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: src/lib/libpthread/thread/thr_exit.c,v 1.39 2004/10/23 23:37:54 davidxu Exp $
33  * $DragonFly: src/lib/libthread_xu/thread/thr_exit.c,v 1.1 2005/02/01 12:38:27 davidxu Exp $
34  */
35 #include <errno.h>
36 #include <unistd.h>
37 #include <fcntl.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <pthread.h>
42 #include "thr_private.h"
43 
44 void	_pthread_exit(void *status);
45 
46 __weak_reference(_pthread_exit, pthread_exit);
47 
48 void
49 _thread_exit(char *fname, int lineno, char *msg)
50 {
51 
52 	/* Write an error message to the standard error file descriptor: */
53 	_thread_printf(2,
54 	    "Fatal error '%s' at line %d in file %s (errno = %d)\n",
55 	    msg, lineno, fname, errno);
56 
57 	abort();
58 }
59 
60 /*
61  * Only called when a thread is cancelled.  It may be more useful
62  * to call it from pthread_exit() if other ways of asynchronous or
63  * abnormal thread termination can be found.
64  */
65 void
66 _thr_exit_cleanup(void)
67 {
68 	struct pthread	*curthread = _get_curthread();
69 
70 	/*
71 	 * POSIX states that cancellation/termination of a thread should
72 	 * not release any visible resources (such as mutexes) and that
73 	 * it is the applications responsibility.  Resources that are
74 	 * internal to the threads library, including file and fd locks,
75 	 * are not visible to the application and need to be released.
76 	 */
77 	/* Unlock all private mutexes: */
78 	_mutex_unlock_private(curthread);
79 
80 	/*
81 	 * This still isn't quite correct because we don't account
82 	 * for held spinlocks (see libc/stdlib/malloc.c).
83 	 */
84 }
85 
86 void
87 _pthread_exit(void *status)
88 {
89 	struct pthread *curthread = _get_curthread();
90 
91 	/* Check if this thread is already in the process of exiting: */
92 	if ((curthread->cancelflags & THR_CANCEL_EXITING) != 0) {
93 		char msg[128];
94 		snprintf(msg, sizeof(msg), "Thread %p has called "
95 		    "pthread_exit() from a destructor. POSIX 1003.1 "
96 		    "1996 s16.2.5.2 does not allow this!", curthread);
97 		PANIC(msg);
98 	}
99 
100 	/* Flag this thread as exiting. */
101 	atomic_set_int(&curthread->cancelflags, THR_CANCEL_EXITING);
102 
103 	_thr_exit_cleanup();
104 
105 	/* Save the return value: */
106 	curthread->ret = status;
107 	while (curthread->cleanup != NULL) {
108 		pthread_cleanup_pop(1);
109 	}
110 	if (curthread->attr.cleanup_attr != NULL) {
111 		curthread->attr.cleanup_attr(curthread->attr.arg_attr);
112 	}
113 	/* Check if there is thread specific data: */
114 	if (curthread->specific != NULL) {
115 		/* Run the thread-specific data destructors: */
116 		_thread_cleanupspecific();
117 	}
118 
119 	if (!_thr_isthreaded())
120 		exit(0);
121 
122 	THREAD_LIST_LOCK(curthread);
123 	_thread_active_threads--;
124 	if (_thread_active_threads == 0) {
125 		THREAD_LIST_UNLOCK(curthread);
126 		exit(0);
127 		/* Never reach! */
128 	}
129 	if (curthread->tlflags & TLFLAGS_DETACHED)
130 		THR_GCLIST_ADD(curthread);
131 	curthread->state = PS_DEAD;
132 	THREAD_LIST_UNLOCK(curthread);
133 	if (curthread->joiner)
134 		_thr_umtx_wake(&curthread->state, INT_MAX);
135 	/* XXX
136 	 * All the code is incorrect on DragonFly.
137 	 * DragonFly has race condition here. it should provide
138 	 * an interface to tell userland that a thread is now
139 	 * in kernel, and userland stack can be safely recycled
140 	 * by userland GC code.
141 	 */
142 	curthread->terminated = 1;
143 	_exit(0);
144 	PANIC("thr_exit() returned");
145 	/* Never reach! */
146 }
147