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| -rw-r--r-- | include/apr_allocator.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/include/apr_allocator.h b/include/apr_allocator.h new file mode 100644 index 0000000..be05d0e --- /dev/null +++ b/include/apr_allocator.h @@ -0,0 +1,179 @@ +/* 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) + __attribute__((nonnull(1))); + +/** + * 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) + __attribute__((nonnull(1))); + +/** + * 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) + __attribute__((nonnull(1))); + +/** + * 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) + __attribute__((nonnull(1,2))); + +/** + * Get the true size that would be allocated for the given size (including + * the header and alignment). + * @param allocator The allocator from which to the memory would be allocated + * @param size The size to align + * @return The aligned size (or zero on apr_size_t overflow) + */ +APR_DECLARE(apr_size_t) apr_allocator_align(apr_allocator_t *allocator, + apr_size_t size); + +#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) + __attribute__((nonnull(1))); + +/** + * 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) + __attribute__((nonnull(1))); + +/** + * Set the current threshold at which the allocator should start + * giving blocks back to the system. + * @param allocator The allocator to 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) + __attribute__((nonnull(1))); + +#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) + __attribute__((nonnull(1))); + +/** + * 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) + __attribute__((nonnull(1))); + +#endif /* APR_HAS_THREADS */ + +/** @} */ + +#ifdef __cplusplus +} +#endif + +#endif /* !APR_ALLOCATOR_H */ |