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_FROM + + + + 92 * _FOREACH_SAFE + + + + 93 * _FOREACH_FROM_SAFE + + + + 94 * _FOREACH_REVERSE - - - + 95 * _FOREACH_REVERSE_FROM - - - + 96 * _FOREACH_REVERSE_SAFE - - - + 97 * _FOREACH_REVERSE_FROM_SAFE - - - + 98 * _INSERT_HEAD + + + + 99 * _INSERT_BEFORE - + - + 100 * _INSERT_AFTER + + + + 101 * _INSERT_TAIL - - + + 102 * _CONCAT - - + + 103 * _REMOVE_AFTER + - + - 104 * _REMOVE_HEAD + - + - 105 * _REMOVE + + + + 106 * _SWAP + + + + 107 * 108 */ 109 #ifdef QUEUE_MACRO_DEBUG 110 /* Store the last 2 places the queue element or head was altered */ 111 struct qm_trace { 112 unsigned long lastline; 113 unsigned long prevline; 114 const char *lastfile; 115 const char *prevfile; 116 }; 117 118 #define TRACEBUF struct qm_trace trace; 119 #define TRACEBUF_INITIALIZER { __FILE__, __LINE__, NULL, 0 } , 120 #define TRASHIT(x) do {(x) = (void *)-1;} while (0) 121 #define QMD_SAVELINK(name, link) void **name = (void *)&(link) 122 123 #define QMD_TRACE_HEAD(head) do { \ 124 (head)->trace.prevline = (head)->trace.lastline; \ 125 (head)->trace.prevfile = (head)->trace.lastfile; \ 126 (head)->trace.lastline = __LINE__; \ 127 (head)->trace.lastfile = __FILE__; \ 128 } while (0) 129 130 #define QMD_TRACE_ELEM(elem) do { \ 131 (elem)->trace.prevline = (elem)->trace.lastline; \ 132 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 133 (elem)->trace.lastline = __LINE__; \ 134 (elem)->trace.lastfile = __FILE__; \ 135 } while (0) 136 137 #else 138 #define QMD_TRACE_ELEM(elem) 139 #define QMD_TRACE_HEAD(head) 140 #define QMD_SAVELINK(name, link) 141 #define TRACEBUF 142 #define TRACEBUF_INITIALIZER 143 #define TRASHIT(x) 144 #endif /* QUEUE_MACRO_DEBUG */ 145 146 /* 147 * Singly-linked List declarations. 148 */ 149 #define SLIST_HEAD(name, type) \ 150 struct name { \ 151 struct type *slh_first; /* first element */ \ 152 } 153 154 #define SLIST_HEAD_INITIALIZER(head) \ 155 { NULL } 156 157 #define SLIST_ENTRY(type) \ 158 struct { \ 159 struct type *sle_next; /* next element */ \ 160 } 161 162 /* 163 * Singly-linked List functions. 164 */ 165 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 166 167 #define SLIST_FIRST(head) ((head)->slh_first) 168 169 #define SLIST_FOREACH(var, head, field) \ 170 for ((var) = SLIST_FIRST((head)); \ 171 (var); \ 172 (var) = SLIST_NEXT((var), field)) 173 174 #define SLIST_FOREACH_FROM(var, head, field) \ 175 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 176 (var); \ 177 (var) = SLIST_NEXT((var), field)) 178 179 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 180 for ((var) = SLIST_FIRST((head)); \ 181 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 182 (var) = (tvar)) 183 184 #define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 185 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 186 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 187 (var) = (tvar)) 188 189 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 190 for ((varp) = &SLIST_FIRST((head)); \ 191 ((var) = *(varp)) != NULL; \ 192 (varp) = &SLIST_NEXT((var), field)) 193 194 #define SLIST_INIT(head) do { \ 195 SLIST_FIRST((head)) = NULL; \ 196 } while (0) 197 198 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 199 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 200 SLIST_NEXT((slistelm), field) = (elm); \ 201 } while (0) 202 203 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 204 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 205 SLIST_FIRST((head)) = (elm); \ 206 } while (0) 207 208 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 209 210 #define SLIST_REMOVE(head, elm, type, field) do { \ 211 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \ 212 if (SLIST_FIRST((head)) == (elm)) { \ 213 SLIST_REMOVE_HEAD((head), field); \ 214 } \ 215 else { \ 216 struct type *curelm = SLIST_FIRST((head)); \ 217 while (SLIST_NEXT(curelm, field) != (elm)) \ 218 curelm = SLIST_NEXT(curelm, field); \ 219 SLIST_REMOVE_AFTER(curelm, field); \ 220 } \ 221 TRASHIT(*oldnext); \ 222 } while (0) 223 224 #define SLIST_REMOVE_AFTER(elm, field) do { \ 225 SLIST_NEXT(elm, field) = \ 226 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 227 } while (0) 228 229 #define SLIST_REMOVE_HEAD(head, field) do { \ 230 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 231 } while (0) 232 233 #define SLIST_SWAP(head1, head2, type) do { \ 234 struct type *swap_first = SLIST_FIRST(head1); \ 235 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 236 SLIST_FIRST(head2) = swap_first; \ 237 } while (0) 238 239 /* 240 * Singly-linked Tail queue declarations. 