1 /* $NetBSD: atexit.c,v 1.12 1999/09/20 04:39:36 lukem Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #if defined(LIBC_SCCS) && !defined(lint) 41 #if 0 42 static char sccsid[] = "@(#)atexit.c 8.2 (Berkeley) 7/3/94"; 43 #else 44 __RCSID("$NetBSD: atexit.c,v 1.12 1999/09/20 04:39:36 lukem Exp $"); 45 #endif 46 #endif /* LIBC_SCCS and not lint */ 47 48 #include <assert.h> 49 #include <errno.h> 50 #include <stdlib.h> 51 #include "reentrant.h" 52 #include "atexit.h" 53 54 struct atexit *__atexit; /* points to head of LIFO stack */ 55 56 #ifdef _REENT 57 mutex_t __atexit_mutex = MUTEX_INITIALIZER; 58 #endif 59 60 /* 61 * Register a function to be performed at exit. 62 */ 63 int 64 atexit(fn) 65 void (*fn) __P((void)); 66 { 67 static struct atexit __atexit0; /* one guaranteed table */ 68 struct atexit *p; 69 70 _DIAGASSERT(fn != NULL); 71 72 mutex_lock(&__atexit_mutex); 73 if ((p = __atexit) == NULL) 74 __atexit = p = &__atexit0; 75 else if (p->ind >= ATEXIT_SIZE) { 76 if ((p = malloc(sizeof(*p))) == NULL) { 77 mutex_unlock(&__atexit_mutex); 78 return (-1); 79 } 80 p->ind = 0; 81 p->next = __atexit; 82 __atexit = p; 83 } 84 p->fns[p->ind++] = fn; 85 mutex_unlock(&__atexit_mutex); 86 return (0); 87 } 88