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 * 3. 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_FROM + + + + 92 * _FOREACH_MUTABLE + + + + 93 * _FOREACH_FROM_MUTABLE + + + + 94 * _FOREACH_REVERSE - - - + 95 * _FOREACH_REVERSE_MUTABLE - - - + 96 * _INSERT_HEAD + + + + 97 * _INSERT_BEFORE - + - + 98 * _INSERT_AFTER + + + + 99 * _INSERT_TAIL - - + + 100 * _CONCAT - - + + 101 * _REMOVE_AFTER + - + - 102 * _REMOVE_HEAD + - + - 103 * _REMOVE + + + + 104 * _SWAP + + + + 105 * 106 */ 107 #ifdef QUEUE_MACRO_DEBUG 108 /* Store the last 2 places the queue element or head was altered */ 109 struct qm_trace { 110 char *lastfile; 111 int lastline; 112 char *prevfile; 113 int prevline; 114 }; 115 116 #define TRACEBUF struct qm_trace trace; 117 #define TRASHIT(x) do {(x) = (void *)-1;} while (0) 118 #define QMD_SAVELINK(name, link) void **name = (void *)&(link) 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 QMD_SAVELINK(name, link) 138 #define TRACEBUF 139 #define TRASHIT(x) 140 #endif /* QUEUE_MACRO_DEBUG */ 141 142 /* 143 * Singly-linked List declarations. 144 */ 145 #define SLIST_HEAD(name, type) \ 146 struct name { \ 147 struct type *slh_first; /* first element */ \ 148 } 149 150 #define SLIST_HEAD_INITIALIZER(head) \ 151 { NULL } 152 153 #define SLIST_ENTRY(type) \ 154 struct { \ 155 struct type *sle_next; /* next element */ \ 156 } 157 158 #define SLIST_ENTRY_INITIALIZER { NULL } 159 160 /* 161 * Singly-linked List functions. 162 */ 163 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 164 165 #define SLIST_FIRST(head) ((head)->slh_first) 166 167 #define SLIST_FOREACH(var, head, field) \ 168 for ((var) = SLIST_FIRST((head)); \ 169 (var); \ 170 (var) = SLIST_NEXT((var), field)) 171 172 #define SLIST_FOREACH_FROM(var, head, field) \ 173 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 174 (var); \ 175 (var) = SLIST_NEXT((var), field)) 176 177 #define SLIST_FOREACH_MUTABLE(var, head, field, tvar) \ 178 for ((var) = SLIST_FIRST((head)); \ 179 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 180 (var) = (tvar)) 181 182 #define SLIST_FOREACH_FROM_MUTABLE(var, head, field, tvar) \ 183 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 184 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 185 (var) = (tvar)) 186 187 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 188 for ((varp) = &SLIST_FIRST((head)); \ 189 ((var) = *(varp)) != NULL; \ 190 (varp) = &SLIST_NEXT((var), field)) 191 192 #define SLIST_INIT(head) do { \ 193 SLIST_FIRST((head)) = NULL; \ 194 } while (0) 195 196 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 197 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 198 SLIST_NEXT((slistelm), field) = (elm); \ 199 } while (0) 200 201 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 202 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 203 SLIST_FIRST((head)) = (elm); \ 204 } while (0) 205 206 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 207 208 #define SLIST_REMOVE(head, elm, type, field) do { \ 209 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \ 210 if (SLIST_FIRST((head)) == (elm)) { \ 211 SLIST_REMOVE_HEAD((head), field); \ 212 } \ 213 else { \ 214 struct type *curelm = SLIST_FIRST((head)); \ 215 while (SLIST_NEXT(curelm, field) != (elm)) \ 216 curelm = SLIST_NEXT(curelm, field); \ 217 SLIST_REMOVE_AFTER(curelm, field); \ 218 } \ 219 TRASHIT(*oldnext); \ 220 } while (0) 221 222 #define SLIST_REMOVE_AFTER(elm, field) do { \ 223 SLIST_NEXT(elm, field) = \ 224 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 225 } while (0) 226 227 #define SLIST_REMOVE_HEAD(head, field) do { \ 228 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 229 } while (0) 230 231 #define SLIST_SWAP(head1, head2, type) do { \ 232 struct type *swap_first = SLIST_FIRST(head1); \ 233 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 234 SLIST_FIRST(head2) = swap_first; \ 235 } while (0) 236 237 /* 238 * Singly-linked Tail queue declarations. 