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 * _REPLACE - + - + 114 * _SWAP + + + + 115 * 116 */ 117 #ifdef QUEUE_MACRO_DEBUG 118 #warn Use QUEUE_MACRO_DEBUG_TRACE and/or QUEUE_MACRO_DEBUG_TRASH 119 #define QUEUE_MACRO_DEBUG_TRACE 120 #define QUEUE_MACRO_DEBUG_TRASH 121 #endif 122 123 #ifdef QUEUE_MACRO_DEBUG_TRACE 124 /* Store the last 2 places the queue element or head was altered */ 125 struct qm_trace { 126 unsigned long lastline; 127 unsigned long prevline; 128 const char *lastfile; 129 const char *prevfile; 130 }; 131 132 #define TRACEBUF struct qm_trace trace; 133 #define TRACEBUF_INITIALIZER { __LINE__, 0, __FILE__, NULL } , 134 135 #define QMD_TRACE_HEAD(head) do { \ 136 (head)->trace.prevline = (head)->trace.lastline; \ 137 (head)->trace.prevfile = (head)->trace.lastfile; \ 138 (head)->trace.lastline = __LINE__; \ 139 (head)->trace.lastfile = __FILE__; \ 140 } while (0) 141 142 #define QMD_TRACE_ELEM(elem) do { \ 143 (elem)->trace.prevline = (elem)->trace.lastline; \ 144 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 145 (elem)->trace.lastline = __LINE__; \ 146 (elem)->trace.lastfile = __FILE__; \ 147 } while (0) 148 149 #else /* !QUEUE_MACRO_DEBUG_TRACE */ 150 #define QMD_TRACE_ELEM(elem) 151 #define QMD_TRACE_HEAD(head) 152 #define TRACEBUF 153 #define TRACEBUF_INITIALIZER 154 #endif /* QUEUE_MACRO_DEBUG_TRACE */ 155 156 #ifdef QUEUE_MACRO_DEBUG_TRASH 157 #define QMD_SAVELINK(name, link) void **name = (void *)&(link) 158 #define TRASHIT(x) do {(x) = (void *)-1;} while (0) 159 #define QMD_IS_TRASHED(x) ((x) == (void *)(intptr_t)-1) 160 #else /* !QUEUE_MACRO_DEBUG_TRASH */ 161 #define QMD_SAVELINK(name, link) 162 #define TRASHIT(x) 163 #define QMD_IS_TRASHED(x) 0 164 #endif /* QUEUE_MACRO_DEBUG_TRASH */ 165 166 #ifdef __cplusplus 167 /* 168 * In C++ there can be structure lists and class lists: 169 */ 170 #define QUEUE_TYPEOF(type) type 171 #else 172 #define QUEUE_TYPEOF(type) struct type 173 #endif 174 175 /* 176 * Singly-linked List declarations. 177 */ 178 #define SLIST_HEAD(name, type) \ 179 struct name { \ 180 struct type *slh_first; /* first element */ \ 181 } 182 183 #define SLIST_CLASS_HEAD(name, type) \ 184 struct name { \ 185 class type *slh_first; /* first element */ \ 186 } 187 188 #define SLIST_HEAD_INITIALIZER(head) \ 189 { NULL } 190 191 #define SLIST_ENTRY(type) \ 192 struct { \ 193 struct type *sle_next; /* next element */ \ 194 } 195 196 #define SLIST_CLASS_ENTRY(type) \ 197 struct { \ 198 class type *sle_next; /* next element */ \ 199 } 200 201 /* 202 * Singly-linked List functions. 203 */ 204 #if (defined(_KERNEL) && defined(INVARIANTS)) 205 #define QMD_SLIST_CHECK_PREVPTR(prevp, elm) do { \ 206 if (*(prevp) != (elm)) \ 207 panic("Bad prevptr *(%p) == %p != %p", \ 208 (prevp), *(prevp), (elm)); \ 209 } while (0) 210 #else 211 #define QMD_SLIST_CHECK_PREVPTR(prevp, elm) 212 #endif 213 214 #define SLIST_CONCAT(head1, head2, type, field) do { \ 215 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head1); \ 216 if (curelm == NULL) { \ 217 if ((SLIST_FIRST(head1) = SLIST_FIRST(head2)) != NULL) \ 218 SLIST_INIT(head2); \ 219 } else if (SLIST_FIRST(head2) != NULL) { \ 220 while (SLIST_NEXT(curelm, field) != NULL) \ 221 curelm = SLIST_NEXT(curelm, field); \ 222 SLIST_NEXT(curelm, field) = SLIST_FIRST(head2); \ 223 SLIST_INIT(head2); \ 224 } \ 225 } while (0) 226 227 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 228 229 #define SLIST_EMPTY_ATOMIC(head) \ 230 (atomic_load_ptr(&(head)->slh_first) == NULL) 231 232 #define SLIST_FIRST(head) ((head)->slh_first) 233 234 #define SLIST_FOREACH(var, head, field) \ 235 for ((var) = SLIST_FIRST((head)); \ 236 (var); \ 237 (var) = SLIST_NEXT((var), field)) 238 239 #define SLIST_FOREACH_FROM(var, head, field) \ 240 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 241 (var); \ 242 (var) = SLIST_NEXT((var), field)) 243 244 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 245 for ((var) = SLIST_FIRST((head)); \ 246 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 247 (var) = (tvar)) 248 249 #define SLIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 250 for ((var) = ((var) ? (var) : SLIST_FIRST((head))); \ 251 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 252 (var) = (tvar)) 253 254 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 255 for ((varp) = &SLIST_FIRST((head)); \ 256 ((var) = *(varp)) != NULL; \ 257 (varp) = &SLIST_NEXT((var), field)) 258 259 #define SLIST_INIT(head) do { \ 260 SLIST_FIRST((head)) = NULL; \ 261 } while (0) 262 263 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 264 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 265 SLIST_NEXT((slistelm), field) = (elm); \ 266 } while (0) 267 268 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 269 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 270 SLIST_FIRST((head)) = (elm); \ 271 } while (0) 272 273 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 274 275 #define SLIST_REMOVE(head, elm, type, field) do { \ 276 if (SLIST_FIRST((head)) == (elm)) { \ 277 SLIST_REMOVE_HEAD((head), field); \ 278 } \ 279 else { \ 280 QUEUE_TYPEOF(type) *curelm = SLIST_FIRST(head); \ 281 while (SLIST_NEXT(curelm, field) != (elm)) \ 282 curelm = SLIST_NEXT(curelm, field); \ 283 SLIST_REMOVE_AFTER(curelm, field); \ 284 } \ 285 } while (0) 286 287 #define SLIST_REMOVE_AFTER(elm, field) do { \ 288 QMD_SAVELINK(oldnext, SLIST_NEXT(elm, field)->field.sle_next); \ 289 SLIST_NEXT(elm, field) = \ 290 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 291 TRASHIT(*oldnext); \ 292 } while (0) 293 294 #define SLIST_REMOVE_HEAD(head, field) do { \ 295 QMD_SAVELINK(oldnext, SLIST_FIRST(head)->field.sle_next); \ 296 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 297 TRASHIT(*oldnext); \ 298 } while (0) 299 300 #define SLIST_REMOVE_PREVPTR(prevp, elm, field) do { \ 301 QMD_SLIST_CHECK_PREVPTR(prevp, elm); \ 302 *(prevp) = SLIST_NEXT(elm, field); \ 303 TRASHIT((elm)->field.sle_next); \ 304 } while (0) 305 306 #define SLIST_SWAP(head1, head2, type) do { \ 307 QUEUE_TYPEOF(type) *swap_first = SLIST_FIRST(head1); \ 308 SLIST_FIRST(head1) = SLIST_FIRST(head2); \ 309 SLIST_FIRST(head2) = swap_first; \ 310 } while (0) 311 312 #define SLIST_END(head) NULL 313 314 /* 315 * Singly-linked Tail queue declarations. 