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 * _LAST_FAST - - - + 97 * _FOREACH + + + + 98 * _FOREACH_FROM + + + + 99 * _FOREACH_SAFE + + + + 100 * _FOREACH_FROM_SAFE + + + + 101 * _FOREACH_REVERSE - - - + 102 * _FOREACH_REVERSE_FROM - - - + 103 * _FOREACH_REVERSE_SAFE - - - + 104 * _FOREACH_REVERSE_FROM_SAFE - - - + 105 * _INSERT_HEAD + + + + 106 * _INSERT_BEFORE - + - + 107 * _INSERT_AFTER + + + + 108 * _INSERT_TAIL - - + + 109 * _CONCAT s s + + 110 * _REMOVE_AFTER + - + - 111 * _REMOVE_HEAD + - + - 112 * _REMOVE s + s + 113 * _SWAP + + + + 114 * 115 */ 116 #ifdef QUEUE_MACRO_DEBUG 117 /* Store the last 2 places the queue element or head was altered */ 118 struct qm_trace { 119 unsigned long lastline; 120 unsigned long prevline; 121 const char *lastfile; 122 const char *prevfile; 123 }; 124 125 #define TRACEBUF struct qm_trace trace; 126 #define TRACEBUF_INITIALIZER { __LINE__, 0, __FILE__, NULL } , 127 #define TRASHIT(x) do {(x) = (void *)-1;} while (0) 128 #define QMD_SAVELINK(name, link) void **name = (void *)&(link) 129 130 #define QMD_TRACE_HEAD(head) do { \ 131 (head)->trace.prevline = (head)->trace.lastline; \ 132 (head)->trace.prevfile = (head)->trace.lastfile; \ 133 (head)->trace.lastline = __LINE__; \ 134 (head)->trace.lastfile = __FILE__; \ 135 } while (0) 136 137 #define QMD_TRACE_ELEM(elem) do { \ 138 (elem)->trace.prevline = (elem)->trace.lastline; \ 139 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 140 (elem)->trace.lastline = __LINE__; \ 141 (elem)->trace.lastfile = __FILE__; \ 142 } while (0) 143 144 #else 145 #define QMD_TRACE_ELEM(elem) 146 #define QMD_TRACE_HEAD(head) 147 #define QMD_SAVELINK(name, link) 148 #define TRACEBUF 149 #define TRACEBUF_INITIALIZER 150 #define TRASHIT(x) 151 #endif /* QUEUE_MACRO_DEBUG */ 152 153 #ifdef __cplusplus 154 /* 155 * In C++ there can be structure lists and class lists: 156 */ 157 #define QUEUE_TYPEOF(type) type 158 #else 159 #define QUEUE_TYPEOF(type) struct type 160 #endif 161 162 /* 163 * Singly-linked List declarations. 164 */ 165 #define SLIST_HEAD(name, type) \ 166 struct name { \ 167 struct type *slh_first; /* first element */ \ 168 } 169 170 #define SLIST_CLASS_HEAD(name, type) \ 171 struct name { \ 172 class type *slh_first; /* first element */ \ 173 } 174 175 #define SLIST_HEAD_INITIALIZER(head) \ 176 { NULL } 177 178 #define SLIST_ENTRY(type) \ 179 struct { \ 180 struct type *sle_next; /* next element */ \ 181 } 182 183 #define SLIST_CLASS_ENTRY(type) \ 184 struct { \ 185 class type *sle_next; /* next element */ \ 186 } 187 188 /* 189 * Singly-linked List functions. 190 */ 191 #define SLIST_CONCAT(head1, head2, type, field) do { \ 192 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head1); \ 193 if (curelm == NULL) { \ 194 if ((SLIST_FIRST(head1) = SLIST_FIRST(head2)) != NULL) \ 195 SLIST_INIT(head2); \ 196 } else if (SLIST_FIRST(head2) != NULL) { \ 197 while (SLIST_NEXT(curelm, field) != NULL) \ 198 curelm = SLIST_NEXT(curelm, field); \ 199 SLIST_NEXT(curelm, field) = SLIST_FIRST(head2); \ 200 SLIST_INIT(head2); \ 201 } \ 202 } while (0) 203 204 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 205 206 #define SLIST_FIRST(head) ((head)->slh_first) 207 208 #define SLIST_FOREACH(var, head, field) \ 209 for ((var) = SLIST_FIRST((head)); \ 210 (var); \ 211 (var) = SLIST_NEXT((var), field)) 212 213 #define SLIST_FOREACH_FROM(var, head, field) \ 214 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 215 (var); \ 216 (var) = SLIST_NEXT((var), field)) 217 218 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 219 for ((var) = SLIST_FIRST((head)); \ 220 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 221 (var) = (tvar)) 222 223 #define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 224 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 225 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 226 (var) = (tvar)) 227 228 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 