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/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* 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 the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)atexit.c 8.2 (Berkeley) 7/3/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include "atexit.h"
#include "un-namespace.h"
#include "libc_private.h"
static pthread_mutex_t atexit_mutex = PTHREAD_MUTEX_INITIALIZER;
#define _MUTEX_LOCK(x) if (__isthreaded) _pthread_mutex_lock(x)
#define _MUTEX_UNLOCK(x) if (__isthreaded) _pthread_mutex_unlock(x)
struct atexit *__atexit; /* points to head of LIFO stack */
/*
* Register a function to be performed at exit.
*/
int
atexit(fn)
void (*fn)();
{
static struct atexit __atexit0; /* one guaranteed table */
struct atexit *p;
_MUTEX_LOCK(&atexit_mutex);
if ((p = __atexit) == NULL)
__atexit = p = &__atexit0;
else while (p->ind >= ATEXIT_SIZE) {
struct atexit *old__atexit;
old__atexit = __atexit;
_MUTEX_UNLOCK(&atexit_mutex);
if ((p = (struct atexit *)malloc(sizeof(*p))) == NULL)
return (-1);
_MUTEX_LOCK(&atexit_mutex);
if (old__atexit != __atexit) {
/* Lost race, retry operation */
_MUTEX_UNLOCK(&atexit_mutex);
free(p);
_MUTEX_LOCK(&atexit_mutex);
p = __atexit;
continue;
}
p->ind = 0;
p->next = __atexit;
__atexit = p;
}
p->fns[p->ind++] = fn;
_MUTEX_UNLOCK(&atexit_mutex);
return (0);
}
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