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 * Below is a summary of implemented functions where: 80 * + means the macro is available 81 * - means the macro is not available 82 * s means the macro is available but is slow (runs in O(n) time) 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 s s + + 109 * _REMOVE_AFTER + - + - 110 * _REMOVE_HEAD + - + - 111 * _REMOVE s + s + 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_CONCAT(head1, head2, type, field) do { \ 191 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head1); \ 192 if (curelm == NULL) { \ 193 if ((SLIST_FIRST(head1) = SLIST_FIRST(head2)) != NULL) \ 194 SLIST_INIT(head2); \ 195 } else if (SLIST_FIRST(head2) != NULL) { \ 196 while (SLIST_NEXT(curelm, field) != NULL) \ 197 curelm = SLIST_NEXT(curelm, field); \ 198 SLIST_NEXT(curelm, field) = SLIST_FIRST(head2); \ 199 SLIST_INIT(head2); \ 200 } \ 201 } while (0) 202 203 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 204 205 #define SLIST_FIRST(head) ((head)->slh_first) 206 207 #define SLIST_FOREACH(var, head, field) \ 208 for ((var) = SLIST_FIRST((head)); \ 209 (var); \ 210 (var) = SLIST_NEXT((var), field)) 211 212 #define SLIST_FOREACH_FROM(var, head, field) \ 213 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 214 (var); \ 215 (var) = SLIST_NEXT((var), field)) 216 217 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 218 for ((var) = SLIST_FIRST((head)); \ 219 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 220 (var) = (tvar)) 221 222 #define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 223 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 224 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 225 (var) = (tvar)) 226 227 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 228 for ((varp) = &SLIST_FIRST((head)); \ 229 ((var) = *(varp)) != NULL; \ 230 (varp) = &SLIST_NEXT((var), field)) 231 232 #define SLIST_INIT(head) do { \ 233 SLIST_FIRST((head)) = NULL; \ 234 } while (0) 235 236 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 237 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 238 SLIST_NEXT((slistelm), field) = (elm); \ 239 } while (0) 240 241 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 242 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 243 SLIST_FIRST((head)) = (elm); \ 244 } while (0) 245 246 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 247 248 #define SLIST_REMOVE(head, elm, type, field) do { \ 249 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \ 250 if (SLIST_FIRST((head)) == (elm)) { \ 251 SLIST_REMOVE_HEAD((head), field); \ 252 } \ 253 else { \ 254 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head); \ 255 while (SLIST_NEXT(curelm, field) != (elm)) \ 256 curelm = SLIST_NEXT(curelm, field); \ 257 SLIST_REMOVE_AFTER(curelm, field); \ 258 } \ 259 TRASHIT(*oldnext); \ 260 } while (0) 261 262 #define SLIST_REMOVE_AFTER(elm, field) do { \ 263 SLIST_NEXT(elm, field) = \ 264 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 265 } while (0) 266 267 #define SLIST_REMOVE_HEAD(head, field) do { \ 268 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 269 } while (0) 270 271 #define SLIST_SWAP(head1, head2, type) do { \ 272 QUEUE_TYPEOF(type) *swap_first = SLIST_FIRST(head1); \ 273 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 274 SLIST_FIRST(head2) = swap_first; \ 275 } while (0) 276 277 /* 278 * Singly-linked Tail queue declarations. 279 */ 280 #define STAILQ_HEAD(name, type) \ 281 struct name { \ 282 struct type *stqh_first;/* first element */ \ 283 struct type **stqh_last;/* addr of last next element */ \ 284 } 285 286 #define STAILQ_CLASS_HEAD(name, type) \ 287 struct name { \ 288 class type *stqh_first; /* first element */ \ 289 class type **stqh_last; /* addr of last next element */ \ 290 } 291 292 #define STAILQ_HEAD_INITIALIZER(head) \ 293 { NULL, &(head).stqh_first } 294 295 #define STAILQ_ENTRY(type) \ 296 struct { \ 297 struct type *stqe_next; /* next element */ \ 298 } 299 300 #define STAILQ_CLASS_ENTRY(type) \ 301 struct { \ 302 class type *stqe_next; /* next element */ \ 303 } 304 305 /* 306 * Singly-linked Tail queue functions. 