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Diffstat (limited to 'lib/libpthread/thread/thr_join.c')
-rw-r--r-- | lib/libpthread/thread/thr_join.c | 169 |
1 files changed, 169 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..b9c75ac --- /dev/null +++ b/lib/libpthread/thread/thr_join.c @@ -0,0 +1,169 @@ +/* + * 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(); +} |