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 32 #ifndef _SYS_QUEUE_H_ 33 #define _SYS_QUEUE_H_ 34 35 #include <sys/cdefs.h> 36 37 /* 38 * This file defines four types of data structures: singly-linked lists, 39 * singly-linked tail queues, lists and tail queues. 40 * 41 * A singly-linked list is headed by a single forward pointer. The elements 42 * are singly linked for minimum space and pointer manipulation overhead at 43 * the expense of O(n) removal for arbitrary elements. New elements can be 44 * added to the list after an existing element or at the head of the list. 45 * Elements being removed from the head of the list should use the explicit 46 * macro for this purpose for optimum efficiency. A singly-linked list may 47 * only be traversed in the forward direction. Singly-linked lists are ideal 48 * for applications with large datasets and few or no removals or for 49 * implementing a LIFO queue. 50 * 51 * A singly-linked tail queue is headed by a pair of pointers, one to the 52 * head of the list and the other to the tail of the list. The elements are 53 * singly linked for minimum space and pointer manipulation overhead at the 54 * expense of O(n) removal for arbitrary elements. New elements can be added 55 * to the list after an existing element, at the head of the list, or at the 56 * end of the list. Elements being removed from the head of the tail queue 57 * should use the explicit macro for this purpose for optimum efficiency. 58 * A singly-linked tail queue may only be traversed in the forward direction. 59 * Singly-linked tail queues are ideal for applications with large datasets 60 * and few or no removals or for implementing a FIFO queue. 61 * 62 * A list is headed by a single forward pointer (or an array of forward 63 * pointers for a hash table header). The elements are doubly linked 64 * so that an arbitrary element can be removed without a need to 65 * traverse the list. New elements can be added to the list before 66 * or after an existing element or at the head of the list. A list 67 * may be traversed in either direction. 68 * 69 * A tail queue is headed by a pair of pointers, one to the head of the 70 * list and the other to the tail of the list. The elements are doubly 71 * linked so that an arbitrary element can be removed without a need to 72 * traverse the list. New elements can be added to the list before or 73 * after an existing element, at the head of the list, or at the end of 74 * the list. A tail queue may be traversed in either direction. 75 * 76 * For details on the use of these macros, see the queue(3) manual page. 77 * 78 * Below is a summary of implemented functions where: 79 * + means the macro is available 80 * - means the macro is not available 81 * s means the macro is available but is slow (runs in O(n) time) 82 * 83 * SLIST LIST STAILQ TAILQ 84 * _HEAD + + + + 85 * _CLASS_HEAD + + + + 86 * _HEAD_INITIALIZER + + + + 87 * _ENTRY + + + + 88 * _CLASS_ENTRY + + + + 89 * _INIT + + + + 90 * _EMPTY + + + + 91 * _END + + + + 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 #warn Use QUEUE_MACRO_DEBUG_TRACE and/or QUEUE_MACRO_DEBUG_TRASH 118 #define QUEUE_MACRO_DEBUG_TRACE 119 #define QUEUE_MACRO_DEBUG_TRASH 120 #endif 121 122 #ifdef QUEUE_MACRO_DEBUG_TRACE 123 /* Store the last 2 places the queue element or head was altered */ 124 struct qm_trace { 125 unsigned long lastline; 126 unsigned long prevline; 127 const char *lastfile; 128 const char *prevfile; 129 }; 130 131 #define TRACEBUF struct qm_trace trace; 132 #define TRACEBUF_INITIALIZER { __LINE__, 0, __FILE__, NULL } , 133 134 #define QMD_TRACE_HEAD(head) do { \ 135 (head)->trace.prevline = (head)->trace.lastline; \ 136 (head)->trace.prevfile = (head)->trace.lastfile; \ 137 (head)->trace.lastline = __LINE__; \ 138 (head)->trace.lastfile = __FILE__; \ 139 } while (0) 140 141 #define QMD_TRACE_ELEM(elem) do { \ 142 (elem)->trace.prevline = (elem)->trace.lastline; \ 143 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 144 (elem)->trace.lastline = __LINE__; \ 145 (elem)->trace.lastfile = __FILE__; \ 146 } while (0) 147 148 #else /* !QUEUE_MACRO_DEBUG_TRACE */ 149 #define QMD_TRACE_ELEM(elem) 150 #define QMD_TRACE_HEAD(head) 151 #define TRACEBUF 152 #define TRACEBUF_INITIALIZER 153 #endif /* QUEUE_MACRO_DEBUG_TRACE */ 154 155 #ifdef QUEUE_MACRO_DEBUG_TRASH 156 #define QMD_SAVELINK(name, link) void **name = (void *)&(link) 157 #define TRASHIT(x) do {(x) = (void *)-1;} while (0) 158 #define QMD_IS_TRASHED(x) ((x) == (void *)(intptr_t)-1) 159 #else /* !QUEUE_MACRO_DEBUG_TRASH */ 160 #define QMD_SAVELINK(name, link) 161 #define TRASHIT(x) 162 #define QMD_IS_TRASHED(x) 0 163 #endif /* QUEUE_MACRO_DEBUG_TRASH */ 164 165 #ifdef __cplusplus 166 /* 167 * In C++ there can be structure lists and class lists: 168 */ 169 #define QUEUE_TYPEOF(type) type 170 #else 171 #define QUEUE_TYPEOF(type) struct type 172 #endif 173 174 /* 175 * Singly-linked List declarations. 176 */ 177 #define SLIST_HEAD(name, type) \ 178 struct name { \ 179 struct type *slh_first; /* first element */ \ 180 } 181 182 #define SLIST_CLASS_HEAD(name, type) \ 183 struct name { \ 184 class type *slh_first; /* first element */ \ 185 } 186 187 #define SLIST_HEAD_INITIALIZER(head) \ 188 { NULL } 189 190 #define SLIST_ENTRY(type) \ 191 struct { \ 192 struct type *sle_next; /* next element */ \ 193 } 194 195 #define SLIST_CLASS_ENTRY(type) \ 196 struct { \ 197 class type *sle_next; /* next element */ \ 198 } 199 200 /* 201 * Singly-linked List functions. 202 */ 203 #if (defined(_KERNEL) && defined(INVARIANTS)) 204 #define QMD_SLIST_CHECK_PREVPTR(prevp, elm) do { \ 205 if (*(prevp) != (elm)) \ 206 panic("Bad prevptr *(%p) == %p != %p", \ 207 (prevp), *(prevp), (elm)); \ 208 } while (0) 209 #else 210 #define QMD_SLIST_CHECK_PREVPTR(prevp, elm) 211 #endif 212 213 #define SLIST_CONCAT(head1, head2, type, field) do { \ 214 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head1); \ 215 if (curelm == NULL) { \ 216 if ((SLIST_FIRST(head1) = SLIST_FIRST(head2)) != NULL) \ 217 SLIST_INIT(head2); \ 218 } else if (SLIST_FIRST(head2) != NULL) { \ 219 while (SLIST_NEXT(curelm, field) != NULL) \ 220 curelm = SLIST_NEXT(curelm, field); \ 221 SLIST_NEXT(curelm, field) = SLIST_FIRST(head2); \ 222 SLIST_INIT(head2); \ 223 } \ 224 } while (0) 225 226 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 227 228 #define SLIST_FIRST(head) ((head)->slh_first) 229 230 #define SLIST_FOREACH(var, head, field) \ 231 for ((var) = SLIST_FIRST((head)); \ 232 (var); \ 233 (var) = SLIST_NEXT((var), field)) 234 235 #define SLIST_FOREACH_FROM(var, head, field) \ 236 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 237 (var); \ 238 (var) = SLIST_NEXT((var), field)) 239 240 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 241 for ((var) = SLIST_FIRST((head)); \ 242 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 243 (var) = (tvar)) 244 245 #define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 246 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 247 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 248 (var) = (tvar)) 249 250 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 251 for ((varp) = &SLIST_FIRST((head)); \ 252 ((var) = *(varp)) != NULL; \ 253 (varp) = &SLIST_NEXT((var), field)) 254 255 #define SLIST_INIT(head) do { \ 256 SLIST_FIRST((head)) = NULL; \ 257 } while (0) 258 259 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 260 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 261 SLIST_NEXT((slistelm), field) = (elm); \ 262 } while (0) 263 264 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 265 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 266 SLIST_FIRST((head)) = (elm); \ 267 } while (0) 268 269 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 270 271 #define SLIST_REMOVE(head, elm, type, field) do { \ 272 if (SLIST_FIRST((head)) == (elm)) { \ 273 SLIST_REMOVE_HEAD((head), field); \ 274 } \ 275 else { \ 276 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head); \ 