1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)queue.h 8.5 (Berkeley) 8/20/94 32 * $FreeBSD$ 33 */ 34 35 #ifndef _SYS_QUEUE_H_ 36 #define _SYS_QUEUE_H_ 37 38 #include <sys/cdefs.h> 39 40 /* 41 * This file defines four types of data structures: singly-linked lists, 42 * singly-linked tail queues, lists and tail queues. 43 * 44 * A singly-linked list is headed by a single forward pointer. The elements 45 * are singly linked for minimum space and pointer manipulation overhead at 46 * the expense of O(n) removal for arbitrary elements. New elements can be 47 * added to the list after an existing element or at the head of the list. 48 * Elements being removed from the head of the list should use the explicit 49 * macro for this purpose for optimum efficiency. A singly-linked list may 50 * only be traversed in the forward direction. Singly-linked lists are ideal 51 * for applications with large datasets and few or no removals or for 52 * implementing a LIFO queue. 53 * 54 * A singly-linked tail queue is headed by a pair of pointers, one to the 55 * head of the list and the other to the tail of the list. The elements are 56 * singly linked for minimum space and pointer manipulation overhead at the 57 * expense of O(n) removal for arbitrary elements. New elements can be added 58 * to the list after an existing element, at the head of the list, or at the 59 * end of the list. Elements being removed from the head of the tail queue 60 * should use the explicit macro for this purpose for optimum efficiency. 61 * A singly-linked tail queue may only be traversed in the forward direction. 62 * Singly-linked tail queues are ideal for applications with large datasets 63 * and few or no removals or for implementing a FIFO queue. 64 * 65 * A list is headed by a single forward pointer (or an array of forward 66 * pointers for a hash table header). The elements are doubly linked 67 * so that an arbitrary element can be removed without a need to 68 * traverse the list. New elements can be added to the list before 69 * or after an existing element or at the head of the list. A list 70 * may be traversed in either direction. 71 * 72 * A tail queue is headed by a pair of pointers, one to the head of the 73 * list and the other to the tail of the list. The elements are doubly 74 * linked so that an arbitrary element can be removed without a need to 75 * traverse the list. New elements can be added to the list before or 76 * after an existing element, at the head of the list, or at the end of 77 * the list. A tail queue may be traversed in either direction. 78 * 79 * For details on the use of these macros, see the queue(3) manual page. 80 * 81 * Below is a summary of implemented functions where: 82 * + means the macro is available 83 * - means the macro is not available 84 * s means the macro is available but is slow (runs in O(n) time) 85 * 86 * SLIST LIST STAILQ TAILQ 87 * _HEAD + + + + 88 * _CLASS_HEAD + + + + 89 * _HEAD_INITIALIZER + + + + 90 * _ENTRY + + + + 91 * _CLASS_ENTRY + + + + 92 * _INIT + + + + 93 * _EMPTY + + + + 94 * _END + + + + 95 * _FIRST + + + + 96 * _NEXT + + + + 97 * _PREV - + - + 98 * _LAST - - + + 99 * _LAST_FAST - - - + 100 * _FOREACH + + + + 101 * _FOREACH_FROM + + + + 102 * _FOREACH_SAFE + + + + 103 * _FOREACH_FROM_SAFE + + + + 104 * _FOREACH_REVERSE - - - + 105 * _FOREACH_REVERSE_FROM - - - + 106 * _FOREACH_REVERSE_SAFE - - - + 107 * _FOREACH_REVERSE_FROM_SAFE - - - + 108 * _INSERT_HEAD + + + + 109 * _INSERT_BEFORE - + - + 110 * _INSERT_AFTER + + + + 111 * _INSERT_TAIL - - + + 112 * _CONCAT s s + + 113 * _REMOVE_AFTER + - + - 114 * _REMOVE_HEAD + - + - 115 * _REMOVE