1 /* 2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 /*- 29 * Copyright (c) 1991, 1993 30 * The Regents of the University of California. All rights reserved. 31 * 32 * Redistribution and use in source and binary forms, with or without 33 * modification, are permitted provided that the following conditions 34 * are met: 35 * 1. Redistributions of source code must retain the above copyright 36 * notice, this list of conditions and the following disclaimer. 37 * 2. Redistributions in binary form must reproduce the above copyright 38 * notice, this list of conditions and the following disclaimer in the 39 * documentation and/or other materials provided with the distribution. 40 * 4. Neither the name of the University nor the names of its contributors 41 * may be used to endorse or promote products derived from this software 42 * without specific prior written permission. 43 * 44 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 45 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 46 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 47 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 48 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 49 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 50 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 51 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 52 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 53 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 54 * SUCH DAMAGE. 55 * 56 * @(#)queue.h 8.5 (Berkeley) 8/20/94 57 */ 58 59 #ifndef _SYS_QUEUE_H_ 60 #define _SYS_QUEUE_H_ 61 62 /* 63 * This file defines five types of data structures: singly-linked lists, 64 * singly-linked tail queues, lists, tail queues, and circular queues. 65 * 66 * A singly-linked list is headed by a single forward pointer. The elements 67 * are singly linked for minimum space and pointer manipulation overhead at 68 * the expense of O(n) removal for arbitrary elements. New elements can be 69 * added to the list after an existing element or at the head of the list. 70 * Elements being removed from the head of the list should use the explicit 71 * macro for this purpose for optimum efficiency. A singly-linked list may 72 * only be traversed in the forward direction. Singly-linked lists are ideal 73 * for applications with large datasets and few or no removals or for 74 * implementing a LIFO queue. 75 * 76 * A singly-linked tail queue is headed by a pair of pointers, one to the 77 * head of the list and the other to the tail of the list. The elements are 78 * singly linked for minimum space and pointer manipulation overhead at the 79 * expense of O(n) removal for arbitrary elements. New elements can be added 80 * to the list after an existing element, at the head of the list, or at the 81 * end of the list. Elements being removed from the head of the tail queue 82 * should use the explicit macro for this purpose for optimum efficiency. 83 * A singly-linked tail queue may only be traversed in the forward direction. 84 * Singly-linked tail queues are ideal for applications with large datasets 85 * and few or no removals or for implementing a FIFO queue. 86 * 87 * A list is headed by a single forward pointer (or an array of forward 88 * pointers for a hash table header). The elements are doubly linked 89 * so that an arbitrary element can be removed without a need to 90 * traverse the list. New elements can be added to the list before 91 * or after an existing element or at the head of the list. A list 92 * may only be traversed in the forward direction. 93 * 94 * A tail queue is headed by a pair of pointers, one to the head of the 95 * list and the other to the tail of the list. The elements are doubly 96 * linked so that an arbitrary element can be removed without a need to 97 * traverse the list. New elements can be added to the list before or 98 * after an existing element, at the head of the list, or at the end of 99 * the list. A tail queue may be traversed in either direction. 