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: releng/11.0/sys/sys/queue.h 284915 2015-06-28 21:06:45Z hselasky $ 31 */ 32 33 #ifndef _SYS_QUEUE_H_ 34 #define _SYS_QUEUE_H_ 35 36 #include "config.h" 37 38 #ifdef HAVE_SYS_CDEFS_H 39 #include <sys/cdefs.h> 40 #endif 41 42 /* 43 * This file defines four types of data structures: singly-linked lists, 44 * singly-linked tail queues, lists and tail queues. 45 * 46 * A singly-linked list is headed by a single forward pointer. The elements 47 * are singly linked for minimum space and pointer manipulation overhead at 48 * the expense of O(n) removal for arbitrary elements. New elements can be 49 * added to the list after an existing element or at the head of the list. 50 * Elements being removed from the head of the list should use the explicit 51 * macro for this purpose for optimum efficiency. A singly-linked list may 52 * only be traversed in the forward direction. Singly-linked lists are ideal 53 * for applications with large datasets and few or no removals or for 54 * implementing a LIFO queue. 55 * 56 * A singly-linked tail queue is headed by a pair of pointers, one to the 57 * head of the list and the other to the tail of the list. The elements are 58 * singly linked for minimum space and pointer manipulation overhead at the 59 * expense of O(n) removal for arbitrary elements. New elements can be added 60 * to the list after an existing element, at the head of the list, or at the 61 * end of the list. Elements being removed from the head of the tail queue 62 * should use the explicit macro for this purpose for optimum efficiency. 63 * A singly-linked tail queue may only be traversed in the forward direction. 64 * Singly-linked tail queues are ideal for applications with large datasets 65 * and few or no removals or for implementing a FIFO queue. 66 * 67 * A list is headed by a single forward pointer (or an array of forward 68 * pointers for a hash table header). The elements are doubly linked 69 * so that an arbitrary element can be removed without a need to 70 * traverse the list. New elements can be added to the list before 71 * or after an existing element or at the head of the list. A list 72 * may be traversed in either direction. 73 * 74 * A tail queue is headed by a pair of pointers, one to the head of the 75 * list and the other to the tail of the list. The elements are doubly 76 * linked so that an arbitrary element can be removed without a need to 77 * traverse the list. New elements can be added to the list before or 78 * after an existing element, at the head of the list, or at the end of 79 * the list. A tail queue may be traversed in either direction. 80 * 81 * For details on the use of these macros, see the queue(3) manual page. 82 * 83 * 84 * SLIST LIST STAILQ TAILQ 85 * _HEAD + + + + 86 * _CLASS_HEAD + + + + 87 * _HEAD_INITIALIZER + + + + 88 * _ENTRY + + + + 89 * _CLASS_ENTRY + + + + 90 * _INIT + + + + 91 * _EMPTY + + + + 92 * _FIRST + + + + 93 * _NEXT + + + + 94 * _PREV - + - + 95 * _LAST - - + + 96 * _FOREACH + + + + 97 * _FOREACH_FROM + + + + 98 * _FOREACH_SAFE + + + + 99 * _FOREACH_FROM_SAFE + + + + 100 * _FOREACH_REVERSE - - - + 101 * _FOREACH_REVERSE_FROM - - - + 102 * _FOREACH_REVERSE_SAFE - - - + 103 * _FOREACH_REVERSE_FROM_SAFE - - - + 104 * _INSERT_HEAD + + + + 105 * _INSERT_BEFORE - + - + 106 * _INSERT_AFTER + + + + 107 * _INSERT_TAIL - - + + 108 * _CONCAT - - + + 109 * _REMOVE_AFTER + - + - 110 * _REMOVE_HEAD + - + - 111 * _REMOVE + + + + 112 * _SWAP + + + + 113 * 114 */ 115 #ifdef QUEUE_MACRO_DEBUG 116 /* Store the last 2 places the queue element or head was altered */ 117 struct qm_trace { 118 unsigned long lastline; 119 unsigned long prevline; 120 const char *lastfile; 121 const char *prevfile; 122 }; 123 124 #define TRACEBUF struct qm_trace trace; 125 #define TRACEBUF_INITIALIZER { __LINE__, 0, __FILE__, NULL } , 126 #define TRASHIT(x) do {(x) = (void *)-1;} while (0) 127 #define QMD_SAVELINK(name, link) void **name = (void *)&(link) 128 129 #define QMD_TRACE_HEAD(head) do { \ 130 (head)->trace.prevline = (head)->trace.lastline; \ 131 (head)->trace.prevfile = (head)->trace.lastfile; \ 132 (head)->trace.lastline = __LINE__; \ 133 (head)->trace.lastfile = __FILE__; \ 134 } while (0) 135 136 #define QMD_TRACE_ELEM(elem) do { \ 137 (elem)->trace.prevline = (elem)->trace.lastline; \ 138 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 139 (elem)->trace.lastline = __LINE__; \ 140 (elem)->trace.lastfile = __FILE__; \ 141 } while (0) 142 143 #else 144 #define QMD_TRACE_ELEM(elem) 145 #define QMD_TRACE_HEAD(head) 146 #define QMD_SAVELINK(name, link) 147 #define TRACEBUF 148 #define TRACEBUF_INITIALIZER 149 #define TRASHIT(x) 150 #endif /* QUEUE_MACRO_DEBUG */ 151 152 #ifdef __cplusplus 153 /* 154 * In C++ there can be structure lists and class lists: 155 */ 156 #define QUEUE_TYPEOF(type) type 157 #else 158 #define QUEUE_TYPEOF(type) struct type 159 #endif 160 161 /* 162 * Singly-linked List declarations. 163 */ 164 #define SLIST_HEAD(name, type) \ 165 struct name { \ 166 struct type *slh_first; /* first element */ \ 167 } 168 169 #define SLIST_CLASS_HEAD(name, type) \ 170 struct name { \ 171 class type *slh_first; /* first element */ \ 172 } 173 174 #define SLIST_HEAD_INITIALIZER(head) \ 175 { NULL } 176 177 #define SLIST_ENTRY(type) \ 178 struct { \ 179 struct type *sle_next; /* next element */ \ 180 } 181 182 #define SLIST_CLASS_ENTRY(type) \ 183 struct { \ 184 class type *sle_next; /* next element */ \ 185 } 186 187 /* 188 * Singly-linked List functions. 189 */ 190 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 191 192 #define SLIST_FIRST(head) ((head)->slh_first) 193 194 #define SLIST_FOREACH(var, head, field) \ 195 for ((var) = SLIST_FIRST((head)); \ 196 (var); \ 197 (var) = SLIST_NEXT((var), field)) 198 199 #define SLIST_FOREACH_FROM(var, head, field) \ 200 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 201 (var); \ 202 (var) = SLIST_NEXT((var), field)) 203 204 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 205 for ((var) = SLIST_FIRST((head)); \ 206 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 207 (var) = (tvar)) 208 209 #define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 210 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 211 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 212 (var) = (tvar)) 213 214 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 215 for ((varp) = &SLIST_FIRST((head)); \ 216 ((var) = *(varp)) != NULL; \ 217 (varp) = &SLIST_NEXT((var), field)) 218 219 #define SLIST_INIT(head) do { \ 220 SLIST_FIRST((head)) = NULL; \ 221 } while (0) 222 223 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 224 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 225 SLIST_NEXT((slistelm), field) = (elm); \ 226 } while (0) 227 228 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 229 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 230 SLIST_FIRST((head)) = (elm); \ 231 } while (0) 232 233 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 234 235 #define SLIST_REMOVE(head, elm, type, field) do { \ 236 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \ 237 if (SLIST_FIRST((head)) == (elm)) { \ 238 SLIST_REMOVE_HEAD((head), field); \ 239 } \ 240 else { \ 241 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head); \ 242 while (SLIST_NEXT(curelm, field) != (elm)) \ 243 curelm = SLIST_NEXT(curelm, field); \ 244 SLIST_REMOVE_AFTER(curelm, field); \ 245 } \ 246 TRASHIT(*oldnext); \ 247 } while (0) 248 249 #define SLIST_REMOVE_AFTER(elm, field) do { \ 250 SLIST_NEXT(elm, field) = \ 251 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 252 } while (0) 253 254 #define SLIST_REMOVE_HEAD(head, field) do { \ 255 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 256 } while (0) 257 258 #define SLIST_SWAP(head1, head2, type) do { \ 259 QUEUE_TYPEOF(type) *swap_first = SLIST_FIRST(head1); \ 260 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 261 SLIST_FIRST(head2) = swap_first; \ 262 } while (0) 263 264 /* 265 * Singly-linked Tail queue declarations. 