1 | /** |
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2 | * @file |
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3 | * |
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4 | * @ingroup ScoreHeap |
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5 | * |
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6 | * @brief Heap Handler implementation. |
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7 | */ |
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8 | |
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9 | /* |
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10 | * COPYRIGHT (c) 1989-1999. |
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11 | * On-Line Applications Research Corporation (OAR). |
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12 | * |
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13 | * Copyright (c) 2009 embedded brains GmbH. |
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14 | * |
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15 | * The license and distribution terms for this file may be |
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16 | * found in the file LICENSE in this distribution or at |
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17 | * http://www.rtems.org/license/LICENSE. |
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18 | */ |
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19 | |
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20 | #if HAVE_CONFIG_H |
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21 | #include "config.h" |
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22 | #endif |
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23 | |
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24 | #include <rtems/system.h> |
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25 | #include <rtems/score/heapimpl.h> |
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26 | |
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27 | #ifndef HEAP_PROTECTION |
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28 | #define _Heap_Protection_free_delayed_blocks( heap, alloc_begin ) false |
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29 | #else |
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30 | static bool _Heap_Protection_free_delayed_blocks( |
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31 | Heap_Control *heap, |
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32 | uintptr_t alloc_begin |
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33 | ) |
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34 | { |
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35 | bool search_again = false; |
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36 | uintptr_t const blocks_to_free_count = |
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37 | (heap->Protection.delayed_free_block_count + 1) / 2; |
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38 | |
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39 | if ( alloc_begin == 0 && blocks_to_free_count > 0 ) { |
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40 | Heap_Block *block_to_free = heap->Protection.first_delayed_free_block; |
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41 | uintptr_t count = 0; |
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42 | |
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43 | for ( count = 0; count < blocks_to_free_count; ++count ) { |
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44 | Heap_Block *next_block_to_free = |
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45 | block_to_free->Protection_begin.next_delayed_free_block; |
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46 | |
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47 | block_to_free->Protection_begin.next_delayed_free_block = |
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48 | HEAP_PROTECTION_OBOLUS; |
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49 | |
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50 | _Heap_Free( |
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51 | heap, |
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52 | (void *) _Heap_Alloc_area_of_block( block_to_free ) |
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53 | ); |
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54 | |
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55 | block_to_free = next_block_to_free; |
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56 | } |
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57 | |
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58 | heap->Protection.delayed_free_block_count -= blocks_to_free_count; |
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59 | heap->Protection.first_delayed_free_block = block_to_free; |
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60 | |
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61 | search_again = true; |
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62 | } |
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63 | |
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64 | return search_again; |
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65 | } |
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66 | #endif |
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67 | |
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68 | #ifdef RTEMS_HEAP_DEBUG |
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69 | static void _Heap_Check_allocation( |
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70 | const Heap_Control *heap, |
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71 | const Heap_Block *block, |
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72 | uintptr_t alloc_begin, |
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73 | uintptr_t alloc_size, |
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74 | uintptr_t alignment, |
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75 | uintptr_t boundary |
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76 | ) |
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77 | { |
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78 | uintptr_t const min_block_size = heap->min_block_size; |
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79 | uintptr_t const page_size = heap->page_size; |
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80 | |
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81 | uintptr_t const block_begin = (uintptr_t) block; |
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82 | uintptr_t const block_size = _Heap_Block_size( block ); |
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83 | uintptr_t const block_end = block_begin + block_size; |
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84 | |
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85 | uintptr_t const alloc_end = alloc_begin + alloc_size; |
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86 | |
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87 | uintptr_t const alloc_area_begin = _Heap_Alloc_area_of_block( block ); |
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88 | uintptr_t const alloc_area_offset = alloc_begin - alloc_area_begin; |
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89 | |
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90 | _HAssert( block_size >= min_block_size ); |
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91 | _HAssert( block_begin < block_end ); |
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92 | _HAssert( |
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93 | _Heap_Is_aligned( block_begin + HEAP_BLOCK_HEADER_SIZE, page_size ) |