241 */ 242 #define STAILQ_HEAD(name, type) \ 243 struct name { \ 244 struct type *stqh_first;/* first element */ \ 245 struct type **stqh_last;/* addr of last next element */ \ 246 } 247 248 #define STAILQ_HEAD_INITIALIZER(head) \ 249 { NULL, &(head).stqh_first } 250 251 #define STAILQ_ENTRY(type) \ 252 struct { \ 253 struct type *stqe_next; /* next element */ \ 254 } 255 256 /* 257 * Singly-linked Tail queue functions. 258 */ 259 #define STAILQ_CONCAT(head1, head2) do { \ 260 if (!STAILQ_EMPTY((head2))) { \ 261 *(head1)->stqh_last = (head2)->stqh_first; \ 262 (head1)->stqh_last = (head2)->stqh_last; \ 263 STAILQ_INIT((head2)); \ 264 } \ 265 } while (0) 266 267 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 268 269 #define STAILQ_FIRST(head) ((head)->stqh_first) 270 271 #define STAILQ_FOREACH(var, head, field) \ 272 for((var) = STAILQ_FIRST((head)); \ 273 (var); \ 274 (var) = STAILQ_NEXT((var), field)) 275 276 #define STAILQ_FOREACH_FROM(var, head, field) \ 277 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 278 (var); \ 279 (var) = STAILQ_NEXT((var), field)) 280 281 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 282 for ((var) = STAILQ_FIRST((head)); \ 283 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 284 (var) = (tvar)) 285 286 #define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 287 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 288 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 289 (var) = (tvar)) 290 291 #define STAILQ_INIT(head) do { \ 292 STAILQ_FIRST((head)) = NULL; \ 293 (head)->stqh_last = &STAILQ_FIRST((head)); \ 294 } while (0) 295 296 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 297 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 298 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 299 STAILQ_NEXT((tqelm), field) = (elm); \ 300 } while (0) 301 302 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 303 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 304 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 305 STAILQ_FIRST((head)) = (elm); \ 306 } while (0) 307 308 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 309 STAILQ_NEXT((elm), field) = NULL; \ 310 *(head)->stqh_last = (elm); \ 311 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 312 } while (0) 313 314 #define STAILQ_LAST(head, type, field) \ 315 (STAILQ_EMPTY((head)) ? NULL : \ 316 __containerof((head)->stqh_last, struct type, field.stqe_next)) 317 318 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 319 320 #define STAILQ_REMOVE(head, elm, type, field) do { \ 321 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 322 if (STAILQ_FIRST((head)) == (elm)) { \ 323 STAILQ_REMOVE_HEAD((head), field); \ 324 } \ 325 else { \ 326 struct type *curelm = STAILQ_FIRST((head)); \ 327 while (STAILQ_NEXT(curelm, field) != (elm)) \ 328 curelm = STAILQ_NEXT(curelm, field); \ 329 STAILQ_REMOVE_AFTER(head, curelm, field); \ 330 } \ 331 TRASHIT(*oldnext); \ 332 } while (0) 333 334 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 335 if ((STAILQ_NEXT(elm, field) = \ 336 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 337 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 338 } while (0) 339 340 #define STAILQ_REMOVE_HEAD(head, field) do { \ 341 if ((STAILQ_FIRST((head)) = \ 342 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 343 (head)->stqh_last = &STAILQ_FIRST((head)); \ 344 } while (0) 345 346 #define STAILQ_SWAP(head1, head2, type) do { \ 347 struct type *swap_first = STAILQ_FIRST(head1); \ 348 struct type **swap_last = (head1)->stqh_last; \ 349 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 350 (head1)->stqh_last = (head2)->stqh_last; \ 351 STAILQ_FIRST(head2) = swap_first; \ 352 (head2)->stqh_last = swap_last; \ 353 if (STAILQ_EMPTY(head1)) \ 354 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 355 if (STAILQ_EMPTY(head2)) \ 356 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 357 } while (0) 358 359 360 /* 361 * List declarations. 