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_HEAD 91 #undef TAILQ_HEAD_INITIALIZER 92 #undef TAILQ_ENTRY 93 #undef TAILQ_FIRST 94 #undef TAILQ_END 95 #undef TAILQ_NEXT 96 #undef TAILQ_LAST 97 #undef TAILQ_PREV 98 #undef TAILQ_EMPTY 99 #undef TAILQ_FOREACH 100 #undef TAILQ_FOREACH_REVERSE 101 #undef TAILQ_FOREACH_SAFE 102 #undef TAILQ_FOREACH_REVERSE_SAFE 103 #undef TAILQ_INIT 104 #undef TAILQ_INSERT_HEAD 105 #undef TAILQ_INSERT_TAIL 106 #undef TAILQ_INSERT_AFTER 107 #undef TAILQ_INSERT_BEFORE 108 #undef TAILQ_REMOVE 109 #undef TAILQ_REPLACE 110 #undef CIRCLEQ_HEAD 111 #undef CIRCLEQ_HEAD_INITIALIZER 112 #undef CIRCLEQ_ENTRY 113 #undef CIRCLEQ_FIRST 114 #undef CIRCLEQ_LAST 115 #undef CIRCLEQ_END 116 #undef CIRCLEQ_NEXT 117 #undef CIRCLEQ_PREV 118 #undef CIRCLEQ_EMPTY 119 #undef CIRCLEQ_FOREACH 120 #undef CIRCLEQ_FOREACH_REVERSE 121 #undef CIRCLEQ_INIT 122 #undef CIRCLEQ_INSERT_AFTER 123 #undef CIRCLEQ_INSERT_BEFORE 124 #undef CIRCLEQ_INSERT_HEAD 125 #undef CIRCLEQ_INSERT_TAIL 126 #undef CIRCLEQ_REMOVE 127 #undef CIRCLEQ_REPLACE 128 129 /* 130 * This file defines five types of data structures: singly-linked lists, 131 * lists, simple queues, tail queues, and circular queues. 132 * 133 * 134 * A singly-linked list is headed by a single forward pointer. The elements 135 * are singly linked for minimum space and pointer manipulation overhead at 136 * the expense of O(n) removal for arbitrary elements. New elements can be 137 * added to the list after an existing element or at the head of the list. 138 * Elements being removed from the head of the list should use the explicit 139 * macro for this purpose for optimum efficiency. A singly-linked list may 140 * only be traversed in the forward direction. Singly-linked lists are ideal 141 * for applications with large datasets and few or no removals or for 142 * implementing a LIFO queue. 143 * 144 * A list is headed by a single forward pointer (or an array of forward 145 * pointers for a hash table header). The elements are doubly linked 146 * so that an arbitrary element can be removed without a need to 147 * traverse the list. New elements can be added to the list before 148 * or after an existing element or at the head of the list. A list 149 * may only be traversed in the forward direction. 150 * 151 * A simple queue is headed by a pair of pointers, one the head of the 152 * list and the other to the tail of the list. The elements are singly 153 * linked to save space, so elements can only be removed from the 154 * head of the list. New elements can be added to the list before or after 155 * an existing element, at the head of the list, or at the end of the 156 * list. A simple queue may only be traversed in the forward direction. 157 * 158 * A tail queue is headed by a pair of pointers, one to the head of the 159 * list and the other to the tail of the list. The elements are doubly 160 * linked so that an arbitrary element can be removed without a need to 161 * traverse the list. New elements can be added to the list before or 162 * after an existing element, at the head of the list, or at the end of 163 * the list. A tail queue may be traversed in either direction. 164 * 165 * A circle queue is headed by a pair of pointers, one to the head of the 166 * list and the other to the tail of the list. The elements are doubly 167 * linked so that an arbitrary element can be removed without a need to 168 * traverse the list. New elements can be added to the list before or after 169 * an existing element, at the head of the list, or at the end of the list. 170 * A circle queue may be traversed in either direction, but has a more 171 * complex end of list detection. 172 * 173 * For details on the use of these macros, see the queue(3) manual page. 174 */ 175 176 #if defined(QUEUE_MACRO_DEBUG) || (defined(_KERNEL) && defined(DIAGNOSTIC)) 177 #define _Q_INVALIDATE(a) (a) = ((void *)-1) 178 #else 179 #define _Q_INVALIDATE(a) 180 #endif 181 182 /* 183 * Singly-linked List definitions. 