1 /*
2  * Copyright (c) 1995 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 
33 #include "namespace.h"
34 #include <machine/tls.h>
35 
36 #include <errno.h>
37 #include <pthread.h>
38 #include "un-namespace.h"
39 
40 #include "thr_private.h"
41 
42 int _pthread_timedjoin_np(pthread_t pthread, void **thread_return,
43 	const struct timespec *abstime);
44 
45 static int join_common(pthread_t, void **, const struct timespec *);
46 
47 static void backout_join(void *arg)
48 {
49 	struct pthread *curthread = tls_get_curthread();
50 	struct pthread *pthread = (struct pthread *)arg;
51 
52 	THREAD_LIST_LOCK(curthread);
53 	pthread->joiner = NULL;
54 	THREAD_LIST_UNLOCK(curthread);
55 }
56 
57 int
58 _pthread_join(pthread_t pthread, void **thread_return)
59 {
60 	return (join_common(pthread, thread_return, NULL));
61 }
62 
63 int
64 _pthread_timedjoin_np(pthread_t pthread, void **thread_return,
65 	const struct timespec *abstime)
66 {
67 	if (abstime == NULL || abstime->tv_sec < 0 || abstime->tv_nsec < 0 ||
68 	    abstime->tv_nsec >= 1000000000)
69 		return (EINVAL);
70 
71 	return (join_common(pthread, thread_return, abstime));
72 }
73 
74 static int
75 join_common(pthread_t pthread, void **thread_return,
76 	const struct timespec *abstime)
77 {
78 	struct pthread *curthread = tls_get_curthread();
79 	struct timespec ts, ts2, *tsp;
80 	void *tmp;
81 	long state;
82 	int oldcancel;
83 	int ret = 0;
84 
85 	if (pthread == NULL)
86 		return (EINVAL);
87 
88 	if (pthread == curthread)
89 		return (EDEADLK);
90 
91 	THREAD_LIST_LOCK(curthread);
92 	if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0) {
93 		ret = ESRCH;
94 	} else if ((pthread->tlflags & TLFLAGS_DETACHED) != 0) {
95 		ret = EINVAL;
96 	} else if (pthread->joiner != NULL) {
97 		/* Multiple joiners are not supported. */
98 		ret = ENOTSUP;
99 	}
100 	if (ret) {
101 		THREAD_LIST_UNLOCK(curthread);
102 		return (ret);
103 	}
104 	/* Set the running thread to be the joiner: */
105 	pthread->joiner = curthread;
106 
107 	THREAD_LIST_UNLOCK(curthread);
108 
109 	THR_CLEANUP_PUSH(curthread, backout_join, pthread);
110 	oldcancel = _thr_cancel_enter(curthread);
111 
112 	while ((state = pthread->state) != PS_DEAD) {
113 		if (abstime != NULL) {
114 			clock_gettime(CLOCK_REALTIME, &ts);
115 			TIMESPEC_SUB(&ts2, abstime, &ts);
116 			if (ts2.tv_sec < 0) {
117 				ret = ETIMEDOUT;
118 				break;
119 			}
120 			tsp = &ts2;
121 		} else
122 			tsp = NULL;
123 		ret = _thr_umtx_wait(&pthread->state, state, tsp,
124 			 CLOCK_REALTIME);
125 		if (ret == ETIMEDOUT)
126 			break;
127 	}
128 
129 	_thr_cancel_leave(curthread, oldcancel);
130 	THR_CLEANUP_POP(curthread, 0);
131 
132 	if (ret == ETIMEDOUT) {
133 		THREAD_LIST_LOCK(curthread);
134 		pthread->joiner = NULL;
135 		THREAD_LIST_UNLOCK(curthread);
136 	} else {
137 		ret = 0;
138 		tmp = pthread->ret;
139 		THREAD_LIST_LOCK(curthread);
140 		pthread->tlflags |= TLFLAGS_DETACHED;
141 		pthread->joiner = NULL;
142 		THR_GCLIST_ADD(pthread);
143 		THREAD_LIST_UNLOCK(curthread);
144 
145 		if (thread_return != NULL)
146 			*thread_return = tmp;
147 	}
148 	return (ret);
149 }
150 
151 __strong_reference(_pthread_join, pthread_join);
152 __strong_reference(_pthread_timedjoin_np, pthread_timedjoin_np);
153 
154