266 */ 267 #define STAILQ_HEAD(name, type) \ 268 struct name { \ 269 struct type *stqh_first;/* first element */ \ 270 struct type **stqh_last;/* addr of last next element */ \ 271 } 272 273 #define STAILQ_CLASS_HEAD(name, type) \ 274 struct name { \ 275 class type *stqh_first; /* first element */ \ 276 class type **stqh_last; /* addr of last next element */ \ 277 } 278 279 #define STAILQ_HEAD_INITIALIZER(head) \ 280 { NULL, &(head).stqh_first } 281 282 #define STAILQ_ENTRY(type) \ 283 struct { \ 284 struct type *stqe_next; /* next element */ \ 285 } 286 287 #define STAILQ_CLASS_ENTRY(type) \ 288 struct { \ 289 class type *stqe_next; /* next element */ \ 290 } 291 292 /* 293 * Singly-linked Tail queue functions. 294 */ 295 #define STAILQ_CONCAT(head1, head2) do { \ 296 if (!STAILQ_EMPTY((head2))) { \ 297 *(head1)->stqh_last = (head2)->stqh_first; \ 298 (head1)->stqh_last = (head2)->stqh_last; \ 299 STAILQ_INIT((head2)); \ 300 } \ 301 } while (0) 302 303 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 304 305 #define STAILQ_FIRST(head) ((head)->stqh_first) 306 307 #define STAILQ_FOREACH(var, head, field) \ 308 for((var) = STAILQ_FIRST((head)); \ 309 (var); \ 310 (var) = STAILQ_NEXT((var), field)) 311 312 #define STAILQ_FOREACH_FROM(var, head, field) \ 313 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 314 (var); \ 315 (var) = STAILQ_NEXT((var), field)) 316 317 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 318 for ((var) = STAILQ_FIRST((head)); \ 319 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 320 (var) = (tvar)) 321 322 #define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 323 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 324 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 325 (var) = (tvar)) 326 327 #define STAILQ_INIT(head) do { \ 328 STAILQ_FIRST((head)) = NULL; \ 329 (head)->stqh_last = &STAILQ_FIRST((head)); \ 330 } while (0) 331 332 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 333 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 334 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 335 STAILQ_NEXT((tqelm), field) = (elm); \ 336 } while (0) 337 338 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 339 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 340 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 341 STAILQ_FIRST((head)) = (elm); \ 342 } while (0) 343 344 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 345 STAILQ_NEXT((elm), field) = NULL; \ 346 *(head)->stqh_last = (elm); \ 347 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 348 } while (0) 349 350 #define STAILQ_LAST(head, type, field) \ 351 (STAILQ_EMPTY((head)) ? NULL : \ 352 __containerof((head)->stqh_last, \ 353 QUEUE_TYPEOF(type), field.stqe_next)) 354 355 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 356 357 #define STAILQ_REMOVE(head, elm, type, field) do { \ 358 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 359 if (STAILQ_FIRST((head)) == (elm)) { \ 360 STAILQ_REMOVE_HEAD((head), field); \ 361 } \ 362 else { \ 363 QUEUE_TYPEOF(type) *curelm = STAILQ_FIRST(head); \ 364 while (STAILQ_NEXT(curelm, field) != (elm)) \ 365 curelm = STAILQ_NEXT(curelm, field); \ 366 STAILQ_REMOVE_AFTER(head, curelm, field); \ 367 } \ 368 TRASHIT(*oldnext); \ 369 } while (0) 370 371 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 372 if ((STAILQ_NEXT(elm, field) = \ 373 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 374 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 375 } while (0) 376 377 #define STAILQ_REMOVE_HEAD(head, field) do { \ 378 if ((STAILQ_FIRST((head)) = \ 379 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 380 (head)->stqh_last = &STAILQ_FIRST((head)); \ 381 } while (0) 382 383 #define STAILQ_SWAP(head1, head2, type) do { \ 384 QUEUE_TYPEOF(type) *swap_first = STAILQ_FIRST(head1); \ 385 QUEUE_TYPEOF(type) **swap_last = (head1)->stqh_last; \ 386 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 387 (head1)->stqh_last = (head2)->stqh_last; \ 388 STAILQ_FIRST(head2) = swap_first; \ 389 (head2)->stqh_last = swap_last; \ 390 if (STAILQ_EMPTY(head1)) \ 391 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 392 if (STAILQ_EMPTY(head2)) \ 393 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 394 } while (0) 395 396 397 /* 398 * List declarations. 