queue.h revision 225736
1/*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)queue.h 8.5 (Berkeley) 8/20/94 30 * $FreeBSD: stable/9/sys/sys/queue.h 221843 2011-05-13 15:49:23Z mdf $ 31 */ 32 33#ifndef _SYS_QUEUE_H_ 34#define _SYS_QUEUE_H_ 35 36#include <sys/cdefs.h> 37 38/* 39 * This file defines four types of data structures: singly-linked lists, 40 * singly-linked tail queues, lists and tail queues. 41 * 42 * A singly-linked list is headed by a single forward pointer. The elements 43 * are singly linked for minimum space and pointer manipulation overhead at 44 * the expense of O(n) removal for arbitrary elements. New elements can be 45 * added to the list after an existing element or at the head of the list. 46 * Elements being removed from the head of the list should use the explicit 47 * macro for this purpose for optimum efficiency. A singly-linked list may 48 * only be traversed in the forward direction. Singly-linked lists are ideal 49 * for applications with large datasets and few or no removals or for 50 * implementing a LIFO queue. 51 * 52 * A singly-linked tail queue is headed by a pair of pointers, one to the 53 * head of the list and the other to the tail of the list. The elements are 54 * singly linked for minimum space and pointer manipulation overhead at the 55 * expense of O(n) removal for arbitrary elements. New elements can be added 56 * to the list after an existing element, at the head of the list, or at the 57 * end of the list. Elements being removed from the head of the tail queue 58 * should use the explicit macro for this purpose for optimum efficiency. 59 * A singly-linked tail queue may only be traversed in the forward direction. 60 * Singly-linked tail queues are ideal for applications with large datasets 61 * and few or no removals or for implementing a FIFO queue. 62 * 63 * A list is headed by a single forward pointer (or an array of forward 64 * pointers for a hash table header). The elements are doubly linked 65 * so that an arbitrary element can be removed without a need to 66 * traverse the list. New elements can be added to the list before 67 * or after an existing element or at the head of the list. A list 68 * may only be traversed in the forward direction. 69 * 70 * A tail queue is headed by a pair of pointers, one to the head of the 71 * list and the other to the tail of the list. The elements are doubly 72 * linked so that an arbitrary element can be removed without a need to 73 * traverse the list. New elements can be added to the list before or 74 * after an existing element, at the head of the list, or at the end of 75 * the list. A tail queue may be traversed in either direction. 76 * 77 * For details on the use of these macros, see the queue(3) manual page. 78 * 79 * 80 * SLIST LIST STAILQ TAILQ 81 * _HEAD + + + + 82 * _HEAD_INITIALIZER + + + + 83 * _ENTRY + + + + 84 * _INIT + + + + 85 * _EMPTY + + + + 86 * _FIRST + + + + 87 * _NEXT + + + + 88 * _PREV - - - + 89 * _LAST - - + + 90 * _FOREACH + + + + 91 * _FOREACH_SAFE + + + + 92 * _FOREACH_REVERSE - - - + 93 * _FOREACH_REVERSE_SAFE - - - + 94 * _INSERT_HEAD + + + + 95 * _INSERT_BEFORE - + - + 96 * _INSERT_AFTER + + + + 97 * _INSERT_TAIL - - + + 98 * _CONCAT - - + + 99 * _REMOVE_AFTER + - + - 100 * _REMOVE_HEAD + - + - 101 * _REMOVE + + + + 102 * _SWAP + + + + 103 * 104 */ 105#ifdef QUEUE_MACRO_DEBUG 106/* Store the last 2 places the queue element or head was altered */ 107struct qm_trace { 108 char * lastfile; 109 int lastline; 110 char * prevfile; 111 int prevline; 112}; 113 114#define TRACEBUF struct qm_trace trace; 115#define TRASHIT(x) do {(x) = (void *)-1;} while (0) 116#define QMD_SAVELINK(name, link) void **name = (void *)&(link) 117 118#define QMD_TRACE_HEAD(head) do { \ 119 (head)->trace.prevline = (head)->trace.lastline; \ 120 (head)->trace.prevfile = (head)->trace.lastfile; \ 121 (head)->trace.lastline = __LINE__; \ 122 (head)->trace.lastfile = __FILE__; \ 123} while (0) 124 125#define QMD_TRACE_ELEM(elem) do { \ 126 (elem)->trace.prevline = (elem)->trace.lastline; \ 127 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 128 (elem)->trace.lastline = __LINE__; \ 129 (elem)->trace.lastfile = __FILE__; \ 130} while (0) 131 132#else 133#define QMD_TRACE_ELEM(elem) 134#define QMD_TRACE_HEAD(head) 135#define QMD_SAVELINK(name, link) 136#define TRACEBUF 137#define TRASHIT(x) 138#endif /* QUEUE_MACRO_DEBUG */ 139 140/* 141 * Singly-linked List declarations. 