229 for ((varp) = &SLIST_FIRST((head)); \ 230 ((var) = *(varp)) != NULL; \ 231 (varp) = &SLIST_NEXT((var), field)) 232 233 #define SLIST_INIT(head) do { \ 234 SLIST_FIRST((head)) = NULL; \ 235 } while (0) 236 237 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 238 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 239 SLIST_NEXT((slistelm), field) = (elm); \ 240 } while (0) 241 242 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 243 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 244 SLIST_FIRST((head)) = (elm); \ 245 } while (0) 246 247 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 248 249 #define SLIST_REMOVE(head, elm, type, field) do { \ 250 QMD_SAVELINK(oldnext, (elm)->field.sle_next); \ 251 if (SLIST_FIRST((head)) == (elm)) { \ 252 SLIST_REMOVE_HEAD((head), field); \ 253 } \ 254 else { \ 255 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head); \ 256 while (SLIST_NEXT(curelm, field) != (elm)) \ 257 curelm = SLIST_NEXT(curelm, field); \ 258 SLIST_REMOVE_AFTER(curelm, field); \ 259 } \ 260 TRASHIT(*oldnext); \ 261 } while (0) 262 263 #define SLIST_REMOVE_AFTER(elm, field) do { \ 264 SLIST_NEXT(elm, field) = \ 265 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 266 } while (0) 267 268 #define SLIST_REMOVE_HEAD(head, field) do { \ 269 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 270 } while (0) 271 272 #define SLIST_SWAP(head1, head2, type) do { \ 273 QUEUE_TYPEOF(type) *swap_first = SLIST_FIRST(head1); \ 274 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 275 SLIST_FIRST(head2) = swap_first; \ 276 } while (0) 277 278 /* 279 * Singly-linked Tail queue declarations. 280 */ 281 #define STAILQ_HEAD(name, type) \ 282 struct name { \ 283 struct type *stqh_first;/* first element */ \ 284 struct type **stqh_last;/* addr of last next element */ \ 285 } 286 287 #define STAILQ_CLASS_HEAD(name, type) \ 288 struct name { \ 289 class type *stqh_first; /* first element */ \ 290 class type **stqh_last; /* addr of last next element */ \ 291 } 292 293 #define STAILQ_HEAD_INITIALIZER(head) \ 294 { NULL, &(head).stqh_first } 295 296 #define STAILQ_ENTRY(type) \ 297 struct { \ 298 struct type *stqe_next; /* next element */ \ 299 } 300 301 #define STAILQ_CLASS_ENTRY(type) \ 302 struct { \ 303 class type *stqe_next; /* next element */ \ 304 } 305 306 /* 307 * Singly-linked Tail queue functions. 308 */ 309 #define STAILQ_CONCAT(head1, head2) do { \ 310 if (!STAILQ_EMPTY((head2))) { \ 311 *(head1)->stqh_last = (head2)->stqh_first; \ 312 (head1)->stqh_last = (head2)->stqh_last; \ 313 STAILQ_INIT((head2)); \ 314 } \ 315 } while (0) 316 317 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 318 319 #define STAILQ_FIRST(head) ((head)->stqh_first) 320 321 #define STAILQ_FOREACH(var, head, field) \ 322 for((var) = STAILQ_FIRST((head)); \ 323 (var); \ 324 (var) = STAILQ_NEXT((var), field)) 325 326 #define STAILQ_FOREACH_FROM(var, head, field) \ 327 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 328 (var); \ 329 (var) = STAILQ_NEXT((var), field)) 330 331 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 332 for ((var) = STAILQ_FIRST((head)); \ 333 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 334 (var) = (tvar)) 335 336 #define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 337 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 338 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 339 (var) = (tvar)) 340 341 #define STAILQ_INIT(head) do { \ 342 STAILQ_FIRST((head)) = NULL; \ 343 (head)->stqh_last = &STAILQ_FIRST((head)); \ 344 } while (0) 345 346 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 347 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 348 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 349 STAILQ_NEXT((tqelm), field) = (elm); \ 350 } while (0) 351 352 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 353 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 