >= NANOSEC) {
61 nsec -= NANOSEC;
62 sec++;
63 }
64 tsp->tv_sec = (time_t)sec;
65 tsp->tv_nsec = nsec;
66 #endif /* defined(__amd64) */
67 }
68
69 /*
70 * Convert absolute time to relative time.
71 * All *timedwait() system call traps expect relative time.
72 */
73 void
abstime_to_reltime(clockid_t clock_id,const timespec_t * abstime,timespec_t * reltime)74 abstime_to_reltime(clockid_t clock_id, const timespec_t *abstime,
75 timespec_t *reltime)
76 {
77 extern int __clock_gettime(clockid_t, timespec_t *);
78 timespec_t now;
79
80 if (clock_id == CLOCK_HIGHRES)
81 hrt2ts(gethrtime(), &now);
82 else
83 (void) __clock_gettime(clock_id, &now);
84 if (abstime->tv_nsec >= now.tv_nsec) {
85 reltime->tv_sec = abstime->tv_sec - now.tv_sec;
86 reltime->tv_nsec = abstime->tv_nsec - now.tv_nsec;
87 } else {
88 reltime->tv_sec = abstime->tv_sec - now.tv_sec - 1;
89 reltime->tv_nsec = abstime->tv_nsec - now.tv_nsec + NANOSEC;
90 }
91 /*
92 * If the absolute time has already passed,
93 * just set the relative time to zero.
94 */
95 if (reltime->tv_sec < 0) {
96 reltime->tv_sec = 0;
97 reltime->tv_nsec = 0;
98 }
99 /*
100 * If the specified absolute time has a bad nanoseconds value,
101 * assign it to the relative time value. If the interface
102 * attempts to sleep, the bad value will be detected then.
103 * The SUSV3 Posix spec is very clear that such detection
104 * should not happen until an attempt to sleep is made.
105 */
106 if ((ulong_t)abstime->tv_nsec >= NANOSEC)
107 reltime->tv_nsec = abstime->tv_nsec;
108 }
109