freebsd-dev/lib/libthr/thread/thr_join.c

150 lines
4.1 KiB
C

/*
* Copyright (c) 2005, David Xu <davidxu@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*
*/
#include "namespace.h"
#include <errno.h>
#include <pthread.h>
#include "un-namespace.h"
#include "thr_private.h"
int _pthread_timedjoin_np(pthread_t pthread, void **thread_return,
const struct timespec *abstime);
static int join_common(pthread_t, void **, const struct timespec *);
__weak_reference(_pthread_join, pthread_join);
__weak_reference(_pthread_timedjoin_np, pthread_timedjoin_np);
static void backout_join(void *arg)
{
struct pthread *pthread = (struct pthread *)arg;
struct pthread *curthread = _get_curthread();
THR_THREAD_LOCK(curthread, pthread);
pthread->joiner = NULL;
THR_THREAD_LOCK(curthread, pthread);
}
int
_pthread_join(pthread_t pthread, void **thread_return)
{
return (join_common(pthread, thread_return, NULL));
}
int
_pthread_timedjoin_np(pthread_t pthread, void **thread_return,
const struct timespec *abstime)
{
if (abstime == NULL || abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
abstime->tv_nsec >= 1000000000)
return (EINVAL);
return (join_common(pthread, thread_return, abstime));
}
/*
* Cancellation behavior:
* if the thread is canceled, joinee is not recycled.
*/
static int
join_common(pthread_t pthread, void **thread_return,
const struct timespec *abstime)
{
struct pthread *curthread = _get_curthread();
struct timespec ts, ts2, *tsp;
void *tmp;
long tid;
int ret = 0;
if (pthread == NULL)
return (EINVAL);
if (pthread == curthread)
return (EDEADLK);
if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0)
return (ESRCH);
if ((pthread->flags & THR_FLAGS_DETACHED) != 0) {
ret = EINVAL;
} else if (pthread->joiner != NULL) {
/* Multiple joiners are not supported. */
ret = ENOTSUP;
}
if (ret) {
THR_THREAD_UNLOCK(curthread, pthread);
return (ret);
}
/* Set the running thread to be the joiner: */
pthread->joiner = curthread;
THR_THREAD_UNLOCK(curthread, pthread);
THR_CLEANUP_PUSH(curthread, backout_join, pthread);
_thr_cancel_enter(curthread);
tid = pthread->tid;
while (pthread->tid != TID_TERMINATED) {
_thr_testcancel(curthread);
if (abstime != NULL) {
clock_gettime(CLOCK_REALTIME, &ts);
TIMESPEC_SUB(&ts2, abstime, &ts);
if (ts2.tv_sec < 0) {
ret = ETIMEDOUT;
break;
}
tsp = &ts2;
} else
tsp = NULL;
ret = _thr_umtx_wait(&pthread->tid, tid, tsp);
if (ret == ETIMEDOUT)
break;
}
_thr_cancel_leave(curthread, 0);
THR_CLEANUP_POP(curthread, 0);
if (ret == ETIMEDOUT) {
THR_THREAD_LOCK(curthread, pthread);
pthread->joiner = NULL;
THR_THREAD_UNLOCK(curthread, pthread);
} else {
ret = 0;
tmp = pthread->ret;
THR_THREAD_LOCK(curthread, pthread);
pthread->flags |= THR_FLAGS_DETACHED;
pthread->joiner = NULL;
_thr_try_gc(curthread, pthread); /* thread lock released */
if (thread_return != NULL)
*thread_return = tmp;
}
return (ret);
}