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94 | ); |
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95 | _HAssert( |
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96 | _Heap_Is_aligned( block_size, page_size ) |
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97 | ); |
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98 | |
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99 | _HAssert( alloc_end <= block_end + HEAP_ALLOC_BONUS ); |
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100 | _HAssert( alloc_area_begin == block_begin + HEAP_BLOCK_HEADER_SIZE); |
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101 | _HAssert( alloc_area_offset < page_size ); |
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102 | |
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103 | _HAssert( _Heap_Is_aligned( alloc_area_begin, page_size ) ); |
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104 | if ( alignment == 0 ) { |
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105 | _HAssert( alloc_begin == alloc_area_begin ); |
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106 | } else { |
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107 | _HAssert( _Heap_Is_aligned( alloc_begin, alignment ) ); |
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108 | } |
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109 | |
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110 | if ( boundary != 0 ) { |
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111 | uintptr_t boundary_line = _Heap_Align_down( alloc_end, boundary ); |
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112 | |
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113 | _HAssert( alloc_size <= boundary ); |
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114 | _HAssert( boundary_line <= alloc_begin || alloc_end <= boundary_line ); |
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115 | } |
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116 | } |
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117 | #else |
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118 | #define _Heap_Check_allocation( h, b, ab, as, ag, bd ) ((void) 0) |
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119 | #endif |
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120 | |
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121 | static uintptr_t _Heap_Check_block( |
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122 | const Heap_Control *heap, |
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123 | const Heap_Block *block, |
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124 | uintptr_t alloc_size, |
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125 | uintptr_t alignment, |
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126 | uintptr_t boundary |
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127 | ) |
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128 | { |
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129 | uintptr_t const page_size = heap->page_size; |
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130 | uintptr_t const min_block_size = heap->min_block_size; |
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131 | |
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132 | uintptr_t const block_begin = (uintptr_t) block; |
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133 | uintptr_t const block_size = _Heap_Block_size( block ); |
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134 | uintptr_t const block_end = block_begin + block_size; |
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135 | |
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136 | uintptr_t const alloc_begin_floor = _Heap_Alloc_area_of_block( block ); |
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137 | uintptr_t const alloc_begin_ceiling = block_end - min_block_size |
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138 | + HEAP_BLOCK_HEADER_SIZE + page_size - 1; |
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139 | |
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140 | uintptr_t alloc_end = block_end + HEAP_ALLOC_BONUS; |
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141 | uintptr_t alloc_begin = alloc_end - alloc_size; |
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142 | |
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143 | alloc_begin = _Heap_Align_down( alloc_begin, alignment ); |
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144 | |
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145 | /* Ensure that the we have a valid new block at the end */ |
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146 | if ( alloc_begin > alloc_begin_ceiling ) { |
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147 | alloc_begin = _Heap_Align_down( alloc_begin_ceiling, alignment ); |
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148 | } |
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149 | |
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150 | alloc_end = alloc_begin + alloc_size; |
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151 | |
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152 | /* Ensure boundary constaint */ |
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153 | if ( boundary != 0 ) { |
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154 | uintptr_t const boundary_floor = alloc_begin_floor + alloc_size; |
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155 | uintptr_t boundary_line = _Heap_Align_down( alloc_end, boundary ); |
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156 | |
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157 | while ( alloc_begin < boundary_line && boundary_line < alloc_end ) { |
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158 | if ( boundary_line < boundary_floor ) { |
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159 | return 0; |
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160 | } |
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161 | alloc_begin = boundary_line - alloc_size; |
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162 | alloc_begin = _Heap_Align_down( alloc_begin, alignment ); |
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163 | alloc_end = alloc_begin + alloc_size; |
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164 | boundary_line = _Heap_Align_down( alloc_end, boundary ); |
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165 | } |
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166 | } |
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167 | |
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168 | /* Ensure that the we have a valid new block at the beginning */ |
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169 | if ( alloc_begin >= alloc_begin_floor ) { |
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170 | uintptr_t const alloc_block_begin = |
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171 | (uintptr_t) _Heap_Block_of_alloc_area( alloc_begin, page_size ); |
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172 | uintptr_t const free_size = alloc_block_begin - block_begin; |
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173 | |
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174 | if ( free_size >= min_block_size || free_size == 0 ) { |
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175 | return alloc_begin; |
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176 | } |
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177 | } |
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178 | |
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179 | return 0; |
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180 | } |
