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 1.74 2010/12/03 16:07:50 kib Exp $ 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_MUTABLE + + + + 92 * _FOREACH_REVERSE - - - + 93 * _FOREACH_REVERSE_MUTABLE - - - + 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 #define SLIST_ENTRY_INITIALIZER { NULL } 157 158 /* 159 * Singly-linked List functions. 160 */ 161 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 162 163 #define SLIST_FIRST(head) ((head)->slh_first) 164 165 #define SLIST_FOREACH(var, head, field) \ 166 for ((var) = SLIST_FIRST((head)); \ 167 (var); \ 168 (var) = SLIST_NEXT((var), field)) 169 170 #define SLIST_FOREACH_MUTABLE(var, head, field, tvar) \ 171 for ((var) = SLIST_FIRST((head)); \ 172 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 173 (var) = (tvar)) 174 175 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 176 for ((varp) = &SLIST_FIRST((head)); \ 177 ((var) = *(varp)) != NULL; \ 178 (varp) = &SLIST_NEXT((var), field)) 179 180 #define SLIST_INIT(head) do { \ 181 SLIST_FIRST((head)) = NULL; \ 182 } while (0) 183 184 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 185 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 186 SLIST_NEXT((slistelm), field) = (elm); \ 187 } while (0) 188 189 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 190 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 191 SLIST_FIRST((head)) = (elm); \ 192 } while (0) 193 194 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 195 196 #define SLIST_REMOVE(head, elm, type, field) do { \ 197 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \ 198 if (SLIST_FIRST((head)) == (elm)) { \ 199 SLIST_REMOVE_HEAD((head), field); \ 200 } \ 201 else { \ 202 struct type *curelm = SLIST_FIRST((head)); \ 203 while (SLIST_NEXT(curelm, field) != (elm)) \ 204 curelm = SLIST_NEXT(curelm, field); \ 205 SLIST_REMOVE_AFTER(curelm, field); \ 206 } \ 207 TRASHIT(*oldnext); \ 208 } while (0) 209 210 #define SLIST_REMOVE_AFTER(elm, field) do { \ 211 SLIST_NEXT(elm, field) = \ 212 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 213 } while (0) 214 215 #define SLIST_REMOVE_HEAD(head, field) do { \ 216 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 217 } while (0) 218 219 #define SLIST_SWAP(head1, head2, type) do { \ 220 struct type *swap_first = SLIST_FIRST(head1); \ 221 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 222 SLIST_FIRST(head2) = swap_first; \ 223 } while (0) 224 225 /* 226 * Singly-linked Tail queue declarations. 227 */ 228 #define STAILQ_HEAD(name, type) \ 229 struct name { \ 230 struct type *stqh_first;/* first element */ \ 231 struct type **stqh_last;/* addr of last next element */ \ 232 } 233 234 #define STAILQ_HEAD_INITIALIZER(head) \ 235 { NULL, &(head).stqh_first } 236 237 #define STAILQ_ENTRY(type) \ 238 struct { \ 239 struct type *stqe_next; /* next element */ \ 240 } 241 242 /* 243 * Singly-linked Tail queue functions. 244 */ 245 #define STAILQ_CONCAT(head1, head2) do { \ 246 if (!STAILQ_EMPTY((head2))) { \ 247 *(head1)->stqh_last = (head2)->stqh_first; \ 248 (head1)->stqh_last = (head2)->stqh_last; \ 249 STAILQ_INIT((head2)); \ 250 } \ 251 } while (0) 252 253 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 254 255 #define STAILQ_FIRST(head) ((head)->stqh_first) 256 257 #define STAILQ_FOREACH(var, head, field) \ 258 for((var) = STAILQ_FIRST((head)); \ 259 (var); \ 260 (var) = STAILQ_NEXT((var), field)) 261 262 263 #define STAILQ_FOREACH_MUTABLE(var, head, field, tvar) \ 264 for ((var) = STAILQ_FIRST((head)); \ 265 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 266 (var) = (tvar)) 267 268 #define STAILQ_INIT(head) do { \ 269 STAILQ_FIRST((head)) = NULL; \ 270 (head)->stqh_last = &STAILQ_FIRST((head)); \ 271 } while (0) 272 273 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 274 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 275 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 276 STAILQ_NEXT((tqelm), field) = (elm); \ 277 } while (0) 278 279 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 280 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 281 