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 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 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