100 * 101 * A circle queue is headed by a pair of pointers, one to the head of the 102 * list and the other to the tail of the list. The elements are doubly 103 * linked so that an arbitrary element can be removed without a need to 104 * traverse the list. New elements can be added to the list before or after 105 * an existing element, at the head of the list, or at the end of the list. 106 * A circle queue may be traversed in either direction, but has a more 107 * complex end of list detection. 108 * Note that circle queues are deprecated, because, as the removal log 109 * in FreeBSD states, "CIRCLEQs are a disgrace to everything Knuth taught 110 * us in Volume 1 Chapter 2. [...] Use TAILQ instead, it provides the same 111 * functionality." Code using them will continue to compile, but they 112 * are no longer documented on the man page. 113 * 114 * For details on the use of these macros, see the queue(3) manual page. 115 * 116 * 117 * SLIST LIST STAILQ TAILQ CIRCLEQ 118 * _HEAD + + + + + 119 * _HEAD_INITIALIZER + + + + - 120 * _ENTRY + + + + + 121 * _INIT + + + + + 122 * _EMPTY + + + + + 123 * _FIRST + + + + + 124 * _NEXT + + + + + 125 * _PREV - - - + + 126 * _LAST - - + + + 127 * _FOREACH + + + + + 128 * _FOREACH_SAFE + + + + - 129 * _FOREACH_REVERSE - - - + - 130 * _FOREACH_REVERSE_SAFE - - - + - 131 * _INSERT_HEAD + + + + + 132 * _INSERT_BEFORE - + - + + 133 * _INSERT_AFTER + + + + + 134 * _INSERT_TAIL - - + + + 135 * _CONCAT - - + + - 136 * _REMOVE_AFTER + - + - - 137 * _REMOVE_HEAD + - + - - 138 * _REMOVE_HEAD_UNTIL - - + - - 139 * _REMOVE + + + + + 140 * _SWAP - + + + - 141 * 142 */ 143 #ifdef QUEUE_MACRO_DEBUG 144 /* Store the last 2 places the queue element or head was altered */ 145 struct qm_trace { 146 char * lastfile; 147 int lastline; 148 char * prevfile; 149 int prevline; 150 }; 151 152 #define TRACEBUF struct qm_trace trace; 153 #define TRASHIT(x) do {(x) = (void *)-1;} while (0) 154 155 #define QMD_TRACE_HEAD(head) do { \ 156 (head)->trace.prevline = (head)->trace.lastline; \ 157 (head)->trace.prevfile = (head)->trace.lastfile; \ 158 (head)->trace.lastline = __LINE__; \ 159 (head)->trace.lastfile = __FILE__; \ 160 } while (0) 161 162 #define QMD_TRACE_ELEM(elem) do { \ 163 (elem)->trace.prevline = (elem)->trace.lastline; \ 164 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 165 (elem)->trace.lastline = __LINE__; \ 166 (elem)->trace.lastfile = __FILE__; \ 167 } while (0) 168 169 #else 170 #define QMD_TRACE_ELEM(elem) 171 #define QMD_TRACE_HEAD(head) 172 #define TRACEBUF 173 #define TRASHIT(x) 174 #endif /* QUEUE_MACRO_DEBUG */ 175 176 /* 177 * Singly-linked List declarations. 178 */ 179 #define SLIST_HEAD(name, type) \ 180 struct name { \ 181 struct type *slh_first; /* first element */ \ 182 } 183 184 #define SLIST_HEAD_INITIALIZER(head) \ 185 { NULL } 186 187 #define SLIST_ENTRY(type) \ 188 struct { \ 189 struct type *sle_next; /* next element */ \ 190 } 191 192 /* 193 * Singly-linked List functions. 194 */ 195 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 196 197 #define SLIST_FIRST(head) ((head)->slh_first) 198 199 #define SLIST_FOREACH(var, head, field) \ 200 for ((var) = SLIST_FIRST((head)); \ 201 (var); \ 202 (var) = SLIST_NEXT((var), field)) 203 204 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 205 for ((var) = SLIST_FIRST((head)); \ 206 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 207 (var) = (tvar)) 208 209 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 210 for ((varp) = &SLIST_FIRST((head)); \ 211 ((var) = *(varp)) != NULL; \ 212 (varp) = &SLIST_NEXT((var), field)) 213 214 #define SLIST_INIT(head) do { \ 215 SLIST_FIRST((head)) = NULL; \ 216 } while (0) 217 218 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 219 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 220 SLIST_NEXT((slistelm), field) = (elm); \ 221 } while (0) 222 223 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 224 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 225 SLIST_FIRST((head)) = (elm); \ 226 } while (0) 227 228 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 229 230 #define SLIST_REMOVE(head, elm, type, field) do { \ 231 if (SLIST_FIRST((head)) == (elm)) { \ 232 SLIST_REMOVE_HEAD((head), field); \ 233 } \ 234 else { \ 235 struct type *curelm = SLIST_FIRST((head)); \ 236 while (SLIST_NEXT(curelm, field) != (elm)) \ 237 curelm = SLIST_NEXT(curelm, field); \ 238 SLIST_REMOVE_AFTER(curelm, field); \ 239 } \ 240 TRASHIT((elm)->field.sle_next); \ 241 } while (0) 242 243 #define SLIST_REMOVE_AFTER(elm, field) do { \ 244 SLIST_NEXT(elm, field) = \ 245 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 246 } while (0) 247 248 #define SLIST_REMOVE_HEAD(head, field) do { \ 249 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 250 } while (0) 251 252 /* 253 * Singly-linked Tail queue declarations. 