xref: /freebsd/lib/libthr/thread/thr_cancel.c (revision 8a802df1de2d77fd0a62996bd785ca3f1326887f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2005, David Xu <davidxu@freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include "namespace.h"
30 #include <pthread.h>
31 #include "un-namespace.h"
32 
33 #include "thr_private.h"
34 
35 __weak_reference(_thr_cancel, pthread_cancel);
36 __weak_reference(_thr_cancel, _pthread_cancel);
37 __weak_reference(_thr_setcancelstate, pthread_setcancelstate);
38 __weak_reference(_thr_setcancelstate, _pthread_setcancelstate);
39 __weak_reference(_thr_setcanceltype, pthread_setcanceltype);
40 __weak_reference(_thr_setcanceltype, _pthread_setcanceltype);
41 __weak_reference(_Tthr_testcancel, pthread_testcancel);
42 __weak_reference(_Tthr_testcancel, _pthread_testcancel);
43 __weak_reference(_Tthr_cancel_enter, _pthread_cancel_enter);
44 __weak_reference(_Tthr_cancel_leave, _pthread_cancel_leave);
45 
46 static inline void
47 testcancel(struct pthread *curthread)
48 {
49 	if (__predict_false(SHOULD_CANCEL(curthread) &&
50 	    !THR_IN_CRITICAL(curthread)))
51 		_pthread_exit(PTHREAD_CANCELED);
52 }
53 
54 void
55 _thr_testcancel(struct pthread *curthread)
56 {
57 	testcancel(curthread);
58 }
59 
60 int
61 _thr_cancel(pthread_t pthread)
62 {
63 	struct pthread *curthread = _get_curthread();
64 	int ret;
65 
66 	/*
67 	 * POSIX says _pthread_cancel should be async cancellation safe.
68 	 * _thr_find_thread and THR_THREAD_UNLOCK will enter and leave critical
69 	 * region automatically.
70 	 */
71 	if ((ret = _thr_find_thread(curthread, pthread, 1)) == 0) {
72 		if (!pthread->cancel_pending) {
73 			pthread->cancel_pending = 1;
74 			if (pthread->state != PS_DEAD)
75 				_thr_send_sig(pthread, SIGCANCEL);
76 		}
77 		THR_THREAD_UNLOCK(curthread, pthread);
78 	}
79 	return (ret);
80 }
81 
82 int
83 _thr_setcancelstate(int state, int *oldstate)
84 {
85 	struct pthread *curthread = _get_curthread();
86 	int oldval;
87 
88 	oldval = curthread->cancel_enable;
89 	switch (state) {
90 	case PTHREAD_CANCEL_DISABLE:
91 		curthread->cancel_enable = 0;
92 		break;
93 	case PTHREAD_CANCEL_ENABLE:
94 		curthread->cancel_enable = 1;
95 		if (curthread->cancel_async)
96 			testcancel(curthread);
97 		break;
98 	default:
99 		return (EINVAL);
100 	}
101 
102 	if (oldstate) {
103 		*oldstate = oldval ? PTHREAD_CANCEL_ENABLE :
104 			PTHREAD_CANCEL_DISABLE;
105 	}
106 	return (0);
107 }
108 
109 int
110 _thr_setcanceltype(int type, int *oldtype)
111 {
112 	struct pthread	*curthread = _get_curthread();
113 	int oldval;
114 
115 	oldval = curthread->cancel_async;
116 	switch (type) {
117 	case PTHREAD_CANCEL_ASYNCHRONOUS:
118 		curthread->cancel_async = 1;
119 		testcancel(curthread);
120 		break;
121 	case PTHREAD_CANCEL_DEFERRED:
122 		curthread->cancel_async = 0;
123 		break;
124 	default:
125 		return (EINVAL);
126 	}
127 
128 	if (oldtype) {
129 		*oldtype = oldval ? PTHREAD_CANCEL_ASYNCHRONOUS :
130 		 	PTHREAD_CANCEL_DEFERRED;
131 	}
132 	return (0);
133 }
134 
135 void
136 _Tthr_testcancel(void)
137 {
138 	struct pthread *curthread;
139 
140 	_thr_check_init();
141 	curthread = _get_curthread();
142 	testcancel(curthread);
143 }
144 
145 void
146 _thr_cancel_enter(struct pthread *curthread)
147 {
148 	curthread->cancel_point = 1;
149 	testcancel(curthread);
150 }
151 
152 void
153 _thr_cancel_enter2(struct pthread *curthread, int maycancel)
154 {
155 	curthread->cancel_point = 1;
156 	if (__predict_false(SHOULD_CANCEL(curthread) &&
157 	    !THR_IN_CRITICAL(curthread))) {
158 		if (!maycancel)
159 			thr_wake(curthread->tid);
160 		else
161 			_pthread_exit(PTHREAD_CANCELED);
162 	}
163 }
164 
165 void
166 _thr_cancel_leave(struct pthread *curthread, int maycancel)
167 {
168 	curthread->cancel_point = 0;
169 	if (__predict_false(SHOULD_CANCEL(curthread) &&
170 	    !THR_IN_CRITICAL(curthread) && maycancel))
171 		_pthread_exit(PTHREAD_CANCELED);
172 }
173 
174 void
175 _Tthr_cancel_enter(int maycancel)
176 {
177 	_thr_cancel_enter2(_get_curthread(), maycancel);
178 }
179 
180 void
181 _Tthr_cancel_leave(int maycancel)
182 {
183 	_thr_cancel_leave(_get_curthread(), maycancel);
184 }
185