kern

annotate src/rbtree.c @ 68:0a205396e1a0

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- added a generic red-black tree data structure - added a VM map as an red-black tree of vm_pages in the process structure - constructed the vm map of the memory passed by the kernel initially to the first process.
author John Tsiombikas <nuclear@mutantstargoat.com>
date Mon, 10 Oct 2011 04:16:01 +0300
parents
children b45e2d5f0ae1
rev   line source
nuclear@68 1 #include <stdio.h>
nuclear@68 2 #include <stdlib.h>
nuclear@68 3 #include <string.h>
nuclear@68 4 #include "rbtree.h"
nuclear@68 5
nuclear@68 6 #define INT2PTR(x) ((void*)(x))
nuclear@68 7 #define PTR2INT(x) ((int)(x))
nuclear@68 8
nuclear@68 9 static int cmpaddr(void *ap, void *bp);
nuclear@68 10 static int cmpint(void *ap, void *bp);
nuclear@68 11
nuclear@68 12 static int count_nodes(struct rbnode *node);
nuclear@68 13 static void del_tree(struct rbnode *node, void (*delfunc)(struct rbnode*, void*), void *cls);
nuclear@68 14 static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data);
nuclear@68 15 static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key);
nuclear@68 16 /*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key);*/
nuclear@68 17 static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls);
nuclear@68 18
nuclear@68 19 struct rbtree *rb_create(rb_cmp_func_t cmp_func)
nuclear@68 20 {
nuclear@68 21 struct rbtree *rb;
nuclear@68 22
nuclear@68 23 if(!(rb = malloc(sizeof *rb))) {
nuclear@68 24 return 0;
nuclear@68 25 }
nuclear@68 26 if(rb_init(rb, cmp_func) == -1) {
nuclear@68 27 free(rb);
nuclear@68 28 return 0;
nuclear@68 29 }
nuclear@68 30 return rb;
nuclear@68 31 }
nuclear@68 32
nuclear@68 33 void rb_free(struct rbtree *rb)
nuclear@68 34 {
nuclear@68 35 rb_destroy(rb);
nuclear@68 36 free(rb);
nuclear@68 37 }
nuclear@68 38
nuclear@68 39
nuclear@68 40 int rb_init(struct rbtree *rb, rb_cmp_func_t cmp_func)
nuclear@68 41 {
nuclear@68 42 memset(rb, 0, sizeof *rb);
nuclear@68 43
nuclear@68 44 if(cmp_func == RB_KEY_INT) {
nuclear@68 45 rb->cmp = cmpint;
nuclear@68 46 } else if(cmp_func == RB_KEY_STRING) {
nuclear@68 47 rb->cmp = (rb_cmp_func_t)strcmp;
nuclear@68 48 } else {
nuclear@68 49 rb->cmp = cmpaddr;
nuclear@68 50 }
nuclear@68 51
nuclear@68 52 rb->alloc = malloc;
nuclear@68 53 rb->free = free;
nuclear@68 54 return 0;
nuclear@68 55 }
nuclear@68 56
nuclear@68 57 void rb_destroy(struct rbtree *rb)
nuclear@68 58 {
nuclear@68 59 del_tree(rb->root, rb->del, rb->del_cls);
nuclear@68 60 }
nuclear@68 61
nuclear@68 62 void rb_set_allocator(struct rbtree *rb, rb_alloc_func_t alloc, rb_free_func_t free)
nuclear@68 63 {
nuclear@68 64 rb->alloc = alloc;
nuclear@68 65 rb->free = free;
nuclear@68 66 }
nuclear@68 67
nuclear@68 68
nuclear@68 69 void rb_set_compare_func(struct rbtree *rb, rb_cmp_func_t func)
nuclear@68 70 {
nuclear@68 71 rb->cmp = func;
nuclear@68 72 }
nuclear@68 73
nuclear@68 74 void rb_set_delete_func(struct rbtree *rb, rb_del_func_t func, void *cls)
nuclear@68 75 {
nuclear@68 76 rb->del = func;
nuclear@68 77 rb->del_cls = cls;
nuclear@68 78 }
nuclear@68 79
nuclear@68 80 int rb_size(struct rbtree *rb)
nuclear@68 81 {
nuclear@68 82 return count_nodes(rb->root);