354 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 355 STAILQ_FIRST((head)) = (elm); \ 356 } while (0) 357 358 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 359 STAILQ_NEXT((elm), field) = NULL; \ 360 *(head)->stqh_last = (elm); \ 361 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 362 } while (0) 363 364 #define STAILQ_LAST(head, type, field) \ 365 (STAILQ_EMPTY((head)) ? NULL : \ 366 __containerof((head)->stqh_last, \ 367 QUEUE_TYPEOF(type), field.stqe_next)) 368 369 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 370 371 #define STAILQ_REMOVE(head, elm, type, field) do { \ 372 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 373 if (STAILQ_FIRST((head)) == (elm)) { \ 374 STAILQ_REMOVE_HEAD((head), field); \ 375 } \ 376 else { \ 377 QUEUE_TYPEOF(type) *curelm = STAILQ_FIRST(head); \ 378 while (STAILQ_NEXT(curelm, field) != (elm)) \ 379 curelm = STAILQ_NEXT(curelm, field); \ 380 STAILQ_REMOVE_AFTER(head, curelm, field); \ 381 } \ 382 TRASHIT(*oldnext); \ 383 } while (0) 384 385 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 386 if ((STAILQ_NEXT(elm, field) = \ 387 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 388 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 389 } while (0) 390 391 #define STAILQ_REMOVE_HEAD(head, field) do { \ 392 if ((STAILQ_FIRST((head)) = \ 393 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 394 (head)->stqh_last = &STAILQ_FIRST((head)); \ 395 } while (0) 396 397 #define STAILQ_SWAP(head1, head2, type) do { \ 398 QUEUE_TYPEOF(type) *swap_first = STAILQ_FIRST(head1); \ 399 QUEUE_TYPEOF(type) **swap_last = (head1)->stqh_last; \ 400 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 401 (head1)->stqh_last = (head2)->stqh_last; \ 402 STAILQ_FIRST(head2) = swap_first; \ 403 (head2)->stqh_last = swap_last; \ 404 if (STAILQ_EMPTY(head1)) \ 405 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 406 if (STAILQ_EMPTY(head2)) \ 407 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 408 } while (0) 409 410 411 /* 412 * List declarations. 413 */ 414 #define LIST_HEAD(name, type) \ 415 struct name { \ 416 struct type *lh_first; /* first element */ \ 417 } 418 419 #define LIST_CLASS_HEAD(name, type) \ 420 struct name { \ 421 class type *lh_first; /* first element */ \ 422 } 423 424 #define LIST_HEAD_INITIALIZER(head) \ 425 { NULL } 426 427 #define LIST_ENTRY(type) \ 428 struct { \ 429 struct type *le_next; /* next element */ \ 430 struct type **le_prev; /* address of previous next element */ \ 431 } 432 433 #define LIST_CLASS_ENTRY(type) \ 434 struct { \ 435 class type *le_next; /* next element */ \ 436 class type **le_prev; /* address of previous next element */ \ 437 } 438 439 /* 440 * List functions. 441 */ 442 443 #if (defined(_KERNEL) && defined(INVARIANTS)) 444 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 445 if (LIST_FIRST((head)) != NULL && \ 446 LIST_FIRST((head))->field.le_prev != \ 447 &LIST_FIRST((head))) \ 448 panic("Bad list head %p first->prev != head", (head)); \ 449 } while (0) 450 451 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 452 if (LIST_NEXT((elm), field) != NULL && \ 453 LIST_NEXT((elm), field)->field.le_prev != \ 454 &((elm)->field.le_next)) \ 455 panic("Bad link elm %p next->prev != elm", (elm)); \ 456 } while (0) 457 458 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 459 if (*(elm)->field.le_prev != (elm)) \ 460 panic("Bad link elm %p prev->next != elm", (elm)); \ 461 } while (0) 462 #else 463 #define QMD_LIST_CHECK_HEAD(head, field) 464 #define QMD_LIST_CHECK_NEXT(elm, field) 465 #define QMD_LIST_CHECK_PREV(elm, field) 466 #endif /* (_KERNEL && INVARIANTS) */ 467 468 #define LIST_CONCAT(head1, head2, type, field) do { \ 469 QUEUE_TYPEOF(type) *curelm = LIST_FIRST(head1); \ 470 if (curelm == NULL) { \ 471 if ((LIST_FIRST(head1) = LIST_FIRST(head2)) != NULL) { \ 472 LIST_FIRST(head2)->field.le_prev = \ 473 &LIST_FIRST((head1)); \ 