src/glsl/list.h

   1 /*
   2  * Copyright © 2008, 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * \file list.h
  26  * \brief Doubly-linked list abstract container type.
  27  *
  28  * Each doubly-linked list has a sentinel head and tail node.  These nodes
  29  * contain no data.  The head sentinel can be identified by its \c prev
  30  * pointer being \c NULL.  The tail sentinel can be identified by its
  31  * \c next pointer being \c NULL.
  32  *
  33  * A list is empty if either the head sentinel's \c next pointer points to the
  34  * tail sentinel or the tail sentinel's \c prev poiner points to the head
  35  * sentinel.
  36  *
  37  * Instead of tracking two separate \c node structures and a \c list structure
  38  * that points to them, the sentinel nodes are in a single structure.  Noting
  39  * that each sentinel node always has one \c NULL pointer, the \c NULL
  40  * pointers occupy the same memory location.  In the \c list structure
  41  * contains a the following:
  42  *
  43  *   - A \c head pointer that represents the \c next pointer of the
  44  *     head sentinel node.
  45  *   - A \c tail pointer that represents the \c prev pointer of the head
  46  *     sentinel node and the \c next pointer of the tail sentinel node.  This
  47  *     pointer is \b always \c NULL.
  48  *   - A \c tail_prev pointer that represents the \c prev pointer of the
  49  *     tail sentinel node.
  50  *
  51  * Therefore, if \c head->next is \c NULL or \c tail_prev->prev is \c NULL,
  52  * the list is empty.
  53  *
  54  * To anyone familiar with "exec lists" on the Amiga, this structure should
  55  * be immediately recognizable.  See the following link for the original Amiga
  56  * operating system documentation on the subject.
  57  *
  58  * http://www.natami.net/dev/Libraries_Manual_guide/node02D7.html
  59  *
  60  * \author Ian Romanick <ian.d.romanick@intel.com>
  61  */
  62
  63 #pragma once
  64 #ifndef LIST_CONTAINER_H
  65 #define LIST_CONTAINER_H
  66
  67 #ifndef __cplusplus
  68 #include <stddef.h>
  69 #endif
  70 #include <assert.h>
  71
  72 #include "ralloc.h"
  73
  74 struct exec_node {
  75    struct exec_node *next;
  76    struct exec_node *prev;
  77
  78 #ifdef __cplusplus
  79    DECLARE_RALLOC_CXX_OPERATORS(exec_node)
  80
  81    exec_node() : next(NULL), prev(NULL)
  82    {
  83       /* empty */
  84    }
  85
  86    const exec_node *get_next() const;
  87    exec_node *get_next();
  88
  89    const exec_node *get_prev() const;
  90    exec_node *get_prev();
  91
  92    void remove();
  93
  94    /**
  95     * Link a node with itself
  96     *
  97     * This creates a sort of degenerate list that is occasionally useful.
  98     */
  99    void self_link();
 100
 101    /**
 102     * Insert a node in the list after the current node
 103     */
 104    void insert_after(exec_node *after);
 105    /**
 106     * Insert a node in the list before the current node
 107     */
 108    void insert_before(exec_node *before);
 109
 110    /**
 111     * Insert another list in the list before the current node
 112     */
 113    void insert_before(struct exec_list *before);
 114
 115    /**
 116     * Replace the current node with the given node.
 117     */
 118    void replace_with(exec_node *replacement);
 119
 120    /**
 121     * Is this the sentinel at the tail of the list?
 122     */
 123    bool is_tail_sentinel() const;
 124
 125    /**
 126     * Is this the sentinel at the head of the list?
