[apple/libc.git] / stdlib / FreeBSD / atexit.c

/*-
 * 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: src/lib/libc/stdlib/atexit.c,v 1.7 2003/12/19 17:11:20 kan Exp $");

#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"

#define	ATEXIT_FN_EMPTY	0
#define	ATEXIT_FN_STD	1
#define	ATEXIT_FN_CXA	2

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 {
	struct atexit *next;			/* next in list */
	int ind;				/* next index in this table */
	struct atexit_fn {
		int fn_type;			/* ATEXIT_? from above */
		union {
			void (*std_func)(void);
			void (*cxa_func)(void *);
		} fn_ptr;			/* function pointer */
		void *fn_arg;			/* argument for CXA callback */
		void *fn_dso;			/* shared module handle */
	} fns[ATEXIT_SIZE];			/* the table itself */
};

static struct atexit *__atexit;		/* points to head of LIFO stack */

/*
 * Register the function described by 'fptr' to be called at application
 * exit or owning shared object unload time. This is a helper function
 * for atexit and __cxa_atexit.
 */
static int
atexit_register(struct atexit_fn *fptr)
{
	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++] = *fptr;
	_MUTEX_UNLOCK(&atexit_mutex);
	return 0;
}

/*
 * Register a function to be performed at exit.
 */
int
atexit(void (*func)(void))
{
	struct atexit_fn fn;
	int error;

	fn.fn_type = ATEXIT_FN_STD;
	fn.fn_ptr.std_func = func;;
	fn.fn_arg = NULL;
	fn.fn_dso = NULL;

 	error = atexit_register(&fn);	
	return (error);
}

/*
 * Register a function to be performed at exit or when an shared object
 * with given dso handle is unloaded dynamically.
 */
int
__cxa_atexit(void (*func)(void *), void *arg, void *dso)
{
	struct atexit_fn fn;
	int error;

	fn.fn_type = ATEXIT_FN_CXA;
	fn.fn_ptr.cxa_func = func;;
	fn.fn_arg = arg;
	fn.fn_dso = dso;

 	error = atexit_register(&fn);	
	return (error);
}

/*
 * Call all handlers registered with __cxa_atexit for the shared
 * object owning 'dso'.  Note: if 'dso' is NULL, then all remaining
 * handlers are called.
 */
void
__cxa_finalize(void *dso)
{
	struct atexit *p;
	struct atexit_fn fn;
	int n;

	_MUTEX_LOCK(&atexit_mutex);
	for (p = __atexit; p; p = p->next) {
		for (n = p->ind; --n >= 0;) {
			if (p->fns[n].fn_type == ATEXIT_FN_EMPTY)
				continue; /* already been called */
			if (dso != NULL && dso != p->fns[n].fn_dso)
				continue; /* wrong DSO */
			fn = p->fns[n];
			/*
			  Mark entry to indicate that this particular handler
			  has already been called.
			*/
			p->fns[n].fn_type = ATEXIT_FN_EMPTY;
		        _MUTEX_UNLOCK(&atexit_mutex);
		