277 while (SLIST_NEXT(curelm, field) != (elm)) \ 278 curelm = SLIST_NEXT(curelm, field); \ 279 SLIST_REMOVE_AFTER(curelm, field); \ 280 } \ 281 } while (0) 282 283 #define SLIST_REMOVE_AFTER(elm, field) do { \ 284 QMD_SAVELINK(oldnext, SLIST_NEXT(elm, field)->field.sle_next); \ 285 SLIST_NEXT(elm, field) = \ 286 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 287 TRASHIT(*oldnext); \ 288 } while (0) 289 290 #define SLIST_REMOVE_HEAD(head, field) do { \ 291 QMD_SAVELINK(oldnext, SLIST_FIRST(head)->field.sle_next); \ 292 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 293 TRASHIT(*oldnext); \ 294 } while (0) 295 296 #define SLIST_REMOVE_PREVPTR(prevp, elm, field) do { \ 297 QMD_SLIST_CHECK_PREVPTR(prevp, elm); \ 298 *(prevp) = SLIST_NEXT(elm, field); \ 299 TRASHIT((elm)->field.sle_next); \ 300 } while (0) 301 302 #define SLIST_SWAP(head1, head2, type) do { \ 303 QUEUE_TYPEOF(type) *swap_first = SLIST_FIRST(head1); \ 304 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 305 SLIST_FIRST(head2) = swap_first; \ 306 } while (0) 307 308 #define SLIST_END(head) NULL 309 310 /* 311 * Singly-linked Tail queue declarations. 312 */ 313 #define STAILQ_HEAD(name, type) \ 314 struct name { \ 315 struct type *stqh_first;/* first element */ \ 316 struct type **stqh_last;/* addr of last next element */ \ 317 } 318 319 #define STAILQ_CLASS_HEAD(name, type) \ 320 struct name { \ 321 class type *stqh_first; /* first element */ \ 322 class type **stqh_last; /* addr of last next element */ \ 323 } 324 325 #define STAILQ_HEAD_INITIALIZER(head) \ 326 { NULL, &(head).stqh_first } 327 328 #define STAILQ_ENTRY(type) \ 329 struct { \ 330 struct type *stqe_next; /* next element */ \ 331 } 332 333 #define STAILQ_CLASS_ENTRY(type) \ 334 struct { \ 335 class type *stqe_next; /* next element */ \ 336 } 337 338 /* 339 * Singly-linked Tail queue functions. 340 */ 341 #define STAILQ_CONCAT(head1, head2) do { \ 342 if (!STAILQ_EMPTY((head2))) { \ 343 *(head1)->stqh_last = (head2)->stqh_first; \ 344 (head1)->stqh_last = (head2)->stqh_last; \ 345 STAILQ_INIT((head2)); \ 346 } \ 347 } while (0) 348 349 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 350 351 #define STAILQ_FIRST(head) ((head)->stqh_first) 352 353 #define STAILQ_FOREACH(var, head, field) \ 354 for((var) = STAILQ_FIRST((head)); \ 355 (var); \ 356 (var) = STAILQ_NEXT((var), field)) 357 358 #define STAILQ_FOREACH_FROM(var, head, field) \ 359 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 360 (var); \ 361 (var) = STAILQ_NEXT((var), field)) 362 363 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 364 for ((var) = STAILQ_FIRST((head)); \ 365 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 366 (var) = (tvar)) 367 368 #define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 369 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 370 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 371 (var) = (tvar)) 372 373 #define STAILQ_INIT(head) do { \ 374 STAILQ_FIRST((head)) = NULL; \ 375 (head)->stqh_last = &STAILQ_FIRST((head)); \ 376 } while (0) 377 378 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 379 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 380 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 381 STAILQ_NEXT((tqelm), field) = (elm); \ 382 } while (0) 383 384 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 385 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 386 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 387 STAILQ_FIRST((head)) = (elm); \ 388 } while (0) 389 390 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 391 STAILQ_NEXT((elm), field) = NULL; \ 392 *(head)->stqh_last = (elm); \ 393 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 394 } while (0) 395 396 #define STAILQ_LAST(head, type, field) \ 397 (STAILQ_EMPTY((head)) ? NULL : \ 398 __containerof((head)->stqh_last, \ 399 QUEUE_TYPEOF(type), field.stqe_next)) 400 401 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 402 403 #define STAILQ_REMOVE(head, elm, type, field) do { \ 404 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 405 if (STAILQ_FIRST((head)) == (elm)) { \ 406 STAILQ_REMOVE_HEAD((head), field); \ 407 } \ 408 else { \ 409 QUEUE_TYPEOF(type) *curelm = STAILQ_FIRST(head); \ 410 while (STAILQ_NEXT(curelm, field) != (elm)) \ 411 curelm = STAILQ_NEXT(curelm, field); \ 412 STAILQ_REMOVE_AFTER(head, curelm, field); \ 413 } \ 414 TRASHIT(*oldnext); \ 415 } while (0) 416 417 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 418 if ((STAILQ_NEXT(elm, field) = \ 419 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 420 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 421 } while (0) 422 423 #define STAILQ_REMOVE_HEAD(head, field) do { \ 424 if ((STAILQ_FIRST((head)) = \ 425 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 426 (head)->stqh_last = &STAILQ_FIRST((head)); \ 427 } while (0) 428 429 #define STAILQ_SWAP(head1, head2, type) do { \ 430 QUEUE_TYPEOF(type) *swap_first = STAILQ_FIRST(head1); \ 431 QUEUE_TYPEOF(type) **swap_last = (head1)->stqh_last; \ 432 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 433 (head1)->stqh_last = (head2)->stqh_last; \ 434 STAILQ_FIRST(head2) = swap_first; \ 435 (head2)->stqh_last = swap_last; \ 436 if (STAILQ_EMPTY(head1)) \ 437 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 438 if (STAILQ_EMPTY(head2)) \ 439 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 440 } while (0) 441 442 #define STAILQ_END(head) NULL 443 444 445 /* 446 * List declarations. 447 */ 448 #define LIST_HEAD(name, type) \ 449 struct name { \ 450 struct type *lh_first; /* first element */ \ 451 } 452 453 #define LIST_CLASS_HEAD(name, type) \ 454 struct name { \ 455 class type *lh_first; /* first element */ \ 456 } 457 458 #define LIST_HEAD_INITIALIZER(head) \ 459 { NULL } 460 461 #define LIST_ENTRY(type) \ 462 struct { \ 463 struct type *le_next; /* next element */ \ 464 struct type **le_prev; /* address of previous next element */ \ 465 } 466 467 #define LIST_CLASS_ENTRY(type) \ 468 struct { \ 469 class type *le_next; /* next element */ \ 470 class type **le_prev; /* address of previous next element */ \ 471 } 472 473 /* 474 * List functions. 475 */ 476 477 #if (defined(_KERNEL) && defined(INVARIANTS)) 478 /* 479 * QMD_LIST_CHECK_HEAD(LIST_HEAD *head, LIST_ENTRY NAME) 480 * 481 * If the list is non-empty, validates that the first element of the list 482 * points back at 'head.' 483 */ 484 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 485 if (LIST_FIRST((head)) != NULL && \ 486 LIST_FIRST((head))->field.le_prev != \ 487 &LIST_FIRST((head))) \ 488 panic("Bad list head %p first->prev != head", (head)); \ 489 } while (0) 490 491 /* 492 * QMD_LIST_CHECK_NEXT(TYPE *elm, LIST_ENTRY NAME) 493 * 494 * If an element follows 'elm' in the list, validates that the next element 495 * points back at 'elm.' 496 */ 497 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 498 if (LIST_NEXT((elm), field) != NULL && \ 499 LIST_NEXT((elm), field)->field.le_prev != \ 500 &((elm)->field.le_next)) \ 501 panic("Bad link elm %p next->prev != elm", (elm)); \ 502 } while (0) 503 504 /* 505 * QMD_LIST_CHECK_PREV(TYPE *elm, LIST_ENTRY NAME) 506 * 507 * Validates that the previous element (or head of the list) points to 'elm.' 508 */ 509 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 510 if (*(elm)->field.le_prev != (elm)) \ 511 panic("Bad link elm %p prev->next != elm", (elm)); \ 512 } while (0) 513 #else 514 #define QMD_LIST_CHECK_HEAD(head, field) 515 #define QMD_LIST_CHECK_NEXT(elm, field) 516 #define QMD_LIST_CHECK_PREV(elm, field) 517 #endif /* (_KERNEL && INVARIANTS) */ 518 519 #define LIST_CONCAT(head1, head2, type, field) do { \ 520 QUEUE_TYPEOF(type) *curelm = LIST_FIRST(head1); \ 521 if (curelm == NULL) { \ 522 if ((LIST_FIRST(head1) = LIST_FIRST(head2)) != NULL) { \ 523 LIST_FIRST(head2)->field.le_prev = \ 524 &LIST_FIRST((head1)); \ 525 LIST_INIT(head2); \ 526 } \ 527 } else if (LIST_FIRST(head2) != NULL) { \ 528 while (LIST_NEXT(curelm, field) != NULL) \ 529 curelm = LIST_NEXT(curelm, field); \ 530 LIST_NEXT(curelm, field) = LIST_FIRST(head2); \ 531 LIST_FIRST(head2)->field.le_prev = &LIST_NEXT(curelm, field); \ 532 LIST_INIT(head2); \ 533 } \ 534 } while (0) 535 536 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 537 538 #define LIST_FIRST(head) ((head)->lh_first) 539 540 #define LIST_FOREACH(var, head, field) \ 541 for ((var) = LIST_FIRST((head)); \ 542 (var); \ 543 (var) = LIST_NEXT((var), field)) 544 545 #define LIST_FOREACH_FROM(var, head, field) \ 546 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 547 (var); \ 548 (var) = LIST_NEXT((var), field)) 549 550 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 551 for ((var) = LIST_FIRST((head)); \ 552 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 553 (var) = (tvar)) 554 555 #define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 556 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 557 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 558 (var) = (tvar)) 559 560 #define LIST_INIT(head) do { \ 561 LIST_FIRST((head)) = NULL; \ 562 } while (0) 563 564 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 565 QMD_LIST_CHECK_NEXT(listelm, field); \ 566 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 567 LIST_NEXT((listelm), field)->field.le_prev = \ 568 &LIST_NEXT((elm), field); \ 569 LIST_NEXT((listelm), field) = (elm); \ 570 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 571 } while (0) 572 573 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 574 QMD_LIST_CHECK_PREV(listelm, field); \ 575 (elm)->field.le_prev = (listelm)->field.le_prev; \ 576 LIST_NEXT((elm), field) = (listelm); \ 577 *(listelm)->field.le_prev = (elm); \ 578 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 579 } while (0) 580 581 #define LIST_INSERT_HEAD(head, elm, field) do { \ 582 QMD_LIST_CHECK_HEAD((head), field); \ 583 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 584 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 585 LIST_FIRST((head)) = (elm); \ 586 (elm)->field.le_prev = &LIST_FIRST((head)); \ 587 } while (0) 588 589 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 590 591 #define LIST_PREV(elm, head, type, field) \ 592 ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \ 593 __containerof((elm)->field.le_prev, \ 594 QUEUE_TYPEOF(type), field.le_next)) 595 596 #define LIST_REMOVE_HEAD(head, field) \ 597 LIST_REMOVE(LIST_FIRST(head), field) 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(head, field) \ 846 TAILQ_REMOVE(head, TAILQ_FIRST(head), field) 847 848 #define TAILQ_REMOVE(head, elm, field) do { \ 849 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 850 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 851 QMD_TAILQ_CHECK_NEXT(elm, field); \ 852 QMD_TAILQ_CHECK_PREV(elm, field); \ 853 if ((TAILQ_NEXT((elm), field)) != NULL) \ 854 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 855 (elm)->field.tqe_prev; \ 856 else { \ 857 (head)->tqh_last = (elm)->field.tqe_prev; \ 858 QMD_TRACE_HEAD(head); \ 859 } \ 860 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 861 TRASHIT(*oldnext); \ 862 TRASHIT(*oldprev); \ 863 QMD_TRACE_ELEM(&(elm)->field); \ 864 } while (0) 865 866 #define TAILQ_SWAP(head1, head2, type, field) do { \ 867 QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first; \ 868 QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last; \ 869 (head1)->tqh_first = (head2)->tqh_first; \ 870 (head1)->tqh_last = (head2)->tqh_last; \ 871 (head2)->tqh_first = swap_first; \ 872 (head2)->tqh_last = swap_last; \ 873 if ((swap_first = (head1)->tqh_first) != NULL) \ 874 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 875 else \ 876 (head1)->tqh_last = &(head1)->tqh_first; \ 877 if ((swap_first = (head2)->tqh_first) != NULL) \ 878 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 879 else \ 880 (head2)->tqh_last = &(head2)->tqh_first; \ 881 } while (0) 882 883 #define TAILQ_END(head) NULL 884 885 #endif /* !_SYS_QUEUE_H_ */ 886