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181 | |
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182 | void *_Heap_Allocate_aligned_with_boundary( |
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183 | Heap_Control *heap, |
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184 | uintptr_t alloc_size, |
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185 | uintptr_t alignment, |
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186 | uintptr_t boundary |
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187 | ) |
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188 | { |
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189 | Heap_Statistics *const stats = &heap->stats; |
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190 | uintptr_t const block_size_floor = alloc_size + HEAP_BLOCK_HEADER_SIZE |
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191 | - HEAP_ALLOC_BONUS; |
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192 | uintptr_t const page_size = heap->page_size; |
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193 | Heap_Block *block = NULL; |
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194 | uintptr_t alloc_begin = 0; |
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195 | uint32_t search_count = 0; |
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196 | bool search_again = false; |
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197 | |
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198 | if ( block_size_floor < alloc_size ) { |
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199 | /* Integer overflow occured */ |
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200 | return NULL; |
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201 | } |
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202 | |
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203 | if ( boundary != 0 ) { |
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204 | if ( boundary < alloc_size ) { |
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205 | return NULL; |
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206 | } |
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207 | |
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208 | if ( alignment == 0 ) { |
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209 | alignment = page_size; |
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210 | } |
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211 | } |
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212 | |
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213 | do { |
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214 | Heap_Block *const free_list_tail = _Heap_Free_list_tail( heap ); |
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215 | |
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216 | block = _Heap_Free_list_first( heap ); |
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217 | while ( block != free_list_tail ) { |
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218 | _HAssert( _Heap_Is_prev_used( block ) ); |
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219 | |
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220 | _Heap_Protection_block_check( heap, block ); |
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221 | |
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222 | /* |
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223 | * The HEAP_PREV_BLOCK_USED flag is always set in the block size_and_flag |
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224 | * field. Thus the value is about one unit larger than the real block |
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225 | * size. The greater than operator takes this into account. |
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226 | */ |
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227 | if ( block->size_and_flag > block_size_floor ) { |
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228 | if ( alignment == 0 ) { |
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229 | alloc_begin = _Heap_Alloc_area_of_block( block ); |
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230 | } else { |
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231 | alloc_begin = _Heap_Check_block( |
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232 | heap, |
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233 | block, |
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234 | alloc_size, |
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235 | alignment, |
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236 | boundary |
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237 | ); |
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238 | } |
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239 | } |
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240 | |
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241 | /* Statistics */ |
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242 | ++search_count; |
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243 | |
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244 | if ( alloc_begin != 0 ) { |
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245 | break; |
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246 | } |
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247 | |
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248 | block = block->next; |
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249 | } |
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250 | |
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251 | search_again = _Heap_Protection_free_delayed_blocks( heap, alloc_begin ); |
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252 | } while ( search_again ); |
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253 | |
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254 | if ( alloc_begin != 0 ) { |
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255 | /* Statistics */ |
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256 | ++stats->allocs; |
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257 | stats->searches += search_count; |
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258 | |
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259 | block = _Heap_Block_allocate( heap, block, alloc_begin, alloc_size ); |
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260 | |
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261 | _Heap_Check_allocation( |
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262 | heap, |
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263 | block, |
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264 | alloc_begin, |
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265 | alloc_size, |
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266 | alignment, |
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267 | boundary |
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268 | ); |
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269 | } |
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270 | |
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271 | /* Statistics */ |
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272 | if ( stats->max_search < search_count ) { |
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273 | stats->max_search = search_count; |
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274 | } |
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275 | |
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276 | return (void *) alloc_begin; |
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277 | } |
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