307 */ 308 #define STAILQ_CONCAT(head1, head2) do { \ 309 if (!STAILQ_EMPTY((head2))) { \ 310 *(head1)->stqh_last = (head2)->stqh_first; \ 311 (head1)->stqh_last = (head2)->stqh_last; \ 312 STAILQ_INIT((head2)); \ 313 } \ 314 } while (0) 315 316 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 317 318 #define STAILQ_FIRST(head) ((head)->stqh_first) 319 320 #define STAILQ_FOREACH(var, head, field) \ 321 for((var) = STAILQ_FIRST((head)); \ 322 (var); \ 323 (var) = STAILQ_NEXT((var), field)) 324 325 #define STAILQ_FOREACH_FROM(var, head, field) \ 326 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 327 (var); \ 328 (var) = STAILQ_NEXT((var), field)) 329 330 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 331 for ((var) = STAILQ_FIRST((head)); \ 332 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 333 (var) = (tvar)) 334 335 #define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 336 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 337 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 338 (var) = (tvar)) 339 340 #define STAILQ_INIT(head) do { \ 341 STAILQ_FIRST((head)) = NULL; \ 342 (head)->stqh_last = &STAILQ_FIRST((head)); \ 343 } while (0) 344 345 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 346 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 347 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 348 STAILQ_NEXT((tqelm), field) = (elm); \ 349 } while (0) 350 351 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 352 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 353 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 354 STAILQ_FIRST((head)) = (elm); \ 355 } while (0) 356 357 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 358 STAILQ_NEXT((elm), field) = NULL; \ 359 *(head)->stqh_last = (elm); \ 360 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 361 } while (0) 362 363 #define STAILQ_LAST(head, type, field) \ 364 (STAILQ_EMPTY((head)) ? NULL : \ 365 __containerof((head)->stqh_last, \ 366 QUEUE_TYPEOF(type), field.stqe_next)) 367 368 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 369 370 #define STAILQ_REMOVE(head, elm, type, field) do { \ 371 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 372 if (STAILQ_FIRST((head)) == (elm)) { \ 373 STAILQ_REMOVE_HEAD((head), field); \ 374 } \ 375 else { \ 376 QUEUE_TYPEOF(type) *curelm = STAILQ_FIRST(head); \ 377 while (STAILQ_NEXT(curelm, field) != (elm)) \ 378 curelm = STAILQ_NEXT(curelm, field); \ 379 STAILQ_REMOVE_AFTER(head, curelm, field); \ 380 } \ 381 TRASHIT(*oldnext); \ 382 } while (0) 383 384 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 385 if ((STAILQ_NEXT(elm, field) = \ 386 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 387 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 388 } while (0) 389 390 #define STAILQ_REMOVE_HEAD(head, field) do { \ 391 if ((STAILQ_FIRST((head)) = \ 392 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 393 (head)->stqh_last = &STAILQ_FIRST((head)); \ 394 } while (0) 395 396 #define STAILQ_SWAP(head1, head2, type) do { \ 397 QUEUE_TYPEOF(type) *swap_first = STAILQ_FIRST(head1); \ 398 QUEUE_TYPEOF(type) **swap_last = (head1)->stqh_last; \ 399 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 400 (head1)->stqh_last = (head2)->stqh_last; \ 401 STAILQ_FIRST(head2) = swap_first; \ 402 (head2)->stqh_last = swap_last; \ 403 if (STAILQ_EMPTY(head1)) \ 404 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 405 if (STAILQ_EMPTY(head2)) \ 406 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 407 } while (0) 408 409 410 /* 411 * List declarations. 412 */ 413 #define LIST_HEAD(name, type) \ 414 struct name { \ 415 struct type *lh_first; /* first element */ \ 416 } 417 418 #define LIST_CLASS_HEAD(name, type) \ 419 struct name { \ 420 class type *lh_first; /* first element */ \ 421 } 422 423 #define LIST_HEAD_INITIALIZER(head) \ 424 { NULL } 425 426 #define LIST_ENTRY(type) \ 427 struct { \ 428 struct type *le_next; /* next element */ \ 429 struct type **le_prev; /* address of previous next element */ \ 430 } 431 432 #define LIST_CLASS_ENTRY(type) \ 433 struct { \ 434 class type *le_next; /* next element */ \ 435 class type **le_prev; /* address of previous next element */ \ 436 } 437 438 /* 439 * List functions. 