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. Neither the name of the author nor the names of any co-contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD: src/lib/libpthread/thread/thr_exit.c,v 1.39 2004/10/23 23:37:54 davidxu Exp $
30  */
31 
32 #include "namespace.h"
33 #include <machine/tls.h>
34 #include <errno.h>
35 #include <unistd.h>
36 #include <fcntl.h>
37 #include <stdarg.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <pthread.h>
42 #include "un-namespace.h"
43 
44 #include "libc_private.h"
45 #include "thr_private.h"
46 
47 static void	exit_thread(void) __dead2;
48 
49 void
50 _thread_exitf(const char *fname, int lineno, const char *fmt, ...)
51 {
52 	va_list ap;
53 
54 	/* Write an error message to the standard error file descriptor: */
55 	_thread_printf(STDERR_FILENO, "Fatal error '");
56 
57 	va_start(ap, fmt);
58 	_thread_vprintf(STDERR_FILENO, fmt, ap);
59 	va_end(ap);
60 
61 	_thread_printf(STDERR_FILENO, "' at line %d in file %s (errno = %d)\n",
62 	    lineno, fname, errno);
63 
64 	abort();
65 }
66 
67 void
68 _thread_exit(const char *fname, int lineno, const char *msg)
69 {
70 	_thread_exitf(fname, lineno, "%s", msg);
71 }
72 
73 /*
74  * Only called when a thread is cancelled.  It may be more useful
75  * to call it from pthread_exit() if other ways of asynchronous or
76  * abnormal thread termination can be found.
77  */
78 void
79 _thr_exit_cleanup(void)
80 {
81 	struct pthread	*curthread = tls_get_curthread();
82 
83 	/*
84 	 * POSIX states that cancellation/termination of a thread should
85 	 * not release any visible resources (such as mutexes) and that
86 	 * it is the applications responsibility.  Resources that are
87 	 * internal to the threads library, including file and fd locks,
88 	 * are not visible to the application and need to be released.
89 	 */
90 	/* Unlock all private mutexes: */
91 	_mutex_unlock_private(curthread);
92 
93 	/*
94 	 * This still isn't quite correct because we don't account
95 	 * for held spinlocks (see libc/stdlib/malloc.c).
96 	 */
97 }
98 
99 void
100 _pthread_exit(void *status)
101 {
102 	struct pthread *curthread = tls_get_curthread();
103 
104 	/* Check if this thread is already in the process of exiting: */
105 	if ((curthread->cancelflags & THR_CANCEL_EXITING) != 0) {
106 		PANIC("Thread %p has called "
107 		    "pthread_exit() from a destructor. POSIX 1003.1 "
108 		    "1996 s16.2.5.2 does not allow this!", curthread);
109 	}
110 
111 	/* Flag this thread as exiting. */
112 	atomic_set_int(&curthread->cancelflags, THR_CANCEL_EXITING);
113 
114 	_thr_exit_cleanup();
115 
116 	/* Save the return value: */
117 	curthread->ret = status;
118 	while (curthread->cleanup != NULL) {
119 		_pthread_cleanup_pop(1);
120 	}
121 	/* Call TLS destructors, if any. */
122 	_thread_finalize();
123 
124 	exit_thread();
125 }
126 
127 __strong_reference(_pthread_exit, pthread_exit);
128 
129 static void
130 exit_thread(void)
131 {
132 	struct pthread *curthread = tls_get_curthread();
133 
134 	/* Check if there is thread specific data: */
135 	if (curthread->specific != NULL) {
136 		/* Run the thread-specific data destructors: */
137 		_thread_cleanupspecific();
138 	}
139 
140 	if (!_thr_isthreaded())
141 		exit(0);
142 
143 	THREAD_LIST_LOCK(curthread);
144 	_thread_active_threads--;
145 	if (_thread_active_threads == 0) {
146 		THREAD_LIST_UNLOCK(curthread);
147 		exit(0);
148 		/* Never reach! */
149 	}
150 	THR_LOCK(curthread);
151 	curthread->state = PS_DEAD;
152 	THR_UNLOCK(curthread);
153 	curthread->refcount--;
154 	if (curthread->tlflags & TLFLAGS_DETACHED)
155 		THR_GCLIST_ADD(curthread);
156 	THREAD_LIST_UNLOCK(curthread);
157 	if (curthread->joiner)
158 		_thr_umtx_wake(&curthread->state, 0);
159 	if (SHOULD_REPORT_EVENT(curthread, TD_DEATH))
160 		_thr_report_death(curthread);
161 	/* Exit and set terminated to once we're really dead. */
162 	extexit(EXTEXIT_SETINT|EXTEXIT_LWP, 1, &curthread->terminated);
163 	PANIC("thr_exit() returned");
164 	/* Never reach! */
165 }
166