ucx/mempool.h

Thu, 08 Sep 2016 15:12:56 +0200

author
Mike Becker <universe@uap-core.de>
date
Thu, 08 Sep 2016 15:12:56 +0200
changeset 225
a1a068c2c4ef
parent 215
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child 241
661f33ef20d8
permissions
-rw-r--r--

updates documenting comments

universe@103 1 /*
universe@103 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
olaf@13 3 *
universe@225 4 * Copyright 2016 Olaf Wintermann. All rights reserved.
universe@103 5 *
universe@103 6 * Redistribution and use in source and binary forms, with or without
universe@103 7 * modification, are permitted provided that the following conditions are met:
universe@103 8 *
universe@103 9 * 1. Redistributions of source code must retain the above copyright
universe@103 10 * notice, this list of conditions and the following disclaimer.
universe@103 11 *
universe@103 12 * 2. Redistributions in binary form must reproduce the above copyright
universe@103 13 * notice, this list of conditions and the following disclaimer in the
universe@103 14 * documentation and/or other materials provided with the distribution.
universe@103 15 *
universe@103 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@103 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@103 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@103 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@103 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@103 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@103 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@103 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@103 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@103 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@103 26 * POSSIBILITY OF SUCH DAMAGE.
olaf@13 27 */
olaf@13 28
universe@135 29 /**
universe@135 30 * @file mempool.h
universe@135 31 *
universe@135 32 * Memory pool implementation.
universe@135 33 *
universe@135 34 * @author Mike Becker
universe@135 35 * @author Olaf Wintermann
universe@135 36 */
universe@135 37
olaf@120 38 #ifndef UCX_MEMPOOL_H
olaf@120 39 #define UCX_MEMPOOL_H
olaf@13 40
universe@69 41 #include "ucx.h"
universe@38 42 #include <stddef.h>
universe@50 43 #include "allocator.h"
universe@38 44
olaf@13 45 #ifdef __cplusplus
olaf@13 46 extern "C" {
olaf@13 47 #endif
olaf@13 48
universe@135 49 /**
universe@135 50 * UCX mempool structure.
universe@135 51 */
olaf@13 52 typedef struct {
olaf@158 53 /** UcxAllocator based on this pool */
olaf@158 54 UcxAllocator *allocator;
olaf@158 55
universe@135 56 /** List of pointers to pooled memory. */
olaf@158 57 void **data;
universe@146 58
universe@135 59 /** Count of pooled memory items. */
olaf@158 60 size_t ndata;
universe@146 61
universe@135 62 /** Memory pool size. */
olaf@158 63 size_t size;
olaf@13 64 } UcxMempool;
olaf@13 65
universe@135 66 /** Shorthand for a new default memory pool with a capacity of 16 elements. */
universe@135 67 #define ucx_mempool_new_default() ucx_mempool_new(16)
universe@48 68
universe@135 69
universe@135 70 /**
universe@135 71 * Creates a memory pool with the specified initial size.
universe@135 72 *
universe@135 73 * As the created memory pool automatically grows in size by 16 elements, when
universe@135 74 * trying to allocate memory on a full pool, it is recommended that you use
universe@135 75 * a multiple of 16 for the initial size.
universe@135 76 *
universe@135 77 * @param n initial pool size (should be a multiple of 16)
universe@135 78 * @return a pointer to the new memory pool
universe@135 79 */
olaf@13 80 UcxMempool *ucx_mempool_new(size_t n);
universe@135 81
universe@135 82 /**
universe@135 83 * Resizes a memory pool.
universe@135 84 *
universe@135 85 * @param pool the pool to resize
universe@135 86 * @param newcap the new capacity
universe@135 87 * @return <code>EXIT_SUCCESS</code> on success or
universe@135 88 * <code>EXIT_FAILURE</code> on failure
universe@135 89 */
universe@15 90 int ucx_mempool_chcap(UcxMempool *pool, size_t newcap);
olaf@13 91
universe@135 92 /**
universe@141 93 * Changes the pool size to the next smallest multiple of 16.
universe@141 94 *
universe@141 95 * You may use this macro, to reduce the pool size after freeing
universe@141 96 * many pooled memory items.
universe@141 97 *
universe@141 98 * @param pool the pool to clamp
universe@141 99 * @return <code>EXIT_SUCCESS</code> on success or
universe@141 100 * <code>EXIT_FAILURE</code> on failure
universe@141 101 */
universe@141 102 #define ucx_mempool_clamp(pool) ucx_mempool_chcap(pool, \
universe@141 103 (pool->ndata & ~0xF)+0x10)
universe@141 104
universe@141 105 /**
universe@135 106 * Allocates pooled memory.
universe@135 107 *
universe@135 108 * @param pool the memory pool
