1 /* $OpenBSD: queue.h,v 1.36 2012/04/11 13:29:14 naddy Exp $ */ 2 /* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */ 3 4 /* 5 * Copyright (c) 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)queue.h 8.5 (Berkeley) 8/20/94 33 */ 34 35 /* OPENBSD ORIGINAL: sys/sys/queue.h */ 36 37 #ifndef _FAKE_QUEUE_H_ 38 #define _FAKE_QUEUE_H_ 39 40 /* 41 * Require for OS/X and other platforms that have old/broken/incomplete 42 * <sys/queue.h>. 43 */ 44 #undef SLIST_HEAD 45 #undef SLIST_HEAD_INITIALIZER 46 #undef SLIST_ENTRY 47 #undef SLIST_FOREACH_PREVPTR 48 #undef SLIST_FOREACH_SAFE 49 #undef SLIST_FIRST 50 #undef SLIST_END 51 #undef SLIST_EMPTY 52 #undef SLIST_NEXT 53 #undef SLIST_FOREACH 54 #undef SLIST_INIT 55 #undef SLIST_INSERT_AFTER 56 #undef SLIST_INSERT_HEAD 57 #undef SLIST_REMOVE_HEAD 58 #undef SLIST_REMOVE_AFTER 59 #undef SLIST_REMOVE 60 #undef SLIST_REMOVE_NEXT 61 #undef LIST_HEAD 62 #undef LIST_HEAD_INITIALIZER 63 #undef LIST_ENTRY 64 #undef LIST_FIRST 65 #undef LIST_END 66 #undef LIST_EMPTY 67 #undef LIST_NEXT 68 #undef LIST_FOREACH 69 #undef LIST_FOREACH_SAFE 70 #undef LIST_INIT 71 #undef LIST_INSERT_AFTER 72 #undef LIST_INSERT_BEFORE 73 #undef LIST_INSERT_HEAD 74 #undef LIST_REMOVE 75 #undef LIST_REPLACE 76 #undef SIMPLEQ_HEAD 77 #undef SIMPLEQ_HEAD_INITIALIZER 78 #undef SIMPLEQ_ENTRY 79 #undef SIMPLEQ_FIRST 80 #undef SIMPLEQ_END 81 #undef SIMPLEQ_EMPTY 82 #undef SIMPLEQ_NEXT 83 #undef SIMPLEQ_FOREACH 84 #undef SIMPLEQ_FOREACH_SAFE 85 #undef SIMPLEQ_INIT 86 #undef SIMPLEQ_INSERT_HEAD 87 #undef SIMPLEQ_INSERT_TAIL 88 #undef SIMPLEQ_INSERT_AFTER 89 #undef SIMPLEQ_REMOVE_HEAD 90 #undef TAILQ_CONCAT 91 #undef TAILQ_HEAD 92 #undef TAILQ_HEAD_INITIALIZER 93 #undef TAILQ_ENTRY 94 #undef TAILQ_FIRST 95 #undef TAILQ_END 96 #undef TAILQ_NEXT 97 #undef TAILQ_LAST 98 #undef TAILQ_PREV 99 #undef TAILQ_EMPTY 100 #undef TAILQ_FOREACH 101 #undef TAILQ_FOREACH_REVERSE 102 #undef TAILQ_FOREACH_SAFE 103 #undef TAILQ_FOREACH_REVERSE_SAFE 104 #undef TAILQ_INIT 105 #undef TAILQ_INSERT_HEAD 106 #undef TAILQ_INSERT_TAIL 107 #undef TAILQ_INSERT_AFTER 108 #undef TAILQ_INSERT_BEFORE 109 #undef TAILQ_REMOVE 110 #undef TAILQ_REPLACE 111 #undef CIRCLEQ_HEAD 112 #undef CIRCLEQ_HEAD_INITIALIZER 113 #undef CIRCLEQ_ENTRY 114 #undef CIRCLEQ_FIRST 115 #undef CIRCLEQ_LAST 116 #undef CIRCLEQ_END 117 #undef CIRCLEQ_NEXT 118 #undef CIRCLEQ_PREV 119 #undef CIRCLEQ_EMPTY 120 #undef CIRCLEQ_FOREACH 121 #undef CIRCLEQ_FOREACH_REVERSE 122 #undef CIRCLEQ_INIT 123 #undef CIRCLEQ_INSERT_AFTER 124 #undef CIRCLEQ_INSERT_BEFORE 125 #undef CIRCLEQ_INSERT_HEAD 126 #undef CIRCLEQ_INSERT_TAIL 127 #undef CIRCLEQ_REMOVE 128 #undef CIRCLEQ_REPLACE 129 130 /* 131 * This file defines five types of data structures: singly-linked lists, 132 * lists, simple queues, tail queues, and circular queues. 133 * 134 * 135 * A singly-linked list is headed by a single forward pointer. The elements 136 * are singly linked for minimum space and pointer manipulation overhead at 137 * the expense of O(n) removal for arbitrary elements. New elements can be 138 * added to the list after an existing element or at the head of the list. 139 * Elements being removed from the head of the list should use the explicit 140 * macro for this purpose for optimum efficiency. A singly-linked list may 141 * only be traversed in the forward direction. Singly-linked lists are ideal 142 * for applications with large datasets and few or no removals or for 143 * implementing a LIFO queue. 