1 /* SPDX-License-Identifier: BSD-3-Clause */ 2 /* $NetBSD: queue.h,v 1.49.6.1 2008/11/20 03:22:38 snj 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 #ifndef _SYS_QUEUE_H_ 36 #define _SYS_QUEUE_H_ 37 38 /*#include <sys/null.h> */ 39 40 /* 41 * This file defines five types of data structures: singly-linked lists, 42 * lists, simple queues, tail queues, and circular queues. 43 * 44 * A singly-linked list is headed by a single forward pointer. The 45 * elements are singly linked for minimum space and pointer manipulation 46 * overhead at the expense of O(n) removal for arbitrary elements. New 47 * elements can be added to the list after an existing element or at the 48 * head of the list. Elements being removed from the head of the list 49 * should use the explicit macro for this purpose for optimum 50 * efficiency. A singly-linked list may only be traversed in the forward 51 * direction. Singly-linked lists are ideal for applications with large 52 * datasets and few or no removals or for implementing a LIFO queue. 53 * 54 * A list is headed by a single forward pointer (or an array of forward 55 * pointers for a hash table header). The elements are doubly linked 56 * so that an arbitrary element can be removed without a need to 57 * traverse the list. New elements can be added to the list before 58 * or after an existing element or at the head of the list. A list 59 * may only be traversed in the forward direction. 60 * 61 * A simple queue is headed by a pair of pointers, one the head of the 62 * list and the other to the tail of the list. The elements are singly 63 * linked to save space, so elements can only be removed from the 64 * head of the list. New elements can be added to the list after 65 * an existing element, at the head of the list, or at the end of the 66 * list. A simple queue may only be traversed in the forward direction. 67 * 68 * A tail queue is headed by a pair of pointers, one to the head of the 69 * list and the other to the tail of the list. The elements are doubly 70 * linked so that an arbitrary element can be removed without a need to 71 * traverse the list. New elements can be added to the list before or 72 * after an existing element, at the head of the list, or at the end of 73 * the list. A tail queue may be traversed in either direction. 74 * 75 * A circle queue is headed by a pair of pointers, one to the head of the 76 * list and the other to the tail of the list. The elements are doubly 77 * linked so that an arbitrary element can be removed without a need to 78 * traverse the list. New elements can be added to the list before or after 79 * an existing element, at the head of the list, or at the end of the list. 80 * A circle queue may be traversed in either direction, but has a more 81 * complex end of list detection. 82 * 83 * For details on the use of these macros, see the queue(3) manual page. 84 */ 85 86 /* 87 * List definitions. 88 */ 89 #define LIST_HEAD(name, type) \ 90 struct name { \ 91 struct type *lh_first; /* first element */ \ 92 } 93 94 #define LIST_HEAD_INITIALIZER(head) \ 95 { NULL } 96 97 #define LIST_ENTRY(type) \ 98 struct { \ 99 struct type *le_next; /* next element */ \ 100 struct type **le_prev; /* address of previous next element */ \ 101 } 102 103 /* 104 * List functions. 