362 */ 363 #define LIST_HEAD(name, type) \ 364 struct name { \ 365 struct type *lh_first; /* first element */ \ 366 } 367 368 #define LIST_HEAD_INITIALIZER(head) \ 369 { NULL } 370 371 #define LIST_ENTRY(type) \ 372 struct { \ 373 struct type *le_next; /* next element */ \ 374 struct type **le_prev; /* address of previous next element */ \ 375 } 376 377 /* 378 * List functions. 379 */ 380 381 #if (defined(_KERNEL) && defined(INVARIANTS)) 382 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 383 if (LIST_FIRST((head)) != NULL && \ 384 LIST_FIRST((head))->field.le_prev != \ 385 &LIST_FIRST((head))) \ 386 panic("Bad list head %p first->prev != head", (head)); \ 387 } while (0) 388 389 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 390 if (LIST_NEXT((elm), field) != NULL && \ 391 LIST_NEXT((elm), field)->field.le_prev != \ 392 &((elm)->field.le_next)) \ 393 panic("Bad link elm %p next->prev != elm", (elm)); \ 394 } while (0) 395 396 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 397 if (*(elm)->field.le_prev != (elm)) \ 398 panic("Bad link elm %p prev->next != elm", (elm)); \ 399 } while (0) 400 #else 401 #define QMD_LIST_CHECK_HEAD(head, field) 402 #define QMD_LIST_CHECK_NEXT(elm, field) 403 #define QMD_LIST_CHECK_PREV(elm, field) 404 #endif /* (_KERNEL && INVARIANTS) */ 405 406 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 407 408 #define LIST_FIRST(head) ((head)->lh_first) 409 410 #define LIST_FOREACH(var, head, field) \ 411 for ((var) = LIST_FIRST((head)); \ 412 (var); \ 413 (var) = LIST_NEXT((var), field)) 414 415 #define LIST_FOREACH_FROM(var, head, field) \ 416 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 417 (var); \ 418 (var) = LIST_NEXT((var), field)) 419 420 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 421 for ((var) = LIST_FIRST((head)); \ 422 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 423 (var) = (tvar)) 424 425 #define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 426 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 427 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 428 (var) = (tvar)) 429 430 #define LIST_INIT(head) do { \ 431 LIST_FIRST((head)) = NULL; \ 432 } while (0) 433 434 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 435 QMD_LIST_CHECK_NEXT(listelm, field); \ 436 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 437 LIST_NEXT((listelm), field)->field.le_prev = \ 438 &LIST_NEXT((elm), field); \ 439 LIST_NEXT((listelm), field) = (elm); \ 440 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 441 } while (0) 442 443 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 444 QMD_LIST_CHECK_PREV(listelm, field); \ 445 (elm)->field.le_prev = (listelm)->field.le_prev; \ 446 LIST_NEXT((elm), field) = (listelm); \ 447 *(listelm)->field.le_prev = (elm); \ 448 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 449 } while (0) 450 451 #define LIST_INSERT_HEAD(head, elm, field) do { \ 452 QMD_LIST_CHECK_HEAD((head), field); \ 453 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 454 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 455 LIST_FIRST((head)) = (elm); \ 456 (elm)->field.le_prev = &LIST_FIRST((head)); \ 457 } while (0) 458 459 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 460 461 #define LIST_PREV(elm, head, type, field) \ 462 ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \ 463 __containerof((elm)->field.le_prev, struct type, field.le_next)) 464 465 #define LIST_REMOVE(elm, field) do { \ 466 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 467 