nuclear@68 83 }
nuclear@68 84
nuclear@68 85 int rb_insert(struct rbtree *rb, void *key, void *data)
nuclear@68 86 {
nuclear@68 87 rb->root = insert(rb, rb->root, key, data);
nuclear@68 88 rb->root->red = 0;
nuclear@68 89 return 0;
nuclear@68 90 }
nuclear@68 91
nuclear@68 92 int rb_inserti(struct rbtree *rb, int key, void *data)
nuclear@68 93 {
nuclear@68 94 rb->root = insert(rb, rb->root, INT2PTR(key), data);
nuclear@68 95 rb->root->red = 0;
nuclear@68 96 return 0;
nuclear@68 97 }
nuclear@68 98
nuclear@68 99
nuclear@68 100 int rb_delete(struct rbtree *rb, void *key)
nuclear@68 101 {
nuclear@68 102 rb->root = delete(rb, rb->root, key);
nuclear@68 103 rb->root->red = 0;
nuclear@68 104 return 0;
nuclear@68 105 }
nuclear@68 106
nuclear@68 107 int rb_deletei(struct rbtree *rb, int key)
nuclear@68 108 {
nuclear@68 109 rb->root = delete(rb, rb->root, INT2PTR(key));
nuclear@68 110 rb->root->red = 0;
nuclear@68 111 return 0;
nuclear@68 112 }
nuclear@68 113
nuclear@68 114
nuclear@68 115 void *rb_find(struct rbtree *rb, void *key)
nuclear@68 116 {
nuclear@68 117 struct rbnode *node = rb->root;
nuclear@68 118
nuclear@68 119 while(node) {
nuclear@68 120 int cmp = rb->cmp(key, node->key);
nuclear@68 121 if(cmp == 0) {
nuclear@68 122 return node;
nuclear@68 123 }
nuclear@68 124 node = cmp < 0 ? node->left : node->right;
nuclear@68 125 }
nuclear@68 126 return 0;
nuclear@68 127 }
nuclear@68 128
nuclear@68 129 void *rb_findi(struct rbtree *rb, int key)
nuclear@68 130 {
nuclear@68 131 return rb_find(rb, INT2PTR(key));
nuclear@68 132 }
nuclear@68 133
nuclear@68 134
nuclear@68 135 void rb_foreach(struct rbtree *rb, void (*func)(struct rbnode*, void*), void *cls)
nuclear@68 136 {
nuclear@68 137 traverse(rb->root, func, cls);
nuclear@68 138 }
nuclear@68 139
nuclear@68 140
nuclear@68 141 struct rbnode *rb_root(struct rbtree *rb)
nuclear@68 142 {
nuclear@68 143 return rb->root;
nuclear@68 144 }
nuclear@68 145
nuclear@68 146 void rb_begin(struct rbtree *rb)
nuclear@68 147 {
nuclear@68 148 rb->rstack = 0;
nuclear@68 149 rb->iter = rb->root;
nuclear@68 150 }
nuclear@68 151
nuclear@68 152 #define push(sp, x) ((x)->next = (sp), (sp) = (x))
nuclear@68 153 #define pop(sp) ((sp) = (sp)->next)
nuclear@68 154 #define top(sp) (sp)
nuclear@68 155
nuclear@68 156 struct rbnode *rb_next(struct rbtree *rb)
nuclear@68 157 {
nuclear@68 158 struct rbnode *res = 0;
nuclear@68 159
nuclear@68 160 while(rb->rstack || rb->iter) {
nuclear@68 161 if(rb->iter) {
nuclear@68 162 push(rb->rstack, rb->iter);
nuclear@68 163 rb->iter = rb->iter->left;
nuclear@68 164 } else {
nuclear@68 165 rb->iter = top(rb->rstack);
nuclear@68 166 pop(rb->rstack);
nuclear@68 167 res = rb->iter;
nuclear@68 168 rb->iter = rb->iter->right;
nuclear@68 169 break;
nuclear@68 170 }
nuclear@68 171 }
nuclear@68 172 return res;
nuclear@68 173 }
nuclear@68 174
nuclear@68 175 void *rb_node_key(struct rbnode *node)
nuclear@68 176 {
nuclear@68 177 return node ? node->key : 0;
nuclear@68 178 }
nuclear@68 179
nuclear@68 180 int rb_node_keyi(struct rbnode *node)
nuclear@68 181 {
nuclear@68 182 return node ? PTR2INT(node->key) : 0;
nuclear@68 183 }
nuclear@68 184
nuclear@68 185 void *rb_node_data(struct rbnode *node)