474 LIST_INIT(head2); \ 475 } \ 476 } else if (LIST_FIRST(head2) != NULL) { \ 477 while (LIST_NEXT(curelm, field) != NULL) \ 478 curelm = LIST_NEXT(curelm, field); \ 479 LIST_NEXT(curelm, field) = LIST_FIRST(head2); \ 480 LIST_FIRST(head2)->field.le_prev = &LIST_NEXT(curelm, field); \ 481 LIST_INIT(head2); \ 482 } \ 483 } while (0) 484 485 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 486 487 #define LIST_FIRST(head) ((head)->lh_first) 488 489 #define LIST_FOREACH(var, head, field) \ 490 for ((var) = LIST_FIRST((head)); \ 491 (var); \ 492 (var) = LIST_NEXT((var), field)) 493 494 #define LIST_FOREACH_FROM(var, head, field) \ 495 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 496 (var); \ 497 (var) = LIST_NEXT((var), field)) 498 499 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 500 for ((var) = LIST_FIRST((head)); \ 501 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 502 (var) = (tvar)) 503 504 #define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 505 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 506 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 507 (var) = (tvar)) 508 509 #define LIST_INIT(head) do { \ 510 LIST_FIRST((head)) = NULL; \ 511 } while (0) 512 513 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 514 QMD_LIST_CHECK_NEXT(listelm, field); \ 515 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 516 LIST_NEXT((listelm), field)->field.le_prev = \ 517 &LIST_NEXT((elm), field); \ 518 LIST_NEXT((listelm), field) = (elm); \ 519 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 520 } while (0) 521 522 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 523 QMD_LIST_CHECK_PREV(listelm, field); \ 524 (elm)->field.le_prev = (listelm)->field.le_prev; \ 525 LIST_NEXT((elm), field) = (listelm); \ 526 *(listelm)->field.le_prev = (elm); \ 527 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 528 } while (0) 529 530 #define LIST_INSERT_HEAD(head, elm, field) do { \ 531 QMD_LIST_CHECK_HEAD((head), field); \ 532 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 533 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 534 LIST_FIRST((head)) = (elm); \ 535 (elm)->field.le_prev = &LIST_FIRST((head)); \ 536 } while (0) 537 538 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 539 540 #define LIST_PREV(elm, head, type, field) \ 541 ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \ 542 __containerof((elm)->field.le_prev, \ 543 QUEUE_TYPEOF(type), field.le_next)) 544 545 #define LIST_REMOVE(elm, field) do { \ 546 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 547 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 548 QMD_LIST_CHECK_NEXT(elm, field); \ 549 QMD_LIST_CHECK_PREV(elm, field); \ 550 if (LIST_NEXT((elm), field) != NULL) \ 551 LIST_NEXT((elm), field)->field.le_prev = \ 552 (elm)->field.le_prev; \ 553 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 554 TRASHIT(*oldnext); \ 555 TRASHIT(*oldprev); \ 556 } while (0) 557 558 #define LIST_SWAP(head1, head2, type, field) do { \ 559 QUEUE_TYPEOF(type) *swap_tmp = LIST_FIRST(head1); \ 560 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 561 LIST_FIRST((head2)) = swap_tmp; \ 562 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 563 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 564 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 565 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 566 } while (0) 567 568 /* 569 * Tail queue declarations. 570 */ 571 #define TAILQ_HEAD(name, type) \ 572 struct name { \ 573 struct type *tqh_first; /* first element */ \ 574 struct type **tqh_last; /* addr of last next element */ \ 575 TRACEBUF \ 576 } 577 578 #define TAILQ_CLASS_HEAD(name, type) \ 579 struct name { \ 580 class type *tqh_first; /* first element */ \ 581 class type **tqh_last; /* addr of last next element */ \ 582 TRACEBUF \ 583 } 584 585 #define TAILQ_HEAD_INITIALIZER(head) \ 586 { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER } 587 588 #define TAILQ_ENTRY(type) \ 589 struct { \ 590 struct type *tqe_next; /* next element */ \ 591 struct type **tqe_prev; /* address of previous next element */ \ 592 TRACEBUF \ 593 } 594 595 #define TAILQ_CLASS_ENTRY(type) \ 596 struct { \ 597 class type *tqe_next; /* next element */ \ 598 class type **tqe_prev; /* address of previous next element */ \ 599 TRACEBUF \ 600 } 601 602 /* 603 * Tail queue functions. 