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_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 */ 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) 115 116 #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) \ 141 struct name { \ 142 struct type *slh_first; /* first element */ \ 143 } 144 145 #define SLIST_HEAD_INITIALIZER(head) \ 146 { NULL } 147 148 #define SLIST_ENTRY(type) \ 149 struct { \ 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) \ 217 struct 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) \ 226 struct { \ 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 /* 313 * List declarations. 314 */ 315 #define LIST_HEAD(name, type) \ 316 struct name { \ 317 struct type *lh_first; /* first element */ \ 318 } 319 320 #define LIST_HEAD_INITIALIZER(head) \ 321 { NULL } 322 323 #define LIST_ENTRY(type) \ 324 struct { \ 325 struct type *le_next; /* next element */ \ 326 struct type **le_prev; /* address of previous next element */ \ 327 } 328 329 /* 330 * List functions. 331 */ 332 333 #if (defined(_KERNEL) && defined(INVARIANTS)) 334 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 335 if (LIST_FIRST((head)) != NULL && \ 336 LIST_FIRST((head))->field.le_prev != \ 337 &LIST_FIRST((head))) \ 338 panic("Bad list head %p first->prev != head", (head)); \ 339 } while (0) 340 341 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 342 if (LIST_NEXT((elm), field) != NULL && \ 343 LIST_NEXT((elm), field)->field.le_prev != \ 344 &((elm)->field.le_next)) \ 345 panic("Bad link elm %p next->prev != elm", (elm)); \ 346 } while (0) 347 348 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 349 if (*(elm)->field.le_prev != (elm)) \ 350 panic("Bad link elm %p prev->next != elm", (elm)); \ 351 } while (0) 352 #else 353 #define QMD_LIST_CHECK_HEAD(head, field) 354 #define QMD_LIST_CHECK_NEXT(elm, field) 355 #define QMD_LIST_CHECK_PREV(elm, field) 356 #endif /* (_KERNEL && INVARIANTS) */ 357 358 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 359 360 #define LIST_FIRST(head) ((head)->lh_first) 361 362 #define LIST_FOREACH(var, head, field) \ 363 for ((var) = LIST_FIRST((head)); \ 364 (var); \ 365 (var) = LIST_NEXT((var), field)) 366 367 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 368 for ((var) = LIST_FIRST((head)); \ 369 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 370 (var) = (tvar)) 371 372 #define LIST_INIT(head) do { \ 373 LIST_FIRST((head)) = NULL; \ 374 } while (0) 375 376 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 377 QMD_LIST_CHECK_NEXT(listelm, field); \ 378 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 379 LIST_NEXT((listelm), field)->field.le_prev = \ 380 &LIST_NEXT((elm), field); \ 381 LIST_NEXT((listelm), field) = (elm); \ 382 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 383 } while (0) 384 385 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 386 QMD_LIST_CHECK_PREV(listelm, field); \ 387 (elm)->field.le_prev = (listelm)->field.le_prev; \ 388 LIST_NEXT((elm), field) = (listelm); \ 389 *(listelm)->field.le_prev = (elm); \ 390 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 391 } while (0) 392 393 #define LIST_INSERT_HEAD(head, elm, field) do { \ 394 QMD_LIST_CHECK_HEAD((head), field); \ 395 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 396 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 397 LIST_FIRST((head)) = (elm); \ 398 (elm)->field.le_prev = &LIST_FIRST((head)); \ 399 } while (0) 400 401 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 402 403 #define LIST_REMOVE(elm, field) do { \ 404 QMD_LIST_CHECK_NEXT(elm, field); \ 405 QMD_LIST_CHECK_PREV(elm, field); \ 406 if (LIST_NEXT((elm), field) != NULL) \ 407 LIST_NEXT((elm), field)->field.le_prev = \ 408 (elm)->field.le_prev; \ 409 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 410 TRASHIT((elm)->field.le_next); \ 411 TRASHIT((elm)->field.le_prev); \ 412 } while (0) 413 414 /* 415 * Tail queue declarations. 416 */ 417 #define TAILQ_HEAD(name, type) \ 418 struct name { \ 419 struct type *tqh_first; /* first element */ \ 420 struct type **tqh_last; /* addr of last next element */ \ 421 TRACEBUF \ 422 } 423 424 #define TAILQ_HEAD_INITIALIZER(head) \ 425 { NULL, &(head).tqh_first } 426 427 #define TAILQ_ENTRY(type) \ 428 struct { \ 429 struct type *tqe_next; /* next element */ \ 430 struct type **tqe_prev; /* address of previous next element */ \ 431 TRACEBUF \ 432 } 433 434 /* 435 * Tail queue functions. 436 */ 437 #if (defined(_KERNEL) && defined(INVARIANTS)) 438 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 439 if (!TAILQ_EMPTY(head) && \ 440 TAILQ_FIRST((head))->field.tqe_prev != \ 441 &TAILQ_FIRST((head))) \ 442 panic("Bad tailq head %p first->prev != head", (head)); \ 443 } while (0) 444 445 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 446 if (*(head)->tqh_last != NULL) \ 447 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 448 } while (0) 449 450 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 451 if (TAILQ_NEXT((elm), field) != NULL && \ 452 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 453 &((elm)->field.tqe_next)) \ 454 panic("Bad link elm %p next->prev != elm", (elm)); \ 455 } while (0) 456 457 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 458 if (*(elm)->field.tqe_prev != (elm)) \ 459 panic("Bad