144 * 145 * A list is headed by a single forward pointer (or an array of forward 146 * pointers for a hash table header). The elements are doubly linked 147 * so that an arbitrary element can be removed without a need to 148 * traverse the list. New elements can be added to the list before 149 * or after an existing element or at the head of the list. A list 150 * may only be traversed in the forward direction. 151 * 152 * A simple queue is headed by a pair of pointers, one the head of the 153 * list and the other to the tail of the list. The elements are singly 154 * linked to save space, so elements can only be removed from the 155 * head of the list. New elements can be added to the list before or after 156 * an existing element, at the head of the list, or at the end of the 157 * list. A simple queue may only be traversed in the forward direction. 158 * 159 * A tail queue is headed by a pair of pointers, one to the head of the 160 * list and the other to the tail of the list. The elements are doubly 161 * linked so that an arbitrary element can be removed without a need to 162 * traverse the list. New elements can be added to the list before or 163 * after an existing element, at the head of the list, or at the end of 164 * the list. A tail queue may be traversed in either direction. 165 * 166 * A circle queue is headed by a pair of pointers, one to the head of the 167 * list and the other to the tail of the list. The elements are doubly 168 * linked so that an arbitrary element can be removed without a need to 169 * traverse the list. New elements can be added to the list before or after 170 * an existing element, at the head of the list, or at the end of the list. 171 * A circle queue may be traversed in either direction, but has a more 172 * complex end of list detection. 173 * 174 * For details on the use of these macros, see the queue(3) manual page. 175 */ 176 177 #if defined(QUEUE_MACRO_DEBUG) || (defined(_KERNEL) && defined(DIAGNOSTIC)) 178 #define _Q_INVALIDATE(a) (a) = ((void *)-1) 179 #else 180 #define _Q_INVALIDATE(a) 181 #endif 182 183 /* 184 * Singly-linked List definitions. 185 */ 186 #define SLIST_HEAD(name, type) \ 187 struct name { \ 188 struct type *slh_first; /* first element */ \ 189 } 190 191 #define SLIST_HEAD_INITIALIZER(head) \ 192 { NULL } 193 194 #define SLIST_ENTRY(type) \ 195 struct { \ 196 struct type *sle_next; /* next element */ \ 197 } 198 199 /* 200 * Singly-linked List access methods. 201 */ 202 #define SLIST_FIRST(head) ((head)->slh_first) 203 #define SLIST_END(head) NULL 204 #define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head)) 205 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 206 207 #define SLIST_FOREACH(var, head, field) \ 208 for((var) = SLIST_FIRST(head); \ 209 (var) != SLIST_END(head); \ 210 (var) = SLIST_NEXT(var, field)) 211 212 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 213 for ((var) = SLIST_FIRST(head); \ 214 (var) && ((tvar) = SLIST_NEXT(var, field), 1); \ 215 (var) = (tvar)) 216 217 /* 218 * Singly-linked List functions. 219 */ 220 #define SLIST_INIT(head) { \ 221 SLIST_FIRST(head) = SLIST_END(head); \ 222 } 223 224 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 225 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 226 (slistelm)->field.sle_next = (elm); \ 227 } while (0) 228 229 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 230 (elm)->field.sle_next = (head)->slh_first; \ 231 (head)->slh_first = (elm); \ 232 } while (0) 233 234 #define SLIST_REMOVE_AFTER(elm, field) do { \ 235 (elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \ 236 } while (0) 237 