thr_exit.c revision 177337 
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: head/lib/libthr/thread/thr_exit.c 177337 2008-03-18 02:06:51Z davidxu $
30 */
31
32#include <errno.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <pthread.h>
36
37#include "thr_private.h"
38
39void	_pthread_exit(void *status);
40
41__weak_reference(_pthread_exit, pthread_exit);
42
43void
44_thread_exit(const char *fname, int lineno, const char *msg)
45{
46
47	/* Write an error message to the standard error file descriptor: */
48	_thread_printf(2,
49	    "Fatal error '%s' at line %d in file %s (errno = %d)\n",
50	    msg, lineno, fname, errno);
51
52	abort();
53}
54
55/*
56 * Only called when a thread is cancelled.  It may be more useful
57 * to call it from pthread_exit() if other ways of asynchronous or
58 * abnormal thread termination can be found.
59 */
60void
61_thr_exit_cleanup(void)
62{
63	struct pthread	*curthread = _get_curthread();
64
65	/*
66	 * POSIX states that cancellation/termination of a thread should
67	 * not release any visible resources (such as mutexes) and that
68	 * it is the applications responsibility.  Resources that are
69	 * internal to the threads library, including file and fd locks,
70	 * are not visible to the application and need to be released.
71	 */
72	/* Unlock all private mutexes: */
73	_mutex_unlock_private(curthread);
74
75	/*
76	 * This still isn't quite correct because we don't account
77	 * for held spinlocks (see libc/stdlib/malloc.c).
78	 */
79}
80
81void
82_pthread_exit(void *status)
83{
84	struct pthread *curthread = _get_curthread();
85
86	/* Check if this thread is already in the process of exiting: */
87	if (curthread->cancelling) {
88		char msg[128];
89		snprintf(msg, sizeof(msg), "Thread %p has called "
90		    "pthread_exit() from a destructor. POSIX 1003.1 "
91		    "1996 s16.2.5.2 does not allow this!", curthread);
92		PANIC(msg);
93	}
94
95	/* Flag this thread as exiting. */
96	curthread->cancelling = 1;
97
98	_thr_exit_cleanup();
99
100	/* Save the return value: */
101	curthread->ret = status;
102	while (curthread->cleanup != NULL) {
103		_pthread_cleanup_pop(1);
104	}
105
106	/* Check if there is thread specific data: */
107	if (curthread->specific != NULL) {
108		/* Run the thread-specific data destructors: */
109		_thread_cleanupspecific();
110	}
111
112	if (!_thr_isthreaded())
113		exit(0);
114
115	THREAD_LIST_LOCK(curthread);
116	_thread_active_threads--;
117	if (_thread_active_threads == 0) {
118		THREAD_LIST_UNLOCK(curthread);
119		exit(0);
120		/* Never reach! */
121	}
122	THR_LOCK(curthread);
123	curthread->state = PS_DEAD;
124	if (curthread->flags & THR_FLAGS_NEED_SUSPEND) {
125		curthread->cycle++;
126		_thr_umtx_wake(&curthread->cycle, INT_MAX);
127	}
128	THR_UNLOCK(curthread);
129	/*
130	 * Thread was created with initial refcount 1, we drop the
131	 * reference count to allow it to be garbage collected.
132	 */
133	curthread->refcount--;
134	if (curthread->tlflags & TLFLAGS_DETACHED)
135		THR_GCLIST_ADD(curthread);
136	THREAD_LIST_UNLOCK(curthread);
137	if (!curthread->force_exit && SHOULD_REPORT_EVENT(curthread, TD_DEATH))
138		_thr_report_death(curthread);
139
140	/*
141	 * Kernel will do wakeup at the address, so joiner thread
142	 * will be resumed if it is sleeping at the address.
143	 */
144	thr_exit(&curthread->tid);
145	PANIC("thr_exit() returned");
146	/* Never reach! */
147}
148