s + s + 116 * _SWAP + + + + 117 * 118 */ 119 #ifdef QUEUE_MACRO_DEBUG 120 #warn Use QUEUE_MACRO_DEBUG_TRACE and/or QUEUE_MACRO_DEBUG_TRASH 121 #define QUEUE_MACRO_DEBUG_TRACE 122 #define QUEUE_MACRO_DEBUG_TRASH 123 #endif 124 125 #ifdef QUEUE_MACRO_DEBUG_TRACE 126 /* Store the last 2 places the queue element or head was altered */ 127 struct qm_trace { 128 unsigned long lastline; 129 unsigned long prevline; 130 const char *lastfile; 131 const char *prevfile; 132 }; 133 134 #define TRACEBUF struct qm_trace trace; 135 #define TRACEBUF_INITIALIZER { __LINE__, 0, __FILE__, NULL } , 136 137 #define QMD_TRACE_HEAD(head) do { \ 138 (head)->trace.prevline = (head)->trace.lastline; \ 139 (head)->trace.prevfile = (head)->trace.lastfile; \ 140 (head)->trace.lastline = __LINE__; \ 141 (head)->trace.lastfile = __FILE__; \ 142 } while (0) 143 144 #define QMD_TRACE_ELEM(elem) do { \ 145 (elem)->trace.prevline = (elem)->trace.lastline; \ 146 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 147 (elem)->trace.lastline = __LINE__; \ 148 (elem)->trace.lastfile = __FILE__; \ 149 } while (0) 150 151 #else /* !QUEUE_MACRO_DEBUG_TRACE */ 152 #define QMD_TRACE_ELEM(elem) 153 #define QMD_TRACE_HEAD(head) 154 #define TRACEBUF 155 #define TRACEBUF_INITIALIZER 156 #endif /* QUEUE_MACRO_DEBUG_TRACE */ 157 158 #ifdef QUEUE_MACRO_DEBUG_TRASH 159 #define QMD_SAVELINK(name, link) void **name = (void *)&(link) 160 #define TRASHIT(x) do {(x) = (void *)-1;} while (0) 161 #define QMD_IS_TRASHED(x) ((x) == (void *)(intptr_t)-1) 162 #else /* !QUEUE_MACRO_DEBUG_TRASH */ 163 #define QMD_SAVELINK(name, link) 164 #define TRASHIT(x) 165 #define QMD_IS_TRASHED(x) 0 166 #endif /* QUEUE_MACRO_DEBUG_TRASH */ 167 168 #ifdef __cplusplus 169 /* 170 * In C++ there can be structure lists and class lists: 171 */ 172 #define QUEUE_TYPEOF(type) type 173 #else 174 #define QUEUE_TYPEOF(type) struct type 175 #endif 176 177 /* 178 * Singly-linked List declarations. 179 */ 180 #define SLIST_HEAD(name, type) \ 181 struct name { \ 182 struct type *slh_first; /* first element */ \ 183 } 184 185 #define SLIST_CLASS_HEAD(name, type) \ 186 struct name { \ 187 class type *slh_first; /* first element */ \ 188 } 189 190 #define SLIST_HEAD_INITIALIZER(head) \ 191 { NULL } 192 193 #define SLIST_ENTRY(type) \ 194 struct { \ 195 struct type *sle_next; /* next element */ \ 196 } 197 198 #define SLIST_CLASS_ENTRY(type) \ 199 struct { \ 200 class type *sle_next; /* next element */ \ 201 } 202 203 /* 204 * Singly-linked List functions. 205 */ 206 #if (defined(_KERNEL) && defined(INVARIANTS)) 207 #define QMD_SLIST_CHECK_PREVPTR(prevp, elm) do { \ 208 if (*(prevp) != (elm)) \ 209 panic("Bad prevptr *(%p) == %p != %p", \ 210 (prevp), *(prevp), (elm)); \ 211 } while (0) 212 #else 213 #define QMD_SLIST_CHECK_PREVPTR(prevp, elm) 214 #endif 215 216 #define SLIST_CONCAT(head1, head2, type, field) do { \ 217 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head1); \ 218 if (curelm == NULL) { \ 219 if ((SLIST_FIRST(head1) = SLIST_FIRST(head2)) != NULL) \ 220 SLIST_INIT(head2); \ 221 } else if (SLIST_FIRST(head2) != NULL) { \ 222 while (SLIST_NEXT(curelm, field) != NULL) \ 223 curelm = SLIST_NEXT(curelm, field); \ 224 SLIST_NEXT(curelm, field) = SLIST_FIRST(head2); \ 225 SLIST_INIT(head2); \ 226 } \ 227 } while (0) 228 229 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 230 231 #define SLIST_FIRST(head) ((head)->slh_first) 232 233 #define SLIST_FOREACH(var, head, field) \ 234 for ((var) = SLIST_FIRST((head)); \ 235 (var); \ 236 (var) = SLIST_NEXT((var), field)) 237 238 #define SLIST_FOREACH_FROM(var, head, field) \ 239 