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: src/sys/sys/queue.h,v 1.68 2006/10/24 11:20:29 ru Exp $ 31 */ 32 33#ifndef _SYS_QUEUE_H_ 34#define _SYS_QUEUE_H_ 35 36#include <features.h> 37 38#ifdef _DEFAULT_SOURCE 39 40 41#include <sys/cdefs.h> 42 43/* 44 * This file defines four types of data structures: singly-linked lists, 45 * singly-linked tail queues, lists and tail queues. 46 * 47 * A singly-linked list is headed by a single forward pointer. The elements 48 * are singly linked for minimum space and pointer manipulation overhead at 49 * the expense of O(n) removal for arbitrary elements. New elements can be 50 * added to the list after an existing element or at the head of the list. 51 * Elements being removed from the head of the list should use the explicit 52 * macro for this purpose for optimum efficiency. A singly-linked list may 53 * only be traversed in the forward direction. Singly-linked lists are ideal 54 * for applications with large datasets and few or no removals or for 55 * implementing a LIFO queue. 56 * 57 * A singly-linked tail queue is headed by a pair of pointers, one to the 58 * head of the list and the other to the tail of the list. The elements are 59 * singly linked for minimum space and pointer manipulation overhead at the 60 * expense of O(n) removal for arbitrary elements. New elements can be added 61 * to the list after an existing element, at the head of the list, or at the 62 * end of the list. Elements being removed from the head of the tail queue 63 * should use the explicit macro for this purpose for optimum efficiency. 64 * A singly-linked tail queue may only be traversed in the forward direction. 65 * Singly-linked tail queues are ideal for applications with large datasets 66 * and few or no removals or for implementing a FIFO queue. 67 * 68 * A list is headed by a single forward pointer (or an array of forward 69 * pointers for a hash table header). The elements are doubly linked 70 * 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 72 * or after an existing element or at the head of the list. A list 73 * may only be traversed in the forward direction. 74 * 75 * A tail 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 79 * after an existing element, at the head of the list, or at the end of 80 * the list. A tail queue may be traversed in either direction. 81 * 82 * For details on the use of these macros, see the queue(3) manual page. 83 * 84 * 85 * SLIST LIST STAILQ TAILQ 86 * _HEAD + + + + 87 * _HEAD_INITIALIZER + + + + 88 * _ENTRY + + + + 89 * _INIT + + + + 90 * _EMPTY + + + + 91 * _FIRST + + + + 92 * _NEXT + + + + 93 * _PREV - - - + 94 * _LAST - - + + 95 * _FOREACH + + + + 96 * _FOREACH_SAFE + + + + 97 * _FOREACH_REVERSE - - - + 98 * _FOREACH_REVERSE_SAFE - - - + 99 * _INSERT_HEAD + + + + 100 * _INSERT_BEFORE - + - + 101 * _INSERT_AFTER + + + + 102 * _INSERT_TAIL - - + + 103 * _CONCAT - - + + 104 * _REMOVE_HEAD + - + - 105 * _REMOVE + + + + 106 * 107 */ 108#ifdef QUEUE_MACRO_DEBUG 109/* Store the last 2 places the queue element or head was altered */ 110struct qm_trace { 111 char * lastfile; 112 int lastline; 113 char * prevfile; 114 int prevline; 115}; 116 117#define TRACEBUF struct qm_trace trace; 118#define TRASHIT(x) do {(x) = (void *)-1;} while (0) 119 120#define QMD_TRACE_HEAD(head) do { \ 121 (head)->trace.prevline = (head)->trace.lastline; \ 122 (head)->trace.prevfile = (head)->trace.lastfile; \ 123 (head)->trace.lastline = __LINE__; \ 124 (head)->trace.lastfile = __FILE__; \ 125} while (0) 126 127#define QMD_TRACE_ELEM(elem) do { \ 128 (elem)->trace.prevline = (elem)->trace.lastline; \ 129 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 130 (elem)->trace.lastline = __LINE__; \ 131 (elem)->trace.lastfile = __FILE__; \ 132} while (0) 133 134#else 135#define QMD_TRACE_ELEM(elem) 136#define QMD_TRACE_HEAD(head) 137#define TRACEBUF 138#define TRASHIT(x) 139#endif /* QUEUE_MACRO_DEBUG */ 140 141/* 142 * Singly-linked List declarations. 