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298 | serge | 1 | // Emacs style mode select -*- C++ -*- |
2 | //----------------------------------------------------------------------------- |
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3 | // |
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4 | // $Id: z_zone.c,v 1.2 1997/12/29 19:51:30 pekangas Exp $ |
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5 | // |
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6 | // Copyright (C) 1993-1996 by id Software, Inc. |
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7 | // |
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8 | // This source is available for distribution and/or modification |
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9 | // only under the terms of the DOOM Source Code License as |
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10 | // published by id Software. All rights reserved. |
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11 | // |
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12 | // The source is distributed in the hope that it will be useful, |
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13 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
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14 | // FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License |
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15 | // for more details. |
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16 | // |
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17 | // $Log: z_zone.c,v $ |
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18 | // Revision 1.2 1997/12/29 19:51:30 pekangas |
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19 | // Ported to WinNT/95 environment using Watcom C 10.6. |
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20 | // Everything expect joystick support is implemented, but networking is |
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21 | // untested. Crashes way too often with problems in FixedDiv(). |
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22 | // Compiles with no warnings at warning level 3, uses MIDAS 1.1.1. |
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23 | // |
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24 | // Revision 1.1.1.1 1997/12/28 12:59:07 pekangas |
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25 | // Initial DOOM source release from id Software |
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26 | // |
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27 | // |
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28 | // DESCRIPTION: |
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29 | // Zone Memory Allocation. Neat. |
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30 | // |
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31 | //----------------------------------------------------------------------------- |
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32 | |||
33 | const char |
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34 | z_zone_rcsid[] = "$Id: z_zone.c,v 1.2 1997/12/29 19:51:30 pekangas Exp $"; |
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35 | |||
36 | #include "z_zone.h" |
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37 | #include "i_system.h" |
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38 | #include "doomdef.h" |
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39 | |||
40 | |||
41 | // |
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42 | // ZONE MEMORY ALLOCATION |
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43 | // |
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44 | // There is never any space between memblocks, |
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45 | // and there will never be two contiguous free memblocks. |
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46 | // The rover can be left pointing at a non-empty block. |
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47 | // |
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48 | // It is of no value to free a cachable block, |
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49 | // because it will get overwritten automatically if needed. |
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50 | // |
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51 | |||
52 | #define ZONEID 0x1d4a11 |
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53 | |||
54 | |||
55 | typedef struct |
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56 | { |
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57 | // total bytes malloced, including header |
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58 | int size; |
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59 | |||
60 | // start / end cap for linked list |
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61 | memblock_t blocklist; |
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62 | |||
63 | memblock_t* rover; |
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64 | |||
65 | } memzone_t; |
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66 | |||
67 | |||
68 | |||
69 | memzone_t* mainzone; |
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70 | |||
71 | |||
72 | |||
73 | // |
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74 | // Z_ClearZone |
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75 | // |
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76 | void Z_ClearZone (memzone_t* zone) |
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77 | { |
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78 | memblock_t* block; |
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79 | |||
80 | // set the entire zone to one free block |
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81 | zone->blocklist.next = |
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82 | zone->blocklist.prev = |
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83 | block = (memblock_t *)( (byte *)zone + sizeof(memzone_t) ); |
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84 | |||
85 | zone->blocklist.user = (void *)zone; |
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86 | zone->blocklist.tag = PU_STATIC; |
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87 | zone->rover = block; |
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88 | |||
89 | block->prev = block->next = &zone->blocklist; |
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90 | |||
91 | // NULL indicates a free block. |
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92 | block->user = NULL; |
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93 | |||
94 | block->size = zone->size - sizeof(memzone_t); |
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95 | } |
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96 | |||
97 | |||
98 | |||
99 | // |
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100 | // Z_Init |
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101 | // |
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102 | void Z_Init (void) |
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103 | { |
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104 | memblock_t* block; |
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105 | int size; |
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106 | |||
107 | mainzone = (memzone_t *)I_ZoneBase (&size); |
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108 | mainzone->size = size; |
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109 | |||
110 | // set the entire zone to one free block |
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111 | mainzone->blocklist.next = |
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112 | mainzone->blocklist.prev = |
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113 | block = (memblock_t *)( (byte *)mainzone + sizeof(memzone_t) ); |