316 */ 317 #define STAILQ_HEAD(name, type) \ 318 struct name { \ 319 struct type *stqh_first;/* first element */ \ 320 struct type **stqh_last;/* addr of last next element */ \ 321 } 322 323 #define STAILQ_CLASS_HEAD(name, type) \ 324 struct name { \ 325 class type *stqh_first; /* first element */ \ 326 class type **stqh_last; /* addr of last next element */ \ 327 } 328 329 #define STAILQ_HEAD_INITIALIZER(head) \ 330 { NULL, &(head).stqh_first } 331 332 #define STAILQ_ENTRY(type) \ 333 struct { \ 334 struct type *stqe_next; /* next element */ \ 335 } 336 337 #define STAILQ_CLASS_ENTRY(type) \ 338 struct { \ 339 class type *stqe_next; /* next element */ \ 340 } 341 342 /* 343 * Singly-linked Tail queue functions. 344 */ 345 #if (defined(_KERNEL) && defined(INVARIANTS)) 346 /* 347 * QMD_STAILQ_CHECK_EMPTY(STAILQ_HEAD *head) 348 * 349 * Validates that the stailq head's pointer to the last element's next pointer 350 * actually points to the head's first element pointer field. 351 */ 352 #define QMD_STAILQ_CHECK_EMPTY(head) do { \ 353 if ((head)->stqh_last != &(head)->stqh_first) \ 354 panic("Empty stailq %p->stqh_last is %p, not head's " \ 355 "first field address", (head), (head)->stqh_last); \ 356 } while (0) 357 358 #define STAILQ_ASSERT_EMPTY(head) do { \ 359 if (!STAILQ_EMPTY((head))) \ 360 panic("stailq %p is not empty", (head)); \ 361 } while (0) 362 363 /* 364 * QMD_STAILQ_CHECK_TAIL(STAILQ_HEAD *head) 365 * 366 * Validates that the stailq's last element's next pointer is NULL. 367 */ 368 #define QMD_STAILQ_CHECK_TAIL(head) do { \ 369 if (*(head)->stqh_last != NULL) \ 370 panic("Stailq %p last element's next pointer is %p, " \ 371 "not NULL", (head), *(head)->stqh_last); \ 372 } while (0) 373 #else 374 #define QMD_STAILQ_CHECK_EMPTY(head) 375 #define STAILQ_ASSERT_EMPTY(head) 376 #define QMD_STAILQ_CHECK_TAIL(head) 377 #endif /* (_KERNEL && INVARIANTS) */ 378 379 #define STAILQ_CONCAT(head1, head2) do { \ 380 if (!STAILQ_EMPTY((head2))) { \ 381 *(head1)->stqh_last = (head2)->stqh_first; \ 382 (head1)->stqh_last = (head2)->stqh_last; \ 383 STAILQ_INIT((head2)); \ 384 } \ 385 } while (0) 386 387 #define STAILQ_EMPTY(head) ({ \ 388 if (STAILQ_FIRST(head) == NULL) \ 389 QMD_STAILQ_CHECK_EMPTY(head); \ 390 STAILQ_FIRST(head) == NULL; \ 391 }) 392 393 #define STAILQ_EMPTY_ATOMIC(head) \ 394 (atomic_load_ptr(&(head)->stqh_first) == NULL) 395 396 #define STAILQ_FIRST(head) ((head)->stqh_first) 397 398 #define STAILQ_FOREACH(var, head, field) \ 399 for((var) = STAILQ_FIRST((head)); \ 400 (var); \ 401 (var) = STAILQ_NEXT((var), field)) 402 403 #define STAILQ_FOREACH_FROM(var, head, field) \ 404 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 405 (var); \ 406 (var) = STAILQ_NEXT((var), field)) 407 408 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 409 for ((var) = STAILQ_FIRST((head)); \ 410 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 411 (var) = (tvar)) 412 413 #define STAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 414 for ((var) = ((var) ? (var) : STAILQ_FIRST((head))); \ 415 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 416 (var) = (tvar)) 417 418 #define STAILQ_INIT(head) do { \ 419 STAILQ_FIRST((head)) = NULL; \ 420 (head)->stqh_last = &STAILQ_FIRST((head)); \ 421 } while (0) 422 423 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 424 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 