[444] | 1 | /*
|
---|
| 2 | tre-mem.c - TRE memory allocator
|
---|
| 3 |
|
---|
| 4 | Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi>
|
---|
| 5 | All rights reserved.
|
---|
| 6 |
|
---|
| 7 | Redistribution and use in source and binary forms, with or without
|
---|
| 8 | modification, are permitted provided that the following conditions
|
---|
| 9 | are met:
|
---|
| 10 |
|
---|
| 11 | 1. Redistributions of source code must retain the above copyright
|
---|
| 12 | notice, this list of conditions and the following disclaimer.
|
---|
| 13 |
|
---|
| 14 | 2. Redistributions in binary form must reproduce the above copyright
|
---|
| 15 | notice, this list of conditions and the following disclaimer in the
|
---|
| 16 | documentation and/or other materials provided with the distribution.
|
---|
| 17 |
|
---|
| 18 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS
|
---|
| 19 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
---|
| 20 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
---|
| 21 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
---|
| 22 | HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
---|
| 23 | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
---|
| 24 | LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
---|
| 25 | DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
---|
| 26 | THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
---|
| 27 | (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
---|
| 28 | OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
---|
| 29 |
|
---|
| 30 | */
|
---|
| 31 |
|
---|
| 32 | /*
|
---|
| 33 | This memory allocator is for allocating small memory blocks efficiently
|
---|
| 34 | in terms of memory overhead and execution speed. The allocated blocks
|
---|
| 35 | cannot be freed individually, only all at once. There can be multiple
|
---|
| 36 | allocators, though.
|
---|
| 37 | */
|
---|
| 38 |
|
---|
| 39 | #include <stdlib.h>
|
---|
| 40 | #include <string.h>
|
---|
| 41 |
|
---|
| 42 | #include "tre.h"
|
---|
| 43 |
|
---|
| 44 | /*
|
---|
| 45 | This memory allocator is for allocating small memory blocks efficiently
|
---|
| 46 | in terms of memory overhead and execution speed. The allocated blocks
|
---|
| 47 | cannot be freed individually, only all at once. There can be multiple
|
---|
| 48 | allocators, though.
|
---|
| 49 | */
|
---|
| 50 |
|
---|
| 51 | /* Returns a new memory allocator or NULL if out of memory. */
|
---|
| 52 | tre_mem_t
|
---|
| 53 | tre_mem_new_impl(int provided, void *provided_block)
|
---|
| 54 | {
|
---|
| 55 | tre_mem_t mem;
|
---|
| 56 | if (provided)
|
---|
| 57 | {
|
---|
| 58 | mem = provided_block;
|
---|
| 59 | memset(mem, 0, sizeof(*mem));
|
---|
| 60 | }
|
---|
| 61 | else
|
---|
| 62 | mem = xcalloc(1, sizeof(*mem));
|
---|
| 63 | if (mem == NULL)
|
---|
| 64 | return NULL;
|
---|
| 65 | return mem;
|
---|
| 66 | }
|
---|
| 67 |
|
---|
| 68 |
|
---|
| 69 | /* Frees the memory allocator and all memory allocated with it. */
|
---|
| 70 | void
|
---|
| 71 | tre_mem_destroy(tre_mem_t mem)
|
---|
| 72 | {
|
---|
| 73 | tre_list_t *tmp, *l = mem->blocks;
|
---|
| 74 |
|
---|
| 75 | while (l != NULL)
|
---|
| 76 | {
|
---|
| 77 | xfree(l->data);
|
---|
| 78 | tmp = l->next;
|
---|
| 79 | xfree(l);
|
---|
| 80 | l = tmp;
|
---|
| 81 | }
|
---|
| 82 | xfree(mem);
|
---|
| 83 | }
|
---|
| 84 |
|
---|
| 85 |
|
---|
| 86 | /* Allocates a block of `size' bytes from `mem'. Returns a pointer to the
|
---|
| 87 | allocated block or NULL if an underlying malloc() failed. */
|
---|
| 88 | void *
|
---|
| 89 | tre_mem_alloc_impl(tre_mem_t mem, int provided, void *provided_block,
|
---|
| 90 | int zero, size_t size)
|
---|
| 91 | {
|
---|
| 92 | void *ptr;
|
---|
| 93 |
|
---|
| 94 | if (mem->failed)
|
---|
| 95 | {
|
---|
| 96 | return NULL;
|
---|
| 97 | }
|
---|
| 98 |
|
---|
| 99 | if (mem->n < size)
|
---|
| 100 | {
|
---|
| 101 | /* We need more memory than is available in the current block.
|
---|
| 102 | Allocate a new block. */
|
---|
| 103 | tre_list_t *l;
|
---|
| 104 | if (provided)
|
---|
| 105 | {
|
---|
| 106 | if (provided_block == NULL)
|
---|
| 107 | {
|
---|
| 108 | mem->failed = 1;
|
---|
| 109 | return NULL;
|
---|
| 110 | }
|
---|
| 111 | mem->ptr = provided_block;
|
---|
| 112 | mem->n = TRE_MEM_BLOCK_SIZE;
|
---|
| 113 | }
|
---|
| 114 | else
|
---|
| 115 | {
|
---|
| 116 | int block_size;
|
---|
| 117 | if (size * 8 > TRE_MEM_BLOCK_SIZE)
|
---|
| 118 | block_size = size * 8;
|
---|
| 119 | else
|
---|
| 120 | block_size = TRE_MEM_BLOCK_SIZE;
|
---|
| 121 | l = xmalloc(sizeof(*l));
|
---|
| 122 | if (l == NULL)
|
---|
| 123 | {
|
---|
| 124 | mem->failed = 1;
|
---|
| 125 | return NULL;
|
---|
| 126 | }
|
---|
| 127 | l->data = xmalloc(block_size);
|
---|
| 128 | if (l->data == NULL)
|
---|
| 129 | {
|
---|
| 130 | xfree(l);
|
---|
| 131 | mem->failed = 1;
|
---|
| 132 | return NULL;
|
---|
| 133 | }
|
---|
| 134 | l->next = NULL;
|
---|
| 135 | if (mem->current != NULL)
|
---|
| 136 | mem->current->next = l;
|
---|
| 137 | if (mem->blocks == NULL)
|
---|
| 138 | mem->blocks = l;
|
---|
| 139 | mem->current = l;
|
---|
| 140 | mem->ptr = l->data;
|
---|
| 141 | mem->n = block_size;
|
---|
| 142 | }
|
---|
| 143 | }
|
---|
| 144 |
|
---|
| 145 | /* Make sure the next pointer will be aligned. */
|
---|
| 146 | size += ALIGN(mem->ptr + size, long);
|
---|
| 147 |
|
---|
| 148 | /* Allocate from current block. */
|
---|
| 149 | ptr = mem->ptr;
|
---|
| 150 | mem->ptr += size;
|
---|
| 151 | mem->n -= size;
|
---|
| 152 |
|
---|
| 153 | /* Set to zero if needed. */
|
---|
| 154 | if (zero)
|
---|
| 155 | memset(ptr, 0, size);
|
---|
| 156 |
|
---|
| 157 | return ptr;
|
---|
| 158 | }
|
---|