diff options
Diffstat (limited to 'lib/libthr/thread/thr_join.c')
| -rw-r--r-- | lib/libthr/thread/thr_join.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/lib/libthr/thread/thr_join.c b/lib/libthr/thread/thr_join.c new file mode 100644 index 000000000000..53f28daa258d --- /dev/null +++ b/lib/libthr/thread/thr_join.c @@ -0,0 +1,168 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * 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 "namespace.h" +#include <errno.h> +#include <pthread.h> +#include "un-namespace.h" + +#include "thr_private.h" + +int _pthread_peekjoin_np(pthread_t pthread, void **thread_return); +int _pthread_timedjoin_np(pthread_t pthread, void **thread_return, + const struct timespec *abstime); +static int join_common(pthread_t, void **, const struct timespec *, bool peek); + +__weak_reference(_thr_join, pthread_join); +__weak_reference(_thr_join, _pthread_join); +__weak_reference(_pthread_timedjoin_np, pthread_timedjoin_np); +__weak_reference(_pthread_peekjoin_np, pthread_peekjoin_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 +_thr_join(pthread_t pthread, void **thread_return) +{ + return (join_common(pthread, thread_return, NULL, false)); +} + +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, false)); +} + +int +_pthread_peekjoin_np(pthread_t pthread, void **thread_return) +{ + return (join_common(pthread, thread_return, NULL, true)); +} + +/* + * 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, bool peek) +{ + struct pthread *curthread = _get_curthread(); + struct timespec ts, ts2, *tsp; + void *tmp; + long tid; + int ret; + + 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 != 0) { + THR_THREAD_UNLOCK(curthread, pthread); + return (ret); + } + + /* Only peek into status, do not gc the thread. */ + if (peek) { + if (pthread->tid != TID_TERMINATED) + ret = EBUSY; + else if (thread_return != NULL) + *thread_return = pthread->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); +} |