184 */ 185 #define SLIST_HEAD(name, type) \ 186 struct name { \ 187 struct type *slh_first; /* first element */ \ 188 } 189 190 #define SLIST_HEAD_INITIALIZER(head) \ 191 { NULL } 192 193 #define SLIST_ENTRY(type) \ 194 struct { \ 195 struct type *sle_next; /* next element */ \ 196 } 197 198 /* 199 * Singly-linked List access methods. 200 */ 201 #define SLIST_FIRST(head) ((head)->slh_first) 202 #define SLIST_END(head) NULL 203 #define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head)) 204 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 205 206 #define SLIST_FOREACH(var, head, field) \ 207 for((var) = SLIST_FIRST(head); \ 208 (var) != SLIST_END(head); \ 209 (var) = SLIST_NEXT(var, field)) 210 211 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 212 for ((var) = SLIST_FIRST(head); \ 213 (var) && ((tvar) = SLIST_NEXT(var, field), 1); \ 214 (var) = (tvar)) 215 216 /* 217 * Singly-linked List functions. 218 */ 219 #define SLIST_INIT(head) { \ 220 SLIST_FIRST(head) = SLIST_END(head); \ 221 } 222 223 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 224 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 225 (slistelm)->field.sle_next = (elm); \ 226 } while (0) 227 228 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 229 (elm)->field.sle_next = (head)->slh_first; \ 230 (head)->slh_first = (elm); \ 231 } while (0) 232 233 #define SLIST_REMOVE_AFTER(elm, field) do { \ 234 (elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \ 235 } while (0) 236 237 #define SLIST_REMOVE_HEAD(head, field) do { \ 238 (head)->slh_first = (head)->slh_first->field.sle_next; \ 239 } while (0) 240 241 #define SLIST_REMOVE(head, elm, type, field) do { \ 242 if ((head)->slh_first == (elm)) { \ 243 SLIST_REMOVE_HEAD((head), field); \ 244 } else { \ 245 struct type *curelm = (head)->slh_first; \ 246 \ 247 while (curelm->field.sle_next != (elm)) \ 248 curelm = curelm->field.sle_next; \ 249 curelm->field.sle_next = \ 250 curelm->field.sle_next->field.sle_next; \ 251 _Q_INVALIDATE((elm)->field.sle_next); \ 252 } \ 253 } while (0) 254 255 /* 256 * List definitions. 257 */ 258 #define LIST_HEAD(name, type) \ 259 struct name { \ 260 struct type *lh_first; /* first element */ \ 261 } 262 263 #define LIST_HEAD_INITIALIZER(head) \ 264 { NULL } 265 266 #define LIST_ENTRY(type) \ 267 struct { \ 268 struct type *le_next; /* next element */ \ 269 struct type **le_prev; /* address of previous next element */ \ 270 } 271 272 /* 273 * List access methods 274 */ 275 #define LIST_FIRST(head) ((head)->lh_first) 276 #define LIST_END(head) NULL 277 #define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head)) 278 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 279 280 #define LIST_FOREACH(var, head, field) \ 281 for((var) = LIST_FIRST(head); \ 282 (var)!= LIST_END(head); \ 283 (var) = LIST_NEXT(var, field)) 284 285 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 286 for ((var) = LIST_FIRST(head); \ 287 (var) && ((tvar) = LIST_NEXT(var, field), 1); \ 288 (var) = (tvar)) 289 290 /* 291 * List functions. 292 */ 293 #define LIST_INIT(head) do { \ 294 LIST_FIRST(head) = LIST_END(head); \ 295 } while (0) 296 297 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 298 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 299 (listelm)->field.le_next->field.le_prev = \ 300 &(elm)->field.le_next; \ 301 (listelm)->field.le_next = (elm); \ 302 (elm)->field.le_prev = &(listelm)->field.le_next; \ 303 } while (0) 304 305 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 306 (elm)->field.le_prev = (listelm)->field.le_prev; \ 307 (elm)->field.le_next = (listelm); \ 308 *(listelm)->field.le_prev = (elm); \ 309 (listelm)->field.le_prev = &(elm)->field.le_next; \ 310 } while (0) 311 312 #define