143 */ 144#define SLIST_HEAD(name, type) \ 145struct name { \ 146 struct type *slh_first; /* first element */ \ 147} 148 149#define SLIST_HEAD_INITIALIZER(head) \ 150 { NULL } 151 152#define SLIST_ENTRY(type) \ 153struct { \ 154 struct type *sle_next; /* next element */ \ 155} 156 157/* 158 * Singly-linked List functions. 159 */ 160#define SLIST_EMPTY(head) ((head)->slh_first == NULL) 161 162#define SLIST_FIRST(head) ((head)->slh_first) 163 164#define SLIST_FOREACH(var, head, field) \ 165 for ((var) = SLIST_FIRST((head)); \ 166 (var); \ 167 (var) = SLIST_NEXT((var), field)) 168 169#define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 170 for ((var) = SLIST_FIRST((head)); \ 171 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 172 (var) = (tvar)) 173 174#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 175 for ((varp) = &SLIST_FIRST((head)); \ 176 ((var) = *(varp)) != NULL; \ 177 (varp) = &SLIST_NEXT((var), field)) 178 179#define SLIST_INIT(head) do { \ 180 SLIST_FIRST((head)) = NULL; \ 181} while (0) 182 183#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 184 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 185 SLIST_NEXT((slistelm), field) = (elm); \ 186} while (0) 187 188#define SLIST_INSERT_HEAD(head, elm, field) do { \ 189 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 190 SLIST_FIRST((head)) = (elm); \ 191} while (0) 192 193#define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 194 195#define SLIST_REMOVE(head, elm, type, field) do { \ 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_NEXT(curelm, field) = \ 204 SLIST_NEXT(SLIST_NEXT(curelm, field), field); \ 205 } \ 206 TRASHIT((elm)->field.sle_next); \ 207} while (0) 208 209#define SLIST_REMOVE_HEAD(head, field) do { \ 210 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 211} while (0) 212 213/* 214 * Singly-linked Tail queue declarations. 215 */ 216#define STAILQ_HEAD(name, type) \ 217struct name { \ 218 struct type *stqh_first;/* first element */ \ 219 struct type **stqh_last;/* addr of last next element */ \ 220} 221 222#define STAILQ_HEAD_INITIALIZER(head) \ 223 { NULL, &(head).stqh_first } 224 225#define STAILQ_ENTRY(type) \ 226struct { \ 227 struct type *stqe_next; /* next element */ \ 228} 229 230/* 231 * Singly-linked Tail queue functions. 232 */ 233#define STAILQ_CONCAT(head1, head2) do { \ 234 if (!STAILQ_EMPTY((head2))) { \ 235 *(head1)->stqh_last = (head2)->stqh_first; \ 236 (head1)->stqh_last = (head2)->stqh_last; \ 237 STAILQ_INIT((head2)); \ 238 } \ 239} while (0) 240 241#define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 242 243#define STAILQ_FIRST(head) ((head)->stqh_first) 244 245#define STAILQ_FOREACH(var, head, field) \ 246 for((var) = STAILQ_FIRST((head)); \ 247 (var); \ 248 (var) = STAILQ_NEXT((var), field)) 249 250 251#define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 252 for ((var) = STAILQ_FIRST((head)); \ 253 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 254 (var) = (tvar)) 255 256#define STAILQ_INIT(head) do { \ 257 STAILQ_FIRST((head)) = NULL; \ 258 (head)->stqh_last = &STAILQ_FIRST((head)); \ 259} while (0) 260 261#define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 262 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 263 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 264 STAILQ_NEXT((tqelm), field) = (elm); \ 265} while (0) 266 267#define STAILQ_INSERT_HEAD(head, elm, field) do { \ 268 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 269 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 