src/cx/allocator.h

Sun, 03 Oct 2021 12:02:57 +0200

author
Mike Becker <universe@uap-core.de>
date
Sun, 03 Oct 2021 12:02:57 +0200
changeset 450
7960298039cf
parent 434
38ee262e8b94
child 452
a10c3e127050
permissions
-rw-r--r--

improves usage of attributes

universe@391 1 /*
universe@391 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@391 3 *
universe@391 4 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
universe@391 5 *
universe@391 6 * Redistribution and use in source and binary forms, with or without
universe@391 7 * modification, are permitted provided that the following conditions are met:
universe@391 8 *
universe@391 9 * 1. Redistributions of source code must retain the above copyright
universe@391 10 * notice, this list of conditions and the following disclaimer.
universe@391 11 *
universe@391 12 * 2. Redistributions in binary form must reproduce the above copyright
universe@391 13 * notice, this list of conditions and the following disclaimer in the
universe@391 14 * documentation and/or other materials provided with the distribution.
universe@391 15 *
universe@391 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@391 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@391 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@391 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@391 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@391 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@391 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@391 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@391 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@391 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@391 26 * POSSIBILITY OF SUCH DAMAGE.
universe@391 27 */
universe@429 28 /**
universe@429 29 * \file allocator.h
universe@429 30 * Interface for custom allocators.
universe@429 31 */
universe@391 32
universe@391 33 #ifndef UCX_ALLOCATOR_H
universe@391 34 #define UCX_ALLOCATOR_H
universe@391 35
universe@391 36 #include <stdlib.h>
universe@391 37
universe@415 38 #ifdef __cplusplus
universe@415 39 extern "C" {
universe@415 40 #endif
universe@415 41
universe@429 42 /**
universe@429 43 * The class definition for an allocator.
universe@429 44 */
universe@396 45 typedef struct {
universe@429 46 /**
universe@429 47 * Allocate \p n bytes of memory.
universe@429 48 *
universe@429 49 * @param data the allocator's data
universe@429 50 * @param n the number of bytes
universe@429 51 * @return a pointer to the allocated memory
universe@429 52 */
universe@405 53 void *(*malloc)(void *data, size_t n);
universe@429 54
universe@429 55 /**
universe@429 56 * Re-allocate the previously allocated block in \p mem, making the new block \p n bytes long.
universe@429 57 * This function may return the same pointer that was passed to it, if moving the memory
universe@429 58 * was not necessary.
universe@429 59 *
universe@429 60 * \note Re-allocating a block allocated by a different allocator is undefined.
universe@429 61 *
universe@429 62 * @param data the allocator's data
universe@429 63 * @param mem pointer to the previously allocated block
universe@429 64 * @param n the new size in bytes
universe@429 65 * @return a pointer to the re-allocated memory
universe@429 66 */
universe@450 67 void *(*realloc)(void *data, void *mem, size_t n)
universe@450 68 __attribute__((__warn_unused_result__));
universe@429 69
universe@429 70 /**
universe@429 71 * Allocate \p nelem elements of \p n bytes each, all initialized to zero.
universe@429 72 *
universe@429 73 * @param data the allocator's data
universe@429 74 * @param nelem the number of elements
universe@429 75 * @param n the size of each element in bytes
universe@429 76 * @return a pointer to the allocated memory
universe@429 77 */
universe@405 78 void *(*calloc)(void *data, size_t nelem, size_t n);
universe@429 79
universe@429 80 /**
universe@429 81 * Free a block allocated by this allocator.
universe@429 82 *
universe@429 83 * \note Freeing a block of a different allocator is undefined.
universe@429 84 *
universe@429 85 * @param data the allocator's data
universe@429 86 * @param mem a pointer to the block to free
universe@429 87 */
universe@450 88 void (*free)(void *data, void *mem)
universe@450 89 __attribute__((__nonnull__));