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114 | |||
115 | mainzone->blocklist.user = (void *)mainzone; |
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116 | mainzone->blocklist.tag = PU_STATIC; |
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117 | mainzone->rover = block; |
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118 | |||
119 | block->prev = block->next = &mainzone->blocklist; |
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120 | |||
121 | // NULL indicates a free block. |
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122 | block->user = NULL; |
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123 | |||
124 | block->size = mainzone->size - sizeof(memzone_t); |
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125 | } |
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126 | |||
127 | |||
128 | // |
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129 | // Z_Free |
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130 | // |
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131 | void Z_Free (void* ptr) |
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132 | { |
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133 | memblock_t* block; |
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134 | memblock_t* other; |
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135 | |||
136 | block = (memblock_t *) ( (byte *)ptr - sizeof(memblock_t)); |
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137 | |||
138 | if (block->id != ZONEID) |
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139 | I_Error ("Z_Free: freed a pointer without ZONEID"); |
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140 | |||
141 | if (block->user > (void **)0x100) |
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142 | { |
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143 | // smaller values are not pointers |
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144 | // Note: OS-dependend? |
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145 | |||
146 | // clear the user's mark |
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147 | *block->user = 0; |
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148 | } |
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149 | |||
150 | // mark as free |
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151 | block->user = NULL; |
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152 | block->tag = 0; |
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153 | block->id = 0; |
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154 | |||
155 | other = block->prev; |
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156 | |||
157 | if (!other->user) |
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158 | { |
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159 | // merge with previous free block |
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160 | other->size += block->size; |
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161 | other->next = block->next; |
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162 | other->next->prev = other; |
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163 | |||
164 | if (block == mainzone->rover) |
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165 | mainzone->rover = other; |
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166 | |||
167 | block = other; |
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168 | } |
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169 | |||
170 | other = block->next; |
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171 | if (!other->user) |
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172 | { |
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173 | // merge the next free block onto the end |
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174 | block->size += other->size; |
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175 | block->next = other->next; |
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176 | block->next->prev = block; |
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177 | |||
178 | if (other == mainzone->rover) |
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179 | mainzone->rover = block; |
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180 | } |
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181 | } |
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182 | |||
183 | |||
184 | |||
185 | // |
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186 | // Z_Malloc |
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187 | // You can pass a NULL user if the tag is < PU_PURGELEVEL. |
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188 | // |
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189 | #define MINFRAGMENT 64 |
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190 | |||
191 | |||
192 | void* |
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193 | Z_Malloc |
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194 | ( int size, |
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195 | int tag, |
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196 | void* user ) |
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197 | { |
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198 | int extra; |
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199 | memblock_t* start; |
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200 | memblock_t* rover; |
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201 | memblock_t* newblock; |
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202 | memblock_t* base; |
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203 | |||
204 | size = (size + 3) & ~3; |
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205 | |||
206 | // scan through the block list, |
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207 | // looking for the first free block |
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208 | // of sufficient size, |
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209 | // throwing out any purgable blocks along the way. |
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210 | |||
211 | // account for size of block header |
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212 | size += sizeof(memblock_t); |
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213 | |||
214 | // if there is a free block behind the rover, |
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215 | // back up over them |
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216 | base = mainzone->rover; |
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217 | |||
218 | if (!base->prev->user) |
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219 | base = base->prev; |
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220 | |||
221 | rover = base; |
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222 | start = base->prev; |
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223 | |||
224 | do |
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225 | { |
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226 | if (rover == start) |
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227 | { |
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228 | // scanned all the way around the list |
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229 | I_Error ("Z_Malloc: failed on allocation of %i bytes", size); |
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230 | } |
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231 | |||
232 | if (rover->user) |
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233 | { |
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234 | if (rover->tag < PU_PURGELEVEL) |
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235 | { |
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236 | // hit a block that can't be purged, |
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237 | // so move base past it |
