1 /* $NetBSD: cxa_thread_atexit.c,v 1.1 2017/07/11 15:21:35 joerg Exp $ */
2
3 /*-
4 * Copyright (c) 2017 Joerg Sonnenberger <joerg@NetBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __RCSID("$NetBSD: cxa_thread_atexit.c,v 1.1 2017/07/11 15:21:35 joerg Exp $");
31
32 #include <sys/queue.h>
33 #include <dlfcn.h>
34 #include <stdlib.h>
35
36 #include "atexit.h"
37
38 __dso_hidden bool __cxa_thread_atexit_used;
39
40 struct cxa_dtor {
41 SLIST_ENTRY(cxa_dtor) link;
42 void *dso_symbol;
43 void *obj;
44 void (*dtor)(void *);
45 };
46
47 /* Assumes NULL initialization. */
48 static __thread SLIST_HEAD(, cxa_dtor) cxa_dtors = SLIST_HEAD_INITIALIZER(cxa_dstors);
49
50 void
__cxa_thread_run_atexit(void)51 __cxa_thread_run_atexit(void)
52 {
53 struct cxa_dtor *entry;
54
55 while ((entry = SLIST_FIRST(&cxa_dtors)) != NULL) {
56 SLIST_REMOVE_HEAD(&cxa_dtors, link);
57 (*entry->dtor)(entry->obj);
58 if (entry->dso_symbol)
59 __dl_cxa_refcount(entry->dso_symbol, -1);
60 free(entry);
61 }
62 }
63
64 /*
65 * This dance is necessary since libstdc++ includes
66 * __cxa_thread_atexit unconditionally.
67 */
68 __weak_alias(__cxa_thread_atexit, __cxa_thread_atexit_impl)
69 int __cxa_thread_atexit_impl(void (*)(void *), void *, void *);
70
71 int
__cxa_thread_atexit_impl(void (* dtor)(void *),void * obj,void * dso_symbol)72 __cxa_thread_atexit_impl(void (*dtor)(void *), void *obj, void *dso_symbol)
73 {
74 struct cxa_dtor *entry;
75
76 __cxa_thread_atexit_used = true;
77
78 entry = malloc(sizeof(*entry));
79 if (entry == NULL)
80 return -1;
81 entry->dso_symbol = dso_symbol;
82 if (dso_symbol)
83 __dl_cxa_refcount(entry->dso_symbol, 1);
84 entry->obj = obj;
85 entry->dtor = dtor;
86 SLIST_INSERT_HEAD(&cxa_dtors, entry, link);
87 return 0;
88 }
89