238 #define SLIST_REMOVE_HEAD(head, field) do { \ 239 (head)->slh_first = (head)->slh_first->field.sle_next; \ 240 } while (0) 241 242 #define SLIST_REMOVE(head, elm, type, field) do { \ 243 if ((head)->slh_first == (elm)) { \ 244 SLIST_REMOVE_HEAD((head), field); \ 245 } else { \ 246 struct type *curelm = (head)->slh_first; \ 247 \ 248 while (curelm->field.sle_next != (elm)) \ 249 curelm = curelm->field.sle_next; \ 250 curelm->field.sle_next = \ 251 curelm->field.sle_next->field.sle_next; \ 252 _Q_INVALIDATE((elm)->field.sle_next); \ 253 } \ 254 } while (0) 255 256 /* 257 * List definitions. 258 */ 259 #define LIST_HEAD(name, type) \ 260 struct name { \ 261 struct type *lh_first; /* first element */ \ 262 } 263 264 #define LIST_HEAD_INITIALIZER(head) \ 265 { NULL } 266 267 #define LIST_ENTRY(type) \ 268 struct { \ 269 struct type *le_next; /* next element */ \ 270 struct type **le_prev; /* address of previous next element */ \ 271 } 272 273 /* 274 * List access methods 275 */ 276 #define LIST_FIRST(head) ((head)->lh_first) 277 #define LIST_END(head) NULL 278 #define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head)) 279 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 280 281 #define LIST_FOREACH(var, head, field) \ 282 for((var) = LIST_FIRST(head); \ 283 (var)!= LIST_END(head); \ 284 (var) = LIST_NEXT(var, field)) 285 286 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 287 for ((var) = LIST_FIRST(head); \ 288 (var) && ((tvar) = LIST_NEXT(var, field), 1); \ 289 (var) = (tvar)) 290 291 /* 292 * List functions. 293 */ 294 #define LIST_INIT(head) do { \ 295 LIST_FIRST(head) = LIST_END(head); \ 296 } while (0) 297 298 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 299 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 300 (listelm)->field.le_next->field.le_prev = \ 301 &(elm)->field.le_next; \ 302 (listelm)->field.le_next = (elm); \ 303 (elm)->field.le_prev = &(listelm)->field.le_next; \ 304 } while (0) 305 306 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 307 (elm)->field.le_prev = (listelm)->field.le_prev; \ 308 (elm)->field.le_next = (listelm); \ 309 *(listelm)->field.le_prev = (elm); \ 310 (listelm)->field.le_prev = &(elm)->field.le_next; \ 311 } while (0) 312 313 #define LIST_INSERT_HEAD(head, elm, field) do { \ 314 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 315 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 316 (head)->lh_first = (elm); \ 317 (elm)->field.le_prev = &(head)->lh_first; \ 318 } while (0) 319 320 #define LIST_REMOVE(elm, field) do { \ 321 if ((elm)->field.le_next != NULL) \ 322 (elm)->field.le_next->field.le_prev = \ 323 (elm)->field.le_prev; \ 324 *(elm)->field.le_prev = (elm)->field.le_next; \ 325 _Q_INVALIDATE((elm)->field.le_prev); \ 326 _Q_INVALIDATE((elm)->field.le_next); \ 327 } while (0) 328 329 #define LIST_REPLACE(elm, elm2, field) do { \ 330 if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ 331 (elm2)->field.le_next->field.le_prev = \ 332 &(elm2)->field.le_next; \ 333 (elm2)->field.le_prev = (elm)->field.le_prev; \ 334 *(elm2)->field.le_prev = (elm2); \ 335 _Q_INVALIDATE((elm)->field.le_prev); \ 336 _Q_INVALIDATE((elm)->field.le_next); \ 337 } while (0) 338 339 /* 340 * Simple queue definitions. 341 */ 342 #define SIMPLEQ_HEAD(name, type) \ 343 struct name { \ 344 struct type *sqh_first; /* first element */ \ 345 struct type **sqh_last; /* addr of last next element */ \ 346 } 347 348 #define SIMPLEQ_HEAD_INITIALIZER(head) \ 349 { NULL, &(head).sqh_first } 350 351 #define SIMPLEQ_ENTRY(type) \ 352 struct { \ 353 struct type *sqe_next; /* next element */ \ 354 } 355 356 /* 357 * Simple queue access methods. 