254 */ 255 #define STAILQ_HEAD(name, type) \ 256 struct name { \ 257 struct type *stqh_first;/* first element */ \ 258 struct type **stqh_last;/* addr of last next element */ \ 259 } 260 261 #define STAILQ_HEAD_INITIALIZER(head) \ 262 { NULL, &(head).stqh_first } 263 264 #define STAILQ_ENTRY(type) \ 265 struct { \ 266 struct type *stqe_next; /* next element */ \ 267 } 268 269 /* 270 * Singly-linked Tail queue functions. 271 */ 272 #define STAILQ_CONCAT(head1, head2) do { \ 273 if (!STAILQ_EMPTY((head2))) { \ 274 *(head1)->stqh_last = (head2)->stqh_first; \ 275 (head1)->stqh_last = (head2)->stqh_last; \ 276 STAILQ_INIT((head2)); \ 277 } \ 278 } while (0) 279 280 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 281 282 #define STAILQ_FIRST(head) ((head)->stqh_first) 283 284 #define STAILQ_FOREACH(var, head, field) \ 285 for((var) = STAILQ_FIRST((head)); \ 286 (var); \ 287 (var) = STAILQ_NEXT((var), field)) 288 289 290 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 291 for ((var) = STAILQ_FIRST((head)); \ 292 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 293 (var) = (tvar)) 294 295 #define STAILQ_INIT(head) do { \ 296 STAILQ_FIRST((head)) = NULL; \ 297 (head)->stqh_last = &STAILQ_FIRST((head)); \ 298 } while (0) 299 300 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 301 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 302 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 303 STAILQ_NEXT((tqelm), field) = (elm); \ 304 } while (0) 305 306 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 307 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 308 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 309 STAILQ_FIRST((head)) = (elm); \ 310 } while (0) 311 312 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 313 STAILQ_NEXT((elm), field) = NULL; \ 314 *(head)->stqh_last = (elm); \ 315 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 316 } while (0) 317 318 #define STAILQ_LAST(head, type, field) \ 319 (STAILQ_EMPTY((head)) ? \ 320 NULL : \ 321 ((struct type *)(void *) \ 322 ((char *)((head)->stqh_last) - __offsetof(struct type, field)))) 323 324 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 325 326 #define STAILQ_REMOVE(head, elm, type, field) do { \ 327 if (STAILQ_FIRST((head)) == (elm)) { \ 328 STAILQ_REMOVE_HEAD((head), field); \ 329 } \ 330 else { \ 331 struct type *curelm = STAILQ_FIRST((head)); \ 332 while (STAILQ_NEXT(curelm, field) != (elm)) \ 333 curelm = STAILQ_NEXT(curelm, field); \ 334 STAILQ_REMOVE_AFTER(head, curelm, field); \ 335 } \ 336 TRASHIT((elm)->field.stqe_next); \ 337 } while (0) 338 339 #define STAILQ_REMOVE_HEAD(head, field) do { \ 340 if ((STAILQ_FIRST((head)) = \ 341 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 342 (head)->stqh_last = &STAILQ_FIRST((head)); \ 343 } while (0) 344 345 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \ 346 if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL) \ 347 (head)->stqh_last = &STAILQ_FIRST((head)); \ 348 } while (0) 349 350 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 351 if ((STAILQ_NEXT(elm, field) = \ 352 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 353 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 354 } while (0) 355 356 #define STAILQ_SWAP(head1, head2, type) do { \ 357 struct type *swap_first = STAILQ_FIRST(head1); \ 358 struct type **swap_last = (head1)->stqh_last; \ 359 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 360 (head1)->stqh_last = (head2)->stqh_last; \ 361 STAILQ_FIRST(head2) = swap_first; \ 362 (head2)->stqh_last = swap_last; \ 363 if (STAILQ_EMPTY(head1)) \ 364 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 365 if (STAILQ_EMPTY(head2)) \ 366 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 367 } while (0) 368 369 370 /* 371 * List declarations. 