440 */ 441 442 #if (defined(_KERNEL) && defined(INVARIANTS)) 443 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 444 if (LIST_FIRST((head)) != NULL && \ 445 LIST_FIRST((head))->field.le_prev != \ 446 &LIST_FIRST((head))) \ 447 panic("Bad list head %p first->prev != head", (head)); \ 448 } while (0) 449 450 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 451 if (LIST_NEXT((elm), field) != NULL && \ 452 LIST_NEXT((elm), field)->field.le_prev != \ 453 &((elm)->field.le_next)) \ 454 panic("Bad link elm %p next->prev != elm", (elm)); \ 455 } while (0) 456 457 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 458 if (*(elm)->field.le_prev != (elm)) \ 459 panic("Bad link elm %p prev->next != elm", (elm)); \ 460 } while (0) 461 #else 462 #define QMD_LIST_CHECK_HEAD(head, field) 463 #define QMD_LIST_CHECK_NEXT(elm, field) 464 #define QMD_LIST_CHECK_PREV(elm, field) 465 #endif /* (_KERNEL && INVARIANTS) */ 466 467 #define LIST_CONCAT(head1, head2, type, field) do { \ 468 QUEUE_TYPEOF(type) *curelm = LIST_FIRST(head1); \ 469 if (curelm == NULL) { \ 470 if ((LIST_FIRST(head1) = LIST_FIRST(head2)) != NULL) { \ 471 LIST_FIRST(head2)->field.le_prev = \ 472 &LIST_FIRST((head1)); \ 473 LIST_INIT(head2); \ 474 } \ 475 } else if (LIST_FIRST(head2) != NULL) { \ 476 while (LIST_NEXT(curelm, field) != NULL) \ 477 curelm = LIST_NEXT(curelm, field); \ 478 LIST_NEXT(curelm, field) = LIST_FIRST(head2); \ 479 LIST_FIRST(head2)->field.le_prev = &LIST_NEXT(curelm, field); \ 480 LIST_INIT(head2); \ 481 } \ 482 } while (0) 483 484 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 485 486 #define LIST_FIRST(head) ((head)->lh_first) 487 488 #define LIST_FOREACH(var, head, field) \ 489 for ((var) = LIST_FIRST((head)); \ 490 (var); \ 491 (var) = LIST_NEXT((var), field)) 492 493 #define LIST_FOREACH_FROM(var, head, field) \ 494 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 495 (var); \ 496 (var) = LIST_NEXT((var), field)) 497 498 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 499 for ((var) = LIST_FIRST((head)); \ 500 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 501 (var) = (tvar)) 502 503 #define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 504 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 505 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 506 (var) = (tvar)) 507 508 #define LIST_INIT(head) do { \ 509 LIST_FIRST((head)) = NULL; \ 510 } while (0) 511 512 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 513 QMD_LIST_CHECK_NEXT(listelm, field); \ 514 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 515 LIST_NEXT((listelm), field)->field.le_prev = \ 516 &LIST_NEXT((elm), field); \ 517 LIST_NEXT((listelm), field) = (elm); \ 518 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 519 } while (0) 520 521 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 522 QMD_LIST_CHECK_PREV(listelm, field); \ 523 (elm)->field.le_prev = (listelm)->field.le_prev; \ 524 LIST_NEXT((elm), field) = (listelm); \ 525 *(listelm)->field.le_prev = (elm); \ 526 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 527 } while (0) 528 529 #define LIST_INSERT_HEAD(head, elm, field) do { \ 530 QMD_LIST_CHECK_HEAD((head), field); \ 531 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 532 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 533 LIST_FIRST((head)) = (elm); \ 534 (elm)->field.le_prev = &LIST_FIRST((head)); \ 535 } while (0) 536 537 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 538 539 #define LIST_PREV(elm, head, type, field) \ 540 ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \ 541 __containerof((elm)->field.le_prev, \ 542 QUEUE_TYPEOF(type), field.le_next)) 543 544 #define LIST_REMOVE(elm, field) do { \ 545 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 546 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 547 QMD_LIST_CHECK_NEXT(elm, field); \ 548 QMD_LIST_CHECK_PREV(elm, field); \ 549 if (LIST_NEXT((elm), field) != NULL) \ 550 LIST_NEXT((elm), field)->field.le_prev = \ 551 (elm)->field.le_prev; \ 552 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 553 TRASHIT(*oldnext); \ 554 TRASHIT(*oldprev); \ 555 } while (0) 556 557 #define LIST_SWAP(head1, head2, type, field) do { \ 558 QUEUE_TYPEOF(type) *swap_tmp = LIST_FIRST(head1); \ 559 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 560 LIST_FIRST((head2)) = swap_tmp; \ 561 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 562 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 563 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 564 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 565 } while (0) 566 567 /* 568 * Tail queue declarations. 569 */ 570 #define TAILQ_HEAD(name, type) \ 571 struct name { \ 572 struct type *tqh_first; /* first element */ \ 573 struct type **tqh_last; /* addr of last next element */ \ 574 TRACEBUF \ 575 } 576 577 #define TAILQ_CLASS_HEAD(name, type) \ 578 struct name { \ 579 class type *tqh_first; /* first element */ \ 580 class type **tqh_last; /* addr of last next element */ \ 581 TRACEBUF \ 582 } 583 584 #define TAILQ_HEAD_INITIALIZER(head) \ 585 { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER } 586 587 #define TAILQ_ENTRY(type) \ 588 struct { \ 589 struct type *tqe_next; /* next element */ \ 590 struct type **tqe_prev; /* address of previous next element */ \ 591 TRACEBUF \ 592 } 593 594 #define TAILQ_CLASS_ENTRY(type) \ 595 struct { \ 596 class type *tqe_next; /* next element */ \ 597 class type **tqe_prev; /* address of previous next element */ \ 598 TRACEBUF \ 599 } 600 601 /* 602 * Tail queue functions. 603 */ 604 #if (defined(_KERNEL) && defined(INVARIANTS)) 605 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 606 if (!TAILQ_EMPTY(head) && \ 607 TAILQ_FIRST((head))->field.tqe_prev != \ 608 &TAILQ_FIRST((head))) \ 609 panic("Bad tailq head %p first->prev != head", (head)); \ 610 } while (0) 611 612 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 613 if (*(head)->tqh_last != NULL) \ 614 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 615 } while (0) 616 617 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 618 if (TAILQ_NEXT((elm), field) != NULL && \ 619 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 620 &((elm)->field.tqe_next)) \ 621 panic("Bad link elm %p next->prev != elm", (elm)); \ 622 } while (0) 623 624 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 625 if (*(elm)->field.tqe_prev != (elm)) \ 626 panic("Bad link elm %p prev->next != elm", (elm)); \ 627 } while (0) 628 #else 629 #define QMD_TAILQ_CHECK_HEAD(head, field) 630 #define QMD_TAILQ_CHECK_TAIL(head, headname) 631 #define QMD_TAILQ_CHECK_NEXT(elm, field) 632 #define QMD_TAILQ_CHECK_PREV(elm, field) 633 #endif /* (_KERNEL && INVARIANTS) */ 634 635 #define TAILQ_CONCAT(head1, head2, field) do { \ 636 if (!TAILQ_EMPTY(head2)) { \ 637 *(head1)->tqh_last = (head2)->tqh_first; \ 638 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 639 (head1)->tqh_last = (head2)->tqh_last; \ 640 TAILQ_INIT((head2)); \ 641 QMD_TRACE_HEAD(head1); \ 642 QMD_TRACE_HEAD(head2); \ 643 } \ 644 } while (0) 645 646 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 647 648 #define TAILQ_FIRST(head) ((head)->tqh_first) 649 650 #define TAILQ_FOREACH(var, head, field) \ 651 for ((var) = TAILQ_FIRST((head)); \ 652 (var); \ 653 (var) = TAILQ_NEXT((var), field)) 654 655 #define TAILQ_FOREACH_FROM(var, head, field) \ 656 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 657 (var); \ 658 (var) = TAILQ_NEXT((var), field)) 659 660 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 661 for ((var) = TAILQ_FIRST((head)); \ 662 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 663 (var) = (tvar)) 664 665 #define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 666 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 667 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 668 (var) = (tvar)) 669 670 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 671 for ((var) = TAILQ_LAST((head), headname); \ 672 (var); \ 673 (var) = TAILQ_PREV((var), headname, field)) 674 675 #define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \ 676 