105 */ 106 #if defined(_KERNEL) && defined(QUEUEDEBUG) 107 #define QUEUEDEBUG_LIST_INSERT_HEAD(head, elm, field) \ 108 if ((head)->lh_first && \ 109 (head)->lh_first->field.le_prev != &(head)->lh_first) \ 110 panic("LIST_INSERT_HEAD %p %s:%d", (head), __FILE__, __LINE__); 111 #define QUEUEDEBUG_LIST_OP(elm, field) \ 112 if ((elm)->field.le_next && \ 113 (elm)->field.le_next->field.le_prev != \ 114 &(elm)->field.le_next) \ 115 panic("LIST_* forw %p %s:%d", (elm), __FILE__, __LINE__);\ 116 if (*(elm)->field.le_prev != (elm)) \ 117 panic("LIST_* back %p %s:%d", (elm), __FILE__, __LINE__); 118 #define QUEUEDEBUG_LIST_POSTREMOVE(elm, field) \ 119 (elm)->field.le_next = (void *)1L; \ 120 (elm)->field.le_prev = (void *)1L; 121 #else 122 #define QUEUEDEBUG_LIST_INSERT_HEAD(head, elm, field) 123 #define QUEUEDEBUG_LIST_OP(elm, field) 124 #define QUEUEDEBUG_LIST_POSTREMOVE(elm, field) 125 #endif 126 127 #define LIST_INIT(head) do { \ 128 (head)->lh_first = NULL; \ 129 } while (/* CONSTCOND */0) 130 131 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 132 QUEUEDEBUG_LIST_OP((listelm), field) \ 133 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 134 (listelm)->field.le_next->field.le_prev = \ 135 &(elm)->field.le_next; \ 136 (listelm)->field.le_next = (elm); \ 137 (elm)->field.le_prev = &(listelm)->field.le_next; \ 138 } while (/* CONSTCOND */0) 139 140 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 141 QUEUEDEBUG_LIST_OP((listelm), field) \ 142 (elm)->field.le_prev = (listelm)->field.le_prev; \ 143 (elm)->field.le_next = (listelm); \ 144 *(listelm)->field.le_prev = (elm); \ 145 (listelm)->field.le_prev = &(elm)->field.le_next; \ 146 } while (/* CONSTCOND */0) 147 148 #define LIST_INSERT_HEAD(head, elm, field) do { \ 149 QUEUEDEBUG_LIST_INSERT_HEAD((head), (elm), field) \ 150 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 151 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 152 (head)->lh_first = (elm); \ 153 (elm)->field.le_prev = &(head)->lh_first; \ 154 } while (/* CONSTCOND */0) 155 156 #define LIST_REMOVE(elm, field) do { \ 157 QUEUEDEBUG_LIST_OP((elm), field) \ 158 if ((elm)->field.le_next != NULL) \ 159 (elm)->field.le_next->field.le_prev = \ 160 (elm)->field.le_prev; \ 161 *(elm)->field.le_prev = (elm)->field.le_next; \ 162 QUEUEDEBUG_LIST_POSTREMOVE((elm), field) \ 163 } while (/* CONSTCOND */0) 164 165 #define LIST_FOREACH(var, head, field) \ 166 for ((var) = ((head)->lh_first); \ 167 (var); \ 168 (var) = ((var)->field.le_next)) 169 170 /* 171 * List access methods. 172 */ 173 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 174 #define LIST_FIRST(head) ((head)->lh_first) 175 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 176 177 /* 178 * Singly-linked List definitions. 179 */ 180 #define SLIST_HEAD(name, type) \ 181 struct name { \ 182 struct type *slh_first; /* first element */ \ 183 } 184 185 #define SLIST_HEAD_INITIALIZER(head) \ 186 { NULL } 187 188 #define SLIST_ENTRY(type) \ 189 struct { \ 190 struct type *sle_next; /* next element */ \ 191 } 192 193 /* 194 * Singly-linked List functions. 195 */ 196 #define SLIST_INIT(head) do { \ 197 (head)->slh_first = NULL; \ 198 } while (/* CONSTCOND */0) 199 200 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 201 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 202 (slistelm)->field.sle_next = (elm); \ 203 } while (/* CONSTCOND */0) 204 205 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 206 (elm)->field.sle_next = (head)->slh_first; \ 207 (head)->slh_first = (elm); \ 208 } while (/* CONSTCOND */0) 209 210 #define SLIST_REMOVE_HEAD(head, field) do { \ 211 (head)->slh_first = (head)->slh_first->field.sle_next; \ 212 } while (/* CONSTCOND */0) 213 214 #define SLIST_REMOVE(head, elm, type, field) do { \ 215 if ((head)->slh_first == (elm)) { \ 216 SLIST_REMOVE_HEAD((head), field); \ 217 } \ 218 else { \ 219 struct type *curelm = (head)->slh_first; \ 220 while(curelm->field.sle_next != (elm)) \ 221 curelm = curelm->field.sle_next; \ 222 curelm->field.sle_next = \ 223 curelm->field.sle_next->field.sle_next; \ 224 } \ 225 } while (/* CONSTCOND */0) 226 227 #define SLIST_REMOVE_AFTER(slistelm, field) do { \ 228 (slistelm)->field.sle_next = \ 229 SLIST_NEXT(SLIST_NEXT((slistelm), field), field); \ 230 } while (/* CONSTCOND */0) 231 232 #define SLIST_FOREACH(var, head, field) \ 233 for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next) 234 235 /* 236 * Singly-linked List access methods. 237 */ 238 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 239 #define SLIST_FIRST(head) ((head)->slh_first) 240 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 241 242 /* 243 * Singly-linked Tail queue declarations. 244 */ 245 #define STAILQ_HEAD(name, type) \ 246 struct name { \ 247 struct type *stqh_first; /* first element */ \ 248 struct type **stqh_last; /* addr of last next element */ \ 249 } 250 251 #define STAILQ_HEAD_INITIALIZER(head) \ 252 { NULL, &(head).stqh_first } 253 254 #define STAILQ_ENTRY(type) \ 255 struct { \ 256 struct type *stqe_next; /* next element */ \ 257 } 258 259 /* 260 * Singly-linked Tail queue functions. 261 */ 262 #define STAILQ_INIT(head) do { \ 263 (head)->stqh_first = NULL; \ 264 (head)->stqh_last = &(head)->stqh_first; \ 265 } while (/* CONSTCOND */0) 266 267 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 268 if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \ 269 (head)->stqh_last = &(elm)->field.stqe_next; \ 270 (head)->stqh_first = (elm); \ 271 } while (/* CONSTCOND */0) 272 273 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 274 (elm)->field.stqe_next = NULL; \ 275 *(head)->stqh_last = (elm); \ 276 (head)->stqh_last = &(elm)->field.stqe_next; \ 277 } while (/* CONSTCOND */0) 278 279 #define STAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 280 if (((elm)->field.stqe_next = (listelm)->field.stqe_next) == NULL)\ 281 (head)->stqh_last = &(elm)->field.stqe_next; \ 282 (listelm)->field.stqe_next = (elm); \ 283 } while (/* CONSTCOND */0) 284 285 #define STAILQ_REMOVE_HEAD(head, field) do { \ 286 if (((head)->stqh_first = (head)->stqh_first->field.stqe_next) == NULL) \ 287 (head)->stqh_last = &(head)->stqh_first; \ 288 } while (/* CONSTCOND */0) 289 290 #define STAILQ_REMOVE(head, elm, type, field) do { \ 291 if ((head)->stqh_first == (elm)) { \ 292 STAILQ_REMOVE_HEAD((head), field); \ 293 } else { \ 294 struct type *curelm = (head)->stqh_first; \ 295 while (curelm->field.stqe_next != (elm)) \ 296 curelm = curelm->field.stqe_next; \ 297 if ((curelm->field.stqe_next = \ 298 curelm->field.stqe_next->field.stqe_next) == NULL) \ 299 (head)->stqh_last = &(curelm)->field.stqe_next; \ 300 } \ 301 } while (/* CONSTCOND */0) 302 303 #define STAILQ_FOREACH(var, head, field) \ 304 for ((var) = ((head)->stqh_first); \ 305 (var); \ 306 (var) = ((var)->field.stqe_next)) 307 308 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 309 for ((var) = STAILQ_FIRST((head)); \ 310 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 311 (var) = (tvar)) 312 313 #define STAILQ_CONCAT(head1, head2) do { \ 314 if (!STAILQ_EMPTY((head2))) { \ 315 *(head1)->stqh_last = (head2)->stqh_first; \ 316 (head1)->stqh_last = (head2)->stqh_last; \ 317 STAILQ_INIT((head2)); \ 318 } \ 319 } while (/* CONSTCOND */0) 320 321 /* 322 * Singly-linked Tail queue access methods. 