LIST_INSERT_HEAD(head, elm, field) do { \ 313 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 314 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 315 (head)->lh_first = (elm); \ 316 (elm)->field.le_prev = &(head)->lh_first; \ 317 } while (0) 318 319 #define LIST_REMOVE(elm, field) do { \ 320 if ((elm)->field.le_next != NULL) \ 321 (elm)->field.le_next->field.le_prev = \ 322 (elm)->field.le_prev; \ 323 *(elm)->field.le_prev = (elm)->field.le_next; \ 324 _Q_INVALIDATE((elm)->field.le_prev); \ 325 _Q_INVALIDATE((elm)->field.le_next); \ 326 } while (0) 327 328 #define LIST_REPLACE(elm, elm2, field) do { \ 329 if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ 330 (elm2)->field.le_next->field.le_prev = \ 331 &(elm2)->field.le_next; \ 332 (elm2)->field.le_prev = (elm)->field.le_prev; \ 333 *(elm2)->field.le_prev = (elm2); \ 334 _Q_INVALIDATE((elm)->field.le_prev); \ 335 _Q_INVALIDATE((elm)->field.le_next); \ 336 } while (0) 337 338 /* 339 * Simple queue definitions. 340 */ 341 #define SIMPLEQ_HEAD(name, type) \ 342 struct name { \ 343 struct type *sqh_first; /* first element */ \ 344 struct type **sqh_last; /* addr of last next element */ \ 345 } 346 347 #define SIMPLEQ_HEAD_INITIALIZER(head) \ 348 { NULL, &(head).sqh_first } 349 350 #define SIMPLEQ_ENTRY(type) \ 351 struct { \ 352 struct type *sqe_next; /* next element */ \ 353 } 354 355 /* 356 * Simple queue access methods. 357 */ 358 #define SIMPLEQ_FIRST(head) ((head)->sqh_first) 359 #define SIMPLEQ_END(head) NULL 360 #define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head)) 361 #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 362 363 #define SIMPLEQ_FOREACH(var, head, field) \ 364 for((var) = SIMPLEQ_FIRST(head); \ 365 (var) != SIMPLEQ_END(head); \ 366 (var) = SIMPLEQ_NEXT(var, field)) 367 368 #define SIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \ 369 for ((var) = SIMPLEQ_FIRST(head); \ 370 (var) && ((tvar) = SIMPLEQ_NEXT(var, field), 1); \ 371 (var) = (tvar)) 372 373 /* 374 * Simple queue functions. 375 */ 376 #define SIMPLEQ_INIT(head) do { \ 377 (head)->sqh_first = NULL; \ 378 (head)->sqh_last = &(head)->sqh_first; \ 379 } while (0) 380 381 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 382 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ 383 (head)->sqh_last = &(elm)->field.sqe_next; \ 384 (head)->sqh_first = (elm); \ 385 } while (0) 386 387 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 388 (elm)->field.sqe_next = NULL; \ 389 *(head)->sqh_last = (elm); \ 390 (head)->sqh_last = &(elm)->field.sqe_next; \ 391 } while (0) 392 393 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 394 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ 395 (head)->sqh_last = &(elm)->field.sqe_next; \ 396 (listelm)->field.sqe_next = (elm); \ 397 } while (0) 398 399 #define SIMPLEQ_REMOVE_HEAD(head, field) do { \ 400 if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \ 401 (head)->sqh_last = &(head)->sqh_first; \ 402 } while (0) 403 404 #define SIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ 405 if (((elm)->field.sqe_next = (elm)->field.sqe_next->field.sqe_next) \ 406 == NULL) \ 407 (head)->sqh_last = &(elm)->field.sqe_next; \ 408 } while (0) 409 410 /* 411 * Tail queue definitions. 412 */ 413 #define TAILQ_HEAD(name, type) \ 414 struct name { \ 415 struct type *tqh_first; /* first element */ \ 416 struct type **tqh_last; /* addr of last next element */ \ 417 } 418 419 #define TAILQ_HEAD_INITIALIZER(head) \ 420 { NULL, &(head).tqh_first } 421 422 #define TAILQ_ENTRY(type) \ 423 struct { \ 424 struct type *tqe_next; /* next element */ \ 425 struct type **tqe_prev; /* address of previous next element */ \ 426 } 427 428 /* 429 * tail queue access methods 430 */ 431 #define TAILQ_FIRST(head) ((head)->tqh_first) 432 #define TAILQ_END(head) NULL 433 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 434 #define TAILQ_LAST(head, headname) \ 435 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 436 /* XXX */ 437 #define TAILQ_PREV(elm, headname, field) \ 438 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 439 #define TAILQ_EMPTY(head) \ 440 (TAILQ_FIRST(head) == TAILQ_END(head)) 441 442 #define TAILQ_FOREACH(var, head, field) \ 443 for((var) = TAILQ_FIRST(head); \ 444 (var) != TAILQ_END(head); \ 445 (var) = TAILQ_NEXT(var, field)) 446 447 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 448 for ((var) = TAILQ_FIRST(head); \ 449 (var) != TAILQ_END(head) && \ 450 ((tvar) = TAILQ_NEXT(var, field), 1); \ 451 (var) = (tvar)) 452 453 454 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 455 for((var) = TAILQ_LAST(head, headname); \ 456 (var) != TAILQ_END(head); \ 457 (var) = TAILQ_PREV(var, headname, field)) 458 459 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 460 for ((var) = TAILQ_LAST(head, headname); \ 461 (var) != TAILQ_END(head) && \ 462 ((tvar) = TAILQ_PREV(var, headname, field), 1); \ 463 (var) = (tvar)) 464 465 /* 466 * Tail queue functions. 467 */ 468 #define TAILQ_INIT(head) do { \ 469 (head)->tqh_first = NULL; \ 470 (head)->tqh_last = &(head)->tqh_first; \ 471 } while (0) 472 473 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 474 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 475 (head)->tqh_first->field.tqe_prev = \ 476 &(elm)->field.tqe_next; \ 477 else \ 478 (head)->tqh_last = &(elm)->field.tqe_next; \ 479 (head)->tqh_first = (elm); \ 480 (elm)->field.tqe_prev = &(head)->tqh_first; \ 481 } while (0) 482 483 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 484 (elm)->field.tqe_next = NULL; \ 485 (elm)->field.tqe_prev = (head)->tqh_last; \ 486 *(head)->tqh_last = (elm); \ 487 (head)->tqh_last = &(elm)->field.tqe_next; \ 488 } while (0) 489 490 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 491 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 492 (elm)->field.tqe_next->field.tqe_prev = \ 493 &(elm)->field.tqe_next; \ 494 else \ 495 (head)->tqh_last = &(elm)->field.tqe_next; \ 496 (listelm)->field.tqe_next = (elm); \ 497 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 498 } while (0) 499 500 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 501 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 502 (elm)->field.tqe_next = (listelm); \ 503 *(listelm)->field.tqe_prev = (elm); \ 504 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 505 } while (0) 506 507 #define TAILQ_REMOVE(head, elm, field) do { \ 508 if (((elm)->field.tqe_next) != NULL) \ 509 (elm)->field.tqe_next->field.tqe_prev = \ 510 (elm)->field.tqe_prev; \ 511 else \ 512 (head)->tqh_last = (elm)->field.tqe_prev; \ 513 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 514 _Q_INVALIDATE((elm)->field.tqe_prev); \ 515 _Q_INVALIDATE((elm)->field.tqe_next); \ 516 } while (0) 517 518 #define TAILQ_REPLACE(head, elm, elm2, field) do { \ 519 if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ 520 (elm2)->field.tqe_next->field.tqe_prev = \ 521 &(elm2)->field.tqe_next; \ 522 else \ 523 (head)->tqh_last = &(elm2)->field.tqe_next; \ 524 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ 525 *(elm2)->field.tqe_prev = (elm2); \ 526 _Q_INVALIDATE((elm)->field.tqe_prev); \ 527 _Q_INVALIDATE((elm)->field.tqe_next); \ 528 } while (0) 529 530 /* 531 * Circular queue definitions. 