239 */ 240 #define STAILQ_HEAD(name, type) \ 241 struct name { \ 242 struct type *stqh_first;/* first element */ \ 243 struct type **stqh_last;/* addr of last next element */ \ 244 } 245 246 #define STAILQ_HEAD_INITIALIZER(head) \ 247 { NULL, &(head).stqh_first } 248 249 #define STAILQ_ENTRY(type) \ 250 struct { \ 251 struct type *stqe_next; /* next element */ \ 252 } 253 254 /* 255 * Singly-linked Tail queue functions. 256 */ 257 #define STAILQ_CONCAT(head1, head2) do { \ 258 if (!STAILQ_EMPTY((head2))) { \ 259 *(head1)->stqh_last = (head2)->stqh_first; \ 260 (head1)->stqh_last = (head2)->stqh_last; \ 261 STAILQ_INIT((head2)); \ 262 } \ 263 } while (0) 264 265 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 266 267 #define STAILQ_FIRST(head) ((head)->stqh_first) 268 269 #define STAILQ_FOREACH(var, head, field) \ 270 for((var) = STAILQ_FIRST((head)); \ 271 (var); \ 272 (var) = STAILQ_NEXT((var), field)) 273 274 #define STAILQ_FOREACH_FROM(var, head, field) \ 275 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 276 (var); \ 277 (var) = STAILQ_NEXT((var), field)) 278 279 #define STAILQ_FOREACH_MUTABLE(var, head, field, tvar) \ 280 for ((var) = STAILQ_FIRST((head)); \ 281 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 282 (var) = (tvar)) 283 284 #define STAILQ_FOREACH_FROM_MUTABLE(var, head, field, tvar) \ 285 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 286 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 287 (var) = (tvar)) 288 289 #define STAILQ_INIT(head) do { \ 290 STAILQ_FIRST((head)) = NULL; \ 291 (head)->stqh_last = &STAILQ_FIRST((head)); \ 292 } while (0) 293 294 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 295 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 296 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 297 STAILQ_NEXT((tqelm), field) = (elm); \ 298 } while (0) 299 300 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 301 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 302 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 303 STAILQ_FIRST((head)) = (elm); \ 304 } while (0) 305 306 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 307 STAILQ_NEXT((elm), field) = NULL; \ 308 *(head)->stqh_last = (elm); \ 309 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 310 } while (0) 311 312 #define STAILQ_LAST(head, type, field) \ 313 (STAILQ_EMPTY((head)) ? \ 314 NULL : \ 315 __containerof((head)->stqh_last, struct type, field.stqe_next)) 316 317 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 318 319 #define STAILQ_REMOVE(head, elm, type, field) do { \ 320 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 321 if (STAILQ_FIRST((head)) == (elm)) { \ 322 STAILQ_REMOVE_HEAD((head), field); \ 323 } \ 324 else { \ 325 struct type *curelm = STAILQ_FIRST((head)); \ 326 while (STAILQ_NEXT(curelm, field) != (elm)) \ 327 curelm = STAILQ_NEXT(curelm, field); \ 328 STAILQ_REMOVE_AFTER(head, curelm, field); \ 329 } \ 330 TRASHIT(*oldnext); \ 331 } while (0) 332 333 #define STAILQ_REMOVE_HEAD(head, field) do { \ 334 if ((STAILQ_FIRST((head)) = \ 335 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 336 (head)->stqh_last = &STAILQ_FIRST((head)); \ 337 } while (0) 338 339 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 340 if ((STAILQ_NEXT(elm, field) = \ 341 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 342 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 343 } while (0) 344 345 #define STAILQ_SWAP(head1, head2, type) do { \ 346 struct type *swap_first = STAILQ_FIRST(head1); \ 347 struct type **swap_last = (head1)->stqh_last; \ 348 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 349 (head1)->stqh_last = (head2)->stqh_last; \ 350 STAILQ_FIRST(head2) = swap_first; \ 351 (head2)->stqh_last = swap_last; \ 352 if (STAILQ_EMPTY(head1)) \ 353 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 354 if (STAILQ_EMPTY(head2)) \ 355 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 356 } while (0) 357 358 359 /* 360 * List declarations. 