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238 | base = rover = rover->next; |
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239 | } |
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240 | else |
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241 | { |
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242 | // free the rover block (adding the size to base) |
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243 | |||
244 | // the rover can be the base block |
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245 | base = base->prev; |
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246 | Z_Free ((byte *)rover+sizeof(memblock_t)); |
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247 | base = base->next; |
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248 | rover = base->next; |
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249 | } |
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250 | } |
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251 | else |
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252 | rover = rover->next; |
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253 | } while (base->user || base->size < size); |
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254 | |||
255 | |||
256 | // found a block big enough |
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257 | extra = base->size - size; |
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258 | |||
259 | if (extra > MINFRAGMENT) |
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260 | { |
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261 | // there will be a free fragment after the allocated block |
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262 | newblock = (memblock_t *) ((byte *)base + size ); |
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263 | newblock->size = extra; |
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264 | |||
265 | // NULL indicates free block. |
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266 | newblock->user = NULL; |
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267 | newblock->tag = 0; |
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268 | newblock->prev = base; |
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269 | newblock->next = base->next; |
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270 | newblock->next->prev = newblock; |
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271 | |||
272 | base->next = newblock; |
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273 | base->size = size; |
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274 | } |
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275 | |||
276 | if (user) |
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277 | { |
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278 | // mark as an in use block |
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279 | base->user = user; |
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280 | *(void **)user = (void *) ((byte *)base + sizeof(memblock_t)); |
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281 | } |
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282 | else |
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283 | { |
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284 | if (tag >= PU_PURGELEVEL) |
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285 | I_Error ("Z_Malloc: an owner is required for purgable blocks"); |
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286 | |||
287 | // mark as in use, but unowned |
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288 | base->user = (void *)2; |
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289 | } |
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290 | base->tag = tag; |
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291 | |||
292 | // next allocation will start looking here |
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293 | mainzone->rover = base->next; |
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294 | |||
295 | base->id = ZONEID; |
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296 | |||
297 | return (void *) ((byte *)base + sizeof(memblock_t)); |
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298 | } |
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299 | |||
300 | |||
301 | |||
302 | // |
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303 | // Z_FreeTags |
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304 | // |
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305 | void |
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306 | Z_FreeTags |
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307 | ( int lowtag, |
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308 | int hightag ) |
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309 | { |
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310 | memblock_t* block; |
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311 | memblock_t* next; |
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312 | |||
313 | for (block = mainzone->blocklist.next ; |
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314 | block != &mainzone->blocklist ; |
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315 | block = next) |
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316 | { |
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317 | // get link before freeing |
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318 | next = block->next; |
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319 | |||
320 | // free block? |
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321 | if (!block->user) |
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322 | continue; |
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323 | |||
324 | if (block->tag >= lowtag && block->tag <= hightag) |
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325 | Z_Free ( (byte *)block+sizeof(memblock_t)); |
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326 | } |
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327 | } |
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328 | |||
329 | |||
330 | |||
331 | // |
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332 | // Z_DumpHeap |
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333 | // Note: TFileDumpHeap( stdout ) ? |
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334 | // |
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335 | void |
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336 | Z_DumpHeap |
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337 | ( int lowtag, |
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338 | int hightag ) |
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339 | { |
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340 | memblock_t* block; |
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341 | |||
342 | printf ("zone size: %i location: %p\n", |
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343 | mainzone->size,mainzone); |
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344 | |||
345 | printf ("tag range: %i to %i\n", |
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346 | lowtag, hightag); |
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347 | |||
348 | for (block = mainzone->blocklist.next ; ; block = block->next) |
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349 | { |
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350 | if (block->tag >= lowtag && block->tag <= hightag) |
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351 | printf ("block:%p size:%7i user:%p tag:%3i\n", |
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352 | block, block->size, block->user, block->tag); |
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353 | |||
354 | if (block->next == &mainzone->blocklist) |
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355 | { |