			/* Call the function of correct type. */
			if (fn.fn_type == ATEXIT_FN_CXA)
				fn.fn_ptr.cxa_func(fn.fn_arg);
			else if (fn.fn_type == ATEXIT_FN_STD)
				fn.fn_ptr.std_func();
			_MUTEX_LOCK(&atexit_mutex);
		}
	}
	_MUTEX_UNLOCK(&atexit_mutex);
}
Commit	Line	Data
9385eb3d	1	/*-
e9ce8d39 A	2	* Copyright (c) 1990, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* This code is derived from software contributed to Berkeley by
	6	* Chris Torek.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. All advertising materials mentioning features or use of this software
	17	* must display the following acknowledgement:
	18	* This product includes software developed by the University of
	19	* California, Berkeley and its contributors.
	20	* 4. Neither the name of the University nor the names of its contributors
	21	* may be used to endorse or promote products derived from this software
	22	* without specific prior written permission.
	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	* SUCH DAMAGE.
	35	*/
	36
9385eb3d A	37	#if defined(LIBC_SCCS) && !defined(lint)
	38	static char sccsid[] = "@(#)atexit.c 8.2 (Berkeley) 7/3/94";
	39	#endif /* LIBC_SCCS and not lint */
	40	#include <sys/cdefs.h>
59e0d9fe	41	__FBSDID("$FreeBSD: src/lib/libc/stdlib/atexit.c,v 1.7 2003/12/19 17:11:20 kan Exp $");
e9ce8d39	42
9385eb3d	43	#include "namespace.h"
e9ce8d39 A	44	#include <stddef.h>
e9ce8d39 A	45	#include <stdlib.h>
9385eb3d A	46	#include <unistd.h>
9385eb3d A	47	#include <pthread.h>
e9ce8d39	48	#include "atexit.h"
9385eb3d A	49	#include "un-namespace.h"
	50
	51	#include "libc_private.h"
	52
59e0d9fe A	53	#define ATEXIT_FN_EMPTY 0
	54	#define ATEXIT_FN_STD 1
	55	#define ATEXIT_FN_CXA 2
	56
9385eb3d A	57	static pthread_mutex_t atexit_mutex = PTHREAD_MUTEX_INITIALIZER;
	58
	59	#define _MUTEX_LOCK(x) if (__isthreaded) _pthread_mutex_lock(x)
	60	#define _MUTEX_UNLOCK(x) if (__isthreaded) _pthread_mutex_unlock(x)
e9ce8d39	61
59e0d9fe A	62	struct atexit {
	63	struct atexit next; / next in list */
	64	int ind; /* next index in this table */
	65	struct atexit_fn {
	66	int fn_type; /* ATEXIT_? from above */
	67	union {
	68	void (*std_func)(void);
	69	void (cxa_func)(void );
	70	} fn_ptr; /* function pointer */
	71	void fn_arg; / argument for CXA callback */
	72	void fn_dso; / shared module handle */
	73	} fns[ATEXIT_SIZE]; /* the table itself */
	74	};
	75
	76	static struct atexit __atexit; / points to head of LIFO stack */
e9ce8d39 A	77
e9ce8d39 A	78	/*
59e0d9fe A	79	* Register the function described by 'fptr' to be called at application
	80	* exit or owning shared object unload time. This is a helper function
	81	* for atexit and __cxa_atexit.
e9ce8d39	82	*/
59e0d9fe A	83	static int
59e0d9fe A	84	atexit_register(struct atexit_fn *fptr)
e9ce8d39 A	85	{
e9ce8d39 A	86	static struct atexit __atexit0; /* one guaranteed table */
9385eb3d	87	struct atexit *p;
e9ce8d39	88
9385eb3d	89	_MUTEX_LOCK(&atexit_mutex);
e9ce8d39 A	90	if ((p = __atexit) == NULL)
e9ce8d39 A	91	__atexit = p = &__atexit0;
9385eb3d A	92	else while (p->ind >= ATEXIT_SIZE) {
	93	struct atexit *old__atexit;
	94	old__atexit = __atexit;
	95	_MUTEX_UNLOCK(&atexit_mutex);
	96	if ((p = (struct atexit )malloc(sizeof(p))) == NULL)
e9ce8d39	97	return (-1);
9385eb3d A	98	_MUTEX_LOCK(&atexit_mutex);
	99	if (old__atexit != __atexit) {
	100	/* Lost race, retry operation */
	101	_MUTEX_UNLOCK(&atexit_mutex);
	102	free(p);
	103	_MUTEX_LOCK(&atexit_mutex);
	104	p = __atexit;
	105	continue;
	106	}
e9ce8d39 A	107	p->ind = 0;
	108	p->next = __atexit;
	109	__atexit = p;
	110	}
59e0d9fe A	111	p->fns[p->ind++] = *fptr;
	112	_MUTEX_UNLOCK(&atexit_mutex);
	113	return 0;
	114	}
	115
	116	/*
	117	* Register a function to be performed at exit.
	118	*/
	119	int
	120	atexit(void (*func)(void))
	121	{
	122	struct atexit_fn fn;
	123	int error;
	124
	125	fn.fn_type = ATEXIT_FN_STD;
	126	fn.fn_ptr.std_func = func;;
	127	fn.fn_arg = NULL;
	128	fn.fn_dso = NULL;
	129
	130	error = atexit_register(&fn);
	131	return (error);
	132	}
	133
	134	/*
	135	* Register a function to be performed at exit or when an shared object
	136	* with given dso handle is unloaded dynamically.
	137	*/
	138	int
	139	__cxa_atexit(void (func)(void ), void arg, void dso)
	140	{
	141	struct atexit_fn fn;
	142	int error;
	143
	144	fn.fn_type = ATEXIT_FN_CXA;
	145	fn.fn_ptr.cxa_func = func;;
	146	fn.fn_arg = arg;
	147	fn.fn_dso = dso;
	148
	149	error = atexit_register(&fn);
	150	return (error);
	151	}
	152
	153	/*
	154	* Call all handlers registered with __cxa_atexit for the shared
	155	* object owning 'dso'. Note: if 'dso' is NULL, then all remaining
	156	* handlers are called.
	157	*/
	158	void
	159	__cxa_finalize(void *dso)
	160	{
	161	struct atexit *p;
	162	struct atexit_fn fn;
	163	int n;
	164
	165	_MUTEX_LOCK(&atexit_mutex);
	166	for (p = __atexit; p; p = p->next) {
	167	for (n = p->ind; --n >= 0;) {
	168	if (p->fns[n].fn_type == ATEXIT_FN_EMPTY)
	169	continue; /* already been called */
	170	if (dso != NULL && dso != p->fns[n].fn_dso)
	171	continue; /* wrong DSO */
	172	fn = p->fns[n];
	173	/*
	174	Mark entry to indicate that this particular handler
175	has already been called.
176	*/
177	p->fns[n].fn_type = ATEXIT_FN_EMPTY;
178	_MUTEX_UNLOCK(&atexit_mutex);
179
180	/* Call the function of correct type. */
181	if (fn.fn_type == ATEXIT_FN_CXA)
182	fn.fn_ptr.cxa_func(fn.fn_arg);
183	else if (fn.fn_type == ATEXIT_FN_STD)
184	fn.fn_ptr.std_func();
185	_MUTEX_LOCK(&atexit_mutex);
186	}
187	}
9385eb3d	188	_MUTEX_UNLOCK(&atexit_mutex);
e9ce8d39	189	}