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 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_AFTER + - + - 100 * _REMOVE_HEAD + - + - 101 * _REMOVE + + + + 102 * 103 */ 104 #ifdef QUEUE_MACRO_DEBUG 105 /* Store the last 2 places the queue element or head was altered */ 106 struct 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 #define QMD_SAVELINK(name, link) void **name = (void *)&(link) 116 117 #define QMD_TRACE_HEAD(head) do { \ 118 (head)->trace.prevline = (head)->trace.lastline; \ 119 (head)->trace.prevfile = (head)->trace.lastfile; \ 120 (head)->trace.lastline = __LINE__; \ 121 (head)->trace.lastfile = __FILE__; \ 122 } while (0) 123 124 #define QMD_TRACE_ELEM(elem) do { \ 125 (elem)->trace.prevline = (elem)->trace.lastline; \ 126 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 127 (elem)->trace.lastline = __LINE__; \ 128 (elem)->trace.lastfile = __FILE__; \ 129 } while (0) 130 131 #else 132 #define QMD_TRACE_ELEM(elem) 133 #define QMD_TRACE_HEAD(head) 134 #define QMD_SAVELINK(name, link) 135 #define TRACEBUF 136 #define TRASHIT(x) 137 #endif /* QUEUE_MACRO_DEBUG */ 138 139 /* 140 * Singly-linked List declarations. 141 */ 142 #define SLIST_HEAD(name, type) \ 143 struct name { \ 144 struct type *slh_first; /* first element */ \ 145 } 146 147 #define SLIST_HEAD_INITIALIZER(head) \ 148 { NULL } 149 150 #define SLIST_ENTRY(type) \ 151 struct { \ 152 struct type *sle_next; /* next element */ \ 153 } 154 155 /* 156 * Singly-linked List functions. 157 */ 158 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 159 160 #define SLIST_FIRST(head) ((head)->slh_first) 161 162 #define SLIST_FOREACH(var, head, field) \ 163 for ((var) = SLIST_FIRST((head)); \ 164 (var); \ 165 (var) = SLIST_NEXT((var), field)) 166 167 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 168 for ((var) = SLIST_FIRST((head)); \ 169 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 170 (var) = (tvar)) 171 172 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 173 for ((varp) = &SLIST_FIRST((head)); \ 174 ((var) = *(varp)) != NULL; \ 175 (varp) = &SLIST_NEXT((var), field)) 176 177 #define SLIST_INIT(head) do { \ 178 SLIST_FIRST((head)) = NULL; \ 179 } while (0) 180 181 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 182 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 183 SLIST_NEXT((slistelm), field) = (elm); \ 184 } while (0) 185 186 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 187 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 188 SLIST_FIRST((head)) = (elm); \ 189 } while (0) 190 191 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 192 193 #define SLIST_REMOVE(head, elm, type, field) do { \ 194 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \ 195 if (SLIST_FIRST((head)) == (elm)) { \ 196 SLIST_REMOVE_HEAD((head), field); \ 197 } \ 198 else { \ 199 struct type *curelm = SLIST_FIRST((head)); \ 200 while (SLIST_NEXT(curelm, field) != (elm)) \ 201 curelm = SLIST_NEXT(curelm, field); \ 202 SLIST_REMOVE_AFTER(curelm, field); \ 203 } \ 204 TRASHIT(*oldnext); \ 205 } while (0) 206 207 #define SLIST_REMOVE_AFTER(elm, field) do { \ 208 SLIST_NEXT(elm, field) = \ 209 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 210 } while (0) 211 212 #define SLIST_REMOVE_HEAD(head, field) do { \ 213 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 214 } while (0) 215 216 #define SLIST_SWAP(head1, head2, type) do { \ 217 struct type *swap_first = SLIST_FIRST(head1); \ 218 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 219 SLIST_FIRST(head2) = swap_first; \ 220 } while (0) 221 222 /* 223 * Singly-linked Tail queue declarations. 224 */ 225 #define STAILQ_HEAD(name, type) \ 226 struct name { \ 227 struct type *stqh_first;/* first element */ \ 228 struct type **stqh_last;/* addr of last next element */ \ 229 } 230 231 #define STAILQ_HEAD_INITIALIZER(head) \ 232 { NULL, &(head).stqh_first } 233 234 #define STAILQ_ENTRY(type) \ 235 struct { \ 236 struct type *stqe_next; /* next element */ \ 237 } 238 239 /* 240 * Singly-linked Tail queue functions. 