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 282 STAILQ_FIRST((head)) = (elm); \ 283 } while (0) 284 285 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 286 STAILQ_NEXT((elm), field) = NULL; \ 287 *(head)->stqh_last = (elm); \ 288 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 289 } while (0) 290 291 #define STAILQ_LAST(head, type, field) \ 292 (STAILQ_EMPTY((head)) ? \ 293 NULL : \ 294 ((struct type *)(void *) \ 295 ((char *)((head)->stqh_last) - __offsetof(struct type, field)))) 296 297 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 298 299 #define STAILQ_REMOVE(head, elm, type, field) do { \ 300 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 301 if (STAILQ_FIRST((head)) == (elm)) { \ 302 STAILQ_REMOVE_HEAD((head), field); \ 303 } \ 304 else { \ 305 struct type *curelm = STAILQ_FIRST((head)); \ 306 while (STAILQ_NEXT(curelm, field) != (elm)) \ 307 curelm = STAILQ_NEXT(curelm, field); \ 308 STAILQ_REMOVE_AFTER(head, curelm, field); \ 309 } \ 310 TRASHIT(*oldnext); \ 311 } while (0) 312 313 #define STAILQ_REMOVE_HEAD(head, field) do { \ 314 if ((STAILQ_FIRST((head)) = \ 315 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 316 (head)->stqh_last = &STAILQ_FIRST((head)); \ 317 } while (0) 318 319 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 320 if ((STAILQ_NEXT(elm, field) = \ 321 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 322 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 323 } while (0) 324 325 #define STAILQ_SWAP(head1, head2, type) do { \ 326 struct type *swap_first = STAILQ_FIRST(head1); \ 327 struct type **swap_last = (head1)->stqh_last; \ 328 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 329 (head1)->stqh_last = (head2)->stqh_last; \ 330 STAILQ_FIRST(head2) = swap_first; \ 331 (head2)->stqh_last = swap_last; \ 332 if (STAILQ_EMPTY(head1)) \ 333 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 334 if (STAILQ_EMPTY(head2)) \ 335 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 336 } while (0) 337 338 339 /* 340 * List declarations. 341 */ 342 #define LIST_HEAD(name, type) \ 343 struct name { \ 344 struct type *lh_first; /* first element */ \ 345 } 346 347 #define LIST_HEAD_INITIALIZER(head) \ 348 { NULL } 349 350 #define LIST_ENTRY(type) \ 351 struct { \ 352 struct type *le_next; /* next element */ \ 353 struct type **le_prev; /* address of previous next element */ \ 354 } 355 356 /* 357 * List functions. 358 */ 359 360 #if (defined(_KERNEL) && defined(INVARIANTS)) 361 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 362 if (LIST_FIRST((head)) != NULL && \ 363 LIST_FIRST((head))->field.le_prev != \ 364 &LIST_FIRST((head))) \ 365 panic("Bad list head %p first->prev != head", (head)); \ 366 } while (0) 367 368 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 369 if (LIST_NEXT((elm), field) != NULL && \ 370 LIST_NEXT((elm), field)->field.le_prev != \ 371 &((elm)->field.le_next)) \ 372 panic("Bad link elm %p next->prev != elm", (elm)); \ 373 } while (0) 374 375 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 376 if (*(elm)->field.le_prev != (elm)) \ 377 panic("Bad link elm %p prev->next != elm", (elm)); \ 378 } while (0) 379 #else 380 #define QMD_LIST_CHECK_HEAD(head, field) 381 #define QMD_LIST_CHECK_NEXT(elm, field) 382 #define QMD_LIST_CHECK_PREV(elm, field) 383 #endif /* (_KERNEL && INVARIANTS) */ 384 385 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 386 387 #define LIST_FIRST(head) ((head)->lh_first) 388 389 #define LIST_FOREACH(var, head, field) \ 390 for ((var) = LIST_FIRST((head)); \ 391 (var); \ 392 (var) = LIST_NEXT((var), field)) 393 394 #define LIST_FOREACH_MUTABLE(var, head, field, tvar) \ 395 for ((var) = LIST_FIRST((head)); \ 396 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 397 (var) = (tvar)) 398 399 #define LIST_INIT(head) do { \ 400 LIST_FIRST((head)) = NULL; \ 401 } while (0) 402 403 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 404 QMD_LIST_CHECK_NEXT(listelm, field); \ 405 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 406 LIST_NEXT((listelm), field)->field.le_prev = \ 407 &LIST_NEXT((elm), field); \ 