142 */ 143#define SLIST_HEAD(name, type) \ 144struct name { \ 145 struct type *slh_first; /* first element */ \ 146} 147 148#define SLIST_HEAD_INITIALIZER(head) \ 149 { NULL } 150 151#define SLIST_ENTRY(type) \ 152struct { \ 153 struct type *sle_next; /* next element */ \ 154} 155 156/* 157 * Singly-linked List functions. 158 */ 159#define SLIST_EMPTY(head) ((head)->slh_first == NULL) 160 161#define SLIST_FIRST(head) ((head)->slh_first) 162 163#define SLIST_FOREACH(var, head, field) \ 164 for ((var) = SLIST_FIRST((head)); \ 165 (var); \ 166 (var) = SLIST_NEXT((var), field)) 167 168#define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 169 for ((var) = SLIST_FIRST((head)); \ 170 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 171 (var) = (tvar)) 172 173#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 174 for ((varp) = &SLIST_FIRST((head)); \ 175 ((var) = *(varp)) != NULL; \ 176 (varp) = &SLIST_NEXT((var), field)) 177 178#define SLIST_INIT(head) do { \ 179 SLIST_FIRST((head)) = NULL; \ 180} while (0) 181 182#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 183 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 184 SLIST_NEXT((slistelm), field) = (elm); \ 185} while (0) 186 187#define SLIST_INSERT_HEAD(head, elm, field) do { \ 188 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 189 SLIST_FIRST((head)) = (elm); \ 190} while (0) 191 192#define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 193 194#define SLIST_REMOVE(head, elm, type, field) do { \ 195 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \ 196 if (SLIST_FIRST((head)) == (elm)) { \ 197 SLIST_REMOVE_HEAD((head), field); \ 198 } \ 199 else { \ 200 struct type *curelm = SLIST_FIRST((head)); \ 201 while (SLIST_NEXT(curelm, field) != (elm)) \ 202 curelm = SLIST_NEXT(curelm, field); \ 203 SLIST_REMOVE_AFTER(curelm, field); \ 204 } \ 205 TRASHIT(*oldnext); \ 206} while (0) 207 208#define SLIST_REMOVE_AFTER(elm, field) do { \ 209 SLIST_NEXT(elm, field) = \ 210 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 211} while (0) 212 213#define SLIST_REMOVE_HEAD(head, field) do { \ 214 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 215} while (0) 216 217#define SLIST_SWAP(head1, head2, type) do { \ 218 struct type *swap_first = SLIST_FIRST(head1); \ 219 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 220 SLIST_FIRST(head2) = swap_first; \ 221} while (0) 222 223/* 224 * Singly-linked Tail queue declarations. 225 */ 226#define STAILQ_HEAD(name, type) \ 227struct name { \ 228 struct type *stqh_first;/* first element */ \ 229 struct type **stqh_last;/* addr of last next element */ \ 230} 231 232#define STAILQ_HEAD_INITIALIZER(head) \ 233 { NULL, &(head).stqh_first } 234 235#define STAILQ_ENTRY(type) \ 236struct { \ 237 struct type *stqe_next; /* next element */ \ 238} 239 240/* 241 * Singly-linked Tail queue functions. 