358 */ 359 #define SIMPLEQ_FIRST(head) ((head)->sqh_first) 360 #define SIMPLEQ_END(head) NULL 361 #define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head)) 362 #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 363 364 #define SIMPLEQ_FOREACH(var, head, field) \ 365 for((var) = SIMPLEQ_FIRST(head); \ 366 (var) != SIMPLEQ_END(head); \ 367 (var) = SIMPLEQ_NEXT(var, field)) 368 369 #define SIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \ 370 for ((var) = SIMPLEQ_FIRST(head); \ 371 (var) && ((tvar) = SIMPLEQ_NEXT(var, field), 1); \ 372 (var) = (tvar)) 373 374 /* 375 * Simple queue functions. 376 */ 377 #define SIMPLEQ_INIT(head) do { \ 378 (head)->sqh_first = NULL; \ 379 (head)->sqh_last = &(head)->sqh_first; \ 380 } while (0) 381 382 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 383 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ 384 (head)->sqh_last = &(elm)->field.sqe_next; \ 385 (head)->sqh_first = (elm); \ 386 } while (0) 387 388 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 389 (elm)->field.sqe_next = NULL; \ 390 *(head)->sqh_last = (elm); \ 391 (head)->sqh_last = &(elm)->field.sqe_next; \ 392 } while (0) 393 394 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 395 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ 396 (head)->sqh_last = &(elm)->field.sqe_next; \ 397 (listelm)->field.sqe_next = (elm); \ 398 } while (0) 399 400 #define SIMPLEQ_REMOVE_HEAD(head, field) do { \ 401 if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \ 402 (head)->sqh_last = &(head)->sqh_first; \ 403 } while (0) 404 405 #define SIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ 406 if (((elm)->field.sqe_next = (elm)->field.sqe_next->field.sqe_next) \ 407 == NULL) \ 408 (head)->sqh_last = &(elm)->field.sqe_next; \ 409 } while (0) 410 411 /* 412 * Tail queue definitions. 413 */ 414 #define TAILQ_HEAD(name, type) \ 415 struct name { \ 416 struct type *tqh_first; /* first element */ \ 417 struct type **tqh_last; /* addr of last next element */ \ 418 } 419 420 #define TAILQ_HEAD_INITIALIZER(head) \ 421 { NULL, &(head).tqh_first } 422 423 #define TAILQ_ENTRY(type) \ 424 struct { \ 425 struct type *tqe_next; /* next element */ \ 426 struct type **tqe_prev; /* address of previous next element */ \ 427 } 428 429 /* 430 * tail queue access methods 431 */ 432 #define TAILQ_FIRST(head) ((head)->tqh_first) 433 #define TAILQ_END(head) NULL 434 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 435 #define TAILQ_LAST(head, headname) \ 436 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 437 /* XXX */ 438 #define TAILQ_PREV(elm, headname, field) \ 439 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 440 #define TAILQ_EMPTY(head) \ 441 (TAILQ_FIRST(head) == TAILQ_END(head)) 442 443 #define TAILQ_FOREACH(var, head, field) \ 444 for((var) = TAILQ_FIRST(head); \ 445 (var) != TAILQ_END(head); \ 446 (var) = TAILQ_NEXT(var, field)) 447 448 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 449 for ((var) = TAILQ_FIRST(head); \ 450 (var) != TAILQ_END(head) && \ 451 ((tvar) = TAILQ_NEXT(var, field), 1); \ 452 (var) = (tvar)) 453 454 455 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 456 for((var) = TAILQ_LAST(head, headname); \ 457 (var) != TAILQ_END(head); \ 458 (var) = TAILQ_PREV(var, headname, field)) 459 460 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 461 for ((var) = TAILQ_LAST(head, headname); \ 462 (var) != TAILQ_END(head) && \ 463 ((tvar) = TAILQ_PREV(var, headname, field), 1); \ 464 (var) = (tvar)) 465 466 /* 467 * Tail queue functions. 