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 #include "namespace.h" 33 #include <stdlib.h> 34 #include <pthread.h> 35 #include <unistd.h> 36 #include "un-namespace.h" 37 38 #include "atexit.h" 39 #include "libc_private.h" 40 41 void (*__cleanup)(void); 42 43 /* 44 * This variable is zero until a process has created a thread. 45 * It is used to avoid calling locking functions in libc when they 46 * are not required. By default, libc is intended to be(come) 47 * thread-safe, but without a (significant) penalty to non-threaded 48 * processes. 49 */ 50 int __isthreaded = 0; 51 52 static pthread_mutex_t exit_mutex; 53 static pthread_once_t exit_mutex_once = PTHREAD_ONCE_INIT; 54 55 static void 56 exit_mutex_init_once(void) 57 { 58 pthread_mutexattr_t ma; 59 60 _pthread_mutexattr_init(&ma); 61 _pthread_mutexattr_settype(&ma, PTHREAD_MUTEX_RECURSIVE); 62 _pthread_mutex_init(&exit_mutex, &ma); 63 _pthread_mutexattr_destroy(&ma); 64 } 65 66 /* 67 * Exit, flushing stdio buffers if necessary. 68 */ 69 void 70 exit(int status) 71 { 72 /* Ensure that the auto-initialization routine is linked in: */ 73 extern int _thread_autoinit_dummy_decl; 74 75 _thread_autoinit_dummy_decl = 1; 76 77 /* Make exit(3) thread-safe */ 78 if (__isthreaded) { 79 _once(&exit_mutex_once, exit_mutex_init_once); 80 _pthread_mutex_lock(&exit_mutex); 81 } 82 83 /* 84 * We're dealing with cleaning up thread_local destructors in the case of 85 * the process termination through main() exit. 86 * Other cases are handled elsewhere. 87 */ 88 __cxa_thread_call_dtors(); 89 __cxa_finalize(NULL); 90 if (__cleanup) 91 (*__cleanup)(); 92 _exit(status); 93 } 94