361 */ 362 #define LIST_HEAD(name, type) \ 363 struct name { \ 364 struct type *lh_first; /* first element */ \ 365 } 366 367 #define LIST_HEAD_INITIALIZER(head) \ 368 { NULL } 369 370 #define LIST_ENTRY(type) \ 371 struct { \ 372 struct type *le_next; /* next element */ \ 373 struct type **le_prev; /* address of previous next element */ \ 374 } 375 376 /* 377 * List functions. 378 */ 379 380 #if (defined(_KERNEL) && defined(INVARIANTS)) 381 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 382 if (LIST_FIRST((head)) != NULL && \ 383 LIST_FIRST((head))->field.le_prev != \ 384 &LIST_FIRST((head))) \ 385 panic("Bad list head %p first->prev != head", (head)); \ 386 } while (0) 387 388 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 389 if (LIST_NEXT((elm), field) != NULL && \ 390 LIST_NEXT((elm), field)->field.le_prev != \ 391 &((elm)->field.le_next)) \ 392 panic("Bad link elm %p next->prev != elm", (elm)); \ 393 } while (0) 394 395 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 396 if (*(elm)->field.le_prev != (elm)) \ 397 panic("Bad link elm %p prev->next != elm", (elm)); \ 398 } while (0) 399 #else 400 #define QMD_LIST_CHECK_HEAD(head, field) 401 #define QMD_LIST_CHECK_NEXT(elm, field) 402 #define QMD_LIST_CHECK_PREV(elm, field) 403 #endif /* (_KERNEL && INVARIANTS) */ 404 405 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 406 407 #define LIST_FIRST(head) ((head)->lh_first) 408 409 #define LIST_FOREACH(var, head, field) \ 410 for ((var) = LIST_FIRST((head)); \ 411 (var); \ 412 (var) = LIST_NEXT((var), field)) 413 414 #define LIST_FOREACH_FROM(var, head, field) \ 415 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 416 (var); \ 417 (var) = LIST_NEXT((var), field)) 418 419 #define LIST_FOREACH_MUTABLE(var, head, field, tvar) \ 420 for ((var) = LIST_FIRST((head)); \ 421 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 422 (var) = (tvar)) 423 424 #define LIST_FOREACH_FROM_MUTABLE(var, head, field, tvar) \ 425 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 426 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 427 (var) = (tvar)) 428 429 #define LIST_INIT(head) do { \ 430 LIST_FIRST((head)) = NULL; \ 431 } while (0) 432 433 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 434 QMD_LIST_CHECK_NEXT(listelm, field); \ 435 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 436 LIST_NEXT((listelm), field)->field.le_prev = \ 437 &LIST_NEXT((elm), field); \ 438 LIST_NEXT((listelm), field) = (elm); \ 439 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 440 } while (0) 441 442 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 443 QMD_LIST_CHECK_PREV(listelm, field); \ 444 (elm)->field.le_prev = (listelm)->field.le_prev; \ 445 LIST_NEXT((elm), field) = (listelm); \ 446 *(listelm)->field.le_prev = (elm); \ 447 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 448 } while (0) 449 450 #define LIST_INSERT_HEAD(head, elm, field) do { \ 451 QMD_LIST_CHECK_HEAD((head), field); \ 452 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 453 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 454 LIST_FIRST((head)) = (elm); \ 455 (elm)->field.le_prev = &LIST_FIRST((head)); \ 456 } while (0) 457 458 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 459 460 #define LIST_REMOVE(elm, field) do { \ 461 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 462 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 463 QMD_LIST_CHECK_NEXT(elm, field); \ 464 