242 */ 243#define STAILQ_CONCAT(head1, head2) do { \ 244 if (!STAILQ_EMPTY((head2))) { \ 245 *(head1)->stqh_last = (head2)->stqh_first; \ 246 (head1)->stqh_last = (head2)->stqh_last; \ 247 STAILQ_INIT((head2)); \ 248 } \ 249} while (0) 250 251#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 252 253#define STAILQ_FIRST(head) ((head)->stqh_first) 254 255#define STAILQ_FOREACH(var, head, field) \ 256 for((var) = STAILQ_FIRST((head)); \ 257 (var); \ 258 (var) = STAILQ_NEXT((var), field)) 259 260 261#define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 262 for ((var) = STAILQ_FIRST((head)); \ 263 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 264 (var) = (tvar)) 265 266#define STAILQ_INIT(head) do { \ 267 STAILQ_FIRST((head)) = NULL; \ 268 (head)->stqh_last = &STAILQ_FIRST((head)); \ 269} while (0) 270 271#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 272 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 273 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 274 STAILQ_NEXT((tqelm), field) = (elm); \ 275} while (0) 276 277#define STAILQ_INSERT_HEAD(head, elm, field) do { \ 278 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 279 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 280 STAILQ_FIRST((head)) = (elm); \ 281} while (0) 282 283#define STAILQ_INSERT_TAIL(head, elm, field) do { \ 284 STAILQ_NEXT((elm), field) = NULL; \ 285 *(head)->stqh_last = (elm); \ 286 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 287} while (0) 288 289#define STAILQ_LAST(head, type, field) \ 290 (STAILQ_EMPTY((head)) ? \ 291 NULL : \ 292 ((struct type *)(void *) \ 293 ((char *)((head)->stqh_last) - __offsetof(struct type, field)))) 294 295#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 296 297#define STAILQ_REMOVE(head, elm, type, field) do { \ 298 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 299 if (STAILQ_FIRST((head)) == (elm)) { \ 300 STAILQ_REMOVE_HEAD((head), field); \ 301 } \ 302 else { \ 303 struct type *curelm = STAILQ_FIRST((head)); \ 304 while (STAILQ_NEXT(curelm, field) != (elm)) \ 305 curelm = STAILQ_NEXT(curelm, field); \ 306 STAILQ_REMOVE_AFTER(head, curelm, field); \ 307 } \ 308 TRASHIT(*oldnext); \ 309} while (0) 310 311#define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 312 if ((STAILQ_NEXT(elm, field) = \ 313 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 314 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 315} while (0) 316 317#define STAILQ_REMOVE_HEAD(head, field) do { \ 318 if ((STAILQ_FIRST((head)) = \ 319 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 320 (head)->stqh_last = &STAILQ_FIRST((head)); \ 321} while (0) 322 323#define STAILQ_SWAP(head1, head2, type) do { \ 324 struct type *swap_first = STAILQ_FIRST(head1); \ 325 struct type **swap_last = (head1)->stqh_last; \ 326 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 327 (head1)->stqh_last = (head2)->stqh_last; \ 328 STAILQ_FIRST(head2) = swap_first; \ 329 (head2)->stqh_last = swap_last; \ 330 if (STAILQ_EMPTY(head1)) \ 331 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 332 if (STAILQ_EMPTY(head2)) \ 333 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 334} while (0) 335 336 337/* 338 * List declarations. 339 */ 340#define LIST_HEAD(name, type) \ 341struct name { \ 342 struct type *lh_first; /* first element */ \ 343} 344 345#define LIST_HEAD_INITIALIZER(head) \ 346 { NULL } 347 348#define LIST_ENTRY(type) \ 349struct { \ 350 struct type *le_next; /* next element */ \ 351 struct type **le_prev; /* address of previous next element */ \ 352} 353 354/* 355 * List functions. 356 */ 357 358#if (defined(_KERNEL) && defined(INVARIANTS)) 359#define QMD_LIST_CHECK_HEAD(head, field) do { \ 360 if (LIST_FIRST((head)) != NULL && \ 361 LIST_FIRST((head))->field.le_prev != \ 362 &LIST_FIRST((head))) \ 363 panic("Bad list head %p first->prev != head", (head)); \ 364} while (0) 365 366#define QMD_LIST_CHECK_NEXT(elm, field) do { \ 367 if (LIST_NEXT((elm), field) != NULL && \ 368 LIST_NEXT((elm), field)->field.le_prev != \ 369 &((elm)->field.le_next)) \ 370 panic("Bad link elm %p next->prev != elm", (elm)); \ 371} while (0) 372 373#define QMD_LIST_CHECK_PREV(elm, field) do { \ 374 if (*(elm)->field.le_prev != (elm)) \ 375 panic("Bad link elm %p prev->next != elm", (elm)); \ 376} while (0) 377#else 378#define