 127     */
 128    bool is_head_sentinel() const;
 129 #endif
 130 };
 131
 132 static inline void
 133 exec_node_init(struct exec_node *n)
 134 {
 135    n->next = NULL;
 136    n->prev = NULL;
 137 }
 138
 139 static inline const struct exec_node *
 140 exec_node_get_next_const(const struct exec_node *n)
 141 {
 142    return n->next;
 143 }
 144
 145 static inline struct exec_node *
 146 exec_node_get_next(struct exec_node *n)
 147 {
 148    return n->next;
 149 }
 150
 151 static inline const struct exec_node *
 152 exec_node_get_prev_const(const struct exec_node *n)
 153 {
 154    return n->prev;
 155 }
 156
 157 static inline struct exec_node *
 158 exec_node_get_prev(struct exec_node *n)
 159 {
 160    return n->prev;
 161 }
 162
 163 static inline void
 164 exec_node_remove(struct exec_node *n)
 165 {
 166    n->next->prev = n->prev;
 167    n->prev->next = n->next;
 168    n->next = NULL;
 169    n->prev = NULL;
 170 }
 171
 172 static inline void
 173 exec_node_self_link(struct exec_node *n)
 174 {
 175    n->next = n;
 176    n->prev = n;
 177 }
 178
 179 static inline void
 180 exec_node_insert_after(struct exec_node *n, struct exec_node *after)
 181 {
 182    after->next = n->next;
 183    after->prev = n;
 184
 185    n->next->prev = after;
 186    n->next = after;
 187 }
 188
 189 static inline void
 190 exec_node_insert_node_before(struct exec_node *n, struct exec_node *before)
 191 {
 192    before->next = n;
 193    before->prev = n->prev;
 194
 195    n->prev->next = before;
 196    n->prev = before;
 197 }
 198
 199 static inline void
 200 exec_node_replace_with(struct exec_node *n, struct exec_node *replacement)
 201 {
 202    replacement->prev = n->prev;
 203    replacement->next = n->next;
 204
 205    n->prev->next = replacement;
 206    n->next->prev = replacement;
 207 }
 208
 209 static inline bool
 210 exec_node_is_tail_sentinel(const struct exec_node *n)
 211 {
 212    return n->next == NULL;
 213 }
 214
 215 static inline bool
 216 exec_node_is_head_sentinel(const struct exec_node *n)
 217 {
 218    return n->prev == NULL;
 219 }
 220
 221 #ifdef __cplusplus
 222 inline const exec_node *exec_node::get_next() const
 223 {
 224    return exec_node_get_next_const(this);
 225 }
 226
 227 inline exec_node *exec_node::get_next()
 228 {
 229    return exec_node_get_next(this);
 230 }
 231
 232 inline const exec_node *exec_node::get_prev() const
 233 {
 234    return exec_node_get_prev_const(this);
 235 }
 236
 237 inline exec_node *exec_node::get_prev()
 238 {
 239    return exec_node_get_prev(this);
 240 }
 241
 242 inline void exec_node::remove()
 243 {
 244    exec_node_remove(this);
 245 }
 246
 247 inline void exec_node::self_link()
 248 {
 249    exec_node_self_link(this);
 250 }
 251
 252 inline void exec_node::insert_after(exec_node *after)
 253 {
 254    exec_node_insert_after(this, after);
 255 }
 256
 257 inline void exec_node::insert_before(exec_node *before)
 258 {
 259    exec_node_insert_node_before(this, before);
 260 }
 261
 262 inline void exec_node::replace_with(exec_node *replacement)
 263 {
 264    exec_node_replace_with(this, replacement);
 265 }
 266
 267 inline bool exec_node::is_tail_sentinel() const
 268 {
 269    return exec_node_is_tail_sentinel(this);
 270 }
 271
 272 inline bool exec_node::is_head_sentinel() const
 273 {
 274    return exec_node_is_head_sentinel(this);
 275 }
 276 #endif
 277
 278 #ifdef __cplusplus
 279 /* This macro will not work correctly if `t' uses virtual inheritance.  If you
 280  * are using virtual inheritance, you deserve a slow and painful death.  Enjoy!
 281  */
 282 #define exec_list_offsetof(t, f, p) \
 283    (((char *) &((t *) p)->f) - ((char *) p))
 284 #else
 285 #define exec_list_offsetof(t, f, p) offsetof(t, f)
 286 #endif
 287
 288 /**
 289  * Get a pointer to the structure containing an exec_node
 290  *
 291  * Given a pointer to an \c exec_node embedded in a structure, get a pointer to
 292  * the containing structure.
 293  *
 294  * \param type  Base type of the structure containing the node
 295  * \param node  Pointer to the \c exec_node
 296  * \param field Name of the field in \c type that is the embedded \c exec_node
 297  */
 298 #define exec_node_data(type, node, field) \
 299    ((type *) (((char *) node) - exec_list_offsetof(type, field, node)))
 300
 301 #ifdef __cplusplus
 302 struct exec_node;
 303 #endif
 304
 305 struct exec_list {
 306    struct exec_node *head;
 307    struct exec_node *tail;
 308    struct exec_node *tail_pred;
 309
 310 #ifdef __cplusplus
 311    DECLARE_RALLOC_CXX_OPERATORS(exec_list)
 312
 313    exec_list()
 314    {
 315       make_empty();
 316    }
 317
 318    void make_empty();
 319
 320    bool is_empty() const;
 321
 322    const exec_node *get_head() const;
 323    exec_node *get_head();
 324
 325    const exec_node *get_tail() const;
 326    exec_node *get_tail();
 327
 328    void push_head(exec_node *n);
 329    void push_tail(exec_node *n);
 330    void push_degenerate_list_at_head(exec_node *n);
 331
 332    /**
 333     * Remove the first node from a list and return it
 334     *
 335     * \return
 336     * The first node in the list or \c NULL if the list is empty.
