queue.h revision 192908
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: head/sys/sys/queue.h 192908 2009-05-27 16:36:54Z zml $ 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_HEAD + - + - 100 * _REMOVE_NEXT + - + - 101 * _REMOVE + + + + 102 * 103 */ 104#ifdef QUEUE_MACRO_DEBUG 105/* Store the last 2 places the queue element or head was altered */ 106struct qm_trace { 107 char * lastfile; 108 int lastline; 109 char * prevfile; 110 int prevline; 111}; 112 113#define TRACEBUF struct qm_trace trace; 114#define TRASHIT(x) do {(x) = (void *)-1;} while (0) 115 116#define QMD_TRACE_HEAD(head) do { \ 117 (head)->trace.prevline = (head)->trace.lastline; \ 118 (head)->trace.prevfile = (head)->trace.lastfile; \ 119 (head)->trace.lastline = __LINE__; \ 120 (head)->trace.lastfile = __FILE__; \ 121} while (0) 122 123#define QMD_TRACE_ELEM(elem) do { \ 124 (elem)->trace.prevline = (elem)->trace.lastline; \ 125 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 126 (elem)->trace.lastline = __LINE__; \ 127 (elem)->trace.lastfile = __FILE__; \ 128} while (0) 129 130#else 131#define QMD_TRACE_ELEM(elem) 132#define QMD_TRACE_HEAD(head) 133#define TRACEBUF 134#define TRASHIT(x) 135#endif /* QUEUE_MACRO_DEBUG */ 136 137/* 138 * Singly-linked List declarations. 139 */ 140#define SLIST_HEAD(name, type) \ 141struct name { \ 142 struct type *slh_first; /* first element */ \ 143} 144 145#define SLIST_HEAD_INITIALIZER(head) \ 146 { NULL } 147 148#define SLIST_ENTRY(type) \ 149struct { \ 150 struct type *sle_next; /* next element */ \ 151} 152 153/* 154 * Singly-linked List functions. 155 */ 156#define SLIST_EMPTY(head) ((head)->slh_first == NULL) 157 158#define SLIST_FIRST(head) ((head)->slh_first) 159 160#define SLIST_FOREACH(var, head, field) \ 161 for ((var) = SLIST_FIRST((head)); \ 162 (var); \ 163 (var) = SLIST_NEXT((var), field)) 164 165#define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 166 for ((var) = SLIST_FIRST((head)); \ 167 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 168 (var) = (tvar)) 169 170#define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 171 for ((varp) = &SLIST_FIRST((head)); \ 172 ((var) = *(varp)) != NULL; \ 173 (varp) = &SLIST_NEXT((var), field)) 174 175#define SLIST_INIT(head) do { \ 176 SLIST_FIRST((head)) = NULL; \ 177} while (0) 178 179#define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 180 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 181 SLIST_NEXT((slistelm), field) = (elm); \ 182} while (0) 183 184#define SLIST_INSERT_HEAD(head, elm, field) do { \ 185 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 186 SLIST_FIRST((head)) = (elm); \ 187} while (0) 188 189#define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 190 191#define SLIST_REMOVE(head, elm, type, field) do { \ 192 if (SLIST_FIRST((head)) == (elm)) { \ 193 SLIST_REMOVE_HEAD((head), field); \ 194 } \ 195 else { \ 196 struct type *curelm = SLIST_FIRST((head)); \ 197 while (SLIST_NEXT(curelm, field) != (elm)) \ 198 curelm = SLIST_NEXT(curelm, field); \ 199 SLIST_REMOVE_NEXT(head, curelm, field); \ 200 } \ 201 TRASHIT((elm)->field.sle_next); \ 202} while (0) 203 204#define SLIST_REMOVE_NEXT(head, elm, field) do { \ 205 SLIST_NEXT(elm, field) = \ 206 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 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 STAILQ_REMOVE_NEXT(head, curelm, field); \ 296 } \ 297 TRASHIT((elm)->field.stqe_next); \ 298} while (0) 299 300#define STAILQ_REMOVE_HEAD(head, field) do { \ 301 if ((STAILQ_FIRST((head)) = \ 302 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 303 (head)->stqh_last = &STAILQ_FIRST((head)); \ 