372 */ 373 #define LIST_HEAD(name, type) \ 374 struct name { \ 375 struct type *lh_first; /* first element */ \ 376 } 377 378 #define LIST_HEAD_INITIALIZER(head) \ 379 { NULL } 380 381 #define LIST_ENTRY(type) \ 382 struct { \ 383 struct type *le_next; /* next element */ \ 384 struct type **le_prev; /* address of previous next element */ \ 385 } 386 387 /* 388 * List functions. 389 */ 390 391 #if (defined(_KERNEL) && defined(INVARIANTS)) || defined(QUEUE_MACRO_DEBUG) 392 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 393 if (LIST_FIRST((head)) != NULL && \ 394 LIST_FIRST((head))->field.le_prev != \ 395 &LIST_FIRST((head))) \ 396 panic("Bad list head %p first->prev != head", (head)); \ 397 } while (0) 398 399 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 400 if (LIST_NEXT((elm), field) != NULL && \ 401 LIST_NEXT((elm), field)->field.le_prev != \ 402 &((elm)->field.le_next)) \ 403 panic("Bad link elm %p next->prev != elm", (elm)); \ 404 } while (0) 405 406 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 407 if (*(elm)->field.le_prev != (elm)) \ 408 panic("Bad link elm %p prev->next != elm", (elm)); \ 409 } while (0) 410 #else 411 #define QMD_LIST_CHECK_HEAD(head, field) 412 #define QMD_LIST_CHECK_NEXT(elm, field) 413 #define QMD_LIST_CHECK_PREV(elm, field) 414 #endif /* (_KERNEL && INVARIANTS) || QUEUE_MACRO_DEBUG */ 415 416 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 417 418 #define LIST_FIRST(head) ((head)->lh_first) 419 420 #define LIST_FOREACH(var, head, field) \ 421 for ((var) = LIST_FIRST((head)); \ 422 (var); \ 423 (var) = LIST_NEXT((var), field)) 424 425 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 426 for ((var) = LIST_FIRST((head)); \ 427 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 428 (var) = (tvar)) 429 430 #define LIST_INIT(head) do { \ 431 LIST_FIRST((head)) = NULL; \ 432 } while (0) 433 434 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 435 QMD_LIST_CHECK_NEXT(listelm, field); \ 436 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 437 LIST_NEXT((listelm), field)->field.le_prev = \ 438 &LIST_NEXT((elm), field); \ 439 LIST_NEXT((listelm), field) = (elm); \ 440 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 441 } while (0) 442 443 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 444 QMD_LIST_CHECK_PREV(listelm, field); \ 445 (elm)->field.le_prev = (listelm)->field.le_prev; \ 446 LIST_NEXT((elm), field) = (listelm); \ 447 *(listelm)->field.le_prev = (elm); \ 448 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 449 } while (0) 450 451 #define LIST_INSERT_HEAD(head, elm, field) do { \ 452 QMD_LIST_CHECK_HEAD((head), field); \ 453 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 454 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 455 LIST_FIRST((head)) = (elm); \ 456 (elm)->field.le_prev = &LIST_FIRST((head)); \ 457 } while (0) 458 459 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 460 461 #define LIST_REMOVE(elm, field) do { \ 462 QMD_LIST_CHECK_NEXT(elm, field); \ 463 QMD_LIST_CHECK_PREV(elm, field); \ 464 if (LIST_NEXT((elm), field) != NULL) \ 465 LIST_NEXT((elm), field)->field.le_prev = \ 466 (elm)->field.le_prev; \ 467 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 468 TRASHIT((elm)->field.le_next); \ 469 TRASHIT((elm)->field.le_prev); \ 470 } while (0) 471 472 #define LIST_SWAP(head1, head2, type, field) do { \ 473 struct type *swap_tmp = LIST_FIRST((head1)); \ 474 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 475 LIST_FIRST((head2)) = swap_tmp; \ 476 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 477 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 478 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 479 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 480 } while (0) 481 482 /* 483 * Tail queue declarations. 484 */ 485 #define TAILQ_HEAD(name, type) \ 486 struct name { \ 487 struct type *tqh_first; /* first element */ \ 488 struct type **tqh_last; /* addr of last next element */ \ 489 TRACEBUF \ 490 } 491 492 #define TAILQ_HEAD_INITIALIZER(head) \ 493 { NULL, &(head).tqh_first } 494 495 #define TAILQ_ENTRY(type) \ 496 struct { \ 497 struct type *tqe_next; /* next element */ \ 498 struct type **tqe_prev; /* address of previous next element */ \ 499 TRACEBUF \ 500 } 501 502 /* 503 * Tail queue functions. 