ada33a6e36
module private type, when private type mutex is locked/unlocked, thread critical region is entered or leaved. These changes makes fork() async-signal safe which required by POSIX. Note that user's atfork handler still needs to be async-signal safe, but it is not problem of libthr, it is user's responsiblity.
266 lines
6.5 KiB
C
266 lines
6.5 KiB
C
/*
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* Copyright (c) 2005 David Xu <davidxu@freebsd.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*
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*/
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#include "thr_private.h"
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#include "thr_umtx.h"
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#ifndef HAS__UMTX_OP_ERR
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int _umtx_op_err(void *obj, int op, u_long val, void *uaddr, void *uaddr2)
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{
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if (_umtx_op(obj, op, val, uaddr, uaddr2) == -1)
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return (errno);
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return (0);
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}
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#endif
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void
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_thr_umutex_init(struct umutex *mtx)
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{
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static struct umutex default_mtx = DEFAULT_UMUTEX;
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*mtx = default_mtx;
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}
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void
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_thr_urwlock_init(struct urwlock *rwl)
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{
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static struct urwlock default_rwl = DEFAULT_URWLOCK;
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*rwl = default_rwl;
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}
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int
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__thr_umutex_lock(struct umutex *mtx, uint32_t id)
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{
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uint32_t owner;
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if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
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for (;;) {
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/* wait in kernel */
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_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
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owner = mtx->m_owner;
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if ((owner & ~UMUTEX_CONTESTED) == 0 &&
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atomic_cmpset_acq_32(&mtx->m_owner, owner, id|owner))
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return (0);
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}
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}
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return _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0);
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}
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int
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__thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
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const struct timespec *ets)
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{
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struct timespec timo, cts;
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uint32_t owner;
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int ret;
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clock_gettime(CLOCK_REALTIME, &cts);
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TIMESPEC_SUB(&timo, ets, &cts);
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if (timo.tv_sec < 0)
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return (ETIMEDOUT);
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for (;;) {
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if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
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/* wait in kernel */
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ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, &timo);
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/* now try to lock it */
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owner = mtx->m_owner;
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if ((owner & ~UMUTEX_CONTESTED) == 0 &&
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atomic_cmpset_acq_32(&mtx->m_owner, owner, id|owner))
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return (0);
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} else {
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ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, &timo);
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if (ret == 0)
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break;
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}
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if (ret == ETIMEDOUT)
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break;
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clock_gettime(CLOCK_REALTIME, &cts);
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TIMESPEC_SUB(&timo, ets, &cts);
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if (timo.tv_sec < 0 || (timo.tv_sec == 0 && timo.tv_nsec == 0)) {
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ret = ETIMEDOUT;
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break;
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}
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}
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return (ret);
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}
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int
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__thr_umutex_unlock(struct umutex *mtx, uint32_t id)
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{
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#ifndef __ia64__
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/* XXX this logic has a race-condition on ia64. */
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if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
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atomic_cmpset_rel_32(&mtx->m_owner, id | UMUTEX_CONTESTED, UMUTEX_CONTESTED);
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return _umtx_op_err(mtx, UMTX_OP_MUTEX_WAKE, 0, 0, 0);
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}
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#endif /* __ia64__ */
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return _umtx_op_err(mtx, UMTX_OP_MUTEX_UNLOCK, 0, 0, 0);
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}
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int
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__thr_umutex_trylock(struct umutex *mtx)
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{
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return _umtx_op_err(mtx, UMTX_OP_MUTEX_TRYLOCK, 0, 0, 0);
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}
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int
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__thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
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uint32_t *oldceiling)
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{
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return _umtx_op_err(mtx, UMTX_OP_SET_CEILING, ceiling, oldceiling, 0);
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}
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int
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_thr_umtx_wait(volatile long *mtx, long id, const struct timespec *timeout)
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{
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if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
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timeout->tv_nsec <= 0)))
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return (ETIMEDOUT);
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return _umtx_op_err(__DEVOLATILE(void *, mtx), UMTX_OP_WAIT, id, 0,
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__DECONST(void*, timeout));
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}
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int
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_thr_umtx_wait_uint(volatile u_int *mtx, u_int id, const struct timespec *timeout, int shared)
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{
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if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
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timeout->tv_nsec <= 0)))
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return (ETIMEDOUT);
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return _umtx_op_err(__DEVOLATILE(void *, mtx),
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shared ? UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id, 0,
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__DECONST(void*, timeout));
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}
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int
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_thr_umtx_wake(volatile void *mtx, int nr_wakeup, int shared)
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{
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return _umtx_op_err(__DEVOLATILE(void *, mtx), shared ? UMTX_OP_WAKE : UMTX_OP_WAKE_PRIVATE,
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nr_wakeup, 0, 0);
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}
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void
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_thr_ucond_init(struct ucond *cv)
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{
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bzero(cv, sizeof(struct ucond));
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}
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int
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_thr_ucond_wait(struct ucond *cv, struct umutex *m,
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const struct timespec *timeout, int check_unparking)
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{
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if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
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timeout->tv_nsec <= 0))) {
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struct pthread *curthread = _get_curthread();
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_thr_umutex_unlock(m, TID(curthread));
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return (ETIMEDOUT);
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}
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return _umtx_op_err(cv, UMTX_OP_CV_WAIT,
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check_unparking ? UMTX_CHECK_UNPARKING : 0,
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m, __DECONST(void*, timeout));
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}
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int
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_thr_ucond_signal(struct ucond *cv)
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{
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if (!cv->c_has_waiters)
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return (0);
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return _umtx_op_err(cv, UMTX_OP_CV_SIGNAL, 0, NULL, NULL);
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}
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int
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_thr_ucond_broadcast(struct ucond *cv)
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{
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if (!cv->c_has_waiters)
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return (0);
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return _umtx_op_err(cv, UMTX_OP_CV_BROADCAST, 0, NULL, NULL);
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}
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int
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__thr_rwlock_rdlock(struct urwlock *rwlock, int flags, struct timespec *tsp)
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{
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return _umtx_op_err(rwlock, UMTX_OP_RW_RDLOCK, flags, NULL, tsp);
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}
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int
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__thr_rwlock_wrlock(struct urwlock *rwlock, struct timespec *tsp)
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{
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return _umtx_op_err(rwlock, UMTX_OP_RW_WRLOCK, 0, NULL, tsp);
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}
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int
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__thr_rwlock_unlock(struct urwlock *rwlock)
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{
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return _umtx_op_err(rwlock, UMTX_OP_RW_UNLOCK, 0, NULL, NULL);
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}
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void
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_thr_rwl_rdlock(struct urwlock *rwlock)
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{
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int ret;
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for (;;) {
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if (_thr_rwlock_tryrdlock(rwlock, URWLOCK_PREFER_READER) == 0)
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return;
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ret = __thr_rwlock_rdlock(rwlock, URWLOCK_PREFER_READER, NULL);
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if (ret == 0)
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return;
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if (ret != EINTR)
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PANIC("rdlock error");
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}
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}
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void
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_thr_rwl_wrlock(struct urwlock *rwlock)
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{
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int ret;
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for (;;) {
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if (_thr_rwlock_trywrlock(rwlock) == 0)
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return;
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ret = __thr_rwlock_wrlock(rwlock, NULL);
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if (ret == 0)
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return;
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if (ret != EINTR)
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PANIC("wrlock error");
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}
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}
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void
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_thr_rwl_unlock(struct urwlock *rwlock)
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{
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if (_thr_rwlock_unlock(rwlock))
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PANIC("unlock error");
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}
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