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 240 (var); \ 241 (var) = SLIST_NEXT((var), field)) 242 243 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 244 for ((var) = SLIST_FIRST((head)); \ 245 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 246 (var) = (tvar)) 247 248 #define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 249 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 250 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 251 (var) = (tvar)) 252 253 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 254 for ((varp) = &SLIST_FIRST((head)); \ 255 ((var) = *(varp)) != NULL; \ 256 (varp) = &SLIST_NEXT((var), field)) 257 258 #define SLIST_INIT(head) do { \ 259 SLIST_FIRST((head)) = NULL; \ 260 } while (0) 261 262 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 263 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 264 SLIST_NEXT((slistelm), field) = (elm); \ 265 } while (0) 266 267 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 268 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 269 SLIST_FIRST((head)) = (elm); \ 270 } while (0) 271 272 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 273 274 #define SLIST_REMOVE(head, elm, type, field) do { \ 275 if (SLIST_FIRST((head)) == (elm)) { \ 276 SLIST_REMOVE_HEAD((head), field); \ 277 } \ 278 else { \ 279 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head); \ 280 while (SLIST_NEXT(curelm, field) != (elm)) \ 281 curelm = SLIST_NEXT(curelm, field); \ 282 SLIST_REMOVE_AFTER(curelm, field); \ 283 } \ 284 } while (0) 285 286 #define SLIST_REMOVE_AFTER(elm, field) do { \ 287 QMD_SAVELINK(oldnext, SLIST_NEXT(elm, field)->field.sle_next); \ 288 SLIST_NEXT(elm, field) = \ 289 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 290 TRASHIT(*oldnext); \ 291 } while (0) 292 293 #define SLIST_REMOVE_HEAD(head, field) do { \ 294 QMD_SAVELINK(oldnext, SLIST_FIRST(head)->field.sle_next); \ 295 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 296 TRASHIT(*oldnext); \ 297 } while (0) 298 299 #define SLIST_REMOVE_PREVPTR(prevp, elm, field) do { \ 300 QMD_SLIST_CHECK_PREVPTR(prevp, elm); \ 301 *(prevp) = SLIST_NEXT(elm, field); \ 302 TRASHIT((elm)->field.sle_next); \ 303 } while (0) 304 305 #define SLIST_SWAP(head1, head2, type) do { \ 306 QUEUE_TYPEOF(type) *swap_first = SLIST_FIRST(head1); \ 307 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 308 SLIST_FIRST(head2) = swap_first; \ 309 } while (0) 310 311 #define SLIST_END(head) NULL 312 313 /* 314 * Singly-linked Tail queue declarations. 315 */ 316 #define STAILQ_HEAD(name, type) \ 317 struct name { \ 318 struct type *stqh_first;/* first element */ \ 319 struct type **stqh_last;/* addr of last next element */ \ 320 } 321 322 #define STAILQ_CLASS_HEAD(name, type) \ 323 struct name { \ 324 class type *stqh_first; /* first element */ \ 325 class type **stqh_last; /* addr of last next element */ \ 326 } 327 328 #define STAILQ_HEAD_INITIALIZER(head) \ 329 { NULL, &(head).stqh_first } 330 331 #define STAILQ_ENTRY(type) \ 332 struct { \ 333 struct type *stqe_next; /* next element */ \ 334 } 335 336 #define STAILQ_CLASS_ENTRY(type) \ 337 struct { \ 338 class type *stqe_next; /* next element */ \ 339 } 340 341 /* 342 * Singly-linked Tail queue functions. 