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/*
* 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 "pthread_private.h"
__weak_reference(_pthread_join, pthread_join);
int
_pthread_join(pthread_t pthread, void **thread_return)
{
struct pthread *curthread = _get_curthread();
int ret = 0;
_thread_enter_cancellation_point();
/* Check if the caller has specified an invalid thread: */
if (pthread == NULL || pthread->magic != PTHREAD_MAGIC) {
/* Invalid thread: */
_thread_leave_cancellation_point();
return(EINVAL);
}
/* Check if the caller has specified itself: */
if (pthread == curthread) {
/* Avoid a deadlock condition: */
_thread_leave_cancellation_point();
return(EDEADLK);
}
/*
* Find the thread in the list of active threads or in the
* list of dead threads:
*/
if ((_find_thread(pthread) != 0) && (_find_dead_thread(pthread) != 0))
/* Return an error: */
ret = ESRCH;
/* Check if this thread has been detached: */
else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0)
/* Return an error: */
ret = ESRCH;
/* Check if the thread is not dead: */
else if (pthread->state != PS_DEAD) {
PTHREAD_ASSERT_NOT_IN_SYNCQ(curthread);
/*
* Enter a loop in case this thread is woken prematurely
* in order to invoke a signal handler:
*/
for (;;) {
/* Clear the interrupted flag: */
curthread->interrupted = 0;
/*
* Protect against being context switched out while
* adding this thread to the join queue.
*/
_thread_kern_sig_defer();
/* Add the running thread to the join queue: */
TAILQ_INSERT_TAIL(&(pthread->join_queue),
curthread, sqe);
curthread->flags |= PTHREAD_FLAGS_IN_JOINQ;
curthread->data.thread = pthread;
/* Schedule the next thread: */
_thread_kern_sched_state(PS_JOIN, __FILE__, __LINE__);
if ((curthread->flags & PTHREAD_FLAGS_IN_JOINQ) != 0) {
TAILQ_REMOVE(&(pthread->join_queue),
curthread, sqe);
curthread->flags &= ~PTHREAD_FLAGS_IN_JOINQ;
}
curthread->data.thread = NULL;
_thread_kern_sig_undefer();
if (curthread->interrupted != 0) {
if (curthread->continuation != NULL)
curthread->continuation(curthread);
/*
* This thread was interrupted, probably to
* invoke a signal handler. Make sure the
* target thread is still joinable.
*/
if (((_find_thread(pthread) != 0) &&
(_find_dead_thread(pthread) != 0)) ||
((pthread->attr.flags &
PTHREAD_DETACHED) != 0)) {
/* Return an error: */
ret = ESRCH;
/* We're done; break out of the loop. */
break;
}
else if (pthread->state == PS_DEAD) {
/* We're done; break out of the loop. */
break;
}
} else {
/*
* The thread return value and error are set
* by the thread we're joining to when it
* exits or detaches:
*/
ret = curthread->error;
if ((ret == 0) && (thread_return != NULL))
*thread_return = curthread->ret;
/* We're done; break out of the loop. */
break;
}
}
/* Check if the return value is required: */
} else if (thread_return != NULL)
/* Return the thread's return value: */
*thread_return = pthread->ret;
_thread_leave_cancellation_point();
/* Return the completion status: */
return (ret);
}
void
_join_backout(pthread_t pthread)
{
struct pthread *curthread = _get_curthread();
_thread_kern_sig_defer();
if ((pthread->flags & PTHREAD_FLAGS_IN_JOINQ) != 0) {
TAILQ_REMOVE(&pthread->data.thread->join_queue, pthread, sqe);
curthread->flags &= ~PTHREAD_FLAGS_IN_JOINQ;
}
_thread_kern_sig_undefer();
}
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