freebsd-skq/lib/libthr/thread/thr_join.c
Pedro F. Giffuni 5e53a4f90f lib: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-26 02:00:33 +00:00

152 lines
4.2 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#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_UNLOCK(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);
}