link elm %p prev->next != elm", (elm)); \ 460 } while (0) 461 #else 462 #define QMD_TAILQ_CHECK_HEAD(head, field) 463 #define QMD_TAILQ_CHECK_TAIL(head, headname) 464 #define QMD_TAILQ_CHECK_NEXT(elm, field) 465 #define QMD_TAILQ_CHECK_PREV(elm, field) 466 #endif /* (_KERNEL && INVARIANTS) */ 467 468 #define TAILQ_CONCAT(head1, head2, field) do { \ 469 if (!TAILQ_EMPTY(head2)) { \ 470 *(head1)->tqh_last = (head2)->tqh_first; \ 471 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 472 (head1)->tqh_last = (head2)->tqh_last; \ 473 TAILQ_INIT((head2)); \ 474 QMD_TRACE_HEAD(head1); \ 475 QMD_TRACE_HEAD(head2); \ 476 } \ 477 } while (0) 478 479 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 480 481 #define TAILQ_FIRST(head) ((head)->tqh_first) 482 483 #define TAILQ_FOREACH(var, head, field) \ 484 for ((var) = TAILQ_FIRST((head)); \ 485 (var); \ 486 (var) = TAILQ_NEXT((var), field)) 487 488 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 489 for ((var) = TAILQ_FIRST((head)); \ 490 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 491 (var) = (tvar)) 492 493 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 494 for ((var) = TAILQ_LAST((head), headname); \ 495 (var); \ 496 (var) = TAILQ_PREV((var), headname, field)) 497 498 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 499 for ((var) = TAILQ_LAST((head), headname); \ 500 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 501 (var) = (tvar)) 502 503 #define TAILQ_INIT(head) do { \ 504 TAILQ_FIRST((head)) = NULL; \ 505 (head)->tqh_last = &TAILQ_FIRST((head)); \ 506 QMD_TRACE_HEAD(head); \ 507 } while (0) 508 509 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 510 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 511 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 512 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 513 &TAILQ_NEXT((elm), field); \ 514 else { \ 515 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 516 QMD_TRACE_HEAD(head); \ 517 } \ 518 TAILQ_NEXT((listelm), field) = (elm); \ 519 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 520 QMD_TRACE_ELEM(&(elm)->field); \ 521 QMD_TRACE_ELEM(&listelm->field); \ 522 } while (0) 523 524 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 525 QMD_TAILQ_CHECK_PREV(listelm, field); \ 526 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 527 TAILQ_NEXT((elm), field) = (listelm); \ 528 *(listelm)->field.tqe_prev = (elm); \ 529 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 530 QMD_TRACE_ELEM(&(elm)->field); \ 531 QMD_TRACE_ELEM(&listelm->field); \ 532 } while (0) 533 534 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 535 QMD_TAILQ_CHECK_HEAD(head, field); \ 536 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 537 TAILQ_FIRST((head))->field.tqe_prev = \ 538 &TAILQ_NEXT((elm), field); \ 539 else \ 540 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 541 TAILQ_FIRST((head)) = (elm); \ 542 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 543 QMD_TRACE_HEAD(head); \ 544 QMD_TRACE_ELEM(&(elm)->field); \ 545 } while (0) 546 547 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 548 QMD_TAILQ_CHECK_TAIL(head, field); \ 549 TAILQ_NEXT((elm), field) = NULL; \ 550 (elm)->field.tqe_prev = (head)->tqh_last; \ 551 *(head)->tqh_last = (elm); \ 552 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 553 QMD_TRACE_HEAD(head); \ 554 QMD_TRACE_ELEM(&(elm)->field); \ 555 } while (0) 556 557 #define TAILQ_LAST(head, headname) \ 558 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 559 560 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 561 562 #define TAILQ_PREV(elm, headname, field) \ 563 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 564 565 #define TAILQ_REMOVE(head, elm, field) do { \ 566 QMD_TAILQ_CHECK_NEXT(elm, field); \ 567 QMD_TAILQ_CHECK_PREV(elm, field); \ 568 if ((TAILQ_NEXT((elm), field)) != NULL) \ 569 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 570 (elm)->field.tqe_prev; \ 571 else { \ 572 (head)->tqh_last = (elm)->field.tqe_prev; \ 573 QMD_TRACE_HEAD(head); \ 574 } \ 575 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 576 TRASHIT((elm)->field.tqe_next); \ 577 TRASHIT((elm)->field.tqe_prev); \ 578 QMD_TRACE_ELEM(&(elm)->field); \ 579 } while (0) 580 581 582 #ifdef _KERNEL 583 584 /* 585 * XXX insque() and remque() are an old way of handling certain queues. 586 * They bogusly assumes that all queue heads look alike. 587 */ 588 589 struct quehead { 590 struct quehead *qh_link; 591 struct quehead *qh_rlink; 592 }; 593 594 #ifdef __CC_SUPPORTS___INLINE 595 596 static __inline void 597 insque(void *a, void *b) 598 { 599 struct quehead *element = (struct quehead *)a, 600 *head = (struct quehead *)b; 601 602 element->qh_link = head->qh_link; 603 element->qh_rlink = head; 604 head->qh_link = element; 605 element->qh_link->qh_rlink = element; 606 } 607 608 static __inline void 609 remque(void *a) 610 { 611 struct quehead *element = (struct quehead *)a; 612 613 element->qh_link->qh_rlink = element->qh_rlink; 614 element->qh_rlink->qh_link = element->qh_link; 615 element->qh_rlink = 0; 616 } 617 618 #else /* !__CC_SUPPORTS___INLINE */ 619 620 void insque(void *a, void *b); 621 void remque(void *a); 622 623 #endif /* __CC_SUPPORTS___INLINE */ 624 625 #endif /* _KERNEL */ 626 627 #endif /* !_SYS_QUEUE_H_ */ 628