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..0f5e8fc
--- /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 "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;
+	pthread_t thread;
+ 
+	_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);
+	}
+
+	/*
+	 * Lock the garbage collector mutex to ensure that the garbage
+	 * collector is not using the dead thread list.
+	 */
+	if (pthread_mutex_lock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
+
+	/*
+	 * Defer signals to protect the thread list from access
+	 * by the signal handler:
+	 */
+	_thread_kern_sig_defer();
+
+	/*
+	 * Unlock the garbage collector mutex, now that the garbage collector
+	 * can't be run:
+	 */
+	if (pthread_mutex_unlock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
+
+	/*
+	 * Search for the specified thread in the list of active threads.  This
+	 * is done manually here rather than calling _find_thread() because
+	 * the searches in _thread_list and _dead_list (as well as setting up
+	 * join/detach state) have to be done atomically.
+	 */
+	TAILQ_FOREACH(thread, &_thread_list, tle) {
+		if (thread == pthread)
+			break;
+	}
+	if (thread == NULL) {
+		/*
+		 * Search for the specified thread in the list of dead threads:
+		 */
+		TAILQ_FOREACH(thread, &_dead_list, dle) {
+			if (thread == pthread)
+				break;
+		}
+	}
+
+	/* Check if the thread was not found or has been detached: */
+	if (thread == NULL ||
+	    ((pthread->attr.flags & PTHREAD_DETACHED) != 0)) {
+		/* Undefer and handle pending signals, yielding if necessary: */
+		_thread_kern_sig_undefer();
+
+		/* Return an error: */
+		ret = ESRCH;
+
+	} else if (pthread->joiner != NULL) {
+		/* Undefer and handle pending signals, yielding if necessary: */
+		_thread_kern_sig_undefer();
+
+		/* Multiple joiners are not supported. */
+		ret = ENOTSUP;
+
+	/* Check if the thread is not dead: */
+	} else if (pthread->state != PS_DEAD) {
+		/* 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;
+
+		while (curthread->join_status.thread == pthread) {
+			/* Schedule the next thread: */
+			_thread_kern_sched_state(PS_JOIN, __FILE__, __LINE__);
+		}
+
+		/*
+		 * 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;
+	} else {
+		/*
+		 * The thread exited (is dead) without being detached, and no
+		 * thread has joined it.
+		 */
+
+		/* Check if the return value is required: */
+		if (thread_return != NULL) {
+			/* Return the thread's return value: */
+			*thread_return = pthread->ret;
+		}
+
+		/* Make the thread collectable by the garbage collector. */
+		pthread->attr.flags |= PTHREAD_DETACHED;
+
+		/* Undefer and handle pending signals, yielding if necessary: */
+		_thread_kern_sig_undefer();
+	}
+
+	_thread_leave_cancellation_point();
+
+	/* Return the completion status: */
+	return (ret);
+}