399 */ 400 #define LIST_HEAD(name, type) \ 401 struct name { \ 402 struct type *lh_first; /* first element */ \ 403 } 404 405 #define LIST_CLASS_HEAD(name, type) \ 406 struct name { \ 407 class type *lh_first; /* first element */ \ 408 } 409 410 #define LIST_HEAD_INITIALIZER(head) \ 411 { NULL } 412 413 #define LIST_ENTRY(type) \ 414 struct { \ 415 struct type *le_next; /* next element */ \ 416 struct type **le_prev; /* address of previous next element */ \ 417 } 418 419 #define LIST_CLASS_ENTRY(type) \ 420 struct { \ 421 class type *le_next; /* next element */ \ 422 class type **le_prev; /* address of previous next element */ \ 423 } 424 425 /* 426 * List functions. 427 */ 428 429 #if (defined(_KERNEL) && defined(INVARIANTS)) 430 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 431 if (LIST_FIRST((head)) != NULL && \ 432 LIST_FIRST((head))->field.le_prev != \ 433 &LIST_FIRST((head))) \ 434 panic("Bad list head %p first->prev != head", (head)); \ 435 } while (0) 436 437 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 438 if (LIST_NEXT((elm), field) != NULL && \ 439 LIST_NEXT((elm), field)->field.le_prev != \ 440 &((elm)->field.le_next)) \ 441 panic("Bad link elm %p next->prev != elm", (elm)); \ 442 } while (0) 443 444 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 445 if (*(elm)->field.le_prev != (elm)) \ 446 panic("Bad link elm %p prev->next != elm", (elm)); \ 447 } while (0) 448 #else 449 #define QMD_LIST_CHECK_HEAD(head, field) 450 #define QMD_LIST_CHECK_NEXT(elm, field) 451 #define QMD_LIST_CHECK_PREV(elm, field) 452 #endif /* (_KERNEL && INVARIANTS) */ 453 454 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 455 456 #define LIST_FIRST(head) ((head)->lh_first) 457 458 #define LIST_FOREACH(var, head, field) \ 459 for ((var) = LIST_FIRST((head)); \ 460 (var); \ 461 (var) = LIST_NEXT((var), field)) 462 463 #define LIST_FOREACH_FROM(var, head, field) \ 464 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 465 (var); \ 466 (var) = LIST_NEXT((var), field)) 467 468 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 469 for ((var) = LIST_FIRST((head)); \ 470 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 471 (var) = (tvar)) 472 473 #define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 474 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 475 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 476 (var) = (tvar)) 477 478 #define LIST_INIT(head) do { \ 479 LIST_FIRST((head)) = NULL; \ 480 } while (0) 481 482 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 483 QMD_LIST_CHECK_NEXT(listelm, field); \ 484 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 485 LIST_NEXT((listelm), field)->field.le_prev = \ 486 &LIST_NEXT((elm), field); \ 487 LIST_NEXT((listelm), field) = (elm); \ 488 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 489 } while (0) 490 491 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 492 QMD_LIST_CHECK_PREV(listelm, field); \ 493 (elm)->field.le_prev = (listelm)->field.le_prev; \ 494 LIST_NEXT((elm), field) = (listelm); \ 495 *(listelm)->field.le_prev = (elm); \ 496 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 497 } while (0) 498 499 #define LIST_INSERT_HEAD(head, elm, field) do { \ 500 QMD_LIST_CHECK_HEAD((head), field); \ 501 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 502 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 503 LIST_FIRST((head)) = (elm); \ 504 (elm)->field.le_prev = &LIST_FIRST((head)); \ 505 } while (0) 506 507 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 508 509 #define LIST_PREV(elm, head, type, field) \ 510 ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \ 511 __containerof((elm)->field.le_prev, \ 512 QUEUE_TYPEOF(type), field.le_next)) 513 514 #define LIST_REMOVE(elm, field) do { \ 515 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 516 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 517 QMD_LIST_CHECK_NEXT(elm, field); \ 518 QMD_LIST_CHECK_PREV(elm, field); \ 519 if (LIST_NEXT((elm), field) != NULL) \ 520 LIST_NEXT((elm), field)->field.le_prev = \ 521 (elm)->field.le_prev; \ 522 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 523 TRASHIT(*oldnext); \ 524 TRASHIT(*oldprev); \ 525 } while (0) 526 527 #define LIST_SWAP(head1, head2, type, field) do { \ 528 QUEUE_TYPEOF(type) *swap_tmp = LIST_FIRST(head1); \ 529 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 530 LIST_FIRST((head2)) = swap_tmp; \ 531 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 532 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 533 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 534 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 535 } while (0) 536 537 /* 538 * Tail queue declarations. 