xref: /freebsd/lib/libthr/thread/thr_exit.c (revision db612abe8df3355d1eb23bb3b50fdd97bc21e979)
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  * $FreeBSD$
30  */
31 
32 #include "namespace.h"
33 #include <errno.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <pthread.h>
37 #include "un-namespace.h"
38 
39 #include "thr_private.h"
40 
41 void	_pthread_exit(void *status);
42 
43 __weak_reference(_pthread_exit, pthread_exit);
44 
45 void
46 _thread_exit(const char *fname, int lineno, const char *msg)
47 {
48 
49 	/* Write an error message to the standard error file descriptor: */
50 	_thread_printf(2,
51 	    "Fatal error '%s' at line %d in file %s (errno = %d)\n",
52 	    msg, lineno, fname, errno);
53 
54 	abort();
55 }
56 
57 /*
58  * Only called when a thread is cancelled.  It may be more useful
59  * to call it from pthread_exit() if other ways of asynchronous or
60  * abnormal thread termination can be found.
61  */
62 void
63 _thr_exit_cleanup(void)
64 {
65 	struct pthread	*curthread = _get_curthread();
66 
67 	/*
68 	 * POSIX states that cancellation/termination of a thread should
69 	 * not release any visible resources (such as mutexes) and that
70 	 * it is the applications responsibility.  Resources that are
71 	 * internal to the threads library, including file and fd locks,
72 	 * are not visible to the application and need to be released.
73 	 */
74 	/* Unlock all private mutexes: */
75 	_mutex_unlock_private(curthread);
76 
77 	/*
78 	 * This still isn't quite correct because we don't account
79 	 * for held spinlocks (see libc/stdlib/malloc.c).
80 	 */
81 }
82 
83 void
84 _pthread_exit(void *status)
85 {
86 	struct pthread *curthread = _get_curthread();
87 
88 	/* Check if this thread is already in the process of exiting: */
89 	if (curthread->cancelling) {
90 		char msg[128];
91 		snprintf(msg, sizeof(msg), "Thread %p has called "
92 		    "pthread_exit() from a destructor. POSIX 1003.1 "
93 		    "1996 s16.2.5.2 does not allow this!", curthread);
94 		PANIC(msg);
95 	}
96 
97 	/* Flag this thread as exiting. */
98 	curthread->cancelling = 1;
99 
100 	_thr_exit_cleanup();
101 
102 	/* Save the return value: */
103 	curthread->ret = status;
104 	while (curthread->cleanup != NULL) {
105 		_pthread_cleanup_pop(1);
106 	}
107 
108 	/* Check if there is thread specific data: */
109 	if (curthread->specific != NULL) {
110 		/* Run the thread-specific data destructors: */
111 		_thread_cleanupspecific();
112 	}
113 
114 	if (!_thr_isthreaded())
115 		exit(0);
116 
117 	THREAD_LIST_LOCK(curthread);
118 	_thread_active_threads--;
119 	if (_thread_active_threads == 0) {
120 		THREAD_LIST_UNLOCK(curthread);
121 		exit(0);
122 		/* Never reach! */
123 	}
124 	THR_LOCK(curthread);
125 	curthread->state = PS_DEAD;
126 	if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
127 		curthread->cycle++;
128 		_thr_umtx_wake(&curthread->cycle, INT_MAX);
129 	}
130 	THR_UNLOCK(curthread);
131 	/*
132 	 * Thread was created with initial refcount 1, we drop the
133 	 * reference count to allow it to be garbage collected.
134 	 */
135 	curthread->refcount--;
136 	if (curthread->tlflags & TLFLAGS_DETACHED)
137 		THR_GCLIST_ADD(curthread);
138 	THREAD_LIST_UNLOCK(curthread);
139 	if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
140 		_thr_report_death(curthread);
141 
142 	/*
143 	 * Kernel will do wakeup at the address, so joiner thread
144 	 * will be resumed if it is sleeping at the address.
145 	 */
146 	thr_exit(&curthread->tid);
147 	PANIC("thr_exit() returned");
148 	/* Never reach! */
149 }
150