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 /*Read/Write locking implementation based on the MultiLock code from
18 * Stephen Beaulieu <[email protected]>
19 */
20
21 #include "apr_arch_proc_mutex.h"
22 #include "apr_strings.h"
23 #include "apr_portable.h"
24
_proc_mutex_cleanup(void * data)25 static apr_status_t _proc_mutex_cleanup(void * data)
26 {
27 apr_proc_mutex_t *lock = (apr_proc_mutex_t*)data;
28 if (lock->LockCount != 0) {
29 /* we're still locked... */
30 while (atomic_add(&lock->LockCount , -1) > 1){
31 /* OK we had more than one person waiting on the lock so
32 * the sem is also locked. Release it until we have no more
33 * locks left.
34 */
35 release_sem (lock->Lock);
36 }
37 }
38 delete_sem(lock->Lock);
39 return APR_SUCCESS;
40 }
41
apr_proc_mutex_create(apr_proc_mutex_t ** mutex,const char * fname,apr_lockmech_e mech,apr_pool_t * pool)42 APR_DECLARE(apr_status_t) apr_proc_mutex_create(apr_proc_mutex_t **mutex,
43 const char *fname,
44 apr_lockmech_e mech,
45 apr_pool_t *pool)
46 {
47 apr_proc_mutex_t *new;
48 apr_status_t stat = APR_SUCCESS;
49
50 if (mech != APR_LOCK_DEFAULT) {
51 return APR_ENOTIMPL;
52 }
53
54 new = (apr_proc_mutex_t *)apr_pcalloc(pool, sizeof(apr_proc_mutex_t));
55 if (new == NULL){
56 return APR_ENOMEM;
57 }
58
59 if ((stat = create_sem(0, "APR_Lock")) < B_NO_ERROR) {
60 _proc_mutex_cleanup(new);
61 return stat;
62 }
63 new->LockCount = 0;
64 new->Lock = stat;
65 new->pool = pool;
66
67 apr_pool_cleanup_register(new->pool, (void *)new, _proc_mutex_cleanup,
68 apr_pool_cleanup_null);
69
70 (*mutex) = new;
71 return APR_SUCCESS;
72 }
73
apr_proc_mutex_child_init(apr_proc_mutex_t ** mutex,const char * fname,apr_pool_t * pool)74 APR_DECLARE(apr_status_t) apr_proc_mutex_child_init(apr_proc_mutex_t **mutex,
75 const char *fname,
76 apr_pool_t *pool)
77 {
78 return APR_SUCCESS;
79 }
80
apr_proc_mutex_lock(apr_proc_mutex_t * mutex)81 APR_DECLARE(apr_status_t) apr_proc_mutex_lock(apr_proc_mutex_t *mutex)
82 {
83 int32 stat;
84
85 if (atomic_add(&mutex->LockCount, 1) > 0) {
86 if ((stat = acquire_sem(mutex->Lock)) < B_NO_ERROR) {
87 atomic_add(&mutex->LockCount, -1);
88 return stat;
89 }
90 }
91 return APR_SUCCESS;
92 }
93
apr_proc_mutex_trylock(apr_proc_mutex_t * mutex)94 APR_DECLARE(apr_status_t) apr_proc_mutex_trylock(apr_proc_mutex_t *mutex)
95 {
96 return APR_ENOTIMPL;
97 }
98
apr_proc_mutex_unlock(apr_proc_mutex_t * mutex)99 APR_DECLARE(apr_status_t) apr_proc_mutex_unlock(apr_proc_mutex_t *mutex)
100 {
101 int32 stat;
102
103 if (atomic_add(&mutex->LockCount, -1) > 1) {
104 if ((stat = release_sem(mutex->Lock)) < B_NO_ERROR) {
105 atomic_add(&mutex->LockCount, 1);
106 return stat;
107 }
108 }
109 return APR_SUCCESS;
110 }
111
apr_proc_mutex_destroy(apr_proc_mutex_t * mutex)112 APR_DECLARE(apr_status_t) apr_proc_mutex_destroy(apr_proc_mutex_t *mutex)
113 {
114 apr_status_t stat;
115 if ((stat = _proc_mutex_cleanup(mutex)) == APR_SUCCESS) {
116 apr_pool_cleanup_kill(mutex->pool, mutex, _proc_mutex_cleanup);
117 return APR_SUCCESS;
118 }
119 return stat;
120 }
121
apr_proc_mutex_cleanup(void * mutex)122 APR_DECLARE(apr_status_t) apr_proc_mutex_cleanup(void *mutex)
123 {
124 return _proc_mutex_cleanup(mutex);
125 }
126
127
apr_proc_mutex_lockfile(apr_proc_mutex_t * mutex)128 APR_DECLARE(const char *) apr_proc_mutex_lockfile(apr_proc_mutex_t *mutex)
129 {
130 return NULL;
131 }
132
apr_proc_mutex_name(apr_proc_mutex_t * mutex)133 APR_DECLARE(const char *) apr_proc_mutex_name(apr_proc_mutex_t *mutex)
134 {
135 return "beossem";
136 }
137
apr_proc_mutex_defname(void)138 APR_DECLARE(const char *) apr_proc_mutex_defname(void)
139 {
140 return "beossem";
141 }
142
143 APR_POOL_IMPLEMENT_ACCESSOR(proc_mutex)
144
145 /* Implement OS-specific accessors defined in apr_portable.h */
146
APR_DECLARE(apr_status_t)147 APR_DECLARE(apr_status_t) apr_os_proc_mutex_get(apr_os_proc_mutex_t *ospmutex,
148 apr_proc_mutex_t *pmutex)
149 {
150 ospmutex->sem = pmutex->Lock;
151 ospmutex->ben = pmutex->LockCount;
152 return APR_SUCCESS;
153 }
154
apr_os_proc_mutex_put(apr_proc_mutex_t ** pmutex,apr_os_proc_mutex_t * ospmutex,apr_pool_t * pool)155 APR_DECLARE(apr_status_t) apr_os_proc_mutex_put(apr_proc_mutex_t **pmutex,
156 apr_os_proc_mutex_t *ospmutex,
157 apr_pool_t *pool)
158 {
159 if (pool == NULL) {
160 return APR_ENOPOOL;
161 }
162 if ((*pmutex) == NULL) {
163 (*pmutex) = (apr_proc_mutex_t *)apr_pcalloc(pool, sizeof(apr_proc_mutex_t));
164 (*pmutex)->pool = pool;
165 }
166 (*pmutex)->Lock = ospmutex->sem;
167 (*pmutex)->LockCount = ospmutex->ben;
168 return APR_SUCCESS;
169 }
170
171