304} while (0) 305 306#define STAILQ_REMOVE_NEXT(head, elm, field) do { \ 307 if ((STAILQ_NEXT(elm, field) = \ 308 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 309 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 310} while (0) 311 312#define STAILQ_SWAP(head1, head2, type) do { \ 313 struct type *swap_first = STAILQ_FIRST(head1); \ 314 struct type **swap_last = (head1)->stqh_last; \ 315 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 316 (head1)->stqh_last = (head2)->stqh_last; \ 317 STAILQ_FIRST(head2) = swap_first; \ 318 (head2)->stqh_last = swap_last; \ 319 if (STAILQ_EMPTY(head1)) \ 320 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 321 if (STAILQ_EMPTY(head2)) \ 322 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 323} while (0) 324 325 326/* 327 * List declarations. 328 */ 329#define LIST_HEAD(name, type) \ 330struct name { \ 331 struct type *lh_first; /* first element */ \ 332} 333 334#define LIST_HEAD_INITIALIZER(head) \ 335 { NULL } 336 337#define LIST_ENTRY(type) \ 338struct { \ 339 struct type *le_next; /* next element */ \ 340 struct type **le_prev; /* address of previous next element */ \ 341} 342 343/* 344 * List functions. 345 */ 346 347#if (defined(_KERNEL) && defined(INVARIANTS)) 348#define QMD_LIST_CHECK_HEAD(head, field) do { \ 349 if (LIST_FIRST((head)) != NULL && \ 350 LIST_FIRST((head))->field.le_prev != \ 351 &LIST_FIRST((head))) \ 352 panic("Bad list head %p first->prev != head", (head)); \ 353} while (0) 354 355#define QMD_LIST_CHECK_NEXT(elm, field) do { \ 356 if (LIST_NEXT((elm), field) != NULL && \ 357 LIST_NEXT((elm), field)->field.le_prev != \ 358 &((elm)->field.le_next)) \ 359 panic("Bad link elm %p next->prev != elm", (elm)); \ 360} while (0) 361 362#define QMD_LIST_CHECK_PREV(elm, field) do { \ 363 if (*(elm)->field.le_prev != (elm)) \ 364 panic("Bad link elm %p prev->next != elm", (elm)); \ 365} while (0) 366#else 367#define QMD_LIST_CHECK_HEAD(head, field) 368#define QMD_LIST_CHECK_NEXT(elm, field) 369#define QMD_LIST_CHECK_PREV(elm, field) 370#endif /* (_KERNEL && INVARIANTS) */ 371 372#define LIST_EMPTY(head) ((head)->lh_first == NULL) 373 374#define LIST_FIRST(head) ((head)->lh_first) 375 376#define LIST_FOREACH(var, head, field) \ 377 for ((var) = LIST_FIRST((head)); \ 378 (var); \ 379 (var) = LIST_NEXT((var), field)) 380 381#define LIST_FOREACH_SAFE(var, head, field, tvar) \ 382 for ((var) = LIST_FIRST((head)); \ 383 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 384 (var) = (tvar)) 385 386#define LIST_INIT(head) do { \ 387 LIST_FIRST((head)) = NULL; \ 388} while (0) 389 390#define LIST_INSERT_AFTER(listelm, elm, field) do { \ 391 QMD_LIST_CHECK_NEXT(listelm, field); \ 392 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 393 LIST_NEXT((listelm), field)->field.le_prev = \ 394 &LIST_NEXT((elm), field); \ 395 LIST_NEXT((listelm), field) = (elm); \ 396 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 397} while (0) 398 399#define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 400 QMD_LIST_CHECK_PREV(listelm, field); \ 401 (elm)->field.le_prev = (listelm)->field.le_prev; \ 402 LIST_NEXT((elm), field) = (listelm); \ 403 *(listelm)->field.le_prev = (elm); \ 404 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 405} while (0) 406 407#define LIST_INSERT_HEAD(head, elm, field) do { \ 408 QMD_LIST_CHECK_HEAD((head), field); \ 409 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 410 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 411 LIST_FIRST((head)) = (elm); \ 412 (elm)->field.le_prev = &LIST_FIRST((head)); \ 413} while (0) 414 415#define