universe@396 90 } cx_allocator_class;
universe@396 91
universe@429 92 /**
universe@429 93 * Structure holding the data for an allocator.
universe@429 94 */
universe@394 95 struct cx_allocator_s {
universe@429 96 /**
universe@429 97 * A pointer to the instance of the allocator class.
universe@429 98 */
universe@396 99 cx_allocator_class *cl;
universe@429 100 /**
universe@429 101 * A pointer to the data this allocator uses.
universe@429 102 */
universe@397 103 void *data;
universe@391 104 };
universe@429 105
universe@429 106 /**
universe@429 107 * High-Level type alias for the allocator type.
universe@429 108 */
universe@397 109 typedef struct cx_allocator_s *CxAllocator;
universe@391 110
universe@429 111 /**
universe@429 112 * A default allocator using standard library malloc() etc.
universe@429 113 */
universe@391 114 extern CxAllocator cxDefaultAllocator;
universe@391 115
universe@429 116 /**
universe@429 117 * Allocate \p n bytes of memory.
universe@429 118 *
universe@429 119 * @param allocator the allocator
universe@429 120 * @param n the number of bytes
universe@429 121 * @return a pointer to the allocated memory
universe@429 122 */
universe@450 123 void *cxMalloc(CxAllocator allocator, size_t n)
universe@450 124 __attribute__((__malloc__));
universe@397 125
universe@429 126 /**
universe@429 127 * Re-allocate the previously allocated block in \p mem, making the new block \p n bytes long.
universe@429 128 * This function may return the same pointer that was passed to it, if moving the memory
universe@429 129 * was not necessary.
universe@429 130 *
universe@429 131 * \note Re-allocating a block allocated by a different allocator is undefined.
universe@429 132 *
universe@429 133 * @param allocator the allocator
universe@429 134 * @param mem pointer to the previously allocated block
universe@429 135 * @param n the new size in bytes
universe@429 136 * @return a pointer to the re-allocated memory
universe@429 137 */
universe@450 138 void *cxRealloc(CxAllocator allocator, void *mem, size_t n)
universe@450 139 __attribute__((warn_unused_result));
universe@397 140
universe@429 141 /**
universe@429 142 * Re-allocate a previously allocated block and changes the pointer in-place, if necessary.
universe@429 143 * This function acts like cxRealloc() using the pointer pointed to by \p mem.
universe@429 144 * On success, the pointer is changed to the new location (in case the
universe@429 145 *
universe@429 146 * \note Re-allocating a block allocated by a different allocator is undefined.
universe@429 147 *
universe@429 148 * \par Error handling
universe@429 149 * \c errno will be set, if the underlying realloc function does so.
universe@429 150 *
universe@429 151 * @param allocator the allocator
universe@429 152 * @param mem pointer to the pointer to allocated block
universe@429 153 * @param n the new size in bytes
universe@429 154 * @return zero on success, non-zero on failure
universe@429 155 */
universe@450 156 int cxReallocate(CxAllocator allocator, void **mem, size_t n)
universe@450 157 __attribute__((nonnull));
universe@414 158
universe@429 159 /**
universe@429 160 * Allocate \p nelem elements of \p n bytes each, all initialized to zero.
universe@429 161 *
universe@429 162 * @param allocator the allocator
universe@429 163 * @param nelem the number of elements
universe@429 164 * @param n the size of each element in bytes
universe@429 165 * @return a pointer to the allocated memory
universe@429 166 */
universe@450 167 void *cxCalloc(CxAllocator allocator, size_t nelem, size_t n)
universe@450 168 __attribute__((malloc));
universe@397 169
universe@429 170 /**
universe@429 171 * Free a block allocated by this allocator.
universe@429 172 *
universe@429 173 * \note Freeing a block of a different allocator is undefined.
universe@429 174 *
universe@429 175 * @param allocator the allocator
universe@429 176 * @param mem a pointer to the block to free
universe@429 177 */
universe@450 178 void cxFree(CxAllocator allocator, void *mem)
universe@450 179 __attribute__((nonnull));
universe@391 180
universe@415 181 #ifdef __cplusplus
universe@415 182 } /* extern "C" */
universe@415 183 #endif
universe@415 184
universe@393 185 #endif /* UCX_ALLOCATOR_H */

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