604 */ 605 #if (defined(_KERNEL) && defined(INVARIANTS)) 606 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 607 if (!TAILQ_EMPTY(head) && \ 608 TAILQ_FIRST((head))->field.tqe_prev != \ 609 &TAILQ_FIRST((head))) \ 610 panic("Bad tailq head %p first->prev != head", (head)); \ 611 } while (0) 612 613 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 614 if (*(head)->tqh_last != NULL) \ 615 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 616 } while (0) 617 618 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 619 if (TAILQ_NEXT((elm), field) != NULL && \ 620 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 621 &((elm)->field.tqe_next)) \ 622 panic("Bad link elm %p next->prev != elm", (elm)); \ 623 } while (0) 624 625 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 626 if (*(elm)->field.tqe_prev != (elm)) \ 627 panic("Bad link elm %p prev->next != elm", (elm)); \ 628 } while (0) 629 #else 630 #define QMD_TAILQ_CHECK_HEAD(head, field) 631 #define QMD_TAILQ_CHECK_TAIL(head, headname) 632 #define QMD_TAILQ_CHECK_NEXT(elm, field) 633 #define QMD_TAILQ_CHECK_PREV(elm, field) 634 #endif /* (_KERNEL && INVARIANTS) */ 635 636 #define TAILQ_CONCAT(head1, head2, field) do { \ 637 if (!TAILQ_EMPTY(head2)) { \ 638 *(head1)->tqh_last = (head2)->tqh_first; \ 639 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 640 (head1)->tqh_last = (head2)->tqh_last; \ 641 TAILQ_INIT((head2)); \ 642 QMD_TRACE_HEAD(head1); \ 643 QMD_TRACE_HEAD(head2); \ 644 } \ 645 } while (0) 646 647 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 648 649 #define TAILQ_FIRST(head) ((head)->tqh_first) 650 651 #define TAILQ_FOREACH(var, head, field) \ 652 for ((var) = TAILQ_FIRST((head)); \ 653 (var); \ 654 (var) = TAILQ_NEXT((var), field)) 655 656 #define TAILQ_FOREACH_FROM(var, head, field) \ 657 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 658 (var); \ 659 (var) = TAILQ_NEXT((var), field)) 660 661 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 662 for ((var) = TAILQ_FIRST((head)); \ 663 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 664 (var) = (tvar)) 665 666 #define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 667 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 668 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 669 (var) = (tvar)) 670 671 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 672 for ((var) = TAILQ_LAST((head), headname); \ 673 (var); \ 674 (var) = TAILQ_PREV((var), headname, field)) 675 676 #define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \ 677 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 678 (var); \ 679 (var) = TAILQ_PREV((var), headname, field)) 680 681 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 682 for ((var) = TAILQ_LAST((head), headname); \ 683 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 684 (var) = (tvar)) 685 686 #define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \ 687 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 688 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 689 (var) = (tvar)) 690 691 #define TAILQ_INIT(head) do { \ 692 TAILQ_FIRST((head)) = NULL; \ 693 (head)->tqh_last = &TAILQ_FIRST((head)); \ 694 QMD_TRACE_HEAD(head); \ 695 } while (0) 696 697 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 698 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 699 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 700 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 701 &TAILQ_NEXT((elm), field); \ 702 else { \ 703 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 704 QMD_TRACE_HEAD(head); \ 705 } \ 706 TAILQ_NEXT((listelm), field) = (elm); \ 707 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 708 QMD_TRACE_ELEM(&(elm)->field); \ 709 QMD_TRACE_ELEM(&(listelm)->field); \ 710 } while (0) 711 712 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 713 QMD_TAILQ_CHECK_PREV(listelm, field); \ 714 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 715 TAILQ_NEXT((elm), field) = (listelm); \ 716 *(listelm)->field.tqe_prev = (elm); \ 717 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 718 QMD_TRACE_ELEM(&(elm)->field); \ 719 QMD_TRACE_ELEM(&(listelm)->field); \ 720 } while (0) 721 722 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 723 QMD_TAILQ_CHECK_HEAD(head, field); \ 724 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 725 TAILQ_FIRST((head))->field.tqe_prev = \ 726 &TAILQ_NEXT((elm), field); \ 727 else \ 728 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 729 TAILQ_FIRST((head)) = (elm); \ 730 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 731 QMD_TRACE_HEAD(head); \ 732 QMD_TRACE_ELEM(&(elm)->field); \ 733 } while (0) 734 735 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 736 QMD_TAILQ_CHECK_TAIL(head, field); \ 737 TAILQ_NEXT((elm), field) = NULL; \ 738 (elm)->field.tqe_prev = (head)->tqh_last; \ 739 *(head)->tqh_last = (elm); \ 740 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 741 QMD_TRACE_HEAD(head); \ 742 QMD_TRACE_ELEM(&(elm)->field); \ 743 } while (0) 744 745 #define TAILQ_LAST(head, headname) \ 746 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 747 748 /* 749 * The FAST function is fast in that it causes no data access other 750 * then the access to the head. The standard LAST function above 751 * will cause a data access of both the element you want and 752 * the previous element. FAST is very useful for instances when 753 * you may want to prefetch the last data element. 754 */ 755 #define TAILQ_LAST_FAST(head, type, field) \ 756 (TAILQ_EMPTY(head) ? NULL : __containerof((head)->tqh_last, QUEUE_TYPEOF(type), field.tqe_next)) 757 758 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 759 760 #define TAILQ_PREV(elm, headname, field) \ 761 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 762 763 #define TAILQ_PREV_FAST(elm, head, type, field) \ 764 ((elm)->field.tqe_prev == &(head)->tqh_first ? NULL : \ 765 __containerof((elm)->field.tqe_prev, QUEUE_TYPEOF(type), field.tqe_next)) 766 767 #define TAILQ_REMOVE(head, elm, field) do { \ 768 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 769 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 770 QMD_TAILQ_CHECK_NEXT(elm, field); \ 771 QMD_TAILQ_CHECK_PREV(elm, field); \ 772 if ((TAILQ_NEXT((elm), field)) != NULL) \ 773 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 774 (elm)->field.tqe_prev; \ 775 else { \ 776 (head)->tqh_last = (elm)->field.tqe_prev; \ 777 QMD_TRACE_HEAD(head); \ 778 } \ 779 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 780 TRASHIT(*oldnext); \ 781 TRASHIT(*oldprev); \ 782 QMD_TRACE_ELEM(&(elm)->field); \ 783 } while (0) 784 785 #define TAILQ_SWAP(head1, head2, type, field) do { \ 786 QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first; \ 787 QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last; \ 788 (head1)->tqh_first = (head2)->tqh_first; \ 789 (head1)->tqh_last = (head2)->tqh_last; \ 790 (head2)->tqh_first = swap_first; \ 791 (head2)->tqh_last = swap_last; \ 792 if ((swap_first = (head1)->tqh_first) != NULL) \ 793 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 794 else \ 795 (head1)->tqh_last = &(head1)->tqh_first; \ 796 if ((swap_first = (head2)->tqh_first) != NULL) \ 797 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 798 else \ 799 (head2)->tqh_last = &(head2)->tqh_first; \ 800 } while (0) 801 802 #endif /* !_SYS_QUEUE_H_ */ 803