LIST_NEXT(elm, field) ((elm)->field.le_next) 416 417#define LIST_REMOVE(elm, field) do { \ 418 QMD_LIST_CHECK_NEXT(elm, field); \ 419 QMD_LIST_CHECK_PREV(elm, field); \ 420 if (LIST_NEXT((elm), field) != NULL) \ 421 LIST_NEXT((elm), field)->field.le_prev = \ 422 (elm)->field.le_prev; \ 423 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 424 TRASHIT((elm)->field.le_next); \ 425 TRASHIT((elm)->field.le_prev); \ 426} while (0) 427 428#define LIST_SWAP(head1, head2, type, field) do { \ 429 struct type *swap_tmp = LIST_FIRST((head1)); \ 430 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 431 LIST_FIRST((head2)) = swap_tmp; \ 432 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 433 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 434 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 435 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 436} while (0) 437 438/* 439 * Tail queue declarations. 440 */ 441#define TAILQ_HEAD(name, type) \ 442struct name { \ 443 struct type *tqh_first; /* first element */ \ 444 struct type **tqh_last; /* addr of last next element */ \ 445 TRACEBUF \ 446} 447 448#define TAILQ_HEAD_INITIALIZER(head) \ 449 { NULL, &(head).tqh_first } 450 451#define TAILQ_ENTRY(type) \ 452struct { \ 453 struct type *tqe_next; /* next element */ \ 454 struct type **tqe_prev; /* address of previous next element */ \ 455 TRACEBUF \ 456} 457 458/* 459 * Tail queue functions. 460 */ 461#if (defined(_KERNEL) && defined(INVARIANTS)) 462#define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 463 if (!TAILQ_EMPTY(head) && \ 464 TAILQ_FIRST((head))->field.tqe_prev != \ 465 &TAILQ_FIRST((head))) \ 466 panic("Bad tailq head %p first->prev != head", (head)); \ 467} while (0) 468 469#define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 470 if (*(head)->tqh_last != NULL) \ 471 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 472} while (0) 473 474#define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 475 if (TAILQ_NEXT((elm), field) != NULL && \ 476 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 477 &((elm)->field.tqe_next)) \ 478 panic("Bad link elm %p next->prev != elm", (elm)); \ 479} while (0) 480 481#define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 482 if (*(elm)->field.tqe_prev != (elm)) \ 483 panic("Bad link elm %p prev->next != elm", (elm)); \ 484} while (0) 485#else 486#define QMD_TAILQ_CHECK_HEAD(head, field) 487#define QMD_TAILQ_CHECK_TAIL(head, headname) 488#define QMD_TAILQ_CHECK_NEXT(elm, field) 489#define QMD_TAILQ_CHECK_PREV(elm, field) 490#endif /* (_KERNEL && INVARIANTS) */ 491 492#define TAILQ_CONCAT(head1, head2, field) do { \ 493 if (!TAILQ_EMPTY(head2)) { \ 494 *(head1)->tqh_last = (head2)->tqh_first; \ 495 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 496 (head1)->tqh_last = (head2)->tqh_last; \ 497 TAILQ_INIT((head2)); \ 498 QMD_TRACE_HEAD(head1); \ 499 QMD_TRACE_HEAD(head2); \ 500 } \ 501} while (0) 502 503#define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 504 505#define TAILQ_FIRST(head) ((head)->tqh_first) 506 507#define TAILQ_FOREACH(var, head, field) \ 508 for ((var) = TAILQ_FIRST((head)); \ 509 (var); \ 510 (var) = TAILQ_NEXT((var), field)) 511 512#define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 513 for ((var) = TAILQ_FIRST((head)); \ 514 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 515 (var) = (tvar)) 516 517#define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 518 for ((var) = TAILQ_LAST((head), headname); \ 519 (var); \ 520 (var) = TAILQ_PREV((var), headname, field)) 521 522#define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 523 for ((var) = TAILQ_LAST((head), headname); \ 524 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 525 (var) = (tvar)) 526 527#define TAILQ_INIT(head) do { \ 528 TAILQ_FIRST((head)) = NULL; \ 529 (head)->tqh_last = &TAILQ_FIRST((head)); \ 530 QMD_TRACE_HEAD(head); \ 531} while (0) 532 533#define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 534 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 535 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 536 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 537 &TAILQ_NEXT((elm), field); \ 538 else { \ 539 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 540 QMD_TRACE_HEAD(head); \ 541 } \ 542 TAILQ_NEXT((listelm), field) = (elm); \ 543 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 544 QMD_TRACE_ELEM(&(elm)->field); \ 545 QMD_TRACE_ELEM(&listelm->field); \ 546} while (0) 547 548#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 549 QMD_TAILQ_CHECK_PREV(listelm, field); \ 550 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 551 TAILQ_NEXT((elm), field) = (listelm); \ 552 *(listelm)->field.tqe_prev = (elm); \ 553 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 554 QMD_TRACE_ELEM(&(elm)->field); \ 555 QMD_TRACE_ELEM(&listelm->field); \ 556} while (0) 557 558#define TAILQ_INSERT_HEAD(head, elm, field) do { \ 559 QMD_TAILQ_CHECK_HEAD(head, field); \ 560 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 561 TAILQ_FIRST((head))->field.tqe_prev = \ 562 &TAILQ_NEXT((elm), field); \ 563 else \ 564 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 565 TAILQ_FIRST((head)) = (elm); \ 566 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 567 QMD_TRACE_HEAD(head); \ 568 QMD_TRACE_ELEM(&(elm)->field); \ 569} while (0) 570 571#define TAILQ_INSERT_TAIL(head, elm, field) do { \ 572 QMD_TAILQ_CHECK_TAIL(head, field); \ 573 TAILQ_NEXT((elm), field) = NULL; \ 574 (elm)->field.tqe_prev = (head)->tqh_last; \ 575 *(head)->tqh_last = (elm); \ 576 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 577 QMD_TRACE_HEAD(head); \ 578 QMD_TRACE_ELEM(&(elm)->field); \ 579} while (0) 580 581#define TAILQ_LAST(head, headname) \ 582 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 583 584#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 585 586#define TAILQ_PREV(elm, headname, field) \ 587 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 588 589#define TAILQ_REMOVE(head, elm, field) do { \ 590 QMD_TAILQ_CHECK_NEXT(elm, field); \ 591 QMD_TAILQ_CHECK_PREV(elm, field); \ 592 if ((TAILQ_NEXT((elm), field)) != NULL) \ 593 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 594 (elm)->field.tqe_prev; \ 595 else { \ 596 (head)->tqh_last = (elm)->field.tqe_prev; \ 597 QMD_TRACE_HEAD(head); \ 598 } \ 599 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 600 TRASHIT((elm)->field.tqe_next); \ 601 TRASHIT((elm)->field.tqe_prev); \ 602 QMD_TRACE_ELEM(&(elm)->field); \ 603} while (0) 604 605#define TAILQ_SWAP(head1, head2, type, field) do { \ 606 struct type *swap_first = (head1)->tqh_first; \ 607 struct type **swap_last = (head1)->tqh_last; \ 608 (head1)->tqh_first = (head2)->tqh_first; \ 609 (head1)->tqh_last = (head2)->tqh_last; \ 610 (head2)->tqh_first = swap_first; \ 611 (head2)->tqh_last = swap_last; \ 612 if ((swap_first = (head1)->tqh_first) != NULL) \ 613 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 614 else \ 615 (head1)->tqh_last = &(head1)->tqh_first; \ 616 if ((swap_first = (head2)->tqh_first) != NULL) \ 617 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 618 else \ 619 (head2)->tqh_last = &(head2)->tqh_first; \ 620} while (0) 621 622#endif /* !_SYS_QUEUE_H_ */ 623