src/ucx/mempool.h

Sat, 28 Oct 2017 15:43:51 +0200

author
Mike Becker <universe@uap-core.de>
date
Sat, 28 Oct 2017 15:43:51 +0200
changeset 259
2f5dea574a75
parent 251
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child 326
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modules documentation

universe@103 1 /*
universe@103 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
olaf@13 3 *
universe@259 4 * Copyright 2017 Mike Becker, 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@259 41 #include "ucx.h"
universe@259 42 #include "allocator.h"
universe@38 43 #include <stddef.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@241 73 * As the created memory pool automatically grows in size by factor two when
universe@135 74 * trying to allocate memory on a full pool, it is recommended that you use
universe@241 75 * a power of two for the initial size.
universe@135 76 *
universe@241 77 * @param n initial pool size (should be a power of two, e.g. 16)
universe@135 78 * @return a pointer to the new memory pool
universe@241 79 * @see ucx_mempool_new_default()
universe@135 80 */
olaf@13 81 UcxMempool *ucx_mempool_new(size_t n);
universe@135 82
universe@135 83 /**
universe@135 84 * Resizes a memory pool.
universe@135 85 *
universe@241 86 * This function will fail if the new capacity is not sufficient for the
universe@241 87 * present data.
universe@241 88 *
universe@135 89 * @param pool the pool to resize
universe@135 90 * @param newcap the new capacity
universe@241 91 * @return zero on success or non-zero on failure
universe@135 92 */
universe@15 93 int ucx_mempool_chcap(UcxMempool *pool, size_t newcap);
olaf@13 94
universe@135 95 /**
universe@135 96 * Allocates pooled memory.
universe@135 97 *
universe@135 98 * @param pool the memory pool
universe@135 99 * @param n amount of memory to allocate
universe@135 100 * @return a pointer to the allocated memory
universe@135 101 * @see ucx_allocator_malloc()
universe@135 102 */
olaf@13 103 void *ucx_mempool_malloc(UcxMempool *pool, size_t n);
universe@135 104 /**
universe@135 105 * Allocates a pooled memory array.
universe@135 106 *
universe@181 107 * The content of the allocated memory is set to zero.
universe@135 108 *
universe@135 109 * @param pool the memory pool
universe@135 110 * @param nelem amount of elements to allocate
universe@135 111 * @param elsize amount of memory per element
universe@135 112 * @return a pointer to the allocated memory
universe@135 113 * @see ucx_allocator_calloc()
universe@135 114 */
olaf@13 115 void *ucx_mempool_calloc(UcxMempool *pool, size_t nelem, size_t elsize);
universe@146 116
universe@135 117 /**
universe@135 118 * Reallocates pooled memory.
universe@135 119 *
universe@215 120 * If the memory to be reallocated is not contained by the specified pool, the
universe@215 121 * behavior is undefined.
universe@141 122 *
universe@135 123 * @param pool the memory pool
universe@135 124 * @param ptr a pointer to the memory that shall be reallocated
universe@135 125 * @param n the new size of the memory
universe@181 126 * @return a pointer to the new location of the memory
universe@135 127 * @see ucx_allocator_realloc()
universe@135 128 */
olaf@13 129 void *ucx_mempool_realloc(UcxMempool *pool, void *ptr, size_t n);
universe@146 130
universe@135 131 /**
universe@135 132 * Frees pooled memory.
universe@135 133 *
universe@135 134 * Before freeing the memory, the specified destructor function (if any)
universe@135 135 * is called.
universe@135 136 *
universe@215 137 * If you specify memory, that is not pooled by the specified memory pool, the
universe@241 138 * program will terminate with a call to <code>abort()</code>.
universe@135 139 *
universe@135 140 * @param pool the memory pool
universe@135 141 * @param ptr a pointer to the memory that shall be freed
universe@135 142 * @see ucx_mempool_set_destr()
universe@135 143 */
olaf@113 144 void ucx_mempool_free(UcxMempool *pool, void *ptr);
olaf@13 145
universe@135 146 /**
universe@135 147 * Destroys a memory pool.
universe@135 148 *
universe@135 149 * For each element the destructor function (if any) is called and the element
universe@135 150 * is freed.
universe@135 151 *
universe@135 152 * Each of the registered destructor function that has no corresponding element
universe@135 153 * within the pool (namely those registered by ucx_mempool_reg_destr) is
universe@135 154 * called interleaving with the element destruction, but with guarantee to the
universe@135 155 * order in which they were registered (FIFO order).
universe@135 156 *
universe@135 157 *
universe@135 158 * @param pool the mempool to destroy
universe@135 159 */
olaf@113 160 void ucx_mempool_destroy(UcxMempool *pool);
olaf@13 161
universe@135 162 /**
universe@135 163 * Sets a destructor function for the specified memory.
universe@135 164 *
universe@135 165 * The destructor is automatically called when the memory is freed or the
universe@135 166 * pool is destroyed.
universe@135 167 *
universe@135 168 * The only requirement for the specified memory is, that it <b>MUST</b> be
universe@225 169 * pooled memory by a UcxMempool or an element-compatible mempool. The pointer
universe@135 170 * to the destructor function is saved in a reserved area before the actual
universe@135 171 * memory.
universe@135 172 *
universe@135 173 * @param ptr pooled memory
universe@135 174 * @param func a pointer to the destructor function
universe@135 175 * @see ucx_mempool_free()
universe@135 176 * @see ucx_mempool_destroy()
universe@135 177 */
olaf@13 178 void ucx_mempool_set_destr(void *ptr, ucx_destructor func);
universe@135 179
universe@135 180 /**
universe@135 181 * Registers a destructor function for the specified (non-pooled) memory.
universe@135 182 *
universe@135 183 * This is useful, if you have memory that has not been allocated by a mempool,
universe@135 184 * but shall be managed by a mempool.
universe@135 185 *
universe@135 186 * This function creates an entry in the specified mempool and the memory will
universe@135 187 * therefore (logically) convert to pooled memory.
universe@135 188 *
universe@135 189 * @param pool the memory pool
universe@135 190 * @param ptr data the destructor is registered for
universe@135 191 * @param destr a pointer to the destructor function
universe@135 192 */
olaf@13 193 void ucx_mempool_reg_destr(UcxMempool *pool, void *ptr, ucx_destructor destr);
olaf@13 194
olaf@13 195 #ifdef __cplusplus
olaf@13 196 }
olaf@13 197 #endif
olaf@13 198
olaf@120 199 #endif /* UCX_MEMPOOL_H */
olaf@13 200

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