 337     *
 338     * \sa exec_list::get_head
 339     */
 340    exec_node *pop_head();
 341
 342    /**
 343     * Move all of the nodes from this list to the target list
 344     */
 345    void move_nodes_to(exec_list *target);
 346
 347    /**
 348     * Append all nodes from the source list to the target list
 349     */
 350    void append_list(exec_list *source);
 351 #endif
 352 };
 353
 354 static inline void
 355 exec_list_make_empty(struct exec_list *list)
 356 {
 357    list->head = (struct exec_node *) & list->tail;
 358    list->tail = NULL;
 359    list->tail_pred = (struct exec_node *) & list->head;
 360 }
 361
 362 static inline bool
 363 exec_list_is_empty(const struct exec_list *list)
 364 {
 365    /* There are three ways to test whether a list is empty or not.
 366     *
 367     * - Check to see if the \c head points to the \c tail.
 368     * - Check to see if the \c tail_pred points to the \c head.
 369     * - Check to see if the \c head is the sentinel node by test whether its
 370     *   \c next pointer is \c NULL.
 371     *
 372     * The first two methods tend to generate better code on modern systems
 373     * because they save a pointer dereference.
 374     */
 375    return list->head == (struct exec_node *) &list->tail;
 376 }
 377
 378 static inline const struct exec_node *
 379 exec_list_get_head_const(const struct exec_list *list)
 380 {
 381    return !exec_list_is_empty(list) ? list->head : NULL;
 382 }
 383
 384 static inline struct exec_node *
 385 exec_list_get_head(struct exec_list *list)
 386 {
 387    return !exec_list_is_empty(list) ? list->head : NULL;
 388 }
 389
 390 static inline const struct exec_node *
 391 exec_list_get_tail_const(const struct exec_list *list)
 392 {
 393    return !exec_list_is_empty(list) ? list->tail_pred : NULL;
 394 }
 395
 396 static inline struct exec_node *
 397 exec_list_get_tail(struct exec_list *list)
 398 {
 399    return !exec_list_is_empty(list) ? list->tail_pred : NULL;
 400 }
 401
 402 static inline void
 403 exec_list_push_head(struct exec_list *list, struct exec_node *n)
 404 {
 405    n->next = list->head;
 406    n->prev = (struct exec_node *) &list->head;
 407
 408    n->next->prev = n;
 409    list->head = n;
 410 }
 411
 412 static inline void
 413 exec_list_push_tail(struct exec_list *list, struct exec_node *n)
 414 {
 415    n->next = (struct exec_node *) &list->tail;
 416    n->prev = list->tail_pred;
 417
 418    n->prev->next = n;
 419    list->tail_pred = n;
 420 }
 421
 422 static inline void
 423 exec_list_push_degenerate_list_at_head(struct exec_list *list, struct exec_node *n)
 424 {
 425    assert(n->prev->next == n);
 426
 427    n->prev->next = list->head;
 428    list->head->prev = n->prev;
 429    n->prev = (struct exec_node *) &list->head;
 430    list->head = n;
 431 }
 432
 433 static inline struct exec_node *
 434 exec_list_pop_head(struct exec_list *list)
 435 {
 436    struct exec_node *const n = exec_list_get_head(list);
 437    if (n != NULL)
 438       exec_node_remove(n);
 439
 440    return n;
 441 }
 442
 443 static inline void
 444 exec_list_move_nodes_to(struct exec_list *list, struct exec_list *target)
 445 {
 446    if (exec_list_is_empty(list)) {
 447       exec_list_make_empty(target);
 448    } else {
 449       target->head = list->head;
 450       target->tail = NULL;
 451       target->tail_pred = list->tail_pred;
 452
 453       target->head->prev = (struct exec_node *) &target->head;
 454       target->tail_pred->next = (struct exec_node *) &target->tail;
 455
 456       exec_list_make_empty(list);
 457    }
 458 }
 459
 460 static inline void
 461 exec_list_append(struct exec_list *list, struct exec_list *source)
 462 {
 463    if (exec_list_is_empty(source))
 464       return;
 465
 466    /* Link the first node of the source with the last node of the target list.
 467     */
 468    list->tail_pred->next = source->head;
 469    source->head->prev = list->tail_pred;
 470
 471    /* Make the tail of the source list be the tail of the target list.
