diff options
Diffstat (limited to 'lib/libpthread/thread/thr_join.c')
| -rw-r--r-- | lib/libpthread/thread/thr_join.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/lib/libpthread/thread/thr_join.c b/lib/libpthread/thread/thr_join.c new file mode 100644 index 0000000..9f940da --- /dev/null +++ b/lib/libpthread/thread/thr_join.c @@ -0,0 +1,162 @@ +/* + * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>. + * 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, 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. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by John Birrell. + * 4. Neither the name of the author nor the names of any co-contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <errno.h> +#include <pthread.h> +#include "thr_private.h" + +__weak_reference(_pthread_join, pthread_join); + +int +_pthread_join(pthread_t pthread, void **thread_return) +{ + struct pthread *curthread = _get_curthread(); + void *tmp; + kse_critical_t crit; + int ret = 0; + + _thr_cancel_enter(curthread); + + /* Check if the caller has specified an invalid thread: */ + if (pthread == NULL || pthread->magic != THR_MAGIC) { + /* Invalid thread: */ + _thr_cancel_leave(curthread, 1); + return (EINVAL); + } + + /* Check if the caller has specified itself: */ + if (pthread == curthread) { + /* Avoid a deadlock condition: */ + _thr_cancel_leave(curthread, 1); + return (EDEADLK); + } + + /* + * Find the thread in the list of active threads or in the + * list of dead threads: + */ + if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/1)) != 0) { + /* Return an error: */ + _thr_cancel_leave(curthread, 1); + return (ESRCH); + } + + THR_SCHED_LOCK(curthread, pthread); + /* Check if this thread has been detached: */ + if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) { + THR_SCHED_UNLOCK(curthread, pthread); + /* Remove the reference and return an error: */ + _thr_ref_delete(curthread, pthread); + ret = ESRCH; + } else { + /* Lock the target thread while checking its state. */ + if (pthread->state == PS_DEAD) { + /* Return the thread's return value: */ + tmp = pthread->ret; + + /* Detach the thread. */ + pthread->attr.flags |= PTHREAD_DETACHED; + + /* Unlock the thread. */ + THR_SCHED_UNLOCK(curthread, pthread); + + /* + * Remove the thread from the list of active + * threads and add it to the GC list. + */ + crit = _kse_critical_enter(); + KSE_LOCK_ACQUIRE(curthread->kse, &_thread_list_lock); + THR_LIST_REMOVE(pthread); + THR_GCLIST_ADD(pthread); + KSE_LOCK_RELEASE(curthread->kse, &_thread_list_lock); + _kse_critical_leave(crit); + + /* Remove the reference. */ + _thr_ref_delete(curthread, pthread); + if (thread_return != NULL) + *thread_return = tmp; + } + else if (pthread->joiner != NULL) { + /* Unlock the thread and remove the reference. */ + THR_SCHED_UNLOCK(curthread, pthread); + _thr_ref_delete(curthread, pthread); + + /* Multiple joiners are not supported. */ + ret = ENOTSUP; + } + else { + /* Set the running thread to be the joiner: */ + pthread->joiner = curthread; + + /* Keep track of which thread we're joining to: */ + curthread->join_status.thread = pthread; + + /* Unlock the thread and remove the reference. */ + THR_SCHED_UNLOCK(curthread, pthread); + _thr_ref_delete(curthread, pthread); + + THR_SCHED_LOCK(curthread, curthread); + while (curthread->join_status.thread == pthread) { + THR_SET_STATE(curthread, PS_JOIN); + THR_SCHED_UNLOCK(curthread, curthread); + /* Schedule the next thread: */ + _thr_sched_switch(curthread); + THR_SCHED_LOCK(curthread, curthread); + } + THR_SCHED_UNLOCK(curthread, curthread); + + if ((curthread->cancelflags & THR_CANCELLING) && + !(curthread->cancelflags & PTHREAD_CANCEL_DISABLE)) { + if (_thr_ref_add(curthread, pthread, 1) == 0) { + THR_SCHED_LOCK(curthread, pthread); + pthread->joiner = NULL; + THR_SCHED_UNLOCK(curthread, pthread); + _thr_ref_delete(curthread, pthread); + } + pthread_exit(PTHREAD_CANCELED); + } + + /* + * The thread return value and error are set by the + * thread we're joining to when it exits or detaches: + */ + ret = curthread->join_status.error; + if ((ret == 0) && (thread_return != NULL)) + *thread_return = curthread->join_status.ret; + } + } + _thr_cancel_leave(curthread, 1); + + /* Return the completion status: */ + return (ret); +} |
