Apache Portable Runtime
apr_allocator.h
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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#ifndef APR_ALLOCATOR_H
18#define APR_ALLOCATOR_H
19
20/**
21 * @file apr_allocator.h
22 * @brief APR Internal Memory Allocation
23 */
24
25#include "apr.h"
26#include "apr_errno.h"
27#define APR_WANT_MEMFUNC /**< For no good reason? */
28#include "apr_want.h"
29
30#ifdef __cplusplus
31extern "C" {
32#endif
33
34/**
35 * @defgroup apr_allocator Internal Memory Allocation
36 * @ingroup APR
37 * @{
38 */
39
40/** the allocator structure */
42/** the structure which holds information about the allocation */
44
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()
50 * for details.
51 * The ref and first_avail fields will be properly restored by
52 * apr_allocator_free().
53 */
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 */
61};
62
63/** The base size of a memory node - aligned. */
64#define APR_MEMNODE_T_SIZE APR_ALIGN_DEFAULT(sizeof(apr_memnode_t))
65
66/** Symbolic constants */
67#define APR_ALLOCATOR_MAX_FREE_UNLIMITED 0
68
69/**
70 * Create a new allocator
71 * @param allocator The allocator we have just created.
72 *
73 */
75 __attribute__((nonnull(1)));
76
77/**
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.
82 */
84 __attribute__((nonnull(1)));
85
86/**
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
90 * memnode structure)
91 */
93 apr_size_t size)
94 __attribute__((nonnull(1)));
95
96/**
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
99 * set to NULL.
100 * @param allocator The allocator to give the mem back to
101 * @param memnode The memory node to return
102 */
104 apr_memnode_t *memnode)
105 __attribute__((nonnull(1,2)));
106
107/**
108 * Get the true size that would be allocated for the given size (including
109 * the header and alignment).
110 * @param allocator The allocator from which to the memory would be allocated
111 * @param size The size to align
112 * @return The aligned size (or zero on apr_size_t overflow)
113 */
115 apr_size_t size);
116
117#include "apr_pools.h"
118
119/**
120 * Set the owner of the allocator
121 * @param allocator The allocator to set the owner for
122 * @param pool The pool that is to own the allocator
123 * @remark Typically pool is the highest level pool using the allocator
124 */
125/*
126 * XXX: see if we can come up with something a bit better. Currently
127 * you can make a pool an owner, but if the pool doesn't use the allocator
128 * the allocator will never be destroyed.
129 */
131 apr_pool_t *pool)
132 __attribute__((nonnull(1)));
133
134/**
135 * Get the current owner of the allocator
136 * @param allocator The allocator to get the owner from
137 */
139 __attribute__((nonnull(1)));
140
141/**
142 * Set the current threshold at which the allocator should start
143 * giving blocks back to the system.
144 * @param allocator The allocator to set the threshold on
145 * @param size The threshold. 0 == unlimited.
146 */
148 apr_size_t size)
149 __attribute__((nonnull(1)));
150
151#include "apr_thread_mutex.h"
152
153#if APR_HAS_THREADS
154/**
155 * Set a mutex for the allocator to use
156 * @param allocator The allocator to set the mutex for
157 * @param mutex The mutex
158 */
160 apr_thread_mutex_t *mutex)
161 __attribute__((nonnull(1)));
162
163/**
164 * Get the mutex currently set for the allocator
165 * @param allocator The allocator
166 */
168 apr_allocator_t *allocator)
169 __attribute__((nonnull(1)));
170
171#endif /* APR_HAS_THREADS */
172
173/** @} */
174
175#ifdef __cplusplus
176}
177#endif
178
179#endif /* !APR_ALLOCATOR_H */
APR Platform Definitions.
APR Error Codes.
APR memory allocation.
APR Thread Mutex Routines.
APR Standard Headers Support.
void apr_allocator_free(apr_allocator_t *allocator, apr_memnode_t *memnode)
struct apr_allocator_t apr_allocator_t
Definition: apr_allocator.h:41
void apr_allocator_max_free_set(apr_allocator_t *allocator, apr_size_t size)
apr_memnode_t * apr_allocator_alloc(apr_allocator_t *allocator, apr_size_t size)
apr_thread_mutex_t * apr_allocator_mutex_get(apr_allocator_t *allocator)
apr_pool_t * apr_allocator_owner_get(apr_allocator_t *allocator)
void apr_allocator_destroy(apr_allocator_t *allocator)
apr_size_t apr_allocator_align(apr_allocator_t *allocator, apr_size_t size)
void apr_allocator_mutex_set(apr_allocator_t *allocator, apr_thread_mutex_t *mutex)
void apr_allocator_owner_set(apr_allocator_t *allocator, apr_pool_t *pool)
apr_status_t apr_allocator_create(apr_allocator_t **allocator)
int apr_status_t
Definition: apr_errno.h:44
#define APR_DECLARE(type)
Definition: apr.h:498
struct apr_pool_t apr_pool_t
Definition: apr_pools.h:60
struct apr_thread_mutex_t apr_thread_mutex_t
Definition: apr_thread_mutex.h:41
Definition: apr_allocator.h:54
apr_memnode_t * next
Definition: apr_allocator.h:55
char * endp
Definition: apr_allocator.h:60
apr_uint32_t index
Definition: apr_allocator.h:57
char * first_avail
Definition: apr_allocator.h:59
apr_memnode_t ** ref
Definition: apr_allocator.h:56
apr_uint32_t free_index
Definition: apr_allocator.h:58