 472     */
 473    list->tail_pred = source->tail_pred;
 474    list->tail_pred->next = (struct exec_node *) &list->tail;
 475
 476    /* Make the source list empty for good measure.
 477     */
 478    exec_list_make_empty(source);
 479 }
 480
 481 static inline void
 482 exec_node_insert_list_before(struct exec_node *n, struct exec_list *before)
 483 {
 484    if (exec_list_is_empty(before))
 485       return;
 486
 487    before->tail_pred->next = n;
 488    before->head->prev = n->prev;
 489
 490    n->prev->next = before->head;
 491    n->prev = before->tail_pred;
 492
 493    exec_list_make_empty(before);
 494 }
 495
 496 #ifdef __cplusplus
 497 inline void exec_list::make_empty()
 498 {
 499    exec_list_make_empty(this);
 500 }
 501
 502 inline bool exec_list::is_empty() const
 503 {
 504    return exec_list_is_empty(this);
 505 }
 506
 507 inline const exec_node *exec_list::get_head() const
 508 {
 509    return exec_list_get_head_const(this);
 510 }
 511
 512 inline exec_node *exec_list::get_head()
 513 {
 514    return exec_list_get_head(this);
 515 }
 516
 517 inline const exec_node *exec_list::get_tail() const
 518 {
 519    return exec_list_get_tail_const(this);
 520 }
 521
 522 inline exec_node *exec_list::get_tail()
 523 {
 524    return exec_list_get_tail(this);
 525 }
 526
 527 inline void exec_list::push_head(exec_node *n)
 528 {
 529    exec_list_push_head(this, n);
 530 }
 531
 532 inline void exec_list::push_tail(exec_node *n)
 533 {
 534    exec_list_push_tail(this, n);
 535 }
 536
 537 inline void exec_list::push_degenerate_list_at_head(exec_node *n)
 538 {
 539    exec_list_push_degenerate_list_at_head(this, n);
 540 }
 541
 542 inline exec_node *exec_list::pop_head()
 543 {
 544    return exec_list_pop_head(this);
 545 }
 546
 547 inline void exec_list::move_nodes_to(exec_list *target)
 548 {
 549    exec_list_move_nodes_to(this, target);
 550 }
 551
 552 inline void exec_list::append_list(exec_list *source)
 553 {
 554    exec_list_append(this, source);
 555 }
 556
 557 inline void exec_node::insert_before(exec_list *before)
 558 {
 559    exec_node_insert_list_before(this, before);
 560 }
 561 #endif
 562
 563 /**
 564  * This version is safe even if the current node is removed.
 565  */
 566 #define foreach_list_safe(__node, __list)                                       \
 567    for (struct exec_node * __node = (__list)->head, * __next = __node->next     \
 568         ; __next != NULL                                                        \
 569         ; __node = __next, __next = __next->next)
 570
 571 #define foreach_list(__node, __list)                    \
 572    for (struct exec_node * __node = (__list)->head      \
 573         ; (__node)->next != NULL                        \
 574         ; (__node) = (__node)->next)
 575
 576 /**
 577  * Iterate through two lists at once.  Stops at the end of the shorter list.
 578  *
 579  * This is safe against either current node being removed or replaced.
 580  */
 581 #define foreach_two_lists(__node1, __list1, __node2, __list2) \
 582    for (struct exec_node * __node1 = (__list1)->head,         \
 583                          * __node2 = (__list2)->head,         \
 584                          * __next1 = __node1->next,           \
 585                          * __next2 = __node2->next            \
 586         ; __next1 != NULL && __next2 != NULL                  \
 587         ; __node1 = __next1,                                  \
 588           __node2 = __next2,                                  \
 589           __next1 = __next1->next,                            \
 590           __next2 = __next2->next)
 591
 592 #define foreach_list_const(__node, __list)                      \
 593    for (const struct exec_node * __node = (__list)->head        \
 594         ; (__node)->next != NULL                                \
 595         ; (__node) = (__node)->next)
 596
 597 #define foreach_list_typed(__type, __node, __field, __list)             \
 598    for (__type * __node =                                               \
 599            exec_node_data(__type, (__list)->head, __field);             \
 600         (__node)->__field.next != NULL;                                 \
 601         (__node) = exec_node_data(__type, (__node)->__field.next, __field))
 602
 603 #define foreach_list_typed_const(__type, __node, __field, __list)       \
 604    for (const __type * __node =                                         \
 605            exec_node_data(__type, (__list)->head, __field);             \
 606         (__node)->__field.next != NULL;                                 \
 607         (__node) = exec_node_data(__type, (__node)->__field.next, __field))
 608
 609 #endif /* LIST_CONTAINER_H */