1 /* 2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by John Birrell. 16 * 4. Neither the name of the author nor the names of any co-contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $FreeBSD$ 33 */ 34 #include <errno.h> 35 #include <unistd.h> 36 #include <fcntl.h> 37 #include <stdio.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <pthread.h> 41 #include "thr_private.h" 42 43 __weak_reference(_pthread_exit, pthread_exit); 44 45 void 46 _thread_exit(char *fname, int lineno, char *string) 47 { 48 char s[256]; 49 50 /* Prepare an error message string: */ 51 snprintf(s, sizeof(s), 52 "Fatal error '%s' at line %d in file %s (errno = %d)\n", 53 string, lineno, fname, errno); 54 55 /* Write the string to the standard error file descriptor: */ 56 __sys_write(2, s, strlen(s)); 57 58 /* Force this process to exit: */ 59 /* XXX - Do we want abort to be conditional on _PTHREADS_INVARIANTS? */ 60 #if defined(_PTHREADS_INVARIANTS) 61 abort(); 62 #else 63 __sys_exit(1); 64 #endif 65 } 66 67 /* 68 * Only called when a thread is cancelled. It may be more useful 69 * to call it from pthread_exit() if other ways of asynchronous or 70 * abnormal thread termination can be found. 71 */ 72 void 73 _thread_exit_cleanup(void) 74 { 75 struct pthread *curthread = _get_curthread(); 76 77 /* 78 * POSIX states that cancellation/termination of a thread should 79 * not release any visible resources (such as mutexes) and that 80 * it is the applications responsibility. Resources that are 81 * internal to the threads library, including file and fd locks, 82 * are not visible to the application and need to be released. 83 */ 84 /* Unlock all private mutexes: */ 85 _mutex_unlock_private(curthread); 86 87 /* 88 * This still isn't quite correct because we don't account 89 * for held spinlocks (see libc/stdlib/malloc.c). 90 */ 91 } 92 93 void 94 _pthread_exit(void *status) 95 { 96 struct pthread *curthread = _get_curthread(); 97 pthread_t pthread; 98 99 /* Check if this thread is already in the process of exiting: */ 100 if ((curthread->flags & PTHREAD_EXITING) != 0) { 101 char msg[128]; 102 snprintf(msg, sizeof(msg), "Thread %p has called pthread_exit() from a destructor. POSIX 1003.1 1996 s16.2.5.2 does not allow this!",curthread); 103 PANIC(msg); 104 } 105 106 /* Flag this thread as exiting: */ 107 curthread->flags |= PTHREAD_EXITING; 108 109 /* Save the return value: */ 110 curthread->ret = status; 111 112 while (curthread->cleanup != NULL) { 113 pthread_cleanup_pop(1); 114 } 115 if (curthread->attr.cleanup_attr != NULL) { 116 curthread->attr.cleanup_attr(curthread->attr.arg_attr); 117 } 118 /* Check if there is thread specific data: */ 119 if (curthread->specific != NULL) { 120 /* Run the thread-specific data destructors: */ 121 _thread_cleanupspecific(); 122 } 123 124 /* 125 * Lock the garbage collector mutex to ensure that the garbage 126 * collector is not using the dead thread list. 127 */ 128 if (pthread_mutex_lock(&_gc_mutex) != 0) 129 PANIC("Cannot lock gc mutex"); 130 131 /* Add this thread to the list of dead threads. */ 132 TAILQ_INSERT_HEAD(&_dead_list, curthread, dle); 133 134 /* 135 * Signal the garbage collector thread that there is something 136 * to clean up. 137 */ 138 if (pthread_cond_signal(&_gc_cond) != 0) 139 PANIC("Cannot signal gc cond"); 140 141 /* 142 * Avoid a race condition where a scheduling signal can occur 143 * causing the garbage collector thread to run. If this happens, 144 * the current thread can be cleaned out from under us. 145 */ 146 GIANT_LOCK(curthread); 147 148 /* Unlock the garbage collector mutex. */ 149 if (pthread_mutex_unlock(&_gc_mutex) != 0) 150 PANIC("Cannot unlock gc mutex"); 151 152 /* Check if there is a thread joining this one: */ 153 if (curthread->joiner != NULL) { 154 pthread = curthread->joiner; 155 curthread->joiner = NULL; 156 157 /* Make the joining thread runnable: */ 158 PTHREAD_NEW_STATE(pthread, PS_RUNNING); 159 160 /* Set the return value for the joining thread: */ 161 pthread->join_status.ret = curthread->ret; 162 pthread->join_status.error = 0; 163 pthread->join_status.thread = NULL; 164 165 /* Make this thread collectable by the garbage collector. */ 166 PTHREAD_ASSERT(((curthread->attr.flags & PTHREAD_DETACHED) == 167 0), "Cannot join a detached thread"); 168 curthread->attr.flags |= PTHREAD_DETACHED; 169 } 170 171 /* Remove this thread from the thread list: */ 172 TAILQ_REMOVE(&_thread_list, curthread, tle); 173 174 PTHREAD_SET_STATE(curthread, PS_DEAD); 175 GIANT_UNLOCK(curthread); 176 177 /* 178 * Retire the architecture specific id so that it can be used for 179 * new threads. 180 */ 181 _retire_thread(curthread->arch_id); 182 _thr_exit(); 183 184 /* This point should not be reached. */ 185 PANIC("Dead thread has resumed"); 186 } 187