539 */ 540 #define TAILQ_HEAD(name, type) \ 541 struct name { \ 542 struct type *tqh_first; /* first element */ \ 543 struct type **tqh_last; /* addr of last next element */ \ 544 TRACEBUF \ 545 } 546 547 #define TAILQ_CLASS_HEAD(name, type) \ 548 struct name { \ 549 class type *tqh_first; /* first element */ \ 550 class type **tqh_last; /* addr of last next element */ \ 551 TRACEBUF \ 552 } 553 554 #define TAILQ_HEAD_INITIALIZER(head) \ 555 { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER } 556 557 #define TAILQ_ENTRY(type) \ 558 struct { \ 559 struct type *tqe_next; /* next element */ \ 560 struct type **tqe_prev; /* address of previous next element */ \ 561 TRACEBUF \ 562 } 563 564 #define TAILQ_CLASS_ENTRY(type) \ 565 struct { \ 566 class type *tqe_next; /* next element */ \ 567 class type **tqe_prev; /* address of previous next element */ \ 568 TRACEBUF \ 569 } 570 571 /* 572 * Tail queue functions. 573 */ 574 #if (defined(_KERNEL) && defined(INVARIANTS)) 575 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 576 if (!TAILQ_EMPTY(head) && \ 577 TAILQ_FIRST((head))->field.tqe_prev != \ 578 &TAILQ_FIRST((head))) \ 579 panic("Bad tailq head %p first->prev != head", (head)); \ 580 } while (0) 581 582 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 583 if (*(head)->tqh_last != NULL) \ 584 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 585 } while (0) 586 587 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 588 if (TAILQ_NEXT((elm), field) != NULL && \ 589 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 590 &((elm)->field.tqe_next)) \ 591 panic("Bad link elm %p next->prev != elm", (elm)); \ 592 } while (0) 593 594 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 595 if (*(elm)->field.tqe_prev != (elm)) \ 596 panic("Bad link elm %p prev->next != elm", (elm)); \ 597 } while (0) 598 #else 599 #define QMD_TAILQ_CHECK_HEAD(head, field) 600 #define QMD_TAILQ_CHECK_TAIL(head, headname) 601 #define QMD_TAILQ_CHECK_NEXT(elm, field) 602 #define QMD_TAILQ_CHECK_PREV(elm, field) 603 #endif /* (_KERNEL && INVARIANTS) */ 604 605 #define TAILQ_CONCAT(head1, head2, field) do { \ 606 if (!TAILQ_EMPTY(head2)) { \ 607 *(head1)->tqh_last = (head2)->tqh_first; \ 608 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 609 (head1)->tqh_last = (head2)->tqh_last; \ 610 TAILQ_INIT((head2)); \ 611 QMD_TRACE_HEAD(head1); \ 612 QMD_TRACE_HEAD(head2); \ 613 } \ 614 } while (0) 615 616 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 617 618 #define TAILQ_FIRST(head) ((head)->tqh_first) 619 620 #define TAILQ_FOREACH(var, head, field) \ 621 for ((var) = TAILQ_FIRST((head)); \ 622 (var); \ 623 (var) = TAILQ_NEXT((var), field)) 624 625 #define TAILQ_FOREACH_FROM(var, head, field) \ 626 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 627 (var); \ 628 (var) = TAILQ_NEXT((var), field)) 629 630 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 631 for ((var) = TAILQ_FIRST((head)); \ 632 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 633 (var) = (tvar)) 634 635 #define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 636 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 637 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 638 (var) = (tvar)) 639 640 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 641 for ((var) = TAILQ_LAST((head), headname); \ 642 (var); \ 643 (var) = TAILQ_PREV((var), headname, field)) 644 645 #define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \ 646 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 