universe@135 109 * @param n amount of memory to allocate
universe@135 110 * @return a pointer to the allocated memory
universe@135 111 * @see ucx_allocator_malloc()
universe@135 112 */
olaf@13 113 void *ucx_mempool_malloc(UcxMempool *pool, size_t n);
universe@135 114 /**
universe@135 115 * Allocates a pooled memory array.
universe@135 116 *
universe@181 117 * The content of the allocated memory is set to zero.
universe@135 118 *
universe@135 119 * @param pool the memory pool
universe@135 120 * @param nelem amount of elements to allocate
universe@135 121 * @param elsize amount of memory per element
universe@135 122 * @return a pointer to the allocated memory
universe@135 123 * @see ucx_allocator_calloc()
universe@135 124 */
olaf@13 125 void *ucx_mempool_calloc(UcxMempool *pool, size_t nelem, size_t elsize);
universe@146 126
universe@135 127 /**
universe@135 128 * Reallocates pooled memory.
universe@135 129 *
universe@215 130 * If the memory to be reallocated is not contained by the specified pool, the
universe@215 131 * behavior is undefined.
universe@141 132 *
universe@135 133 * @param pool the memory pool
universe@135 134 * @param ptr a pointer to the memory that shall be reallocated
universe@135 135 * @param n the new size of the memory
universe@181 136 * @return a pointer to the new location of the memory
universe@135 137 * @see ucx_allocator_realloc()
universe@135 138 */
olaf@13 139 void *ucx_mempool_realloc(UcxMempool *pool, void *ptr, size_t n);
universe@146 140
universe@135 141 /**
universe@135 142 * Frees pooled memory.
universe@135 143 *
universe@135 144 * Before freeing the memory, the specified destructor function (if any)
universe@135 145 * is called.
universe@135 146 *
universe@215 147 * If you specify memory, that is not pooled by the specified memory pool, the
universe@215 148 * behavior is undefined.
universe@135 149 *
universe@135 150 * @param pool the memory pool
universe@135 151 * @param ptr a pointer to the memory that shall be freed
universe@135 152 * @see ucx_mempool_set_destr()
universe@135 153 */
olaf@113 154 void ucx_mempool_free(UcxMempool *pool, void *ptr);
olaf@13 155
universe@135 156 /**
universe@135 157 * Destroys a memory pool.
universe@135 158 *
universe@135 159 * For each element the destructor function (if any) is called and the element
universe@135 160 * is freed.
universe@135 161 *
universe@135 162 * Each of the registered destructor function that has no corresponding element
universe@135 163 * within the pool (namely those registered by ucx_mempool_reg_destr) is
universe@135 164 * called interleaving with the element destruction, but with guarantee to the
universe@135 165 * order in which they were registered (FIFO order).
universe@135 166 *
universe@135 167 *
universe@135 168 * @param pool the mempool to destroy
universe@135 169 */
olaf@113 170 void ucx_mempool_destroy(UcxMempool *pool);
olaf@13 171
universe@135 172 /**
universe@135 173 * Sets a destructor function for the specified memory.
universe@135 174 *
universe@135 175 * The destructor is automatically called when the memory is freed or the
universe@135 176 * pool is destroyed.
universe@135 177 *
universe@135 178 * The only requirement for the specified memory is, that it <b>MUST</b> be
universe@225 179 * pooled memory by a UcxMempool or an element-compatible mempool. The pointer
universe@135 180 * to the destructor function is saved in a reserved area before the actual
universe@135 181 * memory.
universe@135 182 *
universe@135 183 * @param ptr pooled memory
universe@135 184 * @param func a pointer to the destructor function
universe@135 185 * @see ucx_mempool_free()
universe@135 186 * @see ucx_mempool_destroy()
universe@135 187 */
olaf@13 188 void ucx_mempool_set_destr(void *ptr, ucx_destructor func);
universe@135 189
universe@135 190 /**
universe@135 191 * Registers a destructor function for the specified (non-pooled) memory.
universe@135 192 *
universe@135 193 * This is useful, if you have memory that has not been allocated by a mempool,
universe@135 194 * but shall be managed by a mempool.
universe@135 195 *
universe@135 196 * This function creates an entry in the specified mempool and the memory will
universe@135 197 * therefore (logically) convert to pooled memory.
universe@135 198 *
universe@135 199 * @param pool the memory pool
universe@135 200 * @param ptr data the destructor is registered for
universe@135 201 * @param destr a pointer to the destructor function
universe@135 202 */
olaf@13 203 void ucx_mempool_reg_destr(UcxMempool *pool, void *ptr, ucx_destructor destr);
olaf@13 204
olaf@13 205 #ifdef __cplusplus
olaf@13 206 }
olaf@13 207 #endif
olaf@13 208
olaf@120 209 #endif /* UCX_MEMPOOL_H */
olaf@13 210

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