1 /* Copyright 2000-2005 The Apache Software Foundation or its licensors, as
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #include "apr_file_info.h"
18 #include "apr_file_io.h"
21 #include "sdbm_private.h"
22 #include "sdbm_tune.h"
24 /* NOTE: this function blocks until it acquires the lock */
25 APU_DECLARE(apr_status_t) apr_sdbm_lock(apr_sdbm_t *db, int type)
29 if (!(type == APR_FLOCK_SHARED || type == APR_FLOCK_EXCLUSIVE))
32 if (db->flags & SDBM_EXCLUSIVE_LOCK) {
36 else if (db->flags & SDBM_SHARED_LOCK) {
38 * Cannot promote a shared lock to an exlusive lock
39 * in a cross-platform compatibile manner.
41 if (type == APR_FLOCK_EXCLUSIVE)
47 * zero size: either a fresh database, or one with a single,
48 * unsplit data page: dirpage is all zeros.
50 if ((status = apr_file_lock(db->dirf, type)) == APR_SUCCESS)
53 if ((status = apr_file_info_get(&finfo, APR_FINFO_SIZE, db->dirf))
55 (void) apr_file_unlock(db->dirf);
59 SDBM_INVALIDATE_CACHE(db, finfo);
62 if (type == APR_FLOCK_SHARED)
63 db->flags |= SDBM_SHARED_LOCK;
64 else if (type == APR_FLOCK_EXCLUSIVE)
65 db->flags |= SDBM_EXCLUSIVE_LOCK;
70 APU_DECLARE(apr_status_t) apr_sdbm_unlock(apr_sdbm_t *db)
72 if (!(db->flags & (SDBM_SHARED_LOCK | SDBM_EXCLUSIVE_LOCK)))
76 db->flags &= ~(SDBM_SHARED_LOCK | SDBM_EXCLUSIVE_LOCK);
77 return apr_file_unlock(db->dirf);