src/cx/allocator.h

Sun, 26 Sep 2021 16:12:21 +0200

author
Mike Becker <universe@uap-core.de>
date
Sun, 26 Sep 2021 16:12:21 +0200
changeset 429
3d8235c96a27
parent 419
b5d6cb88d05d
child 434
38ee262e8b94
permissions
-rw-r--r--

add documentation to allocator.h

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@405 67 void *(*realloc)(void *data, void *mem, size_t n);
universe@429 68
universe@429 69 /**
universe@429 70 * Allocate \p nelem elements of \p n bytes each, all initialized to zero.
universe@429 71 *
universe@429 72 * @param data the allocator's data
universe@429 73 * @param nelem the number of elements
universe@429 74 * @param n the size of each element in bytes
universe@429 75 * @return a pointer to the allocated memory
universe@429 76 */
universe@405 77 void *(*calloc)(void *data, size_t nelem, size_t n);
universe@429 78
universe@429 79 /**
universe@429 80 * Free a block allocated by this allocator.
universe@429 81 *
universe@429 82 * \note Freeing a block of a different allocator is undefined.
universe@429 83 *
universe@429 84 * @param data the allocator's data
universe@429 85 * @param mem a pointer to the block to free
universe@429 86 */
universe@429 87 void (*free)(void *data, void *mem);
universe@396 88 } cx_allocator_class;
universe@396 89
universe@429 90 /**
universe@429 91 * Structure holding the data for an allocator.
universe@429 92 */
universe@394 93 struct cx_allocator_s {
universe@429 94 /**
universe@429 95 * A pointer to the instance of the allocator class.
universe@429 96 */
universe@396 97 cx_allocator_class *cl;
universe@429 98 /**
universe@429 99 * A pointer to the data this allocator uses.
universe@429 100 */
universe@397 101 void *data;
universe@391 102 };
universe@429 103
universe@429 104 /**
universe@429 105 * High-Level type alias for the allocator type.
universe@429 106 */
universe@397 107 typedef struct cx_allocator_s *CxAllocator;
universe@391 108
universe@429 109 /**
universe@429 110 * A default allocator using standard library malloc() etc.
universe@429 111 */
universe@391 112 extern CxAllocator cxDefaultAllocator;
universe@391 113
universe@429 114 /**
universe@429 115 * Allocate \p n bytes of memory.
universe@429 116 *
universe@429 117 * @param allocator the allocator
universe@429 118 * @param n the number of bytes
universe@429 119 * @return a pointer to the allocated memory
universe@429 120 */
universe@397 121 void *cxMalloc(CxAllocator allocator, size_t n);
universe@397 122
universe@429 123 /**
universe@429 124 * Re-allocate the previously allocated block in \p mem, making the new block \p n bytes long.
universe@429 125 * This function may return the same pointer that was passed to it, if moving the memory
universe@429 126 * was not necessary.
universe@429 127 *
universe@429 128 * \note Re-allocating a block allocated by a different allocator is undefined.
universe@429 129 *
universe@429 130 * @param allocator the allocator
universe@429 131 * @param mem pointer to the previously allocated block
universe@429 132 * @param n the new size in bytes
universe@429 133 * @return a pointer to the re-allocated memory
universe@429 134 */
universe@397 135 void *cxRealloc(CxAllocator allocator, void *mem, size_t n);
universe@397 136
universe@429 137 /**
universe@429 138 * Re-allocate a previously allocated block and changes the pointer in-place, if necessary.
universe@429 139 * This function acts like cxRealloc() using the pointer pointed to by \p mem.
universe@429 140 * On success, the pointer is changed to the new location (in case the
universe@429 141 *
universe@429 142 * \note Re-allocating a block allocated by a different allocator is undefined.
universe@429 143 *
universe@429 144 * \par Error handling
universe@429 145 * \c errno will be set, if the underlying realloc function does so.
universe@429 146 *
universe@429 147 * @param allocator the allocator
universe@429 148 * @param mem pointer to the pointer to allocated block
universe@429 149 * @param n the new size in bytes
universe@429 150 * @return zero on success, non-zero on failure
universe@429 151 */
universe@414 152 int cxReallocate(CxAllocator allocator, void **mem, size_t n);
universe@414 153
universe@429 154 /**
universe@429 155 * Allocate \p nelem elements of \p n bytes each, all initialized to zero.
universe@429 156 *
universe@429 157 * @param allocator the allocator
universe@429 158 * @param nelem the number of elements
universe@429 159 * @param n the size of each element in bytes
universe@429 160 * @return a pointer to the allocated memory
universe@429 161 */
universe@397 162 void *cxCalloc(CxAllocator allocator, size_t nelem, size_t n);
universe@397 163
universe@429 164 /**
universe@429 165 * Free a block allocated by this allocator.
universe@429 166 *
universe@429 167 * \note Freeing a block of a different allocator is undefined.
universe@429 168 *
universe@429 169 * @param allocator the allocator
universe@429 170 * @param mem a pointer to the block to free
universe@429 171 */
universe@397 172 void cxFree(CxAllocator allocator, void *mem);
universe@391 173
universe@415 174 #ifdef __cplusplus
universe@415 175 } /* extern "C" */
universe@415 176 #endif
universe@415 177
universe@393 178 #endif /* UCX_ALLOCATOR_H */

mercurial