241 */ 242 #define STAILQ_CONCAT(head1, head2) do { \ 243 if (!STAILQ_EMPTY((head2))) { \ 244 *(head1)->stqh_last = (head2)->stqh_first; \ 245 (head1)->stqh_last = (head2)->stqh_last; \ 246 STAILQ_INIT((head2)); \ 247 } \ 248 } while (0) 249 250 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 251 252 #define STAILQ_FIRST(head) ((head)->stqh_first) 253 254 #define STAILQ_FOREACH(var, head, field) \ 255 for((var) = STAILQ_FIRST((head)); \ 256 (var); \ 257 (var) = STAILQ_NEXT((var), field)) 258 259 260 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 261 for ((var) = STAILQ_FIRST((head)); \ 262 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 263 (var) = (tvar)) 264 265 #define STAILQ_INIT(head) do { \ 266 STAILQ_FIRST((head)) = NULL; \ 267 (head)->stqh_last = &STAILQ_FIRST((head)); \ 268 } while (0) 269 270 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 271 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 272 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 273 STAILQ_NEXT((tqelm), field) = (elm); \ 274 } while (0) 275 276 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 277 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 278 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 279 STAILQ_FIRST((head)) = (elm); \ 280 } while (0) 281 282 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 283 STAILQ_NEXT((elm), field) = NULL; \ 284 *(head)->stqh_last = (elm); \ 285 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 286 } while (0) 287 288 #define STAILQ_LAST(head, type, field) \ 289 (STAILQ_EMPTY((head)) ? \ 290 NULL : \ 291 ((struct type *)(void *) \ 292 ((char *)((head)->stqh_last) - __offsetof(struct type, field)))) 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_HEAD(head, field) do { \ 311 if ((STAILQ_FIRST((head)) = \ 312 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 313 (head)->stqh_last = &STAILQ_FIRST((head)); \ 314 } while (0) 315 316 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 317 if ((STAILQ_NEXT(elm, field) = \ 318 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 319 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 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_REMOVE(elm, field) do { \ 428 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 429 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 430 QMD_LIST_CHECK_NEXT(elm, field); \ 431 QMD_LIST_CHECK_PREV(elm, field); \ 432 if (LIST_NEXT((elm), field) != NULL) \ 433 LIST_NEXT((elm), field)->field.le_prev = \ 434 (elm)->field.le_prev; \ 435 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 436 TRASHIT(*oldnext); \ 437 TRASHIT(*oldprev); \ 438 } while (0) 439 440 #define LIST_SWAP(head1, head2, type, field) do { \ 441 struct type *swap_tmp = LIST_FIRST((head1)); \ 442 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 443 LIST_FIRST((head2)) = swap_tmp; \ 444 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 445 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 446 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 447 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 448 } while (0) 449 450 /* 451 * Tail queue declarations. 452 */ 453 #define TAILQ_HEAD(name, type) \ 454 struct name { \ 455 struct type *tqh_first; /* first element */ \ 456 struct type **tqh_last; /* addr of last next element */ \ 457 TRACEBUF \ 458 } 459 460 #define TAILQ_HEAD_INITIALIZER(head) \ 461 { NULL, &(head).tqh_first } 462 463 #define TAILQ_ENTRY(type) \ 464 struct { \ 465 struct type *tqe_next; /* next element */ \ 466 struct type **tqe_prev; /* address of previous next element */ \ 467 TRACEBUF \ 468 } 469 470 /* 471 * Tail queue functions. 472 */ 473 #if (defined(_KERNEL) && defined(INVARIANTS)) 474 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 475 if (!TAILQ_EMPTY(head) && \ 476 TAILQ_FIRST((head))->field.tqe_prev != \ 477 &TAILQ_FIRST((head))) \ 478 panic("Bad tailq head %p first->prev != head", (head)); \ 479 } while (0) 480 481 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 482 if (*(head)->tqh_last != NULL) \ 483 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 484 } while (0) 485 486 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 487 if (TAILQ_NEXT((elm), field) != NULL && \ 488 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 489 &((elm)->field.tqe_next)) \ 490 panic("Bad link elm %p next->prev != elm", (elm)); \ 491 } while (0) 492 493 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 494 if (*(elm)->field.tqe_prev != (elm)) \ 495 panic("Bad link elm %p prev->next != elm", (elm)); \ 496 } while (0) 497 #else 498 #define QMD_TAILQ_CHECK_HEAD(head, field) 499 #define QMD_TAILQ_CHECK_TAIL(head, headname) 500 #define QMD_TAILQ_CHECK_NEXT(elm, field) 501 #define QMD_TAILQ_CHECK_PREV(elm, field) 502 #endif /* (_KERNEL && INVARIANTS) */ 503 504 #define TAILQ_CONCAT(head1, head2, field) do { \ 505 if (!TAILQ_EMPTY(head2)) { \ 506 *(head1)->tqh_last = (head2)->tqh_first; \ 507 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 508 (head1)->tqh_last = (head2)->tqh_last; \ 509 TAILQ_INIT((head2)); \ 510 QMD_TRACE_HEAD(head1); \ 511 QMD_TRACE_HEAD(head2); \ 512 } \ 513 } while (0) 514 515 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 516 517 #define TAILQ_FIRST(head) ((head)->tqh_first) 518 519 #define TAILQ_FOREACH(var, head, field) \ 520 for ((var) = TAILQ_FIRST((head)); \ 521 (var); \ 522 (var) = TAILQ_NEXT((var), field)) 523 524 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 525 for ((var) = TAILQ_FIRST((head)); \ 526 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 527 (var) = (tvar)) 528 529 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 530 for ((var) = TAILQ_LAST((head), headname); \ 531 (var); \ 532 (var) = TAILQ_PREV((var), headname, field)) 533 534 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 535 for ((var) = TAILQ_LAST((head), headname); \ 536 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 537 (var) = (tvar)) 538 539 #define TAILQ_INIT(head) do { \ 540 TAILQ_FIRST((head)) = NULL; \ 541 (head)->tqh_last = &TAILQ_FIRST((head)); \ 542 QMD_TRACE_HEAD(head); \ 543 } while (0) 544 545 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 546 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 547 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 548 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 549 &TAILQ_NEXT((elm), field); \ 550 else { \ 551 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 552 QMD_TRACE_HEAD(head); \ 553 } \ 554 TAILQ_NEXT((listelm), field) = (elm); \ 555 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 556 QMD_TRACE_ELEM(&(elm)->field); \ 557 QMD_TRACE_ELEM(&listelm->field); \ 558 } while (0) 559 560 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 561 QMD_TAILQ_CHECK_PREV(listelm, field); \ 562 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 563 TAILQ_NEXT((elm), field) = (listelm); \ 564 *(listelm)->field.tqe_prev = (elm); \ 565 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 566 QMD_TRACE_ELEM(&(elm)->field); \ 567 QMD_TRACE_ELEM(&listelm->field); \ 568 } while (0) 569 570 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 571 QMD_TAILQ_CHECK_HEAD(head, field); \ 572 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 573 TAILQ_FIRST((head))->field.tqe_prev = \ 574 &TAILQ_NEXT((elm), field); \ 575 else \ 576 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 577 TAILQ_FIRST((head)) = (elm); \ 578 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 579 QMD_TRACE_HEAD(head); \ 580 QMD_TRACE_ELEM(&(elm)->field); \ 581 } while (0) 582 583 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 584 QMD_TAILQ_CHECK_TAIL(head, field); \ 585 TAILQ_NEXT((elm), field) = NULL; \ 586 (elm)->field.tqe_prev = (head)->tqh_last; \ 587 *(head)->tqh_last = (elm); \ 588 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 589 QMD_TRACE_HEAD(head); \ 590 QMD_TRACE_ELEM(&(elm)->field); \ 591 } while (0) 592 593 #define TAILQ_LAST(head, headname) \ 594 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 595 596 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 597 598 #define TAILQ_PREV(elm, headname, field) \ 599 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 600 601 #define TAILQ_REMOVE(head, elm, field) do { \ 602 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 603 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 604 QMD_TAILQ_CHECK_NEXT(elm, field); \ 605 QMD_TAILQ_CHECK_PREV(elm, field); \ 606 if ((TAILQ_NEXT((elm), field)) != NULL) \ 607 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 608 (elm)->field.tqe_prev; \ 609 else { \ 610 (head)->tqh_last = (elm)->field.tqe_prev; \ 611 QMD_TRACE_HEAD(head); \ 612 } \ 613 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 614 TRASHIT(*oldnext); \ 615 TRASHIT(*oldprev); \ 616 QMD_TRACE_ELEM(&(elm)->field); \ 617 } while (0) 618 619 #define TAILQ_SWAP(head1, head2, type, field) do { \ 620 struct type *swap_first = (head1)->tqh_first; \ 621 struct type **swap_last = (head1)->tqh_last; \ 622 (head1)->tqh_first = (head2)->tqh_first; \ 623 (head1)->tqh_last = (head2)->tqh_last; \ 624 (head2)->tqh_first = swap_first; \ 625 (head2)->tqh_last = swap_last; \ 626 if ((swap_first = (head1)->tqh_first) != NULL) \ 627 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 628 else \ 629 (head1)->tqh_last = &(head1)->tqh_first; \ 630 if ((swap_first = (head2)->tqh_first) != NULL) \ 631 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 632 else \ 633 (head2)->tqh_last = &(head2)->tqh_first; \ 634 } while (0) 635 636 #endif /* !_SYS_QUEUE_H_ */ 637