nuclear@68 186 {
nuclear@68 187 return node ? node->data : 0;
nuclear@68 188 }
nuclear@68 189
nuclear@68 190 static int cmpaddr(void *ap, void *bp)
nuclear@68 191 {
nuclear@68 192 return ap < bp ? -1 : (ap > bp ? 1 : 0);
nuclear@68 193 }
nuclear@68 194
nuclear@68 195 static int cmpint(void *ap, void *bp)
nuclear@68 196 {
nuclear@68 197 return PTR2INT(ap) - PTR2INT(bp);
nuclear@68 198 }
nuclear@68 199
nuclear@68 200
nuclear@68 201 /* ---- left-leaning 2-3 red-black implementation ---- */
nuclear@68 202
nuclear@68 203 /* helper prototypes */
nuclear@68 204 static int is_red(struct rbnode *tree);
nuclear@68 205 static void color_flip(struct rbnode *tree);
nuclear@68 206 static struct rbnode *rot_left(struct rbnode *a);
nuclear@68 207 static struct rbnode *rot_right(struct rbnode *a);
nuclear@68 208 static struct rbnode *find_min(struct rbnode *tree);
nuclear@68 209 static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree);
nuclear@68 210 /*static struct rbnode *move_red_right(struct rbnode *tree);*/
nuclear@68 211 static struct rbnode *move_red_left(struct rbnode *tree);
nuclear@68 212 static struct rbnode *fix_up(struct rbnode *tree);
nuclear@68 213
nuclear@68 214 static int count_nodes(struct rbnode *node)
nuclear@68 215 {
nuclear@68 216 if(!node)
nuclear@68 217 return 0;
nuclear@68 218
nuclear@68 219 return 1 + count_nodes(node->left) + count_nodes(node->right);
nuclear@68 220 }
nuclear@68 221
nuclear@68 222 static void del_tree(struct rbnode *node, rb_del_func_t delfunc, void *cls)
nuclear@68 223 {
nuclear@68 224 if(!node)
nuclear@68 225 return;
nuclear@68 226
nuclear@68 227 del_tree(node->left, delfunc, cls);
nuclear@68 228 del_tree(node->right, delfunc, cls);
nuclear@68 229
nuclear@68 230 delfunc(node, cls);
nuclear@68 231 free(node);
nuclear@68 232 }
nuclear@68 233
nuclear@68 234 static struct rbnode *insert(struct rbtree *rb, struct rbnode *tree, void *key, void *data)
nuclear@68 235 {
nuclear@68 236 int cmp;
nuclear@68 237
nuclear@68 238 if(!tree) {
nuclear@68 239 struct rbnode *node = rb->alloc(sizeof *node);
nuclear@68 240 node->red = 1;
nuclear@68 241 node->key = key;
nuclear@68 242 node->data = data;
nuclear@68 243 node->left = node->right = 0;
nuclear@68 244 return node;
nuclear@68 245 }
nuclear@68 246
nuclear@68 247 cmp = rb->cmp(key, tree->key);
nuclear@68 248
nuclear@68 249 if(cmp < 0) {
nuclear@68 250 tree->left = insert(rb, tree->left, key, data);
nuclear@68 251 } else if(cmp > 0) {
nuclear@68 252 tree->right = insert(rb, tree->right, key, data);
nuclear@68 253 } else {
nuclear@68 254 tree->data = data;
nuclear@68 255 }
nuclear@68 256
nuclear@68 257 /* fix right-leaning reds */
nuclear@68 258 if(is_red(tree->right)) {
nuclear@68 259 tree = rot_left(tree);
nuclear@68 260 }
nuclear@68 261 /* fix two reds in a row */
nuclear@68 262 if(is_red(tree->left) && is_red(tree->left->left)) {
nuclear@68 263 tree = rot_right(tree);
nuclear@68 264 }
nuclear@68 265
nuclear@68 266 /* if 4-node, split it by color inversion */
nuclear@68 267 if(is_red(tree->left) && is_red(tree->right)) {
nuclear@68 268 color_flip(tree);
nuclear@68 269 }
nuclear@68 270
nuclear@68 271 return tree;
nuclear@68 272 }