532 */ 533 #define CIRCLEQ_HEAD(name, type) \ 534 struct name { \ 535 struct type *cqh_first; /* first element */ \ 536 struct type *cqh_last; /* last element */ \ 537 } 538 539 #define CIRCLEQ_HEAD_INITIALIZER(head) \ 540 { CIRCLEQ_END(&head), CIRCLEQ_END(&head) } 541 542 #define CIRCLEQ_ENTRY(type) \ 543 struct { \ 544 struct type *cqe_next; /* next element */ \ 545 struct type *cqe_prev; /* previous element */ \ 546 } 547 548 /* 549 * Circular queue access methods 550 */ 551 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 552 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 553 #define CIRCLEQ_END(head) ((void *)(head)) 554 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) 555 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) 556 #define CIRCLEQ_EMPTY(head) \ 557 (CIRCLEQ_FIRST(head) == CIRCLEQ_END(head)) 558 559 #define CIRCLEQ_FOREACH(var, head, field) \ 560 for((var) = CIRCLEQ_FIRST(head); \ 561 (var) != CIRCLEQ_END(head); \ 562 (var) = CIRCLEQ_NEXT(var, field)) 563 564 #define CIRCLEQ_FOREACH_SAFE(var, head, field, tvar) \ 565 for ((var) = CIRCLEQ_FIRST(head); \ 566 (var) != CIRCLEQ_END(head) && \ 567 ((tvar) = CIRCLEQ_NEXT(var, field), 1); \ 568 (var) = (tvar)) 569 570 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 571 for((var) = CIRCLEQ_LAST(head); \ 572 (var) != CIRCLEQ_END(head); \ 573 (var) = CIRCLEQ_PREV(var, field)) 574 575 #define CIRCLEQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 576 for ((var) = CIRCLEQ_LAST(head, headname); \ 577 (var) != CIRCLEQ_END(head) && \ 578 ((tvar) = CIRCLEQ_PREV(var, headname, field), 1); \ 579 (var) = (tvar)) 580 581 /* 582 * Circular queue functions. 583 */ 584 #define CIRCLEQ_INIT(head) do { \ 585 (head)->cqh_first = CIRCLEQ_END(head); \ 586 (head)->cqh_last = CIRCLEQ_END(head); \ 587 } while (0) 588 589 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 590 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 591 (elm)->field.cqe_prev = (listelm); \ 592 if ((listelm)->field.cqe_next == CIRCLEQ_END(head)) \ 593 (head)->cqh_last = (elm); \ 594 else \ 595 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 596 (listelm)->field.cqe_next = (elm); \ 597 } while (0) 598 599 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 600 (elm)->field.cqe_next = (listelm); \ 601 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 602 if ((listelm)->field.cqe_prev == CIRCLEQ_END(head)) \ 603 (head)->cqh_first = (elm); \ 604 else \ 605 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 606 (listelm)->field.cqe_prev = (elm); \ 607 } while (0) 608 609 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 610 (elm)->field.cqe_next = (head)->cqh_first; \ 611 (elm)->field.cqe_prev = CIRCLEQ_END(head); \ 612 if ((head)->cqh_last == CIRCLEQ_END(head)) \ 613 (head)->cqh_last = (elm); \ 614 else \ 615 (head)->cqh_first->field.cqe_prev = (elm); \ 616 (head)->cqh_first = (elm); \ 617 } while (0) 618 619 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 620 (elm)->field.cqe_next = CIRCLEQ_END(head); \ 621 (elm)->field.cqe_prev = (head)->cqh_last; \ 622 if ((head)->cqh_first == CIRCLEQ_END(head)) \ 623 (head)->cqh_first = (elm); \ 624 else \ 625 (head)->cqh_last->field.cqe_next = (elm); \ 626 (head)->cqh_last = (elm); \ 627 } while (0) 628 629 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 630 if ((elm)->field.cqe_next == CIRCLEQ_END(head)) \ 631 (head)->cqh_last = (elm)->field.cqe_prev; \ 632 else \ 633 (elm)->field.cqe_next->field.cqe_prev = \ 634 (elm)->field.cqe_prev; \ 635 if ((elm)->field.cqe_prev == CIRCLEQ_END(head)) \ 636 (head)->cqh_first = (elm)->field.cqe_next; \ 637 else \ 638 (elm)->field.cqe_prev->field.cqe_next = \ 639 (elm)->field.cqe_next; \ 640 _Q_INVALIDATE((elm)->field.cqe_prev); \ 641 _Q_INVALIDATE((elm)->field.cqe_next); \ 642 } while (0) 643 644 #define CIRCLEQ_REPLACE(head, elm, elm2, field) do { \ 645 if (((elm2)->field.cqe_next = (elm)->field.cqe_next) == \ 646 CIRCLEQ_END(head)) \ 647 (head).cqh_last = (elm2); \ 648 else \ 649 (elm2)->field.cqe_next->field.cqe_prev = (elm2); \ 650 if (((elm2)->field.cqe_prev = (elm)->field.cqe_prev) == \ 651 CIRCLEQ_END(head)) \ 652 (head).cqh_first = (elm2); \ 653 else \ 654 (elm2)->field.cqe_prev->field.cqe_next = (elm2); \ 655 _Q_INVALIDATE((elm)->field.cqe_prev); \ 656 _Q_INVALIDATE((elm)->field.cqe_next); \ 657 } while (0) 658 659 #endif /* !_FAKE_QUEUE_H_ */ 660