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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. 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 <link.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)
#define _MUTEX_DESTROY(x) if (__isthreaded) _pthread_mutex_destroy(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);
}
#pragma weak __pthread_cxa_finalize
void __pthread_cxa_finalize(const struct dl_phdr_info *);
static int global_exit;
/*
* 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 dl_phdr_info phdr_info;
struct atexit *p;
struct atexit_fn fn;
int n, has_phdr;
if (dso != NULL) {
has_phdr = _rtld_addr_phdr(dso, &phdr_info);
} else {
has_phdr = 0;
global_exit = 1;
}
_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 */
fn = p->fns[n];
if (dso != NULL && dso != fn.fn_dso) {
/* wrong DSO ? */
if (!has_phdr || global_exit ||
!__elf_phdr_match_addr(&phdr_info,
fn.fn_ptr.cxa_func))
continue;
}
/*
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);
if (dso == NULL)
_MUTEX_DESTROY(&atexit_mutex);
if (has_phdr && !global_exit && &__pthread_cxa_finalize != NULL)
__pthread_cxa_finalize(&phdr_info);
}
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