xref: /freebsd/lib/libthr/thread/thr_exit.c (revision 8847579c57d6aff2b3371c707dce7a2cee8389aa)
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 
35 #include <errno.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <pthread.h>
39 
40 #include "thr_private.h"
41 
42 void	_pthread_exit(void *status);
43 
44 __weak_reference(_pthread_exit, pthread_exit);
45 
46 void
47 _thread_exit(const char *fname, int lineno, const char *msg)
48 {
49 
50 	/* Write an error message to the standard error file descriptor: */
51 	_thread_printf(2,
52 	    "Fatal error '%s' at line %d in file %s (errno = %d)\n",
53 	    msg, lineno, fname, errno);
54 
55 	abort();
56 }
57 
58 /*
59  * Only called when a thread is cancelled.  It may be more useful
60  * to call it from pthread_exit() if other ways of asynchronous or
61  * abnormal thread termination can be found.
62  */
63 void
64 _thr_exit_cleanup(void)
65 {
66 	struct pthread	*curthread = _get_curthread();
67 
68 	/*
69 	 * POSIX states that cancellation/termination of a thread should
70 	 * not release any visible resources (such as mutexes) and that
71 	 * it is the applications responsibility.  Resources that are
72 	 * internal to the threads library, including file and fd locks,
73 	 * are not visible to the application and need to be released.
74 	 */
75 	/* Unlock all private mutexes: */
76 	_mutex_unlock_private(curthread);
77 
78 	/*
79 	 * This still isn't quite correct because we don't account
80 	 * for held spinlocks (see libc/stdlib/malloc.c).
81 	 */
82 }
83 
84 void
85 _pthread_exit(void *status)
86 {
87 	struct pthread *curthread = _get_curthread();
88 
89 	/* Check if this thread is already in the process of exiting: */
90 	if ((curthread->cancelflags & THR_CANCEL_EXITING) != 0) {
91 		char msg[128];
92 		snprintf(msg, sizeof(msg), "Thread %p has called "
93 		    "pthread_exit() from a destructor. POSIX 1003.1 "
94 		    "1996 s16.2.5.2 does not allow this!", curthread);
95 		PANIC(msg);
96 	}
97 
98 	/* Flag this thread as exiting. */
99 	atomic_set_int(&curthread->cancelflags, THR_CANCEL_EXITING);
100 
101 	_thr_exit_cleanup();
102 
103 	/* Save the return value: */
104 	curthread->ret = status;
105 	while (curthread->cleanup != NULL) {
106 		pthread_cleanup_pop(1);
107 	}
108 
109 	/* Check if there is thread specific data: */
110 	if (curthread->specific != NULL) {
111 		/* Run the thread-specific data destructors: */
112 		_thread_cleanupspecific();
113 	}
114 
115 	if (!_thr_isthreaded())
116 		exit(0);
117 
118 	THREAD_LIST_LOCK(curthread);
119 	_thread_active_threads--;
120 	if (_thread_active_threads == 0) {
121 		THREAD_LIST_UNLOCK(curthread);
122 		exit(0);
123 		/* Never reach! */
124 	}
125 	THR_LOCK(curthread);
126 	curthread->state = PS_DEAD;
127 	THR_UNLOCK(curthread);
128 	/*
129 	 * Thread was created with initial refcount 1, we drop the
130 	 * reference count to allow it to be garbage collected.
131 	 */
132 	curthread->refcount--;
133 	if (curthread->tlflags & TLFLAGS_DETACHED)
134 		THR_GCLIST_ADD(curthread);
135 	THREAD_LIST_UNLOCK(curthread);
136 	if (SHOULD_REPORT_EVENT(curthread, TD_DEATH))
137 		_thr_report_death(curthread);
138 
139 	/*
140 	 * Kernel will do wakeup at the address, so joiner thread
141 	 * will be resumed if it is sleeping at the address.
142 	 */
143 	thr_exit(&curthread->tid);
144 	PANIC("thr_exit() returned");
145 	/* Never reach! */
146 }
147