343 */ 344 #define STAILQ_CONCAT(head1, head2) do { \ 345 if (!STAILQ_EMPTY((head2))) { \ 346 *(head1)->stqh_last = (head2)->stqh_first; \ 347 (head1)->stqh_last = (head2)->stqh_last; \ 348 STAILQ_INIT((head2)); \ 349 } \ 350 } while (0) 351 352 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 353 354 #define STAILQ_FIRST(head) ((head)->stqh_first) 355 356 #define STAILQ_FOREACH(var, head, field) \ 357 for((var) = STAILQ_FIRST((head)); \ 358 (var); \ 359 (var) = STAILQ_NEXT((var), field)) 360 361 #define STAILQ_FOREACH_FROM(var, head, field) \ 362 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 363 (var); \ 364 (var) = STAILQ_NEXT((var), field)) 365 366 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 367 for ((var) = STAILQ_FIRST((head)); \ 368 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 369 (var) = (tvar)) 370 371 #define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 372 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 373 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 374 (var) = (tvar)) 375 376 #define STAILQ_INIT(head) do { \ 377 STAILQ_FIRST((head)) = NULL; \ 378 (head)->stqh_last = &STAILQ_FIRST((head)); \ 379 } while (0) 380 381 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 382 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 383 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 384 STAILQ_NEXT((tqelm), field) = (elm); \ 385 } while (0) 386 387 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 388 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 389 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 390 STAILQ_FIRST((head)) = (elm); \ 391 } while (0) 392 393 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 394 STAILQ_NEXT((elm), field) = NULL; \ 395 *(head)->stqh_last = (elm); \ 396 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 397 } while (0) 398 399 #define STAILQ_LAST(head, type, field) \ 400 (STAILQ_EMPTY((head)) ? NULL : \ 401 __containerof((head)->stqh_last, \ 402 QUEUE_TYPEOF(type), field.stqe_next)) 403 404 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 405 406 #define STAILQ_REMOVE(head, elm, type, field) do { \ 407 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 408 if (STAILQ_FIRST((head)) == (elm)) { \ 409 STAILQ_REMOVE_HEAD((head), field); \ 410 } \ 411 else { \ 412 QUEUE_TYPEOF(type) *curelm = STAILQ_FIRST(head); \ 413 while (STAILQ_NEXT(curelm, field) != (elm)) \ 414 curelm = STAILQ_NEXT(curelm, field); \ 415 STAILQ_REMOVE_AFTER(head, curelm, field); \ 416 } \ 417 TRASHIT(*oldnext); \ 418 } while (0) 419 420 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 421 if ((STAILQ_NEXT(elm, field) = \ 422 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 423 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 424 } while (0) 425 426 #define STAILQ_REMOVE_HEAD(head, field) do { \ 427 if ((STAILQ_FIRST((head)) = \ 428 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 429 (head)->stqh_last = &STAILQ_FIRST((head)); \ 430 } while (0) 431 432 #define STAILQ_SWAP(head1, head2, type) do { \ 433 QUEUE_TYPEOF(type) *swap_first = STAILQ_FIRST(head1); \ 434 QUEUE_TYPEOF(type) **swap_last = (head1)->stqh_last; \ 435 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 436 (head1)->stqh_last = (head2)->stqh_last; \ 437 STAILQ_FIRST(head2) = swap_first; \ 438 (head2)->stqh_last = swap_last; \ 439 if (STAILQ_EMPTY(head1)) \ 440 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 441 if (STAILQ_EMPTY(head2)) \ 442 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 443 } while (0) 444 445 #define STAILQ_END(head) NULL 446 447 448 /* 449 * List declarations. 450 */ 451 #define LIST_HEAD(name, type) \ 452 struct name { \ 453 struct type *lh_first; /* first element */ \ 454 } 455 456 #define LIST_CLASS_HEAD(name, type) \ 457 struct name { \ 458 class type *lh_first; /* first element */ \ 459 } 460 461 #define LIST_HEAD_INITIALIZER(head) \ 462 { NULL } 463 464 #define LIST_ENTRY(type) \ 465 struct { \ 466 struct type *le_next; /* next element */ \ 467 struct type **le_prev; /* address of previous next element */ \ 468 } 469 470 #define LIST_CLASS_ENTRY(type) \ 471 struct { \ 472 class type *le_next; /* next element */ \ 473 class type **le_prev; /* address of previous next element */ \ 474 } 475 476 /* 477 * List functions. 