apr_allocator.h

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00001 /* Copyright 2000-2005 The Apache Software Foundation or its licensors, as
00002  * applicable.
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef APR_ALLOCATOR_H
00018 #define APR_ALLOCATOR_H
00019 
00020 /**
00021  * @file apr_allocator.h
00022  * @brief APR Internal Memory Allocation
00023  */
00024 
00025 #include "apr.h"
00026 #include "apr_errno.h"
00027 #define APR_WANT_MEMFUNC /**< For no good reason? */
00028 #include "apr_want.h"
00029 
00030 #ifdef __cplusplus
00031 extern "C" {
00032 #endif
00033 
00034 /**
00035  * @defgroup apr_allocator Internal Memory Allocation
00036  * @ingroup APR 
00037  * @{
00038  */
00039 
00040 /** the allocator structure */
00041 typedef struct apr_allocator_t apr_allocator_t;
00042 /** the structure which holds information about the allocation */
00043 typedef struct apr_memnode_t apr_memnode_t;
00044 
00045 /** basic memory node structure
00046  * @note The next, ref and first_avail fields are available for use by the
00047  *       caller of apr_allocator_alloc(), the remaining fields are read-only.
00048  *       The next field has to be used with caution and sensibly set when the
00049  *       memnode is passed back to apr_allocator_free().  See apr_allocator_free()
00050  *       for details.  
00051  *       The ref and first_avail fields will be properly restored by
00052  *       apr_allocator_free().
00053  */
00054 struct apr_memnode_t {
00055     apr_memnode_t *next;            /**< next memnode */
00056     apr_memnode_t **ref;            /**< reference to self */
00057     apr_uint32_t   index;           /**< size */
00058     apr_uint32_t   free_index;      /**< how much free */
00059     char          *first_avail;     /**< pointer to first free memory */
00060     char          *endp;            /**< pointer to end of free memory */
00061 };
00062 
00063 /** The base size of a memory node - aligned.  */
00064 #define APR_MEMNODE_T_SIZE APR_ALIGN_DEFAULT(sizeof(apr_memnode_t))
00065 
00066 /** Symbolic constants */
00067 #define APR_ALLOCATOR_MAX_FREE_UNLIMITED 0
00068 
00069 /**
00070  * Create a new allocator
00071  * @param allocator The allocator we have just created.
00072  *
00073  */
00074 APR_DECLARE(apr_status_t) apr_allocator_create(apr_allocator_t **allocator);
00075 
00076 /**
00077  * Destroy an allocator
00078  * @param allocator The allocator to be destroyed
00079  * @remark Any memnodes not given back to the allocator prior to destroying
00080  *         will _not_ be free()d.
00081  */
00082 APR_DECLARE(void) apr_allocator_destroy(apr_allocator_t *allocator);
00083 
00084 /**
00085  * Allocate a block of mem from the allocator
00086  * @param allocator The allocator to allocate from
00087  * @param size The size of the mem to allocate (excluding the
00088  *        memnode structure)
00089  */
00090 APR_DECLARE(apr_memnode_t *) apr_allocator_alloc(apr_allocator_t *allocator,
00091                                                  apr_size_t size);
00092 
00093 /**
00094  * Free a list of blocks of mem, giving them back to the allocator.
00095  * The list is typically terminated by a memnode with its next field
00096  * set to NULL.
00097  * @param allocator The allocator to give the mem back to
00098  * @param memnode The memory node to return
00099  */
00100 APR_DECLARE(void) apr_allocator_free(apr_allocator_t *allocator,
00101                                      apr_memnode_t *memnode);
00102 
00103 #include "apr_pools.h"
00104 
00105 /**
00106  * Set the owner of the allocator
00107  * @param allocator The allocator to set the owner for
00108  * @param pool The pool that is to own the allocator
00109  * @remark Typically pool is the highest level pool using the allocator
00110  */
00111 /*
00112  * XXX: see if we can come up with something a bit better.  Currently
00113  * you can make a pool an owner, but if the pool doesn't use the allocator
00114  * the allocator will never be destroyed.
00115  */
00116 APR_DECLARE(void) apr_allocator_owner_set(apr_allocator_t *allocator,
00117                                           apr_pool_t *pool);
00118 
00119 /**
00120  * Get the current owner of the allocator
00121  * @param allocator The allocator to get the owner from
00122  */
00123 APR_DECLARE(apr_pool_t *) apr_allocator_owner_get(apr_allocator_t *allocator);
00124 
00125 /**
00126  * Set the current threshold at which the allocator should start
00127  * giving blocks back to the system.
00128  * @param allocator The allocator the set the threshold on
00129  * @param size The threshold.  0 == unlimited.
00130  */
00131 APR_DECLARE(void) apr_allocator_max_free_set(apr_allocator_t *allocator,
00132                                              apr_size_t size);
00133 
00134 #include "apr_thread_mutex.h"
00135 
00136 #if APR_HAS_THREADS
00137 /**
00138  * Set a mutex for the allocator to use
00139  * @param allocator The allocator to set the mutex for
00140  * @param mutex The mutex
00141  */
00142 APR_DECLARE(void) apr_allocator_mutex_set(apr_allocator_t *allocator,
00143                                           apr_thread_mutex_t *mutex);
00144 
00145 /**
00146  * Get the mutex currently set for the allocator
00147  * @param allocator The allocator
00148  */
00149 APR_DECLARE(apr_thread_mutex_t *) apr_allocator_mutex_get(
00150                                       apr_allocator_t *allocator);
00151 
00152 #endif /* APR_HAS_THREADS */
00153 
00154 /** @} */
00155 
00156 #ifdef __cplusplus
00157 }
00158 #endif
00159 
00160 #endif /* !APR_ALLOCATOR_H */

Apache Portable Runtimeに対してSun Jul 19 22:04:00 2009に生成されました。  doxygen 1.4.7