/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2003 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

#ifndef APR_ALLOCATOR_H
#define APR_ALLOCATOR_H

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @file apr_allocator.h
 * @brief APR memory allocation
 *
 */
/**
 * @defgroup APR_Pool_allocator Allocator
 * @ingroup APR_Pool
 * @{
 */


#include "apr.h"
#include "apr_errno.h"
#define APR_WANT_MEMFUNC
#include "apr_want.h"

/** 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 */
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 block of mem, giving it back to the allocator
 * @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);

/** @deprecated @see apr_allocator_owner_set */
APR_DECLARE(void) apr_allocator_set_owner(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);

/** @deprecated @see apr_allocator_owner_get */
APR_DECLARE(apr_pool_t *) apr_allocator_get_owner(
                                  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);

/** @deprecated @see apr_allocator_max_free_set */
APR_DECLARE(void) apr_allocator_set_max_free(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);

/** @deprecated @see apr_allocator_mutex_set */
APR_DECLARE(void) apr_allocator_set_mutex(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);

/** @deprecated @see apr_allocator_mutex_get */
APR_DECLARE(apr_thread_mutex_t *) apr_allocator_get_mutex(
                                      apr_allocator_t *allocator);

#endif /* APR_HAS_THREADS */

/** @} */
#ifdef __cplusplus
}
#endif

#endif /* !APR_ALLOCATOR_H */
