1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "apr_arch_thread_mutex.h"
18 #include "apr_arch_thread_cond.h"
19 #include "apr_strings.h"
20 #include "apr_portable.h"
21
thread_cond_cleanup(void * data)22 static apr_status_t thread_cond_cleanup(void *data)
23 {
24 struct waiter *w;
25 apr_thread_cond_t *cond = (apr_thread_cond_t *)data;
26
27 acquire_sem(cond->lock);
28 delete_sem(cond->lock);
29
30 return APR_SUCCESS;
31 }
32
make_waiter(apr_pool_t * pool)33 static struct waiter_t *make_waiter(apr_pool_t *pool)
34 {
35 struct waiter_t *w = (struct waiter_t*)
36 apr_palloc(pool, sizeof(struct waiter_t));
37 if (w == NULL)
38 return NULL;
39
40 w->sem = create_sem(0, "apr conditional waiter");
41 if (w->sem < 0)
42 return NULL;
43
44 APR_RING_ELEM_INIT(w, link);
45
46 return w;
47 }
48
apr_thread_cond_create(apr_thread_cond_t ** cond,apr_pool_t * pool)49 APR_DECLARE(apr_status_t) apr_thread_cond_create(apr_thread_cond_t **cond,
50 apr_pool_t *pool)
51 {
52 apr_thread_cond_t *new_cond;
53 sem_id rv;
54 int i;
55
56 new_cond = (apr_thread_cond_t *)apr_palloc(pool, sizeof(apr_thread_cond_t));
57
58 if (new_cond == NULL)
59 return APR_ENOMEM;
60
61 if ((rv = create_sem(1, "apr conditional lock")) < B_OK)
62 return rv;
63
64 new_cond->lock = rv;
65 new_cond->pool = pool;
66 APR_RING_INIT(&new_cond->alist, waiter_t, link);
67 APR_RING_INIT(&new_cond->flist, waiter_t, link);
68
69 for (i=0;i < 10 ;i++) {
70 struct waiter_t *nw = make_waiter(pool);
71 APR_RING_INSERT_TAIL(&new_cond->flist, nw, waiter_t, link);
72 }
73
74 apr_pool_cleanup_register(new_cond->pool,
75 (void *)new_cond, thread_cond_cleanup,
76 apr_pool_cleanup_null);
77
78 *cond = new_cond;
79 return APR_SUCCESS;
80 }
81
82
do_wait(apr_thread_cond_t * cond,apr_thread_mutex_t * mutex,int timeout)83 static apr_status_t do_wait(apr_thread_cond_t *cond, apr_thread_mutex_t *mutex,
84 int timeout)
85 {
86 struct waiter_t *wait;
87 thread_id cth = find_thread(NULL);
88 apr_status_t rv;
89 int flags = B_RELATIVE_TIMEOUT;
90
91 /* We must be the owner of the mutex or we can't do this... */
92 if (mutex->owner != cth) {
93 /* What should we return??? */
94 return APR_EINVAL;
95 }
96
97 acquire_sem(cond->lock);
98 wait = APR_RING_FIRST(&cond->flist);
99 if (wait)
100 APR_RING_REMOVE(wait, link);
101 else
102 wait = make_waiter(cond->pool);
103 APR_RING_INSERT_TAIL(&cond->alist, wait, waiter_t, link);
104 cond->condlock = mutex;
105 release_sem(cond->lock);
106
107 apr_thread_mutex_unlock(cond->condlock);
108
109 if (timeout == 0)
110 flags = 0;
111
112 rv = acquire_sem_etc(wait->sem, 1, flags, timeout);
113
114 apr_thread_mutex_lock(cond->condlock);
115
116 if (rv != B_OK) {
117 if (rv == B_TIMED_OUT)
118 return APR_TIMEUP;
119 return rv;
120 }
121
122 acquire_sem(cond->lock);
123 APR_RING_REMOVE(wait, link);
124 APR_RING_INSERT_TAIL(&cond->flist, wait, waiter_t, link);
125 release_sem(cond->lock);
126
127 return APR_SUCCESS;
128 }
129
apr_thread_cond_wait(apr_thread_cond_t * cond,apr_thread_mutex_t * mutex)130 APR_DECLARE(apr_status_t) apr_thread_cond_wait(apr_thread_cond_t *cond,
131 apr_thread_mutex_t *mutex)
132 {
133 return do_wait(cond, mutex, 0);
134 }
135
apr_thread_cond_timedwait(apr_thread_cond_t * cond,apr_thread_mutex_t * mutex,apr_interval_time_t timeout)136 APR_DECLARE(apr_status_t) apr_thread_cond_timedwait(apr_thread_cond_t *cond,
137 apr_thread_mutex_t *mutex,
138 apr_interval_time_t timeout)
139 {
140 return do_wait(cond, mutex, timeout);
141 }
142
apr_thread_cond_signal(apr_thread_cond_t * cond)143 APR_DECLARE(apr_status_t) apr_thread_cond_signal(apr_thread_cond_t *cond)
144 {
145 struct waiter_t *wake;
146
147 acquire_sem(cond->lock);
148 if (!APR_RING_EMPTY(&cond->alist, waiter_t, link)) {
149 wake = APR_RING_FIRST(&cond->alist);
150 APR_RING_REMOVE(wake, link);
151 release_sem(wake->sem);
152 APR_RING_INSERT_TAIL(&cond->flist, wake, waiter_t, link);
153 }
154 release_sem(cond->lock);
155
156 return APR_SUCCESS;
157 }
158
apr_thread_cond_broadcast(apr_thread_cond_t * cond)159 APR_DECLARE(apr_status_t) apr_thread_cond_broadcast(apr_thread_cond_t *cond)
160 {
161 struct waiter_t *wake;
162
163 acquire_sem(cond->lock);
164 while (! APR_RING_EMPTY(&cond->alist, waiter_t, link)) {
165 wake = APR_RING_FIRST(&cond->alist);
166 APR_RING_REMOVE(wake, link);
167 release_sem(wake->sem);
168 APR_RING_INSERT_TAIL(&cond->flist, wake, waiter_t, link);
169 }
170 release_sem(cond->lock);
171
172 return APR_SUCCESS;
173 }
174
apr_thread_cond_destroy(apr_thread_cond_t * cond)175 APR_DECLARE(apr_status_t) apr_thread_cond_destroy(apr_thread_cond_t *cond)
176 {
177 apr_status_t stat;
178 if ((stat = thread_cond_cleanup(cond)) == APR_SUCCESS) {
179 apr_pool_cleanup_kill(cond->pool, cond, thread_cond_cleanup);
180 return APR_SUCCESS;
181 }
182 return stat;
183 }
184
185 APR_POOL_IMPLEMENT_ACCESSOR(thread_cond)
186
187