408 LIST_NEXT((listelm), field) = (elm); \ 409 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 410 } while (0) 411 412 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 413 QMD_LIST_CHECK_PREV(listelm, field); \ 414 (elm)->field.le_prev = (listelm)->field.le_prev; \ 415 LIST_NEXT((elm), field) = (listelm); \ 416 *(listelm)->field.le_prev = (elm); \ 417 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 418 } while (0) 419 420 #define LIST_INSERT_HEAD(head, elm, field) do { \ 421 QMD_LIST_CHECK_HEAD((head), field); \ 422 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 423 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 424 LIST_FIRST((head)) = (elm); \ 425 (elm)->field.le_prev = &LIST_FIRST((head)); \ 426 } while (0) 427 428 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 429 430 #define LIST_REMOVE(elm, field) do { \ 431 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 432 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 433 QMD_LIST_CHECK_NEXT(elm, field); \ 434 QMD_LIST_CHECK_PREV(elm, field); \ 435 if (LIST_NEXT((elm), field) != NULL) \ 436 LIST_NEXT((elm), field)->field.le_prev = \ 437 (elm)->field.le_prev; \ 438 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 439 TRASHIT(*oldnext); \ 440 TRASHIT(*oldprev); \ 441 } while (0) 442 443 #define LIST_SWAP(head1, head2, type, field) do { \ 444 struct type *swap_tmp = LIST_FIRST((head1)); \ 445 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 446 LIST_FIRST((head2)) = swap_tmp; \ 447 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 448 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 449 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 450 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 451 } while (0) 452 453 /* 454 * Tail queue declarations. 455 */ 456 #define TAILQ_HEAD(name, type) \ 457 struct name { \ 458 struct type *tqh_first; /* first element */ \ 459 struct type **tqh_last; /* addr of last next element */ \ 460 TRACEBUF \ 461 } 462 463 #define TAILQ_HEAD_INITIALIZER(head) \ 464 { NULL, &(head).tqh_first } 465 466 #define TAILQ_ENTRY(type) \ 467 struct { \ 468 struct type *tqe_next; /* next element */ \ 469 struct type **tqe_prev; /* address of previous next element */ \ 470 TRACEBUF \ 471 } 472 473 /* 474 * Tail queue functions. 475 */ 476 #if (defined(_KERNEL) && defined(INVARIANTS)) 477 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 478 if (!TAILQ_EMPTY(head) && \ 479 TAILQ_FIRST((head))->field.tqe_prev != \ 480 &TAILQ_FIRST((head))) \ 481 panic("Bad tailq head %p first->prev != head", (head)); \ 482 } while (0) 483 484 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 485 if (*(head)->tqh_last != NULL) \ 486 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 487 } while (0) 488 489 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 490 if (TAILQ_NEXT((elm), field) != NULL && \ 491 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 492 &((elm)->field.tqe_next)) \ 493 panic("Bad link elm %p next->prev != elm", (elm)); \ 494 } while (0) 495 496 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 497 if (*(elm)->field.tqe_prev != (elm)) \ 498 panic("Bad link elm %p prev->next != elm", (elm)); \ 499 } while (0) 500 #else 501 #define QMD_TAILQ_CHECK_HEAD(head, field) 502 #define QMD_TAILQ_CHECK_TAIL(head, headname) 503 #define QMD_TAILQ_CHECK_NEXT(elm, field) 504 #define QMD_TAILQ_CHECK_PREV(elm, field) 505 #endif /* (_KERNEL && INVARIANTS) */ 506 507 #define TAILQ_CONCAT(head1, head2, field) do { \ 508 if (!TAILQ_EMPTY(head2)) { \ 509 *(head1)->tqh_last = (head2)->tqh_first; \ 510 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 511 (head1)->tqh_last = (head2)->tqh_last; \ 512 TAILQ_INIT((head2)); \ 513 QMD_TRACE_HEAD(head1); \ 514 QMD_TRACE_HEAD(head2); \ 515 } \ 516 } while (0) 517 518 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 519 520 #define TAILQ_FIRST(head) ((head)->tqh_first) 521 522 #define TAILQ_FOREACH(var, head, field) \ 523 for ((var) = TAILQ_FIRST((head)); \ 524 (var); \ 525 (var) = TAILQ_NEXT((var), field)) 526 527 #define TAILQ_FOREACH_MUTABLE(var, head, field, tvar) \ 