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/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef APR_ALLOCATOR_H
#define APR_ALLOCATOR_H
/**
* @file apr_allocator.h
* @brief APR Internal Memory Allocation
*/
#include "apr.h"
#include "apr_errno.h"
#define APR_WANT_MEMFUNC /**< For no good reason? */
#include "apr_want.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup apr_allocator Internal Memory Allocation
* @ingroup APR
* @{
*/
/** the allocator structure */
typedef struct apr_allocator_t apr_allocator_t;
/** the structure which holds information about the allocation */
typedef struct apr_memnode_t apr_memnode_t;
/** basic memory node structure
* @note The next, ref and first_avail fields are available for use by the
* caller of apr_allocator_alloc(), the remaining fields are read-only.
* The next field has to be used with caution and sensibly set when the
* memnode is passed back to apr_allocator_free(). See apr_allocator_free()
* for details.
* The ref and first_avail fields will be properly restored by
* apr_allocator_free().
*/
struct apr_memnode_t {
apr_memnode_t *next; /**< next memnode */
apr_memnode_t **ref; /**< reference to self */
apr_uint32_t index; /**< size */
apr_uint32_t free_index; /**< how much free */
char *first_avail; /**< pointer to first free memory */
char *endp; /**< pointer to end of free memory */
};
/** The base size of a memory node - aligned. */
#define APR_MEMNODE_T_SIZE APR_ALIGN_DEFAULT(sizeof(apr_memnode_t))
/** Symbolic constants */
#define APR_ALLOCATOR_MAX_FREE_UNLIMITED 0
/**
* Create a new allocator
* @param allocator The allocator we have just created.
*
*/
APR_DECLARE(apr_status_t) apr_allocator_create(apr_allocator_t **allocator);
/**
* Destroy an allocator
* @param allocator The allocator to be destroyed
* @remark Any memnodes not given back to the allocator prior to destroying
* will _not_ be free()d.
*/
APR_DECLARE(void) apr_allocator_destroy(apr_allocator_t *allocator);
/**
* Allocate a block of mem from the allocator
* @param allocator The allocator to allocate from
* @param size The size of the mem to allocate (excluding the
* memnode structure)
*/
APR_DECLARE(apr_memnode_t *) apr_allocator_alloc(apr_allocator_t *allocator,
apr_size_t size);
/**
* Free a list of blocks of mem, giving them back to the allocator.
* The list is typically terminated by a memnode with its next field
* set to NULL.
* @param allocator The allocator to give the mem back to
* @param memnode The memory node to return
*/
APR_DECLARE(void) apr_allocator_free(apr_allocator_t *allocator,
apr_memnode_t *memnode);
#include "apr_pools.h"
/**
* Set the owner of the allocator
* @param allocator The allocator to set the owner for
* @param pool The pool that is to own the allocator
* @remark Typically pool is the highest level pool using the allocator
*/
/*
* XXX: see if we can come up with something a bit better. Currently
* you can make a pool an owner, but if the pool doesn't use the allocator
* the allocator will never be destroyed.
*/
APR_DECLARE(void) apr_allocator_owner_set(apr_allocator_t *allocator,
apr_pool_t *pool);
/**
* Get the current owner of the allocator
* @param allocator The allocator to get the owner from
*/
APR_DECLARE(apr_pool_t *) apr_allocator_owner_get(apr_allocator_t *allocator);
/**
* Set the current threshold at which the allocator should start
* giving blocks back to the system.
* @param allocator The allocator the set the threshold on
* @param size The threshold. 0 == unlimited.
*/
APR_DECLARE(void) apr_allocator_max_free_set(apr_allocator_t *allocator,
apr_size_t size);
#include "apr_thread_mutex.h"
#if APR_HAS_THREADS
/**
* Set a mutex for the allocator to use
* @param allocator The allocator to set the mutex for
* @param mutex The mutex
*/
APR_DECLARE(void) apr_allocator_mutex_set(apr_allocator_t *allocator,
apr_thread_mutex_t *mutex);
/**
* Get the mutex currently set for the allocator
* @param allocator The allocator
*/
APR_DECLARE(apr_thread_mutex_t *) apr_allocator_mutex_get(
apr_allocator_t *allocator);
#endif /* APR_HAS_THREADS */
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* !APR_ALLOCATOR_H */
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