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 * $FreeBSD$ 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 be traversed in either 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 */ 107 struct 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) \ 144 struct name { \ 145 struct type *slh_first; /* first element */ \ 146 } 147 148 #define SLIST_HEAD_INITIALIZER(head) \ 149 { NULL } 150 151 #define SLIST_ENTRY(type) \ 152 struct { \ 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) \ 227 struct 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) \ 236 struct { \ 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 __member2struct(type, field.stqe_next, (head)->stqh_last)) 293 294 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 295 296 #define STAILQ_REMOVE(head, elm, type, field) do { \ 297 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 298 if (STAILQ_FIRST((head)) == (elm)) { \ 299 STAILQ_REMOVE_HEAD((head), field); \ 300 } \ 301 else { \ 302 struct type *curelm = STAILQ_FIRST((head)); \ 303 while (STAILQ_NEXT(curelm, field) != (elm)) \ 304 curelm = STAILQ_NEXT(curelm, field); \ 305 STAILQ_REMOVE_AFTER(head, curelm, field); \ 306 } \ 307 TRASHIT(*oldnext); \ 308 } while (0) 309 310 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 311 if ((STAILQ_NEXT(elm, field) = \ 312 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 313 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 314 } while (0) 315 316 #define STAILQ_REMOVE_HEAD(head, field) do { \ 317 if ((STAILQ_FIRST((head)) = \ 318 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 319 (head)->stqh_last = &STAILQ_FIRST((head)); \ 320 } while (0) 321 322 #define STAILQ_SWAP(head1, head2, type) do { \ 323 struct type *swap_first = STAILQ_FIRST(head1); \ 324 struct type **swap_last = (head1)->stqh_last; \ 325 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 326 (head1)->stqh_last = (head2)->stqh_last; \ 327 STAILQ_FIRST(head2) = swap_first; \ 328 (head2)->stqh_last = swap_last; \ 329 if (STAILQ_EMPTY(head1)) \ 330 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 331 if (STAILQ_EMPTY(head2)) \ 332 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 333 } while (0) 334 335 336 /* 337 * List declarations. 338 */ 339 #define LIST_HEAD(name, type) \ 340 struct name { \ 341 struct type *lh_first; /* first element */ \ 342 } 343 344 #define LIST_HEAD_INITIALIZER(head) \ 345 { NULL } 346 347 #define LIST_ENTRY(type) \ 348 struct { \ 349 struct type *le_next; /* next element */ \ 350 struct type **le_prev; /* address of previous next element */ \ 351 } 352 353 /* 354 * List functions. 355 */ 356 357 #if (defined(_KERNEL) && defined(INVARIANTS)) 358 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 359 if (LIST_FIRST((head)) != NULL && \ 360 LIST_FIRST((head))->field.le_prev != \ 361 &LIST_FIRST((head))) \ 362 panic("Bad list head %p first->prev != head", (head)); \ 363 } while (0) 364 365 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 366 if (LIST_NEXT((elm), field) != NULL && \ 367 LIST_NEXT((elm), field)->field.le_prev != \ 368 &((elm)->field.le_next)) \ 369 panic("Bad link elm %p next->prev != elm", (elm)); \ 370 } while (0) 371 372 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 373 if (*(elm)->field.le_prev != (elm)) \ 374 panic("Bad link elm %p prev->next != elm", (elm)); \ 375 } while (0) 376 #else 377 #define QMD_LIST_CHECK_HEAD(head, field) 378 #define QMD_LIST_CHECK_NEXT(elm, field) 379 #define QMD_LIST_CHECK_PREV(elm, field) 380 #endif /* (_KERNEL && INVARIANTS) */ 381 382 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 383 384 #define LIST_FIRST(head) ((head)->lh_first) 385 386 #define LIST_FOREACH(var, head, field) \ 387 for ((var) = LIST_FIRST((head)); \ 388 (var); \ 389 (var) = LIST_NEXT((var), field)) 390 391 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 392 for ((var) = LIST_FIRST((head)); \ 393 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 394 (var) = (tvar)) 395 396 #define LIST_INIT(head) do { \ 397 LIST_FIRST((head)) = NULL; \ 398 } while (0) 399 400 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 401 QMD_LIST_CHECK_NEXT(listelm, field); \ 402 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 