QMD_LIST_CHECK_PREV(elm, field); \ 465 if (LIST_NEXT((elm), field) != NULL) \ 466 LIST_NEXT((elm), field)->field.le_prev = \ 467 (elm)->field.le_prev; \ 468 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 469 TRASHIT(*oldnext); \ 470 TRASHIT(*oldprev); \ 471 } while (0) 472 473 #define LIST_SWAP(head1, head2, type, field) do { \ 474 struct type *swap_tmp = LIST_FIRST((head1)); \ 475 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 476 LIST_FIRST((head2)) = swap_tmp; \ 477 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 478 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 479 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 480 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 481 } while (0) 482 483 /* 484 * Tail queue declarations. 485 */ 486 #define TAILQ_HEAD(name, type) \ 487 struct name { \ 488 struct type *tqh_first; /* first element */ \ 489 struct type **tqh_last; /* addr of last next element */ \ 490 TRACEBUF \ 491 } 492 493 #define TAILQ_HEAD_INITIALIZER(head) \ 494 { NULL, &(head).tqh_first } 495 496 #define TAILQ_ENTRY(type) \ 497 struct { \ 498 struct type *tqe_next; /* next element */ \ 499 struct type **tqe_prev; /* address of previous next element */ \ 500 TRACEBUF \ 501 } 502 503 /* 504 * Tail queue functions. 505 */ 506 #if (defined(_KERNEL) && defined(INVARIANTS)) 507 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 508 if (!TAILQ_EMPTY(head) && \ 509 TAILQ_FIRST((head))->field.tqe_prev != \ 510 &TAILQ_FIRST((head))) \ 511 panic("Bad tailq head %p first->prev != head", (head)); \ 512 } while (0) 513 514 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 515 if (*(head)->tqh_last != NULL) { \ 516 panic("Bad tailq NEXT(%p->tqh_last) != NULL, last %p", \ 517 (head), *(head)->tqh_last); \ 518 } \ 519 } while (0) 520 521 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 522 if (TAILQ_NEXT((elm), field) != NULL && \ 523 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 524 &((elm)->field.tqe_next)) \ 525 panic("Bad link elm %p next->prev != elm", (elm)); \ 526 } while (0) 527 528 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 529 if (*(elm)->field.tqe_prev != (elm)) \ 530 panic("Bad link elm %p prev->next != elm", (elm)); \ 531 } while (0) 532 #else 533 #define QMD_TAILQ_CHECK_HEAD(head, field) 534 #define QMD_TAILQ_CHECK_TAIL(head, headname) 535 #define QMD_TAILQ_CHECK_NEXT(elm, field) 536 #define QMD_TAILQ_CHECK_PREV(elm, field) 537 #endif /* (_KERNEL && INVARIANTS) */ 538 539 #define TAILQ_CONCAT(head1, head2, field) do { \ 540 if (!TAILQ_EMPTY(head2)) { \ 541 *(head1)->tqh_last = (head2)->tqh_first; \ 542 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 543 (head1)->tqh_last = (head2)->tqh_last; \ 544 TAILQ_INIT((head2)); \ 545 QMD_TRACE_HEAD(head1); \ 546 QMD_TRACE_HEAD(head2); \ 547 } \ 548 } while (0) 549 550 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 551 552 #define TAILQ_FIRST(head) ((head)->tqh_first) 553 554 #define TAILQ_FOREACH(var, head, field) \ 555 for ((var) = TAILQ_FIRST((head)); \ 556 (var); \ 557 (var) = TAILQ_NEXT((var), field)) 558 559 #define TAILQ_FOREACH_FROM(var, head, field) \ 560 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 561 (var); \ 562 (var) = TAILQ_NEXT((var), field)) 563 564 #define TAILQ_FOREACH_MUTABLE(var, head, field, tvar) \ 565 for ((var) = TAILQ_FIRST((head)); \ 566 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 567 (var) = (tvar)) 568 569 #define TAILQ_FOREACH_FROM_MUTABLE(var, head, field, tvar) \ 570 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 571 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 572 (var) = (tvar)) 573 574 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 575 for ((var) = TAILQ_LAST((head), headname); \ 576 (var); \ 577 (var) = TAILQ_PREV((var), headname, field)) 578 579 #define