528 for ((var) = TAILQ_FIRST((head)); \ 529 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 530 (var) = (tvar)) 531 532 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 533 for ((var) = TAILQ_LAST((head), headname); \ 534 (var); \ 535 (var) = TAILQ_PREV((var), headname, field)) 536 537 #define TAILQ_FOREACH_REVERSE_MUTABLE(var, head, headname, field, tvar) \ 538 for ((var) = TAILQ_LAST((head), headname); \ 539 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 540 (var) = (tvar)) 541 542 #define TAILQ_INIT(head) do { \ 543 TAILQ_FIRST((head)) = NULL; \ 544 (head)->tqh_last = &TAILQ_FIRST((head)); \ 545 QMD_TRACE_HEAD(head); \ 546 } while (0) 547 548 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 549 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 550 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 551 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 552 &TAILQ_NEXT((elm), field); \ 553 else { \ 554 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 555 QMD_TRACE_HEAD(head); \ 556 } \ 557 TAILQ_NEXT((listelm), field) = (elm); \ 558 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 559 QMD_TRACE_ELEM(&(elm)->field); \ 560 QMD_TRACE_ELEM(&listelm->field); \ 561 } while (0) 562 563 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 564 QMD_TAILQ_CHECK_PREV(listelm, field); \ 565 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 566 TAILQ_NEXT((elm), field) = (listelm); \ 567 *(listelm)->field.tqe_prev = (elm); \ 568 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 569 QMD_TRACE_ELEM(&(elm)->field); \ 570 QMD_TRACE_ELEM(&listelm->field); \ 571 } while (0) 572 573 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 574 QMD_TAILQ_CHECK_HEAD(head, field); \ 575 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 576 TAILQ_FIRST((head))->field.tqe_prev = \ 577 &TAILQ_NEXT((elm), field); \ 578 else \ 579 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 580 TAILQ_FIRST((head)) = (elm); \ 581 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 582 QMD_TRACE_HEAD(head); \ 583 QMD_TRACE_ELEM(&(elm)->field); \ 584 } while (0) 585 586 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 587 QMD_TAILQ_CHECK_TAIL(head, field); \ 588 TAILQ_NEXT((elm), field) = NULL; \ 589 (elm)->field.tqe_prev = (head)->tqh_last; \ 590 *(head)->tqh_last = (elm); \ 591 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 592 QMD_TRACE_HEAD(head); \ 593 QMD_TRACE_ELEM(&(elm)->field); \ 594 } while (0) 595 596 #define TAILQ_LAST(head, headname) \ 597 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 598 599 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 600 601 #define TAILQ_PREV(elm, headname, field) \ 602 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 603 604 #define TAILQ_REMOVE(head, elm, field) do { \ 605 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 606 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 607 QMD_TAILQ_CHECK_NEXT(elm, field); \ 608 QMD_TAILQ_CHECK_PREV(elm, field); \ 609 if ((TAILQ_NEXT((elm), field)) != NULL) \ 610 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 611 (elm)->field.tqe_prev; \ 612 else { \ 613 (head)->tqh_last = (elm)->field.tqe_prev; \ 614 QMD_TRACE_HEAD(head); \ 615 } \ 616 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 617 TRASHIT(*oldnext); \ 618 TRASHIT(*oldprev); \ 619 QMD_TRACE_ELEM(&(elm)->field); \ 620 } while (0) 621 622 #define TAILQ_SWAP(head1, head2, type, field) do { \ 623 struct type *swap_first = (head1)->tqh_first; \ 624 struct type **swap_last = (head1)->tqh_last; \ 625 (head1)->tqh_first = (head2)->tqh_first; \ 626 (head1)->tqh_last = (head2)->tqh_last; \ 627 (head2)->tqh_first = swap_first; \ 628 (head2)->tqh_last = swap_last; \ 629 if ((swap_first = (head1)->tqh_first) != NULL) \ 630 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 631 else \ 632 (head1)->tqh_last = &(head1)->tqh_first; \ 633 if ((swap_first = (head2)->tqh_first) != NULL) \ 634 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 635 else \ 636 (head2)->tqh_last = &(head2)->tqh_first; \ 637 } while (0) 638 639 #endif /* !_SYS_QUEUE_H_ */ 640