uclibc-ng/libc/stdlib/atexit.c

/* Copyright (C) 1995,1996 Robert de Bath <rdebath@cix.compulink.co.uk>
 * This file is part of the Linux-8086 C library and is distributed
 * under the GNU Library General Public License.
 */

/*
 * This deals with both the atexit and on_exit function calls
 * 
 * Note calls installed with atexit are called with the same args as on_exit
 * fuctions; the void* is given the NULL value.
 * 
 */

#include <errno.h>

/* ATEXIT.H */
#define MAXONEXIT 20			/* AIUI Posix requires 10 */

typedef void (*vfuncp) ();

extern vfuncp __cleanup;
extern void __do_exit();
extern void _exit __P((int __status)) __attribute__ ((__noreturn__));

extern struct exit_table {
	vfuncp called;
	void *argument;
} __on_exit_table[MAXONEXIT];

extern int __on_exit_count;

/* End ATEXIT.H */

#ifdef L_atexit
vfuncp __cleanup;

int atexit(ptr)
vfuncp ptr;
{
	if (__on_exit_count < 0 || __on_exit_count >= MAXONEXIT) {
		errno = ENOMEM;
		return -1;
	}
	__cleanup = __do_exit;
	if (ptr) {
		__on_exit_table[__on_exit_count].called = ptr;
		__on_exit_table[__on_exit_count].argument = 0;
		__on_exit_count++;
	}
	return 0;
}

#endif

#ifdef L_on_exit
int on_exit(ptr, arg)
vfuncp ptr;
void *arg;
{
	if (__on_exit_count < 0 || __on_exit_count >= MAXONEXIT) {
		errno = ENOMEM;
		return -1;
	}
	__cleanup = __do_exit;
	if (ptr) {
		__on_exit_table[__on_exit_count].called = ptr;
		__on_exit_table[__on_exit_count].argument = arg;
		__on_exit_count++;
	}
	return 0;
}

#endif

#ifdef L___do_exit

int __on_exit_count = 0;
struct exit_table __on_exit_table[MAXONEXIT];

void __do_exit(rv)
int rv;
{
	register int count = __on_exit_count - 1;
	register vfuncp ptr;

	__on_exit_count = -1;		/* ensure no more will be added */
	__cleanup = 0;				/* Calling exit won't re-do this */

	/* In reverse order */
	for (; count >= 0; count--) {
		ptr = __on_exit_table[count].called;
		(*ptr) (rv, __on_exit_table[count].argument);
	}
}

#endif

#ifdef L_exit

void exit(rv)
int rv;
{
	if (__cleanup)
		__cleanup();
	_exit(rv);
}

#endif