TAILQ_FOREACH_REVERSE_MUTABLE(var, head, headname, field, tvar) \ 580 for ((var) = TAILQ_LAST((head), headname); \ 581 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 582 (var) = (tvar)) 583 584 #define TAILQ_INIT(head) do { \ 585 TAILQ_FIRST((head)) = NULL; \ 586 (head)->tqh_last = &TAILQ_FIRST((head)); \ 587 QMD_TRACE_HEAD(head); \ 588 } while (0) 589 590 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 591 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 592 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 593 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 594 &TAILQ_NEXT((elm), field); \ 595 else { \ 596 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 597 QMD_TRACE_HEAD(head); \ 598 } \ 599 TAILQ_NEXT((listelm), field) = (elm); \ 600 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 601 QMD_TRACE_ELEM(&(elm)->field); \ 602 QMD_TRACE_ELEM(&listelm->field); \ 603 } while (0) 604 605 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 606 QMD_TAILQ_CHECK_PREV(listelm, field); \ 607 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 608 TAILQ_NEXT((elm), field) = (listelm); \ 609 *(listelm)->field.tqe_prev = (elm); \ 610 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 611 QMD_TRACE_ELEM(&(elm)->field); \ 612 QMD_TRACE_ELEM(&listelm->field); \ 613 } while (0) 614 615 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 616 QMD_TAILQ_CHECK_HEAD(head, field); \ 617 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 618 TAILQ_FIRST((head))->field.tqe_prev = \ 619 &TAILQ_NEXT((elm), field); \ 620 else \ 621 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 622 TAILQ_FIRST((head)) = (elm); \ 623 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 624 QMD_TRACE_HEAD(head); \ 625 QMD_TRACE_ELEM(&(elm)->field); \ 626 } while (0) 627 628 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 629 QMD_TAILQ_CHECK_TAIL(head, field); \ 630 TAILQ_NEXT((elm), field) = NULL; \ 631 (elm)->field.tqe_prev = (head)->tqh_last; \ 632 *(head)->tqh_last = (elm); \ 633 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 634 QMD_TRACE_HEAD(head); \ 635 QMD_TRACE_ELEM(&(elm)->field); \ 636 } while (0) 637 638 #define TAILQ_LAST(head, headname) \ 639 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 640 641 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 642 643 #define TAILQ_PREV(elm, headname, field) \ 644 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 645 646 #define TAILQ_REMOVE(head, elm, field) do { \ 647 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 648 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 649 QMD_TAILQ_CHECK_NEXT(elm, field); \ 650 QMD_TAILQ_CHECK_PREV(elm, field); \ 651 if ((TAILQ_NEXT((elm), field)) != NULL) \ 652 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 653 (elm)->field.tqe_prev; \ 654 else { \ 655 (head)->tqh_last = (elm)->field.tqe_prev; \ 656 QMD_TRACE_HEAD(head); \ 657 } \ 658 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 659 TRASHIT(*oldnext); \ 660 TRASHIT(*oldprev); \ 661 QMD_TRACE_ELEM(&(elm)->field); \ 662 } while (0) 663 664 #define TAILQ_SWAP(head1, head2, type, field) do { \ 665 struct type *swap_first = (head1)->tqh_first; \ 666 struct type **swap_last = (head1)->tqh_last; \ 667 (head1)->tqh_first = (head2)->tqh_first; \ 668 (head1)->tqh_last = (head2)->tqh_last; \ 669 (head2)->tqh_first = swap_first; \ 670 (head2)->tqh_last = swap_last; \ 671 if ((swap_first = (head1)->tqh_first) != NULL) \ 672 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 673 else \ 674 (head1)->tqh_last = &(head1)->tqh_first; \ 675 if ((swap_first = (head2)->tqh_first) != NULL) \ 676 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 677 else \ 678 (head2)->tqh_last = &(head2)->tqh_first; \ 679 } while (0) 680 681 #endif /* !_SYS_QUEUE_H_ */ 682