OpenBSD-4.6/lib/libpthread/uthread/uthread_detach.c

/*	$OpenBSD: uthread_detach.c,v 1.8 2002/03/07 22:36:03 fgsch Exp $	*/
/*
 * 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: uthread_detach.c,v 1.10 1999/08/28 00:03:28 peter Exp $
 */
#include <errno.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"

int
pthread_detach(pthread_t pthread)
{
	int             rval = 0;

	/* Check for invalid calling parameters: */
	if (pthread == NULL || pthread->magic != PTHREAD_MAGIC)
		/* Return an invalid argument error: */
		rval = EINVAL;

	/* Check if the thread has not been detached: */
	else if ((pthread->attr.flags & PTHREAD_DETACHED) == 0) {
		/* Flag the thread as detached: */
		pthread->attr.flags |= PTHREAD_DETACHED;

		/*
		 * Defer signals to protect the scheduling queues from
		 * access by the signal handler:
		 */
		_thread_kern_sig_defer();

		/* Check if there is a joiner: */
		if (pthread->joiner != NULL) {
			struct pthread	*joiner = pthread->joiner;

			/* Make the thread runnable: */
			PTHREAD_NEW_STATE(joiner, PS_RUNNING);

			/* Set the return value for the woken thread: */
			joiner->join_status.error = ESRCH;
			joiner->join_status.ret = NULL;
			joiner->join_status.thread = NULL;

			/*
			 * Disconnect the joiner from the thread being detached:
			 */
			pthread->joiner = NULL;
		}

		/*
		 * Undefer and handle pending signals, yielding if a
		 * scheduling signal occurred while in the critical region.
		 */
		_thread_kern_sig_undefer();
	} else
		/* Return an error: */
		rval = EINVAL;

	/* Return the completion status: */
	return (rval);
}
#endif