270 STAILQ_FIRST((head)) = (elm); \ 271} while (0) 272 273#define STAILQ_INSERT_TAIL(head, elm, field) do { \ 274 STAILQ_NEXT((elm), field) = NULL; \ 275 *(head)->stqh_last = (elm); \ 276 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 277} while (0) 278 279#define STAILQ_LAST(head, type, field) \ 280 (STAILQ_EMPTY((head)) ? \ 281 NULL : \ 282 ((struct type *)(void *) \ 283 ((char *)((head)->stqh_last) - __offsetof(struct type, field)))) 284 285#define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 286 287#define STAILQ_REMOVE(head, elm, type, field) do { \ 288 if (STAILQ_FIRST((head)) == (elm)) { \ 289 STAILQ_REMOVE_HEAD((head), field); \ 290 } \ 291 else { \ 292 struct type *curelm = STAILQ_FIRST((head)); \ 293 while (STAILQ_NEXT(curelm, field) != (elm)) \ 294 curelm = STAILQ_NEXT(curelm, field); \ 295 if ((STAILQ_NEXT(curelm, field) = \ 296 STAILQ_NEXT(STAILQ_NEXT(curelm, field), field)) == NULL)\ 297 (head)->stqh_last = &STAILQ_NEXT((curelm), field);\ 298 } \ 299 TRASHIT((elm)->field.stqe_next); \ 300} while (0) 301 302#define STAILQ_REMOVE_HEAD(head, field) do { \ 303 if ((STAILQ_FIRST((head)) = \ 304 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 305 (head)->stqh_last = &STAILQ_FIRST((head)); \ 306} while (0) 307 308/* 309 * List declarations. 310 */ 311#define LIST_HEAD(name, type) \ 312struct name { \ 313 struct type *lh_first; /* first element */ \ 314} 315 316#define LIST_HEAD_INITIALIZER(head) \ 317 { NULL } 318 319#define LIST_ENTRY(type) \ 320struct { \ 321 struct type *le_next; /* next element */ \ 322 struct type **le_prev; /* address of previous next element */ \ 323} 324 325/* 326 * List functions. 327 */ 328 329#if (defined(_KERNEL) && defined(INVARIANTS)) 330#define QMD_LIST_CHECK_HEAD(head, field) do { \ 331 if (LIST_FIRST((head)) != NULL && \ 332 LIST_FIRST((head))->field.le_prev != \ 333 &LIST_FIRST((head))) \ 334 panic("Bad list head %p first->prev != head", (head)); \ 335} while (0) 336 337#define QMD_LIST_CHECK_NEXT(elm, field) do { \ 338 if (LIST_NEXT((elm), field) != NULL && \ 339 LIST_NEXT((elm), field)->field.le_prev != \ 340 &((elm)->field.le_next)) \ 341 panic("Bad link elm %p next->prev != elm", (elm)); \ 342} while (0) 343 344#define QMD_LIST_CHECK_PREV(elm, field) do { \ 345 if (*(elm)->field.le_prev != (elm)) \ 346 panic("Bad link elm %p prev->next != elm", (elm)); \ 347} while (0) 348#else 349#define QMD_LIST_CHECK_HEAD(head, field) 350#define QMD_LIST_CHECK_NEXT(elm, field) 351#define QMD_LIST_CHECK_PREV(elm, field) 352#endif /* (_KERNEL && INVARIANTS) */ 353 354#define LIST_EMPTY(head) ((head)->lh_first == NULL) 355 356#define LIST_FIRST(head) ((head)->lh_first) 357 358#define LIST_FOREACH(var, head, field) \ 359 for ((var) = LIST_FIRST((head)); \ 360 (var); \ 361 (var) = LIST_NEXT((var), field)) 362 363#define LIST_FOREACH_SAFE(var, head, field, tvar) \ 364 for ((var) = LIST_FIRST((head)); \ 365 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 366 (var) = (tvar)) 367 368#define LIST_INIT(head) do { \ 369 LIST_FIRST((head)) = NULL; \ 370} while (0) 371 372#define LIST_INSERT_AFTER(listelm, elm, field) do { \ 373 QMD_LIST_CHECK_NEXT(listelm, field); \ 374 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 375 LIST_NEXT((listelm), field)->field.le_prev = \ 376 &LIST_NEXT((elm), field); \ 377 LIST_NEXT((listelm), field) = (elm); \ 378 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 379} while (0) 380 381#define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 382 QMD_LIST_CHECK_PREV(listelm, field); \ 383 (elm)->field.le_prev = (listelm)->field.le_prev; \ 384 LIST_NEXT((elm), field) = (listelm); \ 385 *(listelm)->field.le_prev = (elm); \ 386 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 