QMD_LIST_CHECK_HEAD(head, field) 379#define QMD_LIST_CHECK_NEXT(elm, field) 380#define QMD_LIST_CHECK_PREV(elm, field) 381#endif /* (_KERNEL && INVARIANTS) */ 382 383#define LIST_EMPTY(head) ((head)->lh_first == NULL) 384 385#define LIST_FIRST(head) ((head)->lh_first) 386 387#define LIST_FOREACH(var, head, field) \ 388 for ((var) = LIST_FIRST((head)); \ 389 (var); \ 390 (var) = LIST_NEXT((var), field)) 391 392#define LIST_FOREACH_SAFE(var, head, field, tvar) \ 393 for ((var) = LIST_FIRST((head)); \ 394 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 395 (var) = (tvar)) 396 397#define LIST_INIT(head) do { \ 398 LIST_FIRST((head)) = NULL; \ 399} while (0) 400 401#define LIST_INSERT_AFTER(listelm, elm, field) do { \ 402 QMD_LIST_CHECK_NEXT(listelm, field); \ 403 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 404 LIST_NEXT((listelm), field)->field.le_prev = \ 405 &LIST_NEXT((elm), field); \ 406 LIST_NEXT((listelm), field) = (elm); \ 407 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 408} while (0) 409 410#define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 411 QMD_LIST_CHECK_PREV(listelm, field); \ 412 (elm)->field.le_prev = (listelm)->field.le_prev; \ 413 LIST_NEXT((elm), field) = (listelm); \ 414 *(listelm)->field.le_prev = (elm); \ 415 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 416} while (0) 417 418#define LIST_INSERT_HEAD(head, elm, field) do { \ 419 QMD_LIST_CHECK_HEAD((head), field); \ 420 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 421 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 422 LIST_FIRST((head)) = (elm); \ 423 (elm)->field.le_prev = &LIST_FIRST((head)); \ 424} while (0) 425 426#define LIST_NEXT(elm, field) ((elm)->field.le_next) 427 428#define LIST_REMOVE(elm, field) do { \ 429 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 430 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 431 QMD_LIST_CHECK_NEXT(elm, field); \ 432 QMD_LIST_CHECK_PREV(elm, field); \ 433 if (LIST_NEXT((elm), field) != NULL) \ 434 LIST_NEXT((elm), field)->field.le_prev = \ 435 (elm)->field.le_prev; \ 436 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 437 TRASHIT(*oldnext); \ 438 TRASHIT(*oldprev); \ 439} while (0) 440 441#define LIST_SWAP(head1, head2, type, field) do { \ 442 struct type *swap_tmp = LIST_FIRST((head1)); \ 443 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 444 LIST_FIRST((head2)) = swap_tmp; \ 445 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 446 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 447 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 448 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 449} while (0) 450 451/* 452 * Tail queue declarations. 453 */ 454#define TAILQ_HEAD(name, type) \ 455struct name { \ 456 struct type *tqh_first; /* first element */ \ 457 struct type **tqh_last; /* addr of last next element */ \ 458 TRACEBUF \ 459} 460 461#define TAILQ_HEAD_INITIALIZER(head) \ 462 { NULL, &(head).tqh_first } 463 464#define TAILQ_ENTRY(type) \ 465struct { \ 466 struct type *tqe_next; /* next element */ \ 467 struct type **tqe_prev; /* address of previous next element */ \ 468 TRACEBUF \ 469} 470 471/* 472 * Tail queue functions. 473 */ 474#if (defined(_KERNEL) && defined(INVARIANTS)) 475#define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 476 if (!TAILQ_EMPTY(head) && \ 477 TAILQ_FIRST((head))->field.tqe_prev != \ 478 &TAILQ_FIRST((head))) \ 479 panic("Bad tailq head %p first->prev != head", (head)); \ 480} while (0) 481 482#define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 483 if (*(head)->tqh_last != NULL) \ 484 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 485} while (0) 486 487#define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 488 if (TAILQ_NEXT((elm), field) != NULL && \ 489 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 490 &((elm)->field.tqe_next)) \ 491 panic("Bad link