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/*
* 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 <sys/types.h>
#include <pthread.h>
#include <libc_private.h>
#include <spinlock.h>
#include "thr_private.h"
#define MAX_SPINLOCKS 20
/*
* These data structures are used to trace all spinlocks
* in libc.
*/
struct spinlock_extra {
spinlock_t *owner;
};
static umtx_t spinlock_static_lock;
static struct spinlock_extra extra[MAX_SPINLOCKS];
static int spinlock_count;
static int initialized;
static void init_spinlock(spinlock_t *lck);
/*
* These are for compatability only. Spinlocks of this type
* are deprecated.
*/
void
_spinunlock(spinlock_t *lck)
{
THR_UMTX_UNLOCK(_get_curthread(), (umtx_t *)&lck->access_lock);
}
void
_spinlock(spinlock_t *lck)
{
if (!__isthreaded)
PANIC("Spinlock called when not threaded.");
if (!initialized)
PANIC("Spinlocks not initialized.");
if (lck->fname == NULL)
init_spinlock(lck);
THR_UMTX_LOCK(_get_curthread(), (umtx_t *)&lck->access_lock);
}
void
_spinlock_debug(spinlock_t *lck, char *fname, int lineno)
{
_spinlock(lck);
}
static void
init_spinlock(spinlock_t *lck)
{
static int count = 0;
THR_UMTX_LOCK(_get_curthread(), &spinlock_static_lock);
if ((lck->fname == NULL) && (spinlock_count < MAX_SPINLOCKS)) {
lck->fname = (char *)&extra[spinlock_count];
extra[spinlock_count].owner = lck;
spinlock_count++;
}
THR_UMTX_UNLOCK(_get_curthread(), &spinlock_static_lock);
if (lck->fname == NULL && ++count < 5)
stderr_debug("Warning: exceeded max spinlocks");
}
void
_thr_spinlock_init(void)
{
int i;
_thr_umtx_init(&spinlock_static_lock);
if (initialized != 0) {
/*
* called after fork() to reset state of libc spin locks,
* it is not quite right since libc may be in inconsistent
* state, resetting the locks to allow current thread to be
* able to hold them may not help things too much, but
* anyway, we do our best.
* it is better to do pthread_atfork in libc.
*/
for (i = 0; i < spinlock_count; i++)
_thr_umtx_init((umtx_t *)&extra[i].owner->access_lock);
} else {
initialized = 1;
}
}
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