647 (var); \ 648 (var) = TAILQ_PREV((var), headname, field)) 649 650 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 651 for ((var) = TAILQ_LAST((head), headname); \ 652 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 653 (var) = (tvar)) 654 655 #define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \ 656 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 657 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 658 (var) = (tvar)) 659 660 #define TAILQ_INIT(head) do { \ 661 TAILQ_FIRST((head)) = NULL; \ 662 (head)->tqh_last = &TAILQ_FIRST((head)); \ 663 QMD_TRACE_HEAD(head); \ 664 } while (0) 665 666 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 667 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 668 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 669 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 670 &TAILQ_NEXT((elm), field); \ 671 else { \ 672 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 673 QMD_TRACE_HEAD(head); \ 674 } \ 675 TAILQ_NEXT((listelm), field) = (elm); \ 676 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 677 QMD_TRACE_ELEM(&(elm)->field); \ 678 QMD_TRACE_ELEM(&(listelm)->field); \ 679 } while (0) 680 681 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 682 QMD_TAILQ_CHECK_PREV(listelm, field); \ 683 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 684 TAILQ_NEXT((elm), field) = (listelm); \ 685 *(listelm)->field.tqe_prev = (elm); \ 686 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 687 QMD_TRACE_ELEM(&(elm)->field); \ 688 QMD_TRACE_ELEM(&(listelm)->field); \ 689 } while (0) 690 691 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 692 QMD_TAILQ_CHECK_HEAD(head, field); \ 693 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 694 TAILQ_FIRST((head))->field.tqe_prev = \ 695 &TAILQ_NEXT((elm), field); \ 696 else \ 697 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 698 TAILQ_FIRST((head)) = (elm); \ 699 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 700 QMD_TRACE_HEAD(head); \ 701 QMD_TRACE_ELEM(&(elm)->field); \ 702 } while (0) 703 704 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 705 QMD_TAILQ_CHECK_TAIL(head, field); \ 706 TAILQ_NEXT((elm), field) = NULL; \ 707 (elm)->field.tqe_prev = (head)->tqh_last; \ 708 *(head)->tqh_last = (elm); \ 709 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 710 QMD_TRACE_HEAD(head); \ 711 QMD_TRACE_ELEM(&(elm)->field); \ 712 } while (0) 713 714 #define TAILQ_LAST(head, headname) \ 715 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 716 717 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 718 719 #define TAILQ_PREV(elm, headname, field) \ 720 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 721 722 #define TAILQ_REMOVE(head, elm, field) do { \ 723 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 724 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 725 QMD_TAILQ_CHECK_NEXT(elm, field); \ 726 QMD_TAILQ_CHECK_PREV(elm, field); \ 727 if ((TAILQ_NEXT((elm), field)) != NULL) \ 728 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 729 (elm)->field.tqe_prev; \ 730 else { \ 731 (head)->tqh_last = (elm)->field.tqe_prev; \ 732 QMD_TRACE_HEAD(head); \ 733 } \ 734 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 735 TRASHIT(*oldnext); \ 736 TRASHIT(*oldprev); \ 737 QMD_TRACE_ELEM(&(elm)->field); \ 738 } while (0) 739 740 #define TAILQ_SWAP(head1, head2, type, field) do { \ 741 QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first; \ 742 QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last; \ 743 (head1)->tqh_first = (head2)->tqh_first; \ 744 (head1)->tqh_last = (head2)->tqh_last; \ 745 (head2)->tqh_first = swap_first; \ 746 (head2)->tqh_last = swap_last; \ 747 if ((swap_first = (head1)->tqh_first) != NULL) \ 748 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 749 else \ 750 (head1)->tqh_last = &(head1)->tqh_first; \ 751 if ((swap_first = (head2)->tqh_first) != NULL) \ 752 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 753 else \ 754 (head2)->tqh_last = &(head2)->tqh_first; \ 755 } while (0) 756 757 #endif /* !_SYS_QUEUE_H_ */ 758