504 */ 505 #define TAILQ_CONCAT(head1, head2, field) do { \ 506 if (!TAILQ_EMPTY(head2)) { \ 507 *(head1)->tqh_last = (head2)->tqh_first; \ 508 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 509 (head1)->tqh_last = (head2)->tqh_last; \ 510 TAILQ_INIT((head2)); \ 511 QMD_TRACE_HEAD(head1); \ 512 QMD_TRACE_HEAD(head2); \ 513 } \ 514 } while (0) 515 516 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 517 518 #define TAILQ_FIRST(head) ((head)->tqh_first) 519 520 #define TAILQ_FOREACH(var, head, field) \ 521 for ((var) = TAILQ_FIRST((head)); \ 522 (var); \ 523 (var) = TAILQ_NEXT((var), field)) 524 525 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 526 for ((var) = TAILQ_FIRST((head)); \ 527 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 528 (var) = (tvar)) 529 530 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 531 for ((var) = TAILQ_LAST((head), headname); \ 532 (var); \ 533 (var) = TAILQ_PREV((var), headname, field)) 534 535 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 536 for ((var) = TAILQ_LAST((head), headname); \ 537 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 538 (var) = (tvar)) 539 540 #define TAILQ_INIT(head) do { \ 541 TAILQ_FIRST((head)) = NULL; \ 542 (head)->tqh_last = &TAILQ_FIRST((head)); \ 543 QMD_TRACE_HEAD(head); \ 544 } while (0) 545 546 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 547 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 548 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 549 &TAILQ_NEXT((elm), field); \ 550 else { \ 551 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 552 QMD_TRACE_HEAD(head); \ 553 } \ 554 TAILQ_NEXT((listelm), field) = (elm); \ 555 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 556 QMD_TRACE_ELEM(&(elm)->field); \ 557 QMD_TRACE_ELEM(&listelm->field); \ 558 } while (0) 559 560 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 561 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 562 TAILQ_NEXT((elm), field) = (listelm); \ 563 *(listelm)->field.tqe_prev = (elm); \ 564 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 565 QMD_TRACE_ELEM(&(elm)->field); \ 566 QMD_TRACE_ELEM(&listelm->field); \ 567 } while (0) 568 569 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 570 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 571 TAILQ_FIRST((head))->field.tqe_prev = \ 572 &TAILQ_NEXT((elm), field); \ 573 else \ 574 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 575 TAILQ_FIRST((head)) = (elm); \ 576 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 577 QMD_TRACE_HEAD(head); \ 578 QMD_TRACE_ELEM(&(elm)->field); \ 579 } while (0) 580 581 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 582 TAILQ_NEXT((elm), field) = NULL; \ 583 (elm)->field.tqe_prev = (head)->tqh_last; \ 584 *(head)->tqh_last = (elm); \ 585 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 586 QMD_TRACE_HEAD(head); \ 587 QMD_TRACE_ELEM(&(elm)->field); \ 588 } while (0) 589 590 #define TAILQ_LAST(head, headname) \ 591 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 592 593 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 594 595 #define TAILQ_PREV(elm, headname, field) \ 596 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 597 598 #define TAILQ_REMOVE(head, elm, field) do { \ 599 if ((TAILQ_NEXT((elm), field)) != NULL) \ 600 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 601 (elm)->field.tqe_prev; \ 602 else { \ 603 (head)->tqh_last = (elm)->field.tqe_prev; \ 604 QMD_TRACE_HEAD(head); \ 605 } \ 606 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 607 TRASHIT((elm)->field.tqe_next); \ 608 TRASHIT((elm)->field.tqe_prev); \ 609 QMD_TRACE_ELEM(&(elm)->field); \ 610 } while (0) 611 612 #define TAILQ_SWAP(head1, head2, type, field) do { \ 613 struct type *swap_first = (head1)->tqh_first; \ 614 struct type **swap_last = (head1)->tqh_last; \ 615 (head1)->tqh_first = (head2)->tqh_first; \ 616 (head1)->tqh_last = (head2)->tqh_last; \ 617 (head2)->tqh_first = swap_first; \ 618 (head2)->tqh_last = swap_last; \ 619 if ((swap_first = (head1)->tqh_first) != NULL) \ 620 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 621 else \ 622 (head1)->tqh_last = &(head1)->tqh_first; \ 623 if ((swap_first = (head2)->tqh_first) != NULL) \ 624 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 625 else \ 626 (head2)->tqh_last = &(head2)->tqh_first; \ 627 } while (0) 628 629 /* 630 * Circular queue definitions. 