nuclear@68 273
nuclear@68 274 static struct rbnode *delete(struct rbtree *rb, struct rbnode *tree, void *key)
nuclear@68 275 {
nuclear@68 276 int cmp;
nuclear@68 277
nuclear@68 278 if(!tree) {
nuclear@68 279 return 0;
nuclear@68 280 }
nuclear@68 281
nuclear@68 282 cmp = rb->cmp(key, tree->key);
nuclear@68 283
nuclear@68 284 if(cmp < 0) {
nuclear@68 285 if(!is_red(tree->left) && !is_red(tree->left->left)) {
nuclear@68 286 tree = move_red_left(tree);
nuclear@68 287 }
nuclear@68 288 tree->left = delete(rb, tree->left, key);
nuclear@68 289 } else {
nuclear@68 290 /* need reds on the right */
nuclear@68 291 if(is_red(tree->left)) {
nuclear@68 292 tree = rot_right(tree);
nuclear@68 293 }
nuclear@68 294
nuclear@68 295 /* found it at the bottom (XXX what certifies left is null?) */
nuclear@68 296 if(cmp == 0 && !tree->right) {
nuclear@68 297 if(rb->del) {
nuclear@68 298 rb->del(tree, rb->del_cls);
nuclear@68 299 }
nuclear@68 300 rb->free(tree);
nuclear@68 301 return 0;
nuclear@68 302 }
nuclear@68 303
nuclear@68 304 if(!is_red(tree->right) && !is_red(tree->right->left)) {
nuclear@68 305 tree = move_red_left(tree);
nuclear@68 306 }
nuclear@68 307
nuclear@68 308 if(key == tree->key) {
nuclear@68 309 struct rbnode *rmin = find_min(tree->right);
nuclear@68 310 tree->key = rmin->key;
nuclear@68 311 tree->data = rmin->data;
nuclear@68 312 tree->right = del_min(rb, tree->right);
nuclear@68 313 } else {
nuclear@68 314 tree->right = delete(rb, tree->right, key);
nuclear@68 315 }
nuclear@68 316 }
nuclear@68 317
nuclear@68 318 return fix_up(tree);
nuclear@68 319 }
nuclear@68 320
nuclear@68 321 /*static struct rbnode *find(struct rbtree *rb, struct rbnode *node, void *key)
nuclear@68 322 {
nuclear@68 323 int cmp;
nuclear@68 324
nuclear@68 325 if(!node)
nuclear@68 326 return 0;
nuclear@68 327
nuclear@68 328 if((cmp = rb->cmp(key, node->key)) == 0) {
nuclear@68 329 return node;
nuclear@68 330 }
nuclear@68 331 return find(rb, cmp < 0 ? node->left : node->right, key);
nuclear@68 332 }*/
nuclear@68 333
nuclear@68 334 static void traverse(struct rbnode *node, void (*func)(struct rbnode*, void*), void *cls)
nuclear@68 335 {
nuclear@68 336 if(!node)
nuclear@68 337 return;
nuclear@68 338
nuclear@68 339 traverse(node->left, func, cls);
nuclear@68 340 func(node, cls);
nuclear@68 341 traverse(node->right, func, cls);
nuclear@68 342 }
nuclear@68 343
nuclear@68 344 /* helpers */
nuclear@68 345
nuclear@68 346 static int is_red(struct rbnode *tree)
nuclear@68 347 {
nuclear@68 348 return tree && tree->red;
nuclear@68 349 }
nuclear@68 350
nuclear@68 351 static void color_flip(struct rbnode *tree)
nuclear@68 352 {
nuclear@68 353 tree->red = !tree->red;
nuclear@68 354 tree->left->red = !tree->left->red;
nuclear@68 355 tree->right->red = !tree->right->red;
nuclear@68 356 }
nuclear@68 357
nuclear@68 358 static struct rbnode *rot_left(struct rbnode *a)
nuclear@68 359 {
nuclear@68 360 struct rbnode *b = a->right;
nuclear@68 361 a->right = b->left;
nuclear@68 362 b->left = a;
nuclear@68 363 b->red = a->red;
nuclear@68 364 a->red = 1;
nuclear@68 365 return b;
nuclear@68 366 }
nuclear@68 367
nuclear@68 368 static struct rbnode *rot_right(struct rbnode *a)
nuclear@68 369 {