323 */ 324 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 325 #define STAILQ_FIRST(head) ((head)->stqh_first) 326 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 327 328 /* 329 * Simple queue definitions. 330 */ 331 #define SIMPLEQ_HEAD(name, type) \ 332 struct name { \ 333 struct type *sqh_first; /* first element */ \ 334 struct type **sqh_last; /* addr of last next element */ \ 335 } 336 337 #define SIMPLEQ_HEAD_INITIALIZER(head) \ 338 { NULL, &(head).sqh_first } 339 340 #define SIMPLEQ_ENTRY(type) \ 341 struct { \ 342 struct type *sqe_next; /* next element */ \ 343 } 344 345 /* 346 * Simple queue functions. 347 */ 348 #define SIMPLEQ_INIT(head) do { \ 349 (head)->sqh_first = NULL; \ 350 (head)->sqh_last = &(head)->sqh_first; \ 351 } while (/* CONSTCOND */0) 352 353 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 354 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ 355 (head)->sqh_last = &(elm)->field.sqe_next; \ 356 (head)->sqh_first = (elm); \ 357 } while (/* CONSTCOND */0) 358 359 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 360 (elm)->field.sqe_next = NULL; \ 361 *(head)->sqh_last = (elm); \ 362 (head)->sqh_last = &(elm)->field.sqe_next; \ 363 } while (/* CONSTCOND */0) 364 365 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 366 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ 367 (head)->sqh_last = &(elm)->field.sqe_next; \ 368 (listelm)->field.sqe_next = (elm); \ 369 } while (/* CONSTCOND */0) 370 371 #define SIMPLEQ_REMOVE_HEAD(head, field) do { \ 372 if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \ 373 (head)->sqh_last = &(head)->sqh_first; \ 374 } while (/* CONSTCOND */0) 375 376 #define SIMPLEQ_REMOVE(head, elm, type, field) do { \ 377 if ((head)->sqh_first == (elm)) { \ 378 SIMPLEQ_REMOVE_HEAD((head), field); \ 379 } else { \ 380 struct type *curelm = (head)->sqh_first; \ 381 while (curelm->field.sqe_next != (elm)) \ 382 curelm = curelm->field.sqe_next; \ 383 if ((curelm->field.sqe_next = \ 384 curelm->field.sqe_next->field.sqe_next) == NULL) \ 385 (head)->sqh_last = &(curelm)->field.sqe_next; \ 386 } \ 387 } while (/* CONSTCOND */0) 388 389 #define SIMPLEQ_FOREACH(var, head, field) \ 390 for ((var) = ((head)->sqh_first); \ 391 (var); \ 392 (var) = ((var)->field.sqe_next)) 393 394 /* 395 * Simple queue access methods. 396 */ 397 #define SIMPLEQ_EMPTY(head) ((head)->sqh_first == NULL) 398 #define SIMPLEQ_FIRST(head) ((head)->sqh_first) 399 #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 400 401 /* 402 * Tail queue definitions. 403 */ 404 #define _TAILQ_HEAD(name, type, qual) \ 405 struct name { \ 406 qual type *tqh_first; /* first element */ \ 407 qual type *qual *tqh_last; /* addr of last next element */ \ 408 } 409 #define TAILQ_HEAD(name, type) _TAILQ_HEAD(name, struct type,) 410 411 #define TAILQ_HEAD_INITIALIZER(head) \ 412 { NULL, &(head).tqh_first } 413 414 #define _TAILQ_ENTRY(type, qual) \ 415 struct { \ 416 qual type *tqe_next; /* next element */ \ 417 qual type *qual *tqe_prev; /* address of previous next element */\ 418 } 419 #define TAILQ_ENTRY(type) _TAILQ_ENTRY(struct type,) 420 421 /* 422 * Tail queue functions. 