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356 | // all blocks have been hit |
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357 | break; |
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358 | } |
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359 | |||
360 | if ( (byte *)block + block->size != (byte *)block->next) |
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361 | printf ("ERROR: block size does not touch the next block\n"); |
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362 | |||
363 | if ( block->next->prev != block) |
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364 | printf ("ERROR: next block doesn't have proper back link\n"); |
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365 | |||
366 | if (!block->user && !block->next->user) |
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367 | printf ("ERROR: two consecutive free blocks\n"); |
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368 | } |
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369 | } |
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370 | |||
371 | |||
372 | // |
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373 | // Z_FileDumpHeap |
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374 | // |
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375 | void Z_FileDumpHeap (FILE* f) |
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376 | { |
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377 | memblock_t* block; |
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378 | |||
379 | fprintf (f,"zone size: %i location: %p\n",mainzone->size,mainzone); |
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380 | |||
381 | for (block = mainzone->blocklist.next ; ; block = block->next) |
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382 | { |
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383 | fprintf (f,"block:%p size:%7i user:%p tag:%3i\n", |
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384 | block, block->size, block->user, block->tag); |
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385 | |||
386 | if (block->next == &mainzone->blocklist) |
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387 | { |
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388 | // all blocks have been hit |
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389 | break; |
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390 | } |
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391 | |||
392 | if ( (byte *)block + block->size != (byte *)block->next) |
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393 | fprintf (f,"ERROR: block size does not touch the next block\n"); |
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394 | |||
395 | if ( block->next->prev != block) |
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396 | fprintf (f,"ERROR: next block doesn't have proper back link\n"); |
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397 | |||
398 | if (!block->user && !block->next->user) |
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399 | fprintf (f,"ERROR: two consecutive free blocks\n"); |
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400 | } |
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401 | } |
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402 | |||
403 | |||
404 | |||
405 | // |
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406 | // Z_CheckHeap |
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407 | // |
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408 | void Z_CheckHeap (void) |
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409 | { |
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410 | memblock_t* block; |
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411 | |||
412 | for (block = mainzone->blocklist.next ; ; block = block->next) |
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413 | { |
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414 | if (block->next == &mainzone->blocklist) |
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415 | { |
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416 | // all blocks have been hit |
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417 | break; |
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418 | } |
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419 | |||
420 | if ( (byte *)block + block->size != (byte *)block->next) |
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421 | I_Error ("Z_CheckHeap: block size does not touch the next block\n"); |
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422 | |||
423 | if ( block->next->prev != block) |
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424 | I_Error ("Z_CheckHeap: next block doesn't have proper back link\n"); |
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425 | |||
426 | if (!block->user && !block->next->user) |
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427 | I_Error ("Z_CheckHeap: two consecutive free blocks\n"); |
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428 | } |
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429 | } |
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430 | |||
431 | |||
432 | |||
433 | |||
434 | // |
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435 | // Z_ChangeTag |
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436 | // |
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437 | void |
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438 | Z_ChangeTag2 |
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439 | ( void* ptr, |
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440 | int tag ) |
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441 | { |
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442 | memblock_t* block; |
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443 | |||
444 | block = (memblock_t *) ( (byte *)ptr - sizeof(memblock_t)); |
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445 | |||
446 | if (block->id != ZONEID) |
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447 | I_Error ("Z_ChangeTag: freed a pointer without ZONEID"); |
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448 | |||
449 | if (tag >= PU_PURGELEVEL && (unsigned)block->user < 0x100) |
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450 | I_Error ("Z_ChangeTag: an owner is required for purgable blocks"); |
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451 | |||
452 | block->tag = tag; |
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453 | } |
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454 | |||
455 | |||
456 | |||
457 | // |
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458 | // Z_FreeMemory |
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459 | // |
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460 | int Z_FreeMemory (void) |
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461 | { |
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462 | memblock_t* block; |
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463 | int free; |
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464 | |||
465 | free = 0; |
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466 | |||
467 | for (block = mainzone->blocklist.next ; |
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468 | block != &mainzone->blocklist; |
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469 | block = block->next) |
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470 | { |
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471 | if (!block->user || block->tag >= PU_PURGELEVEL) |
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472 | free += block->size; |
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473 | } |
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474 | return free; |
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475 | }>=>=>>>> |
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476 |