631 */ 632 #define CIRCLEQ_HEAD(name, type) \ 633 struct name { \ 634 struct type *cqh_first; /* first element */ \ 635 struct type *cqh_last; /* last element */ \ 636 } 637 638 #define CIRCLEQ_ENTRY(type) \ 639 struct { \ 640 struct type *cqe_next; /* next element */ \ 641 struct type *cqe_prev; /* previous element */ \ 642 } 643 644 /* 645 * Circular queue functions. 646 */ 647 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) 648 649 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 650 651 #define CIRCLEQ_FOREACH(var, head, field) \ 652 for((var) = (head)->cqh_first; \ 653 (var) != (void *)(head); \ 654 (var) = (var)->field.cqe_next) 655 656 #define CIRCLEQ_INIT(head) do { \ 657 (head)->cqh_first = (void *)(head); \ 658 (head)->cqh_last = (void *)(head); \ 659 } while (0) 660 661 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 662 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 663 (elm)->field.cqe_prev = (listelm); \ 664 if ((listelm)->field.cqe_next == (void *)(head)) \ 665 (head)->cqh_last = (elm); \ 666 else \ 667 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 668 (listelm)->field.cqe_next = (elm); \ 669 } while (0) 670 671 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 672 (elm)->field.cqe_next = (listelm); \ 673 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 674 if ((listelm)->field.cqe_prev == (void *)(head)) \ 675 (head)->cqh_first = (elm); \ 676 else \ 677 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 678 (listelm)->field.cqe_prev = (elm); \ 679 } while (0) 680 681 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 682 (elm)->field.cqe_next = (head)->cqh_first; \ 683 (elm)->field.cqe_prev = (void *)(head); \ 684 if ((head)->cqh_last == (void *)(head)) \ 685 (head)->cqh_last = (elm); \ 686 else \ 687 (head)->cqh_first->field.cqe_prev = (elm); \ 688 (head)->cqh_first = (elm); \ 689 } while (0) 690 691 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 692 (elm)->field.cqe_next = (void *)(head); \ 693 (elm)->field.cqe_prev = (head)->cqh_last; \ 694 if ((head)->cqh_first == (void *)(head)) \ 695 (head)->cqh_first = (elm); \ 696 else \ 697 (head)->cqh_last->field.cqe_next = (elm); \ 698 (head)->cqh_last = (elm); \ 699 } while (0) 700 701 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 702 703 #define CIRCLEQ_NEXT(elm,field) ((elm)->field.cqe_next) 704 705 #define CIRCLEQ_PREV(elm,field) ((elm)->field.cqe_prev) 706 707 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 708 if ((elm)->field.cqe_next == (void *)(head)) \ 709 (head)->cqh_last = (elm)->field.cqe_prev; \ 710 else \ 711 (elm)->field.cqe_next->field.cqe_prev = \ 712 (elm)->field.cqe_prev; \ 713 if ((elm)->field.cqe_prev == (void *)(head)) \ 714 (head)->cqh_first = (elm)->field.cqe_next; \ 715 else \ 716 (elm)->field.cqe_prev->field.cqe_next = \ 717 (elm)->field.cqe_next; \ 718 } while (0) 719 720 #ifdef _KERNEL 721 722 #if NOTFB31 723 724 /* 725 * XXX insque() and remque() are an old way of handling certain queues. 726 * They bogusly assumes that all queue heads look alike. 727 */ 728 729 struct quehead { 730 struct quehead *qh_link; 731 struct quehead *qh_rlink; 732 }; 733 734 #ifdef __GNUC__ 735 736 static __inline void 737 insque(void *a, void *b) 738 { 739 struct quehead *element = (struct quehead *)a, 740 *head = (struct quehead *)b; 741 742 element->qh_link = head->qh_link; 743 element->qh_rlink = head; 744 head->qh_link = element; 745 element->qh_link->qh_rlink = element; 746 } 747 748 static __inline void 749 remque(void *a) 750 { 751 struct quehead *element = (struct quehead *)a; 752 753 element->qh_link->qh_rlink = element->qh_rlink; 754 element->qh_rlink->qh_link = element->qh_link; 755 element->qh_rlink = 0; 756 } 757 758 #else /* !__GNUC__ */ 759 760 void insque(void *a, void *b); 761 void remque(void *a); 762 763 #endif /* __GNUC__ */ 764 765 #endif 766 #endif /* _KERNEL */ 767 768 #endif /* !_SYS_QUEUE_H_ */ 769