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 677 (var); \ 678 (var) = TAILQ_PREV((var), headname, field)) 679 680 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 681 for ((var) = TAILQ_LAST((head), headname); \ 682 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 683 (var) = (tvar)) 684 685 #define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \ 686 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 687 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 688 (var) = (tvar)) 689 690 #define TAILQ_INIT(head) do { \ 691 TAILQ_FIRST((head)) = NULL; \ 692 (head)->tqh_last = &TAILQ_FIRST((head)); \ 693 QMD_TRACE_HEAD(head); \ 694 } while (0) 695 696 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 697 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 698 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 699 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 700 &TAILQ_NEXT((elm), field); \ 701 else { \ 702 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 703 QMD_TRACE_HEAD(head); \ 704 } \ 705 TAILQ_NEXT((listelm), field) = (elm); \ 706 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 707 QMD_TRACE_ELEM(&(elm)->field); \ 708 QMD_TRACE_ELEM(&(listelm)->field); \ 709 } while (0) 710 711 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 712 QMD_TAILQ_CHECK_PREV(listelm, field); \ 713 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 714 TAILQ_NEXT((elm), field) = (listelm); \ 715 *(listelm)->field.tqe_prev = (elm); \ 716 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 717 QMD_TRACE_ELEM(&(elm)->field); \ 718 QMD_TRACE_ELEM(&(listelm)->field); \ 719 } while (0) 720 721 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 722 QMD_TAILQ_CHECK_HEAD(head, field); \ 723 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 724 TAILQ_FIRST((head))->field.tqe_prev = \ 725 &TAILQ_NEXT((elm), field); \ 726 else \ 727 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 728 TAILQ_FIRST((head)) = (elm); \ 729 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 730 QMD_TRACE_HEAD(head); \ 731 QMD_TRACE_ELEM(&(elm)->field); \ 732 } while (0) 733 734 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 735 QMD_TAILQ_CHECK_TAIL(head, field); \ 736 TAILQ_NEXT((elm), field) = NULL; \ 737 (elm)->field.tqe_prev = (head)->tqh_last; \ 738 *(head)->tqh_last = (elm); \ 739 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 740 QMD_TRACE_HEAD(head); \ 741 QMD_TRACE_ELEM(&(elm)->field); \ 742 } while (0) 743 744 #define TAILQ_LAST(head, headname) \ 745 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 746 747 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 748 749 #define TAILQ_PREV(elm, headname, field) \ 750 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 751 752 #define TAILQ_REMOVE(head, elm, field) do { \ 753 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 754 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 755 QMD_TAILQ_CHECK_NEXT(elm, field); \ 756 QMD_TAILQ_CHECK_PREV(elm, field); \ 757 if ((TAILQ_NEXT((elm), field)) != NULL) \ 758 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 759 (elm)->field.tqe_prev; \ 760 else { \ 761 (head)->tqh_last = (elm)->field.tqe_prev; \ 762 QMD_TRACE_HEAD(head); \ 763 } \ 764 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 765 TRASHIT(*oldnext); \ 766 TRASHIT(*oldprev); \ 767 QMD_TRACE_ELEM(&(elm)->field); \ 768 } while (0) 769 770 #define TAILQ_SWAP(head1, head2, type, field) do { \ 771 QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first; \ 772 QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last; \ 773 (head1)->tqh_first = (head2)->tqh_first; \ 774 (head1)->tqh_last = (head2)->tqh_last; \ 775 (head2)->tqh_first = swap_first; \ 776 (head2)->tqh_last = swap_last; \ 777 if ((swap_first = (head1)->tqh_first) != NULL) \ 778 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 779 else \ 780 (head1)->tqh_last = &(head1)->tqh_first; \ 781 if ((swap_first = (head2)->tqh_first) != NULL) \ 782 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 783 else \ 784 (head2)->tqh_last = &(head2)->tqh_first; \ 785 } while (0) 786 787 #endif /* !_SYS_QUEUE_H_ */ 788