2 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3 * Copyright (c) 2005 Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * $DragonFly: src/lib/libthread_xu/thread/thr_umtx.c,v 1.3 2006/04/04 14:04:39 davidxu Exp $
36 #include "thr_private.h"
39 * This function is used to acquire a contested lock.
42 __thr_umtx_lock(volatile umtx_t *mtx, int timo)
49 if (v == 2 || atomic_cmpset_acq_int(mtx, 1, 2)) {
51 umtx_sleep(mtx, 2, timo);
52 else if (umtx_sleep(mtx, 2, timo) < 0) {
53 if (errno == EAGAIN) {
54 if (atomic_cmpset_acq_int(mtx, 0, 2))
62 } while (!atomic_cmpset_acq_int(mtx, 0, 2));
68 __thr_umtx_unlock(volatile umtx_t *mtx)
74 if (atomic_cmpset_acq_int(mtx, v, v-1)) {
85 __thr_umtx_timedlock(volatile umtx_t *mtx, const struct timespec *timeout)
87 struct timespec ts, ts2, ts3;
90 if ((timeout->tv_sec < 0) ||
91 (timeout->tv_sec == 0 && timeout->tv_nsec <= 0))
94 /* XXX there should have MONO timer! */
95 clock_gettime(CLOCK_REALTIME, &ts);
96 TIMESPEC_ADD(&ts, &ts, timeout);
101 timo = (int)(ts2.tv_nsec / 1000);
107 ret = __thr_umtx_lock(mtx, timo);
108 if (ret != ETIMEDOUT)
110 clock_gettime(CLOCK_REALTIME, &ts3);
111 TIMESPEC_SUB(&ts2, &ts, &ts3);
112 if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
121 _thr_umtx_wait(volatile umtx_t *mtx, int exp, const struct timespec *timeout,
124 struct timespec ts, ts2, ts3;
130 if (timeout == NULL) {
131 if (umtx_sleep(mtx, exp, 0) < 0) {
138 if ((timeout->tv_sec < 0) ||
139 (timeout->tv_sec == 0 && timeout->tv_nsec <= 0))
142 clock_gettime(clockid, &ts);
143 TIMESPEC_ADD(&ts, &ts, timeout);
148 timo = (int)(ts2.tv_nsec / 1000);
154 if (umtx_sleep(mtx, exp, timo) < 0) {
155 if (errno == EBUSY) {
158 } else if (errno == EINTR) {
163 clock_gettime(clockid, &ts3);
164 TIMESPEC_SUB(&ts2, &ts, &ts3);
165 if (ts2.tv_sec < 0 || (ts2.tv_sec == 0 && ts2.tv_nsec <= 0)) {
173 void _thr_umtx_wake(volatile umtx_t *mtx, int count)
175 umtx_wakeup(mtx, count);