thr_exit.c revision 136262 
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: head/lib/libthr/thread/thr_exit.c 136262 2004-10-08 14:48:02Z mtm $
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
45static void	deadlist_free_threads();
46
47void
48_thread_exit(char *fname, int lineno, char *string)
49{
50	char            s[256];
51
52	/* Prepare an error message string: */
53	snprintf(s, sizeof(s),
54	    "Fatal error '%s' at line %d in file %s (errno = %d)\n",
55	    string, lineno, fname, errno);
56
57	/* Write the string to the standard error file descriptor: */
58	__sys_write(2, s, strlen(s));
59
60	/* Force this process to exit: */
61	/* XXX - Do we want abort to be conditional on _PTHREADS_INVARIANTS? */
62#if defined(_PTHREADS_INVARIANTS)
63	abort();
64#else
65	__sys_exit(1);
66#endif
67}
68
69/*
70 * Only called when a thread is cancelled.  It may be more useful
71 * to call it from pthread_exit() if other ways of asynchronous or
72 * abnormal thread termination can be found.
73 */
74void
75_thread_exit_cleanup(void)
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
93void
94_pthread_exit(void *status)
95{
96	struct pthread *pthread;
97	int exitNow = 0;
98
99	/*
100	 * This thread will no longer handle any signals.
101	 */
102	_thread_sigblock();
103
104	/* Check if this thread is already in the process of exiting: */
105	if (curthread->exiting) {
106		char msg[128];
107		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);
108		PANIC(msg);
109	}
110
111	/* Flag this thread as exiting: */
112	curthread->exiting = 1;
113
114	/* Save the return value: */
115	curthread->ret = status;
116
117	while (curthread->cleanup != NULL) {
118		pthread_cleanup_pop(1);
119	}
120	if (curthread->attr.cleanup_attr != NULL) {
121		curthread->attr.cleanup_attr(curthread->attr.arg_attr);
122	}
123	/* Check if there is thread specific data: */
124	if (curthread->specific != NULL) {
125		/* Run the thread-specific data destructors: */
126		_thread_cleanupspecific();
127	}
128
129	/*
130	 * Remove read-write lock list. It is allocated as-needed.
131	 * Therefore, it must be checked for validity before freeing.
132	 */
133	if (curthread->rwlockList != NULL)
134		free(curthread->rwlockList);
135
136	/* Lock the dead list first to maintain correct lock order */
137	DEAD_LIST_LOCK;
138	THREAD_LIST_LOCK;
139
140	/* Check if there is a thread joining this one: */
141	if (curthread->joiner != NULL) {
142		pthread = curthread->joiner;
143		curthread->joiner = NULL;
144
145		/* Set the return value for the joining thread: */
146		pthread->join_status.ret = curthread->ret;
147		pthread->join_status.error = 0;
148		pthread->join_status.thread = NULL;
149
150		/* Make the joining thread runnable: */
151		PTHREAD_WAKE(pthread);
152
153		curthread->attr.flags |= PTHREAD_DETACHED;
154	}
155
156	/*
157	 * Free any memory allocated for dead threads.
158	 * Add this thread to the list of dead threads, and
159	 * also remove it from the active threads list.
160	 */
161	deadlist_free_threads();
162	TAILQ_INSERT_HEAD(&_dead_list, curthread, dle);
163	TAILQ_REMOVE(&_thread_list, curthread, tle);
164
165	/* If we're the last thread, call it quits */
166	if (TAILQ_EMPTY(&_thread_list))
167		exitNow = 1;
168
169	THREAD_LIST_UNLOCK;
170	DEAD_LIST_UNLOCK;
171
172	if (exitNow)
173		exit(0);
174
175	/*
176	 * This function will not return unless we are the last
177	 * thread, which we can't be because we've already checked
178	 * for that.
179	 */
180	thr_exit((long *)&curthread->isdead);
181
182	/* This point should not be reached. */
183	PANIC("Dead thread has resumed");
184}
185
186/*
187 * Note: this function must be called with the dead thread list
188 *	 locked.
189 */
190static void
191deadlist_free_threads()
192{
193	struct pthread *ptd, *ptdTemp;
194
195	TAILQ_FOREACH_SAFE(ptd, &_dead_list, dle, ptdTemp) {
196		/* Don't destroy the initial thread or non-detached threads. */
197		if (ptd == _thread_initial ||
198		    (ptd->attr.flags & PTHREAD_DETACHED) == 0)
199			continue;
200		TAILQ_REMOVE(&_dead_list, ptd, dle);
201		deadlist_free_onethread(ptd);
202	}
203}
204
205void
206deadlist_free_onethread(struct pthread *ptd)
207{
208
209	if (ptd->attr.stackaddr_attr == NULL && ptd->stack != NULL) {
210		STACK_LOCK;
211		_thread_stack_free(ptd->stack, ptd->attr.stacksize_attr,
212		    ptd->attr.guardsize_attr);
213		STACK_UNLOCK;
214	}
215	_retire_thread(ptd->arch_id);
216	free(ptd);
217}
218