1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. 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 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #if defined(LIBC_SCCS) && !defined(lint) 33 static char sccsid[] = "@(#)exit.c 8.1 (Berkeley) 6/4/93"; 34 #endif /* LIBC_SCCS and not lint */ 35 #include "namespace.h" 36 #include <stdlib.h> 37 #include <pthread.h> 38 #include <unistd.h> 39 #include "un-namespace.h" 40 41 #include "atexit.h" 42 #include "libc_private.h" 43 44 void (*__cleanup)(void); 45 46 /* 47 * This variable is zero until a process has created a thread. 48 * It is used to avoid calling locking functions in libc when they 49 * are not required. By default, libc is intended to be(come) 50 * thread-safe, but without a (significant) penalty to non-threaded 51 * processes. 52 */ 53 int __isthreaded = 0; 54 55 static pthread_mutex_t exit_mutex; 56 static pthread_once_t exit_mutex_once = PTHREAD_ONCE_INIT; 57 58 static void 59 exit_mutex_init_once(void) 60 { 61 pthread_mutexattr_t ma; 62 63 _pthread_mutexattr_init(&ma); 64 _pthread_mutexattr_settype(&ma, PTHREAD_MUTEX_RECURSIVE); 65 _pthread_mutex_init(&exit_mutex, &ma); 66 _pthread_mutexattr_destroy(&ma); 67 } 68 69 /* 70 * Exit, flushing stdio buffers if necessary. 71 */ 72 void 73 exit(int status) 74 { 75 /* Ensure that the auto-initialization routine is linked in: */ 76 extern int _thread_autoinit_dummy_decl; 77 78 _thread_autoinit_dummy_decl = 1; 79 80 /* Make exit(3) thread-safe */ 81 if (__isthreaded) { 82 _once(&exit_mutex_once, exit_mutex_init_once); 83 _pthread_mutex_lock(&exit_mutex); 84 } 85 86 /* 87 * We're dealing with cleaning up thread_local destructors in the case of 88 * the process termination through main() exit. 89 * Other cases are handled elsewhere. 90 */ 91 __cxa_thread_call_dtors(); 92 __cxa_finalize(NULL); 93 if (__cleanup) 94 (*__cleanup)(); 95 _exit(status); 96 } 97