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| 1 /* |
| 2 * Copyright (c) 2007 Intel Corporation. All Rights Reserved. |
| 3 * |
| 4 * Permission is hereby granted, free of charge, to any person obtaining a |
| 5 * copy of this software and associated documentation files (the |
| 6 * "Software"), to deal in the Software without restriction, including |
| 7 * without limitation the rights to use, copy, modify, merge, publish, |
| 8 * distribute, sub license, and/or sell copies of the Software, and to |
| 9 * permit persons to whom the Software is furnished to do so, subject to |
| 10 * the following conditions: |
| 11 * |
| 12 * The above copyright notice and this permission notice (including the |
| 13 * next paragraph) shall be included in all copies or substantial portions |
| 14 * of the Software. |
| 15 * |
| 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| 17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. |
| 19 * IN NO EVENT SHALL PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR |
| 20 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 21 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 22 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 23 */ |
| 24 |
| 25 #include "object_heap.h" |
| 26 |
| 27 #include "assert.h" |
| 28 #include <stdio.h> |
| 29 #include <string.h> |
| 30 #include <stdlib.h> |
| 31 |
| 32 #define ASSERT assert |
| 33 |
| 34 #define LAST_FREE -1 |
| 35 #define ALLOCATED -2 |
| 36 |
| 37 /* |
| 38 * Expands the heap |
| 39 * Return 0 on success, -1 on error |
| 40 */ |
| 41 static int object_heap_expand( object_heap_p heap ) |
| 42 { |
| 43 int i; |
| 44 void *new_heap_index; |
| 45 int next_free; |
| 46 int new_heap_size = heap->heap_size + heap->heap_increment; |
| 47 |
| 48 new_heap_index = (void *) realloc( heap->heap_index, new_heap_size * heap->o
bject_size ); |
| 49 if ( NULL == new_heap_index ) |
| 50 { |
| 51 return -1; /* Out of memory */ |
| 52 } |
| 53 heap->heap_index = new_heap_index; |
| 54 next_free = heap->next_free; |
| 55 for(i = new_heap_size; i-- > heap->heap_size; ) |
| 56 { |
| 57 object_base_p obj = (object_base_p) (heap->heap_index + i * heap->object
_size); |
| 58 obj->id = i + heap->id_offset; |
| 59 obj->next_free = next_free; |
| 60 next_free = i; |
| 61 } |
| 62 heap->next_free = next_free; |
| 63 heap->heap_size = new_heap_size; |
| 64 return 0; /* Success */ |
| 65 } |
| 66 |
| 67 /* |
| 68 * Return 0 on success, -1 on error |
| 69 */ |
| 70 int object_heap_init( object_heap_p heap, int object_size, int id_offset) |
| 71 { |
| 72 heap->object_size = object_size; |
| 73 heap->id_offset = id_offset & OBJECT_HEAP_OFFSET_MASK; |
| 74 heap->heap_size = 0; |
| 75 heap->heap_increment = 16; |
| 76 heap->heap_index = NULL; |
| 77 heap->next_free = LAST_FREE; |
| 78 return object_heap_expand(heap); |
| 79 } |
| 80 |
| 81 /* |
| 82 * Allocates an object |
| 83 * Returns the object ID on success, returns -1 on error |
| 84 */ |
| 85 int object_heap_allocate( object_heap_p heap ) |
| 86 { |
| 87 object_base_p obj; |
| 88 if ( LAST_FREE == heap->next_free ) |
| 89 { |
| 90 if( -1 == object_heap_expand( heap ) ) |
| 91 { |
| 92 return -1; /* Out of memory */ |
| 93 } |
| 94 } |
| 95 ASSERT( heap->next_free >= 0 ); |
| 96 |
| 97 obj = (object_base_p) (heap->heap_index + heap->next_free * heap->object_siz
e); |
| 98 heap->next_free = obj->next_free; |
| 99 obj->next_free = ALLOCATED; |
| 100 return obj->id; |
| 101 } |
| 102 |
| 103 /* |
| 104 * Lookup an object by object ID |
| 105 * Returns a pointer to the object on success, returns NULL on error |
| 106 */ |
| 107 object_base_p object_heap_lookup( object_heap_p heap, int id ) |
| 108 { |
| 109 object_base_p obj; |
| 110 if ( (id < heap->id_offset) || (id > (heap->heap_size+heap->id_offset)) ) |
| 111 { |
| 112 return NULL; |
| 113 } |
| 114 id &= OBJECT_HEAP_ID_MASK; |
| 115 obj = (object_base_p) (heap->heap_index + id * heap->object_size); |
| 116 |
| 117 /* Check if the object has in fact been allocated */ |
| 118 if ( obj->next_free != ALLOCATED ) |
| 119 { |
| 120 return NULL; |
| 121 } |
| 122 return obj; |
| 123 } |
| 124 |
| 125 /* |
| 126 * Iterate over all objects in the heap. |
| 127 * Returns a pointer to the first object on the heap, returns NULL if heap is em
pty. |
| 128 */ |
| 129 object_base_p object_heap_first( object_heap_p heap, object_heap_iterator *iter
) |
| 130 { |
| 131 *iter = -1; |
| 132 return object_heap_next( heap, iter ); |
| 133 } |
| 134 |
| 135 /* |
| 136 * Iterate over all objects in the heap. |
| 137 * Returns a pointer to the next object on the heap, returns NULL if heap is emp
ty. |
| 138 */ |
| 139 object_base_p object_heap_next( object_heap_p heap, object_heap_iterator *iter ) |
| 140 { |
| 141 object_base_p obj; |
| 142 int i = *iter + 1; |
| 143 while ( i < heap->heap_size) |
| 144 { |
| 145 obj = (object_base_p) (heap->heap_index + i * heap->object_size); |
| 146 if (obj->next_free == ALLOCATED) |
| 147 { |
| 148 *iter = i; |
| 149 return obj; |
| 150 } |
| 151 i++; |
| 152 } |
| 153 *iter = i; |
| 154 return NULL; |
| 155 } |
| 156 |
| 157 |
| 158 |
| 159 /* |
| 160 * Frees an object |
| 161 */ |
| 162 void object_heap_free( object_heap_p heap, object_base_p obj ) |
| 163 { |
| 164 /* Don't complain about NULL pointers */ |
| 165 if (NULL != obj) |
| 166 { |
| 167 /* Check if the object has in fact been allocated */ |
| 168 ASSERT( obj->next_free == ALLOCATED ); |
| 169 |
| 170 obj->next_free = heap->next_free; |
| 171 heap->next_free = obj->id & OBJECT_HEAP_ID_MASK; |
| 172 } |
| 173 } |
| 174 |
| 175 /* |
| 176 * Destroys a heap, the heap must be empty. |
| 177 */ |
| 178 void object_heap_destroy( object_heap_p heap ) |
| 179 { |
| 180 object_base_p obj; |
| 181 int i; |
| 182 /* Check if heap is empty */ |
| 183 for (i = 0; i < heap->heap_size; i++) |
| 184 { |
| 185 /* Check if object is not still allocated */ |
| 186 obj = (object_base_p) (heap->heap_index + i * heap->object_size); |
| 187 ASSERT( obj->next_free != ALLOCATED ); |
| 188 } |
| 189 free(heap->heap_index); |
| 190 heap->heap_size = 0; |
| 191 heap->heap_index = NULL; |
| 192 heap->next_free = LAST_FREE; |
| 193 } |
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