freebsd-skq/lib/libthr/thread/thr_spinlock.c

/*
 * Copyright (c) 1997 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 <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sched.h>
#include <pthread.h>
#include <unistd.h>

#include <libc_private.h>

#include "thr_private.h"

void
_spinunlock(spinlock_t *lck)
{
	_spinunlock_pthread(curthread, lck);
}

inline void
_spinunlock_pthread(pthread_t pthread, spinlock_t *lck)
{
	if (umtx_unlock((struct umtx *)lck, pthread->thr_id))
		abort();
}

/*
 * Lock a location for the running thread. Yield to allow other
 * threads to run if this thread is blocked because the lock is
 * not available. Note that this function does not sleep. It
 * assumes that the lock will be available very soon.
 */
void
_spinlock(spinlock_t *lck)
{
	_spinlock_pthread(curthread, lck);
}

int
_spintrylock(spinlock_t *lck)
{
	int error;
	error = umtx_trylock((struct umtx *)lck, curthread->thr_id);
	if (error != 0 && error != EBUSY)
		abort();
	return (error);
}

inline void
_spinlock_pthread(pthread_t pthread, spinlock_t *lck)
{
	if (umtx_lock((struct umtx *)lck, pthread->thr_id))
		abort();
}

/*
 * Lock a location for the running thread. Yield to allow other
 * threads to run if this thread is blocked because the lock is
 * not available. Note that this function does not sleep. It
 * assumes that the lock will be available very soon.
 *
 * This function checks if the running thread has already locked the
 * location, warns if this occurs and creates a thread dump before
 * returning.
 */
void
_spinlock_debug(spinlock_t *lck, char *fname, int lineno)
{
	if (umtx_lock((struct umtx *)lck, curthread->thr_id))
		abort();
}