387} while (0) 388 389#define LIST_INSERT_HEAD(head, elm, field) do { \ 390 QMD_LIST_CHECK_HEAD((head), field); \ 391 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 392 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 393 LIST_FIRST((head)) = (elm); \ 394 (elm)->field.le_prev = &LIST_FIRST((head)); \ 395} while (0) 396 397#define LIST_NEXT(elm, field) ((elm)->field.le_next) 398 399#define LIST_REMOVE(elm, field) do { \ 400 QMD_LIST_CHECK_NEXT(elm, field); \ 401 QMD_LIST_CHECK_PREV(elm, field); \ 402 if (LIST_NEXT((elm), field) != NULL) \ 403 LIST_NEXT((elm), field)->field.le_prev = \ 404 (elm)->field.le_prev; \ 405 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 406 TRASHIT((elm)->field.le_next); \ 407 TRASHIT((elm)->field.le_prev); \ 408} while (0) 409 410/* 411 * Tail queue declarations. 412 */ 413#define TAILQ_HEAD(name, type) \ 414struct name { \ 415 struct type *tqh_first; /* first element */ \ 416 struct type **tqh_last; /* addr of last next element */ \ 417 TRACEBUF \ 418} 419 420#define TAILQ_HEAD_INITIALIZER(head) \ 421 { NULL, &(head).tqh_first } 422 423#define TAILQ_ENTRY(type) \ 424struct { \ 425 struct type *tqe_next; /* next element */ \ 426 struct type **tqe_prev; /* address of previous next element */ \ 427 TRACEBUF \ 428} 429 430/* 431 * Tail queue functions. 432 */ 433#if (defined(_KERNEL) && defined(INVARIANTS)) 434#define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 435 if (!TAILQ_EMPTY(head) && \ 436 TAILQ_FIRST((head))->field.tqe_prev != \ 437 &TAILQ_FIRST((head))) \ 438 panic("Bad tailq head %p first->prev != head", (head)); \ 439} while (0) 440 441#define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 442 if (*(head)->tqh_last != NULL) \ 443 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 444} while (0) 445 446#define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 447 if (TAILQ_NEXT((elm), field) != NULL && \ 448 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 449 &((elm)->field.tqe_next)) \ 450 panic("Bad link elm %p next->prev != elm", (elm)); \ 451} while (0) 452 453#define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 454 if (*(elm)->field.tqe_prev != (elm)) \ 455 panic("Bad link elm %p prev->next != elm", (elm)); \ 456} while (0) 457#else 458#define QMD_TAILQ_CHECK_HEAD(head, field) 459#define QMD_TAILQ_CHECK_TAIL(head, headname) 460#define QMD_TAILQ_CHECK_NEXT(elm, field) 461#define QMD_TAILQ_CHECK_PREV(elm, field) 462#endif /* (_KERNEL && INVARIANTS) */ 463 464#define TAILQ_CONCAT(head1, head2, field) do { \ 465 if (!TAILQ_EMPTY(head2)) { \ 466 *(head1)->tqh_last = (head2)->tqh_first; \ 467 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 468 (head1)->tqh_last = (head2)->tqh_last; \ 469 TAILQ_INIT((head2)); \ 470 QMD_TRACE_HEAD(head1); \ 471 QMD_TRACE_HEAD(head2); \ 472 } \ 473} while (0) 474 475#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 476 477#define TAILQ_FIRST(head) ((head)->tqh_first) 478 479#define TAILQ_FOREACH(var, head, field) \ 480 for ((var) = TAILQ_FIRST((head)); \ 481 (var); \ 482 (var) = TAILQ_NEXT((var), field)) 483 484#define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 485 for ((var) = TAILQ_FIRST((head)); \ 486 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 487 (var) = (tvar)) 488 489#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 490 for ((var) = TAILQ_LAST((head), headname); \ 491 (var); \ 492 (var) = TAILQ_PREV((var), headname, field)) 493 494#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 495 for ((var) = TAILQ_LAST((head), headname); \ 496 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 497 (var) = (tvar)) 498 499#define TAILQ_INIT(head) do { \ 500 TAILQ_FIRST((head)) = NULL; \ 501 (head)->tqh_last = &TAILQ_FIRST((head)); \ 502 