apr_allocator.h revision 251875
1228887Sadrian/* Licensed to the Apache Software Foundation (ASF) under one or more 2228887Sadrian * contributor license agreements. See the NOTICE file distributed with 3228887Sadrian * this work for additional information regarding copyright ownership. 4228887Sadrian * The ASF licenses this file to You under the Apache License, Version 2.0 5228887Sadrian * (the "License"); you may not use this file except in compliance with 6228887Sadrian * the License. You may obtain a copy of the License at 7228887Sadrian * 8228887Sadrian * http://www.apache.org/licenses/LICENSE-2.0 9228887Sadrian * 10228887Sadrian * Unless required by applicable law or agreed to in writing, software 11228887Sadrian * distributed under the License is distributed on an "AS IS" BASIS, 12228887Sadrian * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13228887Sadrian * See the License for the specific language governing permissions and 14228887Sadrian * limitations under the License. 15228887Sadrian */ 16228887Sadrian 17228887Sadrian#ifndef APR_ALLOCATOR_H 18228887Sadrian#define APR_ALLOCATOR_H 19228887Sadrian 20228887Sadrian/** 21228887Sadrian * @file apr_allocator.h 22228887Sadrian * @brief APR Internal Memory Allocation 23228887Sadrian */ 24228887Sadrian 25228887Sadrian#include "apr.h" 26228887Sadrian#include "apr_errno.h" 27228887Sadrian#define APR_WANT_MEMFUNC /**< For no good reason? */ 28228887Sadrian#include "apr_want.h" 29228887Sadrian 30228887Sadrian#ifdef __cplusplus 31228887Sadrianextern "C" { 32228887Sadrian#endif 33228887Sadrian 34228887Sadrian/** 35228888Sadrian * @defgroup apr_allocator Internal Memory Allocation 36228887Sadrian * @ingroup APR 37228887Sadrian * @{ 38 */ 39 40/** the allocator structure */ 41typedef struct apr_allocator_t apr_allocator_t; 42/** the structure which holds information about the allocation */ 43typedef struct apr_memnode_t apr_memnode_t; 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 */ 54struct 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 */ 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 */ 74APR_DECLARE(apr_status_t) apr_allocator_create(apr_allocator_t **allocator); 75 76/** 77 * Destroy an allocator 78 * @param allocator The allocator to be destroyed 79 * @remark Any memnodes not given back to the allocator prior to destroying 80 * will _not_ be free()d. 81 */ 82APR_DECLARE(void) apr_allocator_destroy(apr_allocator_t *allocator); 83 84/** 85 * Allocate a block of mem from the allocator 86 * @param allocator The allocator to allocate from 87 * @param size The size of the mem to allocate (excluding the 88 * memnode structure) 89 */ 90APR_DECLARE(apr_memnode_t *) apr_allocator_alloc(apr_allocator_t *allocator, 91 apr_size_t size); 92 93/** 94 * Free a list of blocks of mem, giving them back to the allocator. 95 * The list is typically terminated by a memnode with its next field 96 * set to NULL. 97 * @param allocator The allocator to give the mem back to 98 * @param memnode The memory node to return 99 */ 100APR_DECLARE(void) apr_allocator_free(apr_allocator_t *allocator, 101 apr_memnode_t *memnode); 102 103#include "apr_pools.h" 104 105/** 106 * Set the owner of the allocator 107 * @param allocator The allocator to set the owner for 108 * @param pool The pool that is to own the allocator 109 * @remark Typically pool is the highest level pool using the allocator 110 */ 111/* 112 * XXX: see if we can come up with something a bit better. Currently 113 * you can make a pool an owner, but if the pool doesn't use the allocator 114 * the allocator will never be destroyed. 115 */ 116APR_DECLARE(void) apr_allocator_owner_set(apr_allocator_t *allocator, 117 apr_pool_t *pool); 118 119/** 120 * Get the current owner of the allocator 121 * @param allocator The allocator to get the owner from 122 */ 123APR_DECLARE(apr_pool_t *) apr_allocator_owner_get(apr_allocator_t *allocator); 124 125/** 126 * Set the current threshold at which the allocator should start 127 * giving blocks back to the system. 128 * @param allocator The allocator the set the threshold on 129 * @param size The threshold. 0 == unlimited. 130 */ 131APR_DECLARE(void) apr_allocator_max_free_set(apr_allocator_t *allocator, 132 apr_size_t size); 133 134#include "apr_thread_mutex.h" 135 136#if APR_HAS_THREADS 137/** 138 * Set a mutex for the allocator to use 139 * @param allocator The allocator to set the mutex for 140 * @param mutex The mutex 141 */ 142APR_DECLARE(void) apr_allocator_mutex_set(apr_allocator_t *allocator, 143 apr_thread_mutex_t *mutex); 144 145/** 146 * Get the mutex currently set for the allocator 147 * @param allocator The allocator 148 */ 149APR_DECLARE(apr_thread_mutex_t *) apr_allocator_mutex_get( 150 apr_allocator_t *allocator); 151 152#endif /* APR_HAS_THREADS */ 153 154/** @} */ 155 156#ifdef __cplusplus 157} 158#endif 159 160#endif /* !APR_ALLOCATOR_H */ 161