468 */ 469 #define TAILQ_INIT(head) do { \ 470 (head)->tqh_first = NULL; \ 471 (head)->tqh_last = &(head)->tqh_first; \ 472 } while (0) 473 474 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 475 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 476 (head)->tqh_first->field.tqe_prev = \ 477 &(elm)->field.tqe_next; \ 478 else \ 479 (head)->tqh_last = &(elm)->field.tqe_next; \ 480 (head)->tqh_first = (elm); \ 481 (elm)->field.tqe_prev = &(head)->tqh_first; \ 482 } while (0) 483 484 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 485 (elm)->field.tqe_next = NULL; \ 486 (elm)->field.tqe_prev = (head)->tqh_last; \ 487 *(head)->tqh_last = (elm); \ 488 (head)->tqh_last = &(elm)->field.tqe_next; \ 489 } while (0) 490 491 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 492 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 493 (elm)->field.tqe_next->field.tqe_prev = \ 494 &(elm)->field.tqe_next; \ 495 else \ 496 (head)->tqh_last = &(elm)->field.tqe_next; \ 497 (listelm)->field.tqe_next = (elm); \ 498 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 499 } while (0) 500 501 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 502 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 503 (elm)->field.tqe_next = (listelm); \ 504 *(listelm)->field.tqe_prev = (elm); \ 505 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 506 } while (0) 507 508 #define TAILQ_REMOVE(head, elm, field) do { \ 509 if (((elm)->field.tqe_next) != NULL) \ 510 (elm)->field.tqe_next->field.tqe_prev = \ 511 (elm)->field.tqe_prev; \ 512 else \ 513 (head)->tqh_last = (elm)->field.tqe_prev; \ 514 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 515 _Q_INVALIDATE((elm)->field.tqe_prev); \ 516 _Q_INVALIDATE((elm)->field.tqe_next); \ 517 } while (0) 518 519 #define TAILQ_REPLACE(head, elm, elm2, field) do { \ 520 if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ 521 (elm2)->field.tqe_next->field.tqe_prev = \ 522 &(elm2)->field.tqe_next; \ 523 else \ 524 (head)->tqh_last = &(elm2)->field.tqe_next; \ 525 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ 526 *(elm2)->field.tqe_prev = (elm2); \ 527 _Q_INVALIDATE((elm)->field.tqe_prev); \ 528 _Q_INVALIDATE((elm)->field.tqe_next); \ 529 } while (0) 530 531 #define TAILQ_CONCAT(head1, head2, field) do { \ 532 if (!TAILQ_EMPTY(head2)) { \ 533 *(head1)->tqh_last = (head2)->tqh_first; \ 534 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 535 (head1)->tqh_last = (head2)->tqh_last; \ 536 TAILQ_INIT((head2)); \ 537 } \ 538 } while (0) 539 540 /* 541 * Circular queue definitions. 542 */ 543 #define CIRCLEQ_HEAD(name, type) \ 544 struct name { \ 545 struct type *cqh_first; /* first element */ \ 546 struct type *cqh_last; /* last element */ \ 547 } 548 549 #define CIRCLEQ_HEAD_INITIALIZER(head) \ 550 { CIRCLEQ_END(&head), CIRCLEQ_END(&head) } 551 552 #define CIRCLEQ_ENTRY(type) \ 553 struct { \ 554 struct type *cqe_next; /* next element */ \ 555 struct type *cqe_prev; /* previous element */ \ 556 } 557 558 /* 559 * Circular queue access methods 560 */ 561 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 562 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 563 #define CIRCLEQ_END(head) ((void *)(head)) 564 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) 565 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) 566 #define CIRCLEQ_EMPTY(head) \ 567 (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head)) 