403 LIST_NEXT((listelm), field)->field.le_prev = \ 404 &LIST_NEXT((elm), field); \ 405 LIST_NEXT((listelm), field) = (elm); \ 406 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 407 } while (0) 408 409 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 410 QMD_LIST_CHECK_PREV(listelm, field); \ 411 (elm)->field.le_prev = (listelm)->field.le_prev; \ 412 LIST_NEXT((elm), field) = (listelm); \ 413 *(listelm)->field.le_prev = (elm); \ 414 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 415 } while (0) 416 417 #define LIST_INSERT_HEAD(head, elm, field) do { \ 418 QMD_LIST_CHECK_HEAD((head), field); \ 419 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 420 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 421 LIST_FIRST((head)) = (elm); \ 422 (elm)->field.le_prev = &LIST_FIRST((head)); \ 423 } while (0) 424 425 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 426 427 #define LIST_PREV(elm, head, type, field) \ 428 ((elm)->field.le_prev == &LIST_FIRST((head)) ? \ 429 NULL : \ 430 __member2struct(type, field.le_next, (elm)->field.le_prev)) 431 432 #define LIST_REMOVE(elm, field) do { \ 433 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 434 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 435 QMD_LIST_CHECK_NEXT(elm, field); \ 436 QMD_LIST_CHECK_PREV(elm, field); \ 437 if (LIST_NEXT((elm), field) != NULL) \ 438 LIST_NEXT((elm), field)->field.le_prev = \ 439 (elm)->field.le_prev; \ 440 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 441 TRASHIT(*oldnext); \ 442 TRASHIT(*oldprev); \ 443 } while (0) 444 445 #define LIST_SWAP(head1, head2, type, field) do { \ 446 struct type *swap_tmp = LIST_FIRST((head1)); \ 447 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 448 LIST_FIRST((head2)) = swap_tmp; \ 449 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 450 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 451 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 452 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 453 } while (0) 454 455 /* 456 * Tail queue declarations. 457 */ 458 #define TAILQ_HEAD(name, type) \ 459 struct name { \ 460 struct type *tqh_first; /* first element */ \ 461 struct type **tqh_last; /* addr of last next element */ \ 462 TRACEBUF \ 463 } 464 465 #define TAILQ_HEAD_INITIALIZER(head) \ 466 { NULL, &(head).tqh_first } 467 468 #define TAILQ_ENTRY(type) \ 469 struct { \ 470 struct type *tqe_next; /* next element */ \ 471 struct type **tqe_prev; /* address of previous next element */ \ 472 TRACEBUF \ 473 } 474 475 /* 476 * Tail queue functions. 477 */ 478 #if (defined(_KERNEL) && defined(INVARIANTS)) 479 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 480 if (!TAILQ_EMPTY(head) && \ 481 TAILQ_FIRST((head))->field.tqe_prev != \ 482 &TAILQ_FIRST((head))) \ 483 panic("Bad tailq head %p first->prev != head", (head)); \ 484 } while (0) 485 486 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 487 if (*(head)->tqh_last != NULL) \ 488 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 489 } while (0) 490 491 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 492 if (TAILQ_NEXT((elm), field) != NULL && \ 493 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 494 &((elm)->field.tqe_next)) \ 495 panic("Bad link elm %p next->prev != elm", (elm)); \ 496 } while (0) 497 498 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 499 if (*(elm)->field.tqe_prev != (elm)) \ 500 panic("Bad link elm %p prev->next != elm", (elm)); \ 501 } while (0) 502 #else 503 #define QMD_TAILQ_CHECK_HEAD(head, field) 504 #define QMD_TAILQ_CHECK_TAIL(head, headname) 505 #define QMD_TAILQ_CHECK_NEXT(elm, field) 506 #define QMD_TAILQ_CHECK_PREV(elm, field) 507 #endif /* (_KERNEL && INVARIANTS) */ 508 509 #define TAILQ_CONCAT(head1, head2, field) do { \ 510 if (!TAILQ_EMPTY(head2)) { \ 511 *(head1)->tqh_last = (head2)->tqh_first; \ 512 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 513 (head1)->tqh_last = (head2)->tqh_last; \ 514 TAILQ_INIT((head2)); \ 515 QMD_TRACE_HEAD(head1); \ 516 QMD_TRACE_HEAD(head2); \ 517 } \ 518 } while (0) 519 520 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 521 522 #define TAILQ_FIRST(head) ((head)->tqh_first) 523 524 #define TAILQ_FOREACH(var, head, field) \ 525 for ((var) = TAILQ_FIRST((head)); \ 526 (var); \ 527 (var) = TAILQ_NEXT((var), field)) 528 529 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 530 for ((var) = TAILQ_FIRST((head)); \ 531 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 532 (var) = (tvar)) 533 534 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 535 for ((var) = TAILQ_LAST((head), headname); \ 536 (var); \ 537 (var) = TAILQ_PREV((var), headname, field)) 538 539 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 540 for ((var) = TAILQ_LAST((head), headname); \ 541 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 542 (var) = (tvar)) 543 544 #define TAILQ_INIT(head) do { \ 545 TAILQ_FIRST((head)) = NULL; \ 546 (head)->tqh_last = &TAILQ_FIRST((head)); \ 547 QMD_TRACE_HEAD(head); \ 548 } while (0) 549 550 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 551 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 552 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 553 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 554 &TAILQ_NEXT((elm), field); \ 555 else { \ 556 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 557 QMD_TRACE_HEAD(head); \ 558 } \ 559 TAILQ_NEXT((listelm), field) = (elm); \ 560 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 561 QMD_TRACE_ELEM(&(elm)->field); \ 562 QMD_TRACE_ELEM(&listelm->field); \ 563 } while (0) 564 565 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 566 QMD_TAILQ_CHECK_PREV(listelm, field); \ 567 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 568 TAILQ_NEXT((elm), field) = (listelm); \ 569 *(listelm)->field.tqe_prev = (elm); \ 570 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 571 QMD_TRACE_ELEM(&(elm)->field); \ 572 QMD_TRACE_ELEM(&listelm->field); \ 573 } while (0) 574 575 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 576 QMD_TAILQ_CHECK_HEAD(head, field); \ 577 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 578 TAILQ_FIRST((head))->field.tqe_prev = \ 579 &TAILQ_NEXT((elm), field); \ 580 else \ 581 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 582 TAILQ_FIRST((head)) = (elm); \ 583 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 584 QMD_TRACE_HEAD(head); \ 585 QMD_TRACE_ELEM(&(elm)->field); \ 586 } while (0) 587 588 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 589 QMD_TAILQ_CHECK_TAIL(head, field); \ 590 TAILQ_NEXT((elm), field) = NULL; \ 591 (elm)->field.tqe_prev = (head)->tqh_last; \ 592 *(head)->tqh_last = (elm); \ 593 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 594 QMD_TRACE_HEAD(head); \ 595 QMD_TRACE_ELEM(&(elm)->field); \ 596 } while (0) 597 598 #define TAILQ_LAST(head, headname) \ 599 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 600 601 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 602 603 #define TAILQ_PREV(elm, headname, field) \ 604 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 605 606 #define TAILQ_REMOVE(head, elm, field) do { \ 607 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 608 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 609 QMD_TAILQ_CHECK_NEXT(elm, field); \ 610 QMD_TAILQ_CHECK_PREV(elm, field); \ 611 if ((TAILQ_NEXT((elm), field)) != NULL) \ 612 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 613 (elm)->field.tqe_prev; \ 614 else { \ 615 (head)->tqh_last = (elm)->field.tqe_prev; \ 616 QMD_TRACE_HEAD(head); \ 617 } \ 618 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 619 TRASHIT(*oldnext); \ 620 TRASHIT(*oldprev); \ 621 QMD_TRACE_ELEM(&(elm)->field); \ 622 } while (0) 623 624 #define TAILQ_SWAP(head1, head2, type, field) do { \ 625 struct type *swap_first = (head1)->tqh_first; \ 626 struct type **swap_last = (head1)->tqh_last; \ 627 (head1)->tqh_first = (head2)->tqh_first; \ 628 (head1)->tqh_last = (head2)->tqh_last; \ 629 (head2)->tqh_first = swap_first; \ 630 (head2)->tqh_last = swap_last; \ 631 if ((swap_first = (head1)->tqh_first) != NULL) \ 632 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 633 else \ 634 (head1)->tqh_last = &(head1)->tqh_first; \ 635 if ((swap_first = (head2)->tqh_first) != NULL) \ 636 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 637 else \ 638 (head2)->tqh_last = &(head2)->tqh_first; \ 639 } while (0) 640 641 #endif /* !_SYS_QUEUE_H_ */ 642