nuclear@68 370 struct rbnode *b = a->left;
nuclear@68 371 a->left = b->right;
nuclear@68 372 b->right = a;
nuclear@68 373 b->red = a->red;
nuclear@68 374 a->red = 1;
nuclear@68 375 return b;
nuclear@68 376 }
nuclear@68 377
nuclear@68 378 static struct rbnode *find_min(struct rbnode *tree)
nuclear@68 379 {
nuclear@68 380 struct rbnode *node;
nuclear@68 381
nuclear@68 382 if(!tree)
nuclear@68 383 return 0;
nuclear@68 384
nuclear@68 385 while(node->left) {
nuclear@68 386 node = node->left;
nuclear@68 387 }
nuclear@68 388 return node;
nuclear@68 389 }
nuclear@68 390
nuclear@68 391 static struct rbnode *del_min(struct rbtree *rb, struct rbnode *tree)
nuclear@68 392 {
nuclear@68 393 if(!tree->left) {
nuclear@68 394 if(rb->del) {
nuclear@68 395 rb->del(tree->left, rb->del_cls);
nuclear@68 396 }
nuclear@68 397 rb->free(tree->left);
nuclear@68 398 return 0;
nuclear@68 399 }
nuclear@68 400
nuclear@68 401 /* make sure we've got red (3/4-nodes) at the left side so we can delete at the bottom */
nuclear@68 402 if(!is_red(tree->left) && !is_red(tree->left->left)) {
nuclear@68 403 tree = move_red_left(tree);
nuclear@68 404 }
nuclear@68 405 tree->left = del_min(rb, tree->left);
nuclear@68 406
nuclear@68 407 /* fix right-reds, red-reds, and split 4-nodes on the way up */
nuclear@68 408 return fix_up(tree);
nuclear@68 409 }
nuclear@68 410
nuclear@68 411 #if 0
nuclear@68 412 /* push a red link on this node to the right */
nuclear@68 413 static struct rbnode *move_red_right(struct rbnode *tree)
nuclear@68 414 {
nuclear@68 415 /* flipping it makes both children go red, so we have a red to the right */
nuclear@68 416 color_flip(tree);
nuclear@68 417
nuclear@68 418 /* if after the flip we've got a red-red situation to the left, fix it */
nuclear@68 419 if(is_red(tree->left->left)) {
nuclear@68 420 tree = rot_right(tree);
nuclear@68 421 color_flip(tree);
nuclear@68 422 }
nuclear@68 423 return tree;
nuclear@68 424 }
nuclear@68 425 #endif
nuclear@68 426
nuclear@68 427 /* push a red link on this node to the left */
nuclear@68 428 static struct rbnode *move_red_left(struct rbnode *tree)
nuclear@68 429 {
nuclear@68 430 /* flipping it makes both children go red, so we have a red to the left */
nuclear@68 431 color_flip(tree);
nuclear@68 432
nuclear@68 433 /* if after the flip we've got a red-red on the right-left, fix it */
nuclear@68 434 if(is_red(tree->right->left)) {
nuclear@68 435 tree->right = rot_right(tree->right);
nuclear@68 436 tree = rot_left(tree);
nuclear@68 437 color_flip(tree);
nuclear@68 438 }
nuclear@68 439 return tree;
nuclear@68 440 }
nuclear@68 441
nuclear@68 442 static struct rbnode *fix_up(struct rbnode *tree)
nuclear@68 443 {
nuclear@68 444 /* fix right-leaning */
nuclear@68 445 if(is_red(tree->right)) {
nuclear@68 446 tree = rot_left(tree);
nuclear@68 447 }
nuclear@68 448 /* change invalid red-red pairs into a proper 4-node */
nuclear@68 449 if(is_red(tree->left) && is_red(tree->left->left)) {
nuclear@68 450 tree = rot_right(tree);
nuclear@68 451 }
nuclear@68 452 /* split 4-nodes */
nuclear@68 453 if(is_red(tree->left) && is_red(tree->right)) {
nuclear@68 454 color_flip(tree);
nuclear@68 455 }
nuclear@68 456 return tree;
nuclear@68 457 }