423 */ 424 #if defined(_KERNEL) && defined(QUEUEDEBUG) 425 #define QUEUEDEBUG_TAILQ_INSERT_HEAD(head, elm, field) \ 426 if ((head)->tqh_first && \ 427 (head)->tqh_first->field.tqe_prev != &(head)->tqh_first) \ 428 panic("TAILQ_INSERT_HEAD %p %s:%d", (head), __FILE__, __LINE__); 429 #define QUEUEDEBUG_TAILQ_INSERT_TAIL(head, elm, field) \ 430 if (*(head)->tqh_last != NULL) \ 431 panic("TAILQ_INSERT_TAIL %p %s:%d", (head), __FILE__, __LINE__); 432 #define QUEUEDEBUG_TAILQ_OP(elm, field) \ 433 if ((elm)->field.tqe_next && \ 434 (elm)->field.tqe_next->field.tqe_prev != \ 435 &(elm)->field.tqe_next) \ 436 panic("TAILQ_* forw %p %s:%d", (elm), __FILE__, __LINE__);\ 437 if (*(elm)->field.tqe_prev != (elm)) \ 438 panic("TAILQ_* back %p %s:%d", (elm), __FILE__, __LINE__); 439 #define QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field) \ 440 if ((elm)->field.tqe_next == NULL && \ 441 (head)->tqh_last != &(elm)->field.tqe_next) \ 442 panic("TAILQ_PREREMOVE head %p elm %p %s:%d", \ 443 (head), (elm), __FILE__, __LINE__); 444 #define QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field) \ 445 (elm)->field.tqe_next = (void *)1L; \ 446 (elm)->field.tqe_prev = (void *)1L; 447 #else 448 #define QUEUEDEBUG_TAILQ_INSERT_HEAD(head, elm, field) 449 #define QUEUEDEBUG_TAILQ_INSERT_TAIL(head, elm, field) 450 #define QUEUEDEBUG_TAILQ_OP(elm, field) 451 #define QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field) 452 #define QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field) 453 #endif 454 455 #define TAILQ_INIT(head) do { \ 456 (head)->tqh_first = NULL; \ 457 (head)->tqh_last = &(head)->tqh_first; \ 458 } while (/* CONSTCOND */0) 459 460 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 461 QUEUEDEBUG_TAILQ_INSERT_HEAD((head), (elm), field) \ 462 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 463 (head)->tqh_first->field.tqe_prev = \ 464 &(elm)->field.tqe_next; \ 465 else \ 466 (head)->tqh_last = &(elm)->field.tqe_next; \ 467 (head)->tqh_first = (elm); \ 468 (elm)->field.tqe_prev = &(head)->tqh_first; \ 469 } while (/* CONSTCOND */0) 470 471 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 472 QUEUEDEBUG_TAILQ_INSERT_TAIL((head), (elm), field) \ 473 (elm)->field.tqe_next = NULL; \ 474 (elm)->field.tqe_prev = (head)->tqh_last; \ 475 *(head)->tqh_last = (elm); \ 476 (head)->tqh_last = &(elm)->field.tqe_next; \ 477 } while (/* CONSTCOND */0) 478 479 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 480 QUEUEDEBUG_TAILQ_OP((listelm), field) \ 481 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 482 (elm)->field.tqe_next->field.tqe_prev = \ 483 &(elm)->field.tqe_next; \ 484 else \ 485 (head)->tqh_last = &(elm)->field.tqe_next; \ 486 (listelm)->field.tqe_next = (elm); \ 487 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 488 } while (/* CONSTCOND */0) 489 490 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 491 QUEUEDEBUG_TAILQ_OP((listelm), field) \ 492 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 493 (elm)->field.tqe_next = (listelm); \ 494 *(listelm)->field.tqe_prev = (elm); \ 495 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 496 } while (/* CONSTCOND */0) 497 498 #define TAILQ_REMOVE(head, elm, field) do { \ 499 QUEUEDEBUG_TAILQ_PREREMOVE((head), (elm), field) \ 500 QUEUEDEBUG_TAILQ_OP((elm), field) \ 501 if (((elm)->field.tqe_next) != NULL) \ 502 (elm)->field.tqe_next->field.tqe_prev = \ 503 (elm)->field.tqe_prev; \ 504 else \ 505 (head)->tqh_last = (elm)->field.tqe_prev; \ 506 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 507 QUEUEDEBUG_TAILQ_POSTREMOVE((elm), field); \ 508 } while (/* CONSTCOND */0) 509 510 #define TAILQ_FOREACH(var, head, field) \ 511 for ((var) = ((head)->tqh_first); \ 512 (var); \ 513 (var) = ((var)->field.tqe_next)) 514 515 #define TAILQ_FOREACH_SAFE(var, head, field, next) \ 516 for ((var) = ((head)->tqh_first); \ 517 (var) != NULL && ((next) = TAILQ_NEXT(var, field), 1); \ 518 (var) = (next)) 519 520 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 521 for ((var) = (*(((struct headname *)((head)->tqh_last))->tqh_last)); \ 522 (var); \ 523 (var) = (*(((struct headname *)((var)->field.tqe_prev))->tqh_last))) 524 525 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, prev) \ 526 for ((var) = TAILQ_LAST((head), headname); \ 527 (var) && ((prev) = TAILQ_PREV((var), headname, field), 1);\ 528 (var) = (prev)) 529 530 #define TAILQ_CONCAT(head1, head2, field) do { \ 531 if (!TAILQ_EMPTY(head2)) { \ 532 *(head1)->tqh_last = (head2)->tqh_first; \ 533 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 534 (head1)->tqh_last = (head2)->tqh_last; \ 535 TAILQ_INIT((head2)); \ 536 } \ 537 } while (/* CONSTCOND */0) 538 539 /* 540 * Tail queue access methods. 541 */ 542 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 543 #define TAILQ_FIRST(head) ((head)->tqh_first) 544 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 545 546 #define TAILQ_LAST(head, headname) \ 547 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 548 #define TAILQ_PREV(elm, headname, field) \ 549 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 550 551 /* 552 * Circular queue definitions. 553 */ 554 #if defined(_KERNEL) && defined(QUEUEDEBUG) 555 #define QUEUEDEBUG_CIRCLEQ_HEAD(head, field) \ 556 if ((head)->cqh_first != (void *)(head) && \ 557 (head)->cqh_first->field.cqe_prev != (void *)(head)) \ 558 panic("CIRCLEQ head forw %p %s:%d", (head), \ 559 __FILE__, __LINE__); \ 560 if ((head)->cqh_last != (void *)(head) && \ 561 (head)->cqh_last->field.cqe_next != (void *)(head)) \ 562 panic("CIRCLEQ head back %p %s:%d", (head), \ 563 __FILE__, __LINE__); 564 #define QUEUEDEBUG_CIRCLEQ_ELM(head, elm, field) \ 565 if ((elm)->field.cqe_next == (void *)(head)) { \ 566 if ((head)->cqh_last != (elm)) \ 567 panic("CIRCLEQ elm last %p %s:%d", (elm), \ 568 __FILE__, __LINE__); \ 569 } else { \ 570 if ((elm)->field.cqe_next->field.cqe_prev != (elm)) \ 571 panic("CIRCLEQ elm forw %p %s:%d", (elm), \ 572 __FILE__, __LINE__); \ 573 } \ 574 if ((elm)->field.cqe_prev == (void *)(head)) { \ 575 if ((head)->cqh_first != (elm)) \ 576 panic("CIRCLEQ elm first %p %s:%d", (elm), \ 577 __FILE__, __LINE__); \ 578 } else { \ 579 if ((elm)->field.cqe_prev->field.cqe_next != (elm)) \ 580 panic("CIRCLEQ elm prev %p %s:%d", (elm), \ 581 __FILE__, __LINE__); \ 582 } 583 #define QUEUEDEBUG_CIRCLEQ_POSTREMOVE(elm, field) \ 584 (elm)->field.cqe_next = (void *)1L; \ 585 (elm)->field.cqe_prev = (void *)1L; 586 #else 587 #define QUEUEDEBUG_CIRCLEQ_HEAD(head, field) 588 #define QUEUEDEBUG_CIRCLEQ_ELM(head, elm, field) 589 #define QUEUEDEBUG_CIRCLEQ_POSTREMOVE(elm, field) 590 #endif 591 592 #define CIRCLEQ_HEAD(name, type) \ 593 struct name { \ 594 struct type *cqh_first; /* first element */ \ 595 struct type *cqh_last; /* last element */ \ 596 } 597 598 #define CIRCLEQ_HEAD_INITIALIZER(head) \ 599 { (void *)&head, (void *)&head } 600 601 #define CIRCLEQ_ENTRY(type) \ 602 struct { \ 603 struct type *cqe_next; /* next element */ \ 604 struct type *cqe_prev; /* previous element */ \ 605 } 606 607 /* 608 * Circular queue functions. 