QMD_TRACE_HEAD(head); \ 503} while (0) 504 505#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 506 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 507 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 508 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 509 &TAILQ_NEXT((elm), field); \ 510 else { \ 511 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 512 QMD_TRACE_HEAD(head); \ 513 } \ 514 TAILQ_NEXT((listelm), field) = (elm); \ 515 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 516 QMD_TRACE_ELEM(&(elm)->field); \ 517 QMD_TRACE_ELEM(&listelm->field); \ 518} while (0) 519 520#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 521 QMD_TAILQ_CHECK_PREV(listelm, field); \ 522 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 523 TAILQ_NEXT((elm), field) = (listelm); \ 524 *(listelm)->field.tqe_prev = (elm); \ 525 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 526 QMD_TRACE_ELEM(&(elm)->field); \ 527 QMD_TRACE_ELEM(&listelm->field); \ 528} while (0) 529 530#define TAILQ_INSERT_HEAD(head, elm, field) do { \ 531 QMD_TAILQ_CHECK_HEAD(head, field); \ 532 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 533 TAILQ_FIRST((head))->field.tqe_prev = \ 534 &TAILQ_NEXT((elm), field); \ 535 else \ 536 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 537 TAILQ_FIRST((head)) = (elm); \ 538 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 539 QMD_TRACE_HEAD(head); \ 540 QMD_TRACE_ELEM(&(elm)->field); \ 541} while (0) 542 543#define TAILQ_INSERT_TAIL(head, elm, field) do { \ 544 QMD_TAILQ_CHECK_TAIL(head, field); \ 545 TAILQ_NEXT((elm), field) = NULL; \ 546 (elm)->field.tqe_prev = (head)->tqh_last; \ 547 *(head)->tqh_last = (elm); \ 548 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 549 QMD_TRACE_HEAD(head); \ 550 QMD_TRACE_ELEM(&(elm)->field); \ 551} while (0) 552 553#define TAILQ_LAST(head, headname) \ 554 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 555 556#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 557 558#define TAILQ_PREV(elm, headname, field) \ 559 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 560 561#define TAILQ_REMOVE(head, elm, field) do { \ 562 QMD_TAILQ_CHECK_NEXT(elm, field); \ 563 QMD_TAILQ_CHECK_PREV(elm, field); \ 564 if ((TAILQ_NEXT((elm), field)) != NULL) \ 565 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 566 (elm)->field.tqe_prev; \ 567 else { \ 568 (head)->tqh_last = (elm)->field.tqe_prev; \ 569 QMD_TRACE_HEAD(head); \ 570 } \ 571 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 572 TRASHIT((elm)->field.tqe_next); \ 573 TRASHIT((elm)->field.tqe_prev); \ 574 QMD_TRACE_ELEM(&(elm)->field); \ 575} while (0) 576 577 578#ifdef _KERNEL 579 580/* 581 * XXX insque() and remque() are an old way of handling certain queues. 582 * They bogusly assumes that all queue heads look alike. 583 */ 584 585struct quehead { 586 struct quehead *qh_link; 587 struct quehead *qh_rlink; 588}; 589 590#ifdef __CC_SUPPORTS___INLINE 591 592static __inline void 593insque(void *a, void *b) 594{ 595 struct quehead *element = (struct quehead *)a, 596 *head = (struct quehead *)b; 597 598 element->qh_link = head->qh_link; 599 element->qh_rlink = head; 600 head->qh_link = element; 601 element->qh_link->qh_rlink = element; 602} 603 604static __inline void 605remque(void *a) 606{ 607 struct quehead *element = (struct quehead *)a; 608 609 element->qh_link->qh_rlink = element->qh_rlink; 610 element->qh_rlink->qh_link = element->qh_link; 611 element->qh_rlink = 0; 612} 613 614#else /* !__CC_SUPPORTS___INLINE */ 615 616void insque(void *a, void *b); 617void remque(void *a); 618 619#endif /* __CC_SUPPORTS___INLINE */ 620 621#endif /* _KERNEL */ 622 623#endif /* _DEFAULT_SOURCE */ 624 625#endif /* !_SYS_QUEUE_H_ */ 626