478 */ 479 480 #if (defined(_KERNEL) && defined(INVARIANTS)) 481 /* 482 * QMD_LIST_CHECK_HEAD(LIST_HEAD *head, LIST_ENTRY NAME) 483 * 484 * If the list is non-empty, validates that the first element of the list 485 * points back at 'head.' 486 */ 487 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 488 if (LIST_FIRST((head)) != NULL && \ 489 LIST_FIRST((head))->field.le_prev != \ 490 &LIST_FIRST((head))) \ 491 panic("Bad list head %p first->prev != head", (head)); \ 492 } while (0) 493 494 /* 495 * QMD_LIST_CHECK_NEXT(TYPE *elm, LIST_ENTRY NAME) 496 * 497 * If an element follows 'elm' in the list, validates that the next element 498 * points back at 'elm.' 499 */ 500 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 501 if (LIST_NEXT((elm), field) != NULL && \ 502 LIST_NEXT((elm), field)->field.le_prev != \ 503 &((elm)->field.le_next)) \ 504 panic("Bad link elm %p next->prev != elm", (elm)); \ 505 } while (0) 506 507 /* 508 * QMD_LIST_CHECK_PREV(TYPE *elm, LIST_ENTRY NAME) 509 * 510 * Validates that the previous element (or head of the list) points to 'elm.' 511 */ 512 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 513 if (*(elm)->field.le_prev != (elm)) \ 514 panic("Bad link elm %p prev->next != elm", (elm)); \ 515 } while (0) 516 #else 517 #define QMD_LIST_CHECK_HEAD(head, field) 518 #define QMD_LIST_CHECK_NEXT(elm, field) 519 #define QMD_LIST_CHECK_PREV(elm, field) 520 #endif /* (_KERNEL && INVARIANTS) */ 521 522 #define LIST_CONCAT(head1, head2, type, field) do { \ 523 QUEUE_TYPEOF(type) *curelm = LIST_FIRST(head1); \ 524 if (curelm == NULL) { \ 525 if ((LIST_FIRST(head1) = LIST_FIRST(head2)) != NULL) { \ 526 LIST_FIRST(head2)->field.le_prev = \ 527 &LIST_FIRST((head1)); \ 528 LIST_INIT(head2); \ 529 } \ 530 } else if (LIST_FIRST(head2) != NULL) { \ 531 while (LIST_NEXT(curelm, field) != NULL) \ 532 curelm = LIST_NEXT(curelm, field); \ 533 LIST_NEXT(curelm, field) = LIST_FIRST(head2); \ 534 LIST_FIRST(head2)->field.le_prev = &LIST_NEXT(curelm, field); \ 535 LIST_INIT(head2); \ 536 } \ 537 } while (0) 538 539 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 540 541 #define LIST_FIRST(head) ((head)->lh_first) 542 543 #define LIST_FOREACH(var, head, field) \ 544 for ((var) = LIST_FIRST((head)); \ 545 (var); \ 546 (var) = LIST_NEXT((var), field)) 547 548 #define LIST_FOREACH_FROM(var, head, field) \ 549 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 550 (var); \ 551 (var) = LIST_NEXT((var), field)) 552 553 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 554 for ((var) = LIST_FIRST((head)); \ 555 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 556 (var) = (tvar)) 557 558 #define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 559 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 560 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 561 (var) = (tvar)) 562 563 #define LIST_INIT(head) do { \ 564 LIST_FIRST((head)) = NULL; \ 565 } while (0) 566 567 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 568 QMD_LIST_CHECK_NEXT(listelm, field); \ 569 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 570 LIST_NEXT((listelm), field)->field.le_prev = \ 571 &LIST_NEXT((elm), field); \ 572 LIST_NEXT((listelm), field) = (elm); \ 573 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 574 } while (0) 575 576 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 