609 */ 610 #define CIRCLEQ_INIT(head) do { \ 611 (head)->cqh_first = (void *)(head); \ 612 (head)->cqh_last = (void *)(head); \ 613 } while (/* CONSTCOND */0) 614 615 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 616 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 617 QUEUEDEBUG_CIRCLEQ_ELM((head), (listelm), field) \ 618 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 619 (elm)->field.cqe_prev = (listelm); \ 620 if ((listelm)->field.cqe_next == (void *)(head)) \ 621 (head)->cqh_last = (elm); \ 622 else \ 623 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 624 (listelm)->field.cqe_next = (elm); \ 625 } while (/* CONSTCOND */0) 626 627 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 628 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 629 QUEUEDEBUG_CIRCLEQ_ELM((head), (listelm), field) \ 630 (elm)->field.cqe_next = (listelm); \ 631 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 632 if ((listelm)->field.cqe_prev == (void *)(head)) \ 633 (head)->cqh_first = (elm); \ 634 else \ 635 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 636 (listelm)->field.cqe_prev = (elm); \ 637 } while (/* CONSTCOND */0) 638 639 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 640 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 641 (elm)->field.cqe_next = (head)->cqh_first; \ 642 (elm)->field.cqe_prev = (void *)(head); \ 643 if ((head)->cqh_last == (void *)(head)) \ 644 (head)->cqh_last = (elm); \ 645 else \ 646 (head)->cqh_first->field.cqe_prev = (elm); \ 647 (head)->cqh_first = (elm); \ 648 } while (/* CONSTCOND */0) 649 650 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 651 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 652 (elm)->field.cqe_next = (void *)(head); \ 653 (elm)->field.cqe_prev = (head)->cqh_last; \ 654 if ((head)->cqh_first == (void *)(head)) \ 655 (head)->cqh_first = (elm); \ 656 else \ 657 (head)->cqh_last->field.cqe_next = (elm); \ 658 (head)->cqh_last = (elm); \ 659 } while (/* CONSTCOND */0) 660 661 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 662 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 663 QUEUEDEBUG_CIRCLEQ_ELM((head), (elm), field) \ 664 if ((elm)->field.cqe_next == (void *)(head)) \ 665 (head)->cqh_last = (elm)->field.cqe_prev; \ 666 else \ 667 (elm)->field.cqe_next->field.cqe_prev = \ 668 (elm)->field.cqe_prev; \ 669 if ((elm)->field.cqe_prev == (void *)(head)) \ 670 (head)->cqh_first = (elm)->field.cqe_next; \ 671 else \ 672 (elm)->field.cqe_prev->field.cqe_next = \ 673 (elm)->field.cqe_next; \ 674 QUEUEDEBUG_CIRCLEQ_POSTREMOVE((elm), field) \ 675 } while (/* CONSTCOND */0) 676 677 #define CIRCLEQ_FOREACH(var, head, field) \ 678 for ((var) = ((head)->cqh_first); \ 679 (var) != (const void *)(head); \ 680 (var) = ((var)->field.cqe_next)) 681 682 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 683 for ((var) = ((head)->cqh_last); \ 684 (var) != (const void *)(head); \ 685 (var) = ((var)->field.cqe_prev)) 686 687 /* 688 * Circular queue access methods. 689 */ 690 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) 691 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 692 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 693 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) 694 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) 695 696 #define CIRCLEQ_LOOP_NEXT(head, elm, field) \ 697 (((elm)->field.cqe_next == (void *)(head)) \ 698 ? ((head)->cqh_first) \ 699 : (elm->field.cqe_next)) 700 #define CIRCLEQ_LOOP_PREV(head, elm, field) \ 701 (((elm)->field.cqe_prev == (void *)(head)) \ 702 ? ((head)->cqh_last) \ 703 : (elm->field.cqe_prev)) 704 705 #endif /* !_SYS_QUEUE_H_ */ 706