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 468 QMD_LIST_CHECK_NEXT(elm, field); \ 469 QMD_LIST_CHECK_PREV(elm, field); \ 470 if (LIST_NEXT((elm), field) != NULL) \ 471 LIST_NEXT((elm), field)->field.le_prev = \ 472 (elm)->field.le_prev; \ 473 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 474 TRASHIT(*oldnext); \ 475 TRASHIT(*oldprev); \ 476 } while (0) 477 478 #define LIST_SWAP(head1, head2, type, field) do { \ 479 struct type *swap_tmp = LIST_FIRST((head1)); \ 480 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 481 LIST_FIRST((head2)) = swap_tmp; \ 482 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 483 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 484 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 485 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 486 } while (0) 487 488 /* 489 * Tail queue declarations. 490 */ 491 #define TAILQ_HEAD(name, type) \ 492 struct name { \ 493 struct type *tqh_first; /* first element */ \ 494 struct type **tqh_last; /* addr of last next element */ \ 495 TRACEBUF \ 496 } 497 498 #define TAILQ_HEAD_INITIALIZER(head) \ 499 { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER } 500 501 #define TAILQ_ENTRY(type) \ 502 struct { \ 503 struct type *tqe_next; /* next element */ \ 504 struct type **tqe_prev; /* address of previous next element */ \ 505 TRACEBUF \ 506 } 507 508 /* 509 * Tail queue functions. 510 */ 511 #if (defined(_KERNEL) && defined(INVARIANTS)) 512 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 513 if (!TAILQ_EMPTY(head) && \ 514 TAILQ_FIRST((head))->field.tqe_prev != \ 515 &TAILQ_FIRST((head))) \ 516 panic("Bad tailq head %p first->prev != head", (head)); \ 517 } while (0) 518 519 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 520 if (*(head)->tqh_last != NULL) \ 521 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 522 } while (0) 523 524 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 525 if (TAILQ_NEXT((elm), field) != NULL && \ 526 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 527 &((elm)->field.tqe_next)) \ 528 panic("Bad link elm %p next->prev != elm", (elm)); \ 529 } while (0) 530 531 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 532 if (*(elm)->field.tqe_prev != (elm)) \ 533 panic("Bad link elm %p prev->next != elm", (elm)); \ 534 } while (0) 535 #else 536 #define QMD_TAILQ_CHECK_HEAD(head, field) 537 #define QMD_TAILQ_CHECK_TAIL(head, headname) 538 #define QMD_TAILQ_CHECK_NEXT(elm, field) 539 #define QMD_TAILQ_CHECK_PREV(elm, field) 540 #endif /* (_KERNEL && INVARIANTS) */ 541 542 #define TAILQ_CONCAT(head1, head2, field) do { \ 543 if (!TAILQ_EMPTY(head2)) { \ 544 *(head1)->tqh_last = (head2)->tqh_first; \ 545 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 546 (head1)->tqh_last = (head2)->tqh_last; \ 547 TAILQ_INIT((head2)); \ 548 QMD_TRACE_HEAD(head1); \ 549 QMD_TRACE_HEAD(head2); \ 550 } \ 551 } while (0) 552 553 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 554 555 #define TAILQ_FIRST(head) ((head)->tqh_first) 556 557 #define TAILQ_FOREACH(var, head, field) \ 558 for ((var) = TAILQ_FIRST((head)); \ 559 (var); \ 560 (var) = TAILQ_NEXT((var), field)) 561 562 #define TAILQ_FOREACH_FROM(var, head, field) \ 563 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 564 (var); \ 565 (var) = TAILQ_NEXT((var), field)) 566 567 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 568 for ((var) = TAILQ_FIRST((head)); \ 569 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 570 (var) = (tvar)) 571 572 #define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 573 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 574 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 575 (var) = (tvar)) 576 577 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 578 for ((var) = TAILQ_LAST((head), headname); \ 579 (var); \ 580 (var) = TAILQ_PREV((var), headname, field)) 581 582 #define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \ 583 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 584 (var); \ 585 (var) = TAILQ_PREV((var), headname, field)) 586 587 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 588 for ((var) = TAILQ_LAST((head), headname); \ 589 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 590 (var) = (tvar)) 591 592 #define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \ 593 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 594 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 595 (var) = (tvar)) 596 597 #define TAILQ_INIT(head) do { \ 598 TAILQ_FIRST((head)) = NULL; \ 599 (head)->tqh_last = &TAILQ_FIRST((head)); \ 600 QMD_TRACE_HEAD(head); \ 601 } while (0) 602 603 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 604 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 605 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 606 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 607 &TAILQ_NEXT((elm), field); \ 608 else { \ 609 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 610 QMD_TRACE_HEAD(head); \ 611 } \ 612 TAILQ_NEXT((listelm), field) = (elm); \ 613 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 614 QMD_TRACE_ELEM(&(elm)->field); \ 615 QMD_TRACE_ELEM(&listelm->field); \ 616 } while (0) 617 618 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 619 QMD_TAILQ_CHECK_PREV(listelm, field); \ 620 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 621 TAILQ_NEXT((elm), field) = (listelm); \ 622 *(listelm)->field.tqe_prev = (elm); \ 623 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 624 QMD_TRACE_ELEM(&(elm)->field); \ 625 QMD_TRACE_ELEM(&listelm->field); \ 626 } while (0) 627 628 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 629 QMD_TAILQ_CHECK_HEAD(head, field); \ 630 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 631 TAILQ_FIRST((head))->field.tqe_prev = \ 632 &TAILQ_NEXT((elm), field); \ 633 else \ 634 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 635 TAILQ_FIRST((head)) = (elm); \ 636 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 637 QMD_TRACE_HEAD(head); \ 638 QMD_TRACE_ELEM(&(elm)->field); \ 639 } while (0) 640 641 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 642 QMD_TAILQ_CHECK_TAIL(head, field); \ 643 TAILQ_NEXT((elm), field) = NULL; \ 644 (elm)->field.tqe_prev = (head)->tqh_last; \ 645 *(head)->tqh_last = (elm); \ 646 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 647 QMD_TRACE_HEAD(head); \ 648 QMD_TRACE_ELEM(&(elm)->field); \ 649 } while (0) 650 651 #define TAILQ_LAST(head, headname) \ 652 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 653 654 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 655 656 #define TAILQ_PREV(elm, headname, field) \ 657 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 658 659 #define TAILQ_REMOVE(head, elm, field) do { \ 660 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 661 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 662 QMD_TAILQ_CHECK_NEXT(elm, field); \ 663 QMD_TAILQ_CHECK_PREV(elm, field); \ 664 if ((TAILQ_NEXT((elm), field)) != NULL) \ 665 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 666 (elm)->field.tqe_prev; \ 667 else { \ 668 (head)->tqh_last = (elm)->field.tqe_prev; \ 669 QMD_TRACE_HEAD(head); \ 670 } \ 671 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 672 TRASHIT(*oldnext); \ 673 TRASHIT(*oldprev); \ 674 QMD_TRACE_ELEM(&(elm)->field); \ 675 } while (0) 676 677 #define TAILQ_SWAP(head1, head2, type, field) do { \ 678 struct type *swap_first = (head1)->tqh_first; \ 679 struct type **swap_last = (head1)->tqh_last; \ 680 (head1)->tqh_first = (head2)->tqh_first; \ 681 (head1)->tqh_last = (head2)->tqh_last; \ 682 (head2)->tqh_first = swap_first; \ 683 (head2)->tqh_last = swap_last; \ 684 if ((swap_first = (head1)->tqh_first) != NULL) \ 685 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 686 else \ 687 (head1)->tqh_last = &(head1)->tqh_first; \ 688 if ((swap_first = (head2)->tqh_first) != NULL) \ 689 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 690 else \ 691 (head2)->tqh_last = &(head2)->tqh_first; \ 692 } while (0) 693 694 #endif /* !_SYS_QUEUE_H_ */ 695