577 QMD_LIST_CHECK_PREV(listelm, field); \ 578 (elm)->field.le_prev = (listelm)->field.le_prev; \ 579 LIST_NEXT((elm), field) = (listelm); \ 580 *(listelm)->field.le_prev = (elm); \ 581 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 582 } while (0) 583 584 #define LIST_INSERT_HEAD(head, elm, field) do { \ 585 QMD_LIST_CHECK_HEAD((head), field); \ 586 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 587 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 588 LIST_FIRST((head)) = (elm); \ 589 (elm)->field.le_prev = &LIST_FIRST((head)); \ 590 } while (0) 591 592 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 593 594 #define LIST_PREV(elm, head, type, field) \ 595 ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \ 596 __containerof((elm)->field.le_prev, \ 597 QUEUE_TYPEOF(type), field.le_next)) 598 599 #define LIST_REMOVE(elm, field) do { \ 600 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 601 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 602 QMD_LIST_CHECK_NEXT(elm, field); \ 603 QMD_LIST_CHECK_PREV(elm, field); \ 604 if (LIST_NEXT((elm), field) != NULL) \ 605 LIST_NEXT((elm), field)->field.le_prev = \ 606 (elm)->field.le_prev; \ 607 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 608 TRASHIT(*oldnext); \ 609 TRASHIT(*oldprev); \ 610 } while (0) 611 612 #define LIST_SWAP(head1, head2, type, field) do { \ 613 QUEUE_TYPEOF(type) *swap_tmp = LIST_FIRST(head1); \ 614 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 615 LIST_FIRST((head2)) = swap_tmp; \ 616 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 617 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 618 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 619 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 620 } while (0) 621 622 #define LIST_END(head) NULL 623 624 /* 625 * Tail queue declarations. 626 */ 627 #define TAILQ_HEAD(name, type) \ 628 struct name { \ 629 struct type *tqh_first; /* first element */ \ 630 struct type **tqh_last; /* addr of last next element */ \ 631 TRACEBUF \ 632 } 633 634 #define TAILQ_CLASS_HEAD(name, type) \ 635 struct name { \ 636 class type *tqh_first; /* first element */ \ 637 class type **tqh_last; /* addr of last next element */ \ 638 TRACEBUF \ 639 } 640 641 #define TAILQ_HEAD_INITIALIZER(head) \ 642 { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER } 643 644 #define TAILQ_ENTRY(type) \ 645 struct { \ 646 struct type *tqe_next; /* next element */ \ 647 struct type **tqe_prev; /* address of previous next element */ \ 648 TRACEBUF \ 649 } 650 651 #define TAILQ_CLASS_ENTRY(type) \ 652 struct { \ 653 class type *tqe_next; /* next element */ \ 654 class type **tqe_prev; /* address of previous next element */ \ 655 TRACEBUF \ 656 } 657 658 /* 659 * Tail queue functions. 660 */ 661 #if (defined(_KERNEL) && defined(INVARIANTS)) 662 /* 663 * QMD_TAILQ_CHECK_HEAD(TAILQ_HEAD *head, TAILQ_ENTRY NAME) 664 * 665 * If the tailq is non-empty, validates that the first element of the tailq 666 * points back at 'head.' 667 */ 668 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 669 if (!TAILQ_EMPTY(head) && \ 670 TAILQ_FIRST((head))->field.tqe_prev != \ 671 &TAILQ_FIRST((head))) \ 672 panic("Bad tailq head %p first->prev != head", (head)); \ 673 } while (0) 674 675 /* 676 * QMD_TAILQ_CHECK_TAIL(TAILQ_HEAD *head, TAILQ_ENTRY NAME) 677 * 678 * Validates that the tail of the tailq is a pointer to pointer to NULL. 679 */ 680 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 681 if (*(head)->tqh_last != NULL) \ 682 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 683 } while (0) 684 685 /* 686 * QMD_TAILQ_CHECK_NEXT(TYPE *elm, TAILQ_ENTRY NAME) 687 * 688 * If an element follows 'elm' in the tailq, validates that the next element 689 * points back at 'elm.' 690 */ 691 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 692 if (TAILQ_NEXT((elm), field) != NULL && \ 693 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 694 &((elm)->field.tqe_next)) \ 695 panic("Bad link elm %p next->prev != elm", (elm)); \ 696 } while (0) 697 698 /* 699 * QMD_TAILQ_CHECK_PREV(TYPE *elm, TAILQ_ENTRY NAME) 700 * 701 * Validates that the previous element (or head of the tailq) points to 'elm.' 702 */ 703 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 704 if (*(elm)->field.tqe_prev != (elm)) \ 705 panic("Bad link elm %p prev->next != elm", (elm)); \ 706 } while (0) 707 #else 708 #define QMD_TAILQ_CHECK_HEAD(head, field) 709 #define QMD_TAILQ_CHECK_TAIL(head, headname) 710 #define QMD_TAILQ_CHECK_NEXT(elm, field) 711 #define QMD_TAILQ_CHECK_PREV(elm, field) 712 #endif /* (_KERNEL && INVARIANTS) */ 713 714 #define TAILQ_CONCAT(head1, head2, field) do { \ 715 if (!TAILQ_EMPTY(head2)) { \ 716 *(head1)->tqh_last = (head2)->tqh_first; \ 717 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 718 (head1)->tqh_last = (head2)->tqh_last; \ 719 TAILQ_INIT((head2)); \ 720 QMD_TRACE_HEAD(head1); \ 721 QMD_TRACE_HEAD(head2); \ 722 } \ 723 } while (0) 724 725 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 726 727 #define TAILQ_FIRST(head) ((head)->tqh_first) 728 729 #define TAILQ_FOREACH(var, head, field) \ 730 for ((var) = TAILQ_FIRST((head)); \ 731 (var); \ 732 (var) = TAILQ_NEXT((var), field)) 733 734 #define TAILQ_FOREACH_FROM(var, head, field) \ 735 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 736 (var); \ 737 (var) = TAILQ_NEXT((var), field)) 738 739 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 740 for ((var) = TAILQ_FIRST((head)); \ 741 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 742 (var) = (tvar)) 743 744 #define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 745 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 746 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 747 (var) = (tvar)) 748 749 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 750 for ((var) = TAILQ_LAST((head), headname); \ 751 (var); \ 752 (var) = TAILQ_PREV((var), headname, field)) 753 754 #define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \ 755 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 756 (var); \ 757 (var) = TAILQ_PREV((var), headname, field)) 758 759 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 760 for ((var) = TAILQ_LAST((head), headname); \ 761 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 762 (var) = (tvar)) 763 764 #define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar) \ 765 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 766 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 767 (var) = (tvar)) 768 769 #define TAILQ_INIT(head) do { \ 770 TAILQ_FIRST((head)) = NULL; \ 771 (head)->tqh_last = &TAILQ_FIRST((head)); \ 772 QMD_TRACE_HEAD(head); \ 773 } while (0) 774 775 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 776 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 777 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 778 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 779 &TAILQ_NEXT((elm), field); \ 780 else { \ 781 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 782 QMD_TRACE_HEAD(head); \ 783 } \ 784 TAILQ_NEXT((listelm), field) = (elm); \ 785 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 786 QMD_TRACE_ELEM(&(elm)->field); \ 787 QMD_TRACE_ELEM(&(listelm)->field); \ 788 } while (0) 