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
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 #ifndef APR_ALLOCATOR_H
18 #define APR_ALLOCATOR_H
21 * @file apr_allocator.h
22 * @brief APR Internal Memory Allocation
26 #include "apr_errno.h"
27 #define APR_WANT_MEMFUNC /**< For no good reason? */
35 * @defgroup apr_allocator Internal Memory Allocation
40 /** the allocator structure */
41 typedef struct apr_allocator_t apr_allocator_t;
42 /** the structure which holds information about the allocation */
43 typedef struct apr_memnode_t apr_memnode_t;
45 /** basic memory node structure
46 * @note The next, ref and first_avail fields are available for use by the
47 * caller of apr_allocator_alloc(), the remaining fields are read-only.
48 * The next field has to be used with caution and sensibly set when the
49 * memnode is passed back to apr_allocator_free(). See apr_allocator_free()
51 * The ref and first_avail fields will be properly restored by
52 * apr_allocator_free().
54 struct apr_memnode_t {
55 apr_memnode_t *next; /**< next memnode */
56 apr_memnode_t **ref; /**< reference to self */
57 apr_uint32_t index; /**< size */
58 apr_uint32_t free_index; /**< how much free */
59 char *first_avail; /**< pointer to first free memory */
60 char *endp; /**< pointer to end of free memory */
63 /** The base size of a memory node - aligned. */
64 #define APR_MEMNODE_T_SIZE APR_ALIGN_DEFAULT(sizeof(apr_memnode_t))
66 /** Symbolic constants */
67 #define APR_ALLOCATOR_MAX_FREE_UNLIMITED 0
70 * Create a new allocator
71 * @param allocator The allocator we have just created.
74 APR_DECLARE(apr_status_t) apr_allocator_create(apr_allocator_t **allocator)
75 __attribute__((nonnull(1)));
78 * Destroy an allocator
79 * @param allocator The allocator to be destroyed
80 * @remark Any memnodes not given back to the allocator prior to destroying
81 * will _not_ be free()d.
83 APR_DECLARE(void) apr_allocator_destroy(apr_allocator_t *allocator)
84 __attribute__((nonnull(1)));
87 * Allocate a block of mem from the allocator
88 * @param allocator The allocator to allocate from
89 * @param size The size of the mem to allocate (excluding the
92 APR_DECLARE(apr_memnode_t *) apr_allocator_alloc(apr_allocator_t *allocator,
94 __attribute__((nonnull(1)));
97 * Free a list of blocks of mem, giving them back to the allocator.
98 * The list is typically terminated by a memnode with its next field
100 * @param allocator The allocator to give the mem back to
101 * @param memnode The memory node to return
103 APR_DECLARE(void) apr_allocator_free(apr_allocator_t *allocator,
104 apr_memnode_t *memnode)
105 __attribute__((nonnull(1,2)));
107 #include "apr_pools.h"
110 * Set the owner of the allocator
111 * @param allocator The allocator to set the owner for
112 * @param pool The pool that is to own the allocator
113 * @remark Typically pool is the highest level pool using the allocator
116 * XXX: see if we can come up with something a bit better. Currently
117 * you can make a pool an owner, but if the pool doesn't use the allocator
118 * the allocator will never be destroyed.
120 APR_DECLARE(void) apr_allocator_owner_set(apr_allocator_t *allocator,
122 __attribute__((nonnull(1)));
125 * Get the current owner of the allocator
126 * @param allocator The allocator to get the owner from
128 APR_DECLARE(apr_pool_t *) apr_allocator_owner_get(apr_allocator_t *allocator)
129 __attribute__((nonnull(1)));
132 * Set the current threshold at which the allocator should start
133 * giving blocks back to the system.
134 * @param allocator The allocator the set the threshold on
135 * @param size The threshold. 0 == unlimited.
137 APR_DECLARE(void) apr_allocator_max_free_set(apr_allocator_t *allocator,
139 __attribute__((nonnull(1)));
141 #include "apr_thread_mutex.h"
145 * Set a mutex for the allocator to use
146 * @param allocator The allocator to set the mutex for
147 * @param mutex The mutex
149 APR_DECLARE(void) apr_allocator_mutex_set(apr_allocator_t *allocator,
150 apr_thread_mutex_t *mutex)
151 __attribute__((nonnull(1)));
154 * Get the mutex currently set for the allocator
155 * @param allocator The allocator
157 APR_DECLARE(apr_thread_mutex_t *) apr_allocator_mutex_get(
158 apr_allocator_t *allocator)
159 __attribute__((nonnull(1)));
161 #endif /* APR_HAS_THREADS */
169 #endif /* !APR_ALLOCATOR_H */