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-rw-r--r--lib/libpthread/thread/thr_join.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/lib/libpthread/thread/thr_join.c b/lib/libpthread/thread/thr_join.c
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+++ b/lib/libpthread/thread/thr_join.c
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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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