789 790 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 791 QMD_TAILQ_CHECK_PREV(listelm, field); \ 792 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 793 TAILQ_NEXT((elm), field) = (listelm); \ 794 *(listelm)->field.tqe_prev = (elm); \ 795 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 796 QMD_TRACE_ELEM(&(elm)->field); \ 797 QMD_TRACE_ELEM(&(listelm)->field); \ 798 } while (0) 799 800 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 801 QMD_TAILQ_CHECK_HEAD(head, field); \ 802 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 803 TAILQ_FIRST((head))->field.tqe_prev = \ 804 &TAILQ_NEXT((elm), field); \ 805 else \ 806 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 807 TAILQ_FIRST((head)) = (elm); \ 808 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 809 QMD_TRACE_HEAD(head); \ 810 QMD_TRACE_ELEM(&(elm)->field); \ 811 } while (0) 812 813 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 814 QMD_TAILQ_CHECK_TAIL(head, field); \ 815 TAILQ_NEXT((elm), field) = NULL; \ 816 (elm)->field.tqe_prev = (head)->tqh_last; \ 817 *(head)->tqh_last = (elm); \ 818 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 819 QMD_TRACE_HEAD(head); \ 820 QMD_TRACE_ELEM(&(elm)->field); \ 821 } while (0) 822 823 #define TAILQ_LAST(head, headname) \ 824 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 825 826 /* 827 * The FAST function is fast in that it causes no data access other 828 * then the access to the head. The standard LAST function above 829 * will cause a data access of both the element you want and 830 * the previous element. FAST is very useful for instances when 831 * you may want to prefetch the last data element. 832 */ 833 #define TAILQ_LAST_FAST(head, type, field) \ 834 (TAILQ_EMPTY(head) ? NULL : __containerof((head)->tqh_last, QUEUE_TYPEOF(type), field.tqe_next)) 835 836 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 837 838 #define TAILQ_PREV(elm, headname, field) \ 839 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 840 841 #define TAILQ_PREV_FAST(elm, head, type, field) \ 842 ((elm)->field.tqe_prev == &(head)->tqh_first ? NULL : \ 843 __containerof((elm)->field.tqe_prev, QUEUE_TYPEOF(type), field.tqe_next)) 844 845 #define TAILQ_REMOVE(head, elm, field) do { \ 846 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 847 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 848 QMD_TAILQ_CHECK_NEXT(elm, field); \ 849 QMD_TAILQ_CHECK_PREV(elm, field); \ 850 if ((TAILQ_NEXT((elm), field)) != NULL) \ 851 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 852 (elm)->field.tqe_prev; \ 853 else { \ 854 (head)->tqh_last = (elm)->field.tqe_prev; \ 855 QMD_TRACE_HEAD(head); \ 856 } \ 857 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 858 TRASHIT(*oldnext); \ 859 TRASHIT(*oldprev); \ 860 QMD_TRACE_ELEM(&(elm)->field); \ 861 } while (0) 862 863 #define TAILQ_SWAP(head1, head2, type, field) do { \ 864 QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first; \ 865 QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last; \ 866 (head1)->tqh_first = (head2)->tqh_first; \ 867 (head1)->tqh_last = (head2)->tqh_last; \ 868 (head2)->tqh_first = swap_first; \ 869 (head2)->tqh_last = swap_last; \ 870 if ((swap_first = (head1)->tqh_first) != NULL) \ 871 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 872 else \ 873 (head1)->tqh_last = &(head1)->tqh_first; \ 874 if ((swap_first = (head2)->tqh_first) != NULL) \ 875 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 876 else \ 877 (head2)->tqh_last = &(head2)->tqh_first; \ 878 } while (0) 879 880 #define TAILQ_END(head) NULL 881 882 #endif /* !_SYS_QUEUE_H_ */ 883