/*      $NetBSD: quick_exit.c,v 1.1 2013/04/26 18:29:55 christos Exp $  */

/*-
* Copyright (c) 2011 David Chisnall
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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: src/lib/libc/stdlib/quick_exit.c,v 1.4 2012/11/17 01:49:41 svnexp Exp $
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: quick_exit.c,v 1.1 2013/04/26 18:29:55 christos Exp $");

#include "namespace.h"
#include "reentrant.h"

#include <stdlib.h>

/**
* Linked list of quick exit handlers.  This is simpler than the atexit()
* version, because it is not required to support C++ destructors or
* DSO-specific cleanups.
*/
struct quick_exit_handler {
       struct quick_exit_handler *next;
       void (*cleanup)(void);
};

/**
* Lock protecting the handlers list.
*/
#ifdef _REENTRANT
extern mutex_t __atexit_mutex;
#endif

/**
* Stack of cleanup handlers.  These will be invoked in reverse order when
*/
static struct quick_exit_handler *handlers;

int
at_quick_exit(void (*func)(void))
{
       struct quick_exit_handler *h;

       h = malloc(sizeof(*h));

       if (NULL == h)
               return 1;
       h->cleanup = func;
#ifdef _REENTRANT
       mutex_lock(&__atexit_mutex);
#endif
       h->next = handlers;
       handlers = h;
#ifdef _REENTRANT
       mutex_unlock(&__atexit_mutex);
#endif
       return 0;
}

void
quick_exit(int status)
{
       struct quick_exit_handler *h;

       /*
        * XXX: The C++ spec requires us to call std::terminate if there is an
        * exception here.
        */
       for (h = handlers; NULL != h; h = h->next)
               (*h->cleanup)();
       _Exit(status);
}