elm %p next->prev != elm", (elm)); \ 492} while (0) 493 494#define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 495 if (*(elm)->field.tqe_prev != (elm)) \ 496 panic("Bad link elm %p prev->next != elm", (elm)); \ 497} while (0) 498#else 499#define QMD_TAILQ_CHECK_HEAD(head, field) 500#define QMD_TAILQ_CHECK_TAIL(head, headname) 501#define QMD_TAILQ_CHECK_NEXT(elm, field) 502#define QMD_TAILQ_CHECK_PREV(elm, field) 503#endif /* (_KERNEL && INVARIANTS) */ 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 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 548 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 549 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 550 &TAILQ_NEXT((elm), field); \ 551 else { \ 552 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 553 QMD_TRACE_HEAD(head); \ 554 } \ 555 TAILQ_NEXT((listelm), field) = (elm); \ 556 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 557 QMD_TRACE_ELEM(&(elm)->field); \ 558 QMD_TRACE_ELEM(&listelm->field); \ 559} while (0) 560 561#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 562 QMD_TAILQ_CHECK_PREV(listelm, field); \ 563 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 564 TAILQ_NEXT((elm), field) = (listelm); \ 565 *(listelm)->field.tqe_prev = (elm); \ 566 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 567 QMD_TRACE_ELEM(&(elm)->field); \ 568 QMD_TRACE_ELEM(&listelm->field); \ 569} while (0) 570 571#define TAILQ_INSERT_HEAD(head, elm, field) do { \ 572 QMD_TAILQ_CHECK_HEAD(head, field); \ 573 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 574 TAILQ_FIRST((head))->field.tqe_prev = \ 575 &TAILQ_NEXT((elm), field); \ 576 else \ 577 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 578 TAILQ_FIRST((head)) = (elm); \ 579 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 580 QMD_TRACE_HEAD(head); \ 581 QMD_TRACE_ELEM(&(elm)->field); \ 582} while (0) 583 584#define TAILQ_INSERT_TAIL(head, elm, field) do { \ 585 QMD_TAILQ_CHECK_TAIL(head, field); \ 586 TAILQ_NEXT((elm), field) = NULL; \ 587 (elm)->field.tqe_prev = (head)->tqh_last; \ 588 *(head)->tqh_last = (elm); \ 589 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 590 QMD_TRACE_HEAD(head); \ 591 QMD_TRACE_ELEM(&(elm)->field); \ 592} while (0) 593 594#define TAILQ_LAST(head, headname) \ 595 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 596 597#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 598 599#define TAILQ_PREV(elm, headname, field) \ 600 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 601 602#define TAILQ_REMOVE(head, elm, field) do { \ 603 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 604 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 605 QMD_TAILQ_CHECK_NEXT(elm, field); \ 606 QMD_TAILQ_CHECK_PREV(elm, field); \ 607 if ((TAILQ_NEXT((elm), field)) != NULL) \ 608 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 609 (elm)->field.tqe_prev; \ 610 else { \ 611 (head)->tqh_last = (elm)->field.tqe_prev; \ 612 QMD_TRACE_HEAD(head); \ 613 } \ 614 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 615 TRASHIT(*oldnext); \ 616 TRASHIT(*oldprev); \ 617 QMD_TRACE_ELEM(&(elm)->field); \ 618} while (0) 619 620#define TAILQ_SWAP(head1, head2, type, field) do { \ 621 struct type *swap_first = (head1)->tqh_first; \ 622 struct type **swap_last = (head1)->tqh_last; \ 623 (head1)->tqh_first = (head2)->tqh_first; \ 624 (head1)->tqh_last = (head2)->tqh_last; \ 625 (head2)->tqh_first = swap_first; \ 626 (head2)->tqh_last = swap_last; \ 627 if ((swap_first = (head1)->tqh_first) != NULL) \ 628 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 629 else \ 630 (head1)->tqh_last = &(head1)->tqh_first; \ 631 if ((swap_first = (head2)->tqh_first) != NULL) \ 632 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 633 else \ 634 (head2)->tqh_last = &(head2)->tqh_first; \ 635} while (0) 636 637#endif /* !_SYS_QUEUE_H_ */ 638