568 569 #define CIRCLEQ_FOREACH(var, head, field) \ 570 for((var) = CIRCLEQ_FIRST(head); \ 571 (var) != CIRCLEQ_END(head); \ 572 (var) = CIRCLEQ_NEXT(var, field)) 573 574 #define CIRCLEQ_FOREACH_SAFE(var, head, field, tvar) \ 575 for ((var) = CIRCLEQ_FIRST(head); \ 576 (var) != CIRCLEQ_END(head) && \ 577 ((tvar) = CIRCLEQ_NEXT(var, field), 1); \ 578 (var) = (tvar)) 579 580 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 581 for((var) = CIRCLEQ_LAST(head); \ 582 (var) != CIRCLEQ_END(head); \ 583 (var) = CIRCLEQ_PREV(var, field)) 584 585 #define CIRCLEQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 586 for ((var) = CIRCLEQ_LAST(head, headname); \ 587 (var) != CIRCLEQ_END(head) && \ 588 ((tvar) = CIRCLEQ_PREV(var, headname, field), 1); \ 589 (var) = (tvar)) 590 591 /* 592 * Circular queue functions. 593 */ 594 #define CIRCLEQ_INIT(head) do { \ 595 (head)->cqh_first = CIRCLEQ_END(head); \ 596 (head)->cqh_last = CIRCLEQ_END(head); \ 597 } while (0) 598 599 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 600 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 601 (elm)->field.cqe_prev = (listelm); \ 602 if ((listelm)->field.cqe_next == CIRCLEQ_END(head)) \ 603 (head)->cqh_last = (elm); \ 604 else \ 605 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 606 (listelm)->field.cqe_next = (elm); \ 607 } while (0) 608 609 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 610 (elm)->field.cqe_next = (listelm); \ 611 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 612 if ((listelm)->field.cqe_prev == CIRCLEQ_END(head)) \ 613 (head)->cqh_first = (elm); \ 614 else \ 615 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 616 (listelm)->field.cqe_prev = (elm); \ 617 } while (0) 618 619 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 620 (elm)->field.cqe_next = (head)->cqh_first; \ 621 (elm)->field.cqe_prev = CIRCLEQ_END(head); \ 622 if ((head)->cqh_last == CIRCLEQ_END(head)) \ 623 (head)->cqh_last = (elm); \ 624 else \ 625 (head)->cqh_first->field.cqe_prev = (elm); \ 626 (head)->cqh_first = (elm); \ 627 } while (0) 628 629 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 630 (elm)->field.cqe_next = CIRCLEQ_END(head); \ 631 (elm)->field.cqe_prev = (head)->cqh_last; \ 632 if ((head)->cqh_first == CIRCLEQ_END(head)) \ 633 (head)->cqh_first = (elm); \ 634 else \ 635 (head)->cqh_last->field.cqe_next = (elm); \ 636 (head)->cqh_last = (elm); \ 637 } while (0) 638 639 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 640 if ((elm)->field.cqe_next == CIRCLEQ_END(head)) \ 641 (head)->cqh_last = (elm)->field.cqe_prev; \ 642 else \ 643 (elm)->field.cqe_next->field.cqe_prev = \ 644 (elm)->field.cqe_prev; \ 645 if ((elm)->field.cqe_prev == CIRCLEQ_END(head)) \ 646 (head)->cqh_first = (elm)->field.cqe_next; \ 647 else \ 648 (elm)->field.cqe_prev->field.cqe_next = \ 649 (elm)->field.cqe_next; \ 650 _Q_INVALIDATE((elm)->field.cqe_prev); \ 651 _Q_INVALIDATE((elm)->field.cqe_next); \ 652 } while (0) 653 654 #define CIRCLEQ_REPLACE(head, elm, elm2, field) do { \ 655 if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \ 656 CIRCLEQ_END(head)) \ 657 (head).cqh_last = (elm2); \ 658 else \ 659 (elm2)->field.cqe_next->field.cqe_prev = (elm2); \ 660 if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \ 661 CIRCLEQ_END(head)) \ 662 (head).cqh_first = (elm2); \ 663 else \ 664 (elm2)->field.cqe_prev->field.cqe_next = (elm2); \ 665 _Q_INVALIDATE((elm)->field.cqe_prev); \ 666 _Q_INVALIDATE((elm)->field.cqe_next); \ 667 } while (0) 668 669 #endif /* !_FAKE_QUEUE_H_ */ 670