425 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 426 STAILQ_NEXT((tqelm), field) = (elm); \ 427 } while (0) 428 429 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 430 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 431 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 432 STAILQ_FIRST((head)) = (elm); \ 433 } while (0) 434 435 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 436 QMD_STAILQ_CHECK_TAIL(head); \ 437 STAILQ_NEXT((elm), field) = NULL; \ 438 *(head)->stqh_last = (elm); \ 439 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 440 } while (0) 441 442 #define STAILQ_LAST(head, type, field) \ 443 (STAILQ_EMPTY((head)) ? NULL : \ 444 __containerof((head)->stqh_last, \ 445 QUEUE_TYPEOF(type), field.stqe_next)) 446 447 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 448 449 #define STAILQ_REMOVE(head, elm, type, field) do { \ 450 QMD_SAVELINK(oldnext, (elm)->field.stqe_next); \ 451 if (STAILQ_FIRST((head)) == (elm)) { \ 452 STAILQ_REMOVE_HEAD((head), field); \ 453 } \ 454 else { \ 455 QUEUE_TYPEOF(type) *curelm = STAILQ_FIRST(head); \ 456 while (STAILQ_NEXT(curelm, field) != (elm)) \ 457 curelm = STAILQ_NEXT(curelm, field); \ 458 STAILQ_REMOVE_AFTER(head, curelm, field); \ 459 } \ 460 TRASHIT(*oldnext); \ 461 } while (0) 462 463 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 464 if ((STAILQ_NEXT(elm, field) = \ 465 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 466 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 467 } while (0) 468 469 #define STAILQ_REMOVE_HEAD(head, field) do { \ 470 if ((STAILQ_FIRST((head)) = \ 471 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 472 (head)->stqh_last = &STAILQ_FIRST((head)); \ 473 } while (0) 474 475 #define STAILQ_SWAP(head1, head2, type) do { \ 476 QUEUE_TYPEOF(type) *swap_first = STAILQ_FIRST(head1); \ 477 QUEUE_TYPEOF(type) **swap_last = (head1)->stqh_last; \ 478 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 479 (head1)->stqh_last = (head2)->stqh_last; \ 480 STAILQ_FIRST(head2) = swap_first; \ 481 (head2)->stqh_last = swap_last; \ 482 if (STAILQ_FIRST(head1) == NULL) \ 483 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 484 if (STAILQ_FIRST(head2) == NULL) \ 485 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 486 } while (0) 487 488 #define STAILQ_END(head) NULL 489 490 491 /* 492 * List declarations. 493 */ 494 #define LIST_HEAD(name, type) \ 495 struct name { \ 496 struct type *lh_first; /* first element */ \ 497 } 498 499 #define LIST_CLASS_HEAD(name, type) \ 500 struct name { \ 501 class type *lh_first; /* first element */ \ 502 } 503 504 #define LIST_HEAD_INITIALIZER(head) \ 505 { NULL } 506 507 #define LIST_ENTRY(type) \ 508 struct { \ 509 struct type *le_next; /* next element */ \ 510 struct type **le_prev; /* address of previous next element */ \ 511 } 512 513 #define LIST_CLASS_ENTRY(type) \ 514 struct { \ 515 class type *le_next; /* next element */ \ 516 class type **le_prev; /* address of previous next element */ \ 517 } 518 519 /* 520 * List functions. 521 */ 522 523 #if (defined(_KERNEL) && defined(INVARIANTS)) 524 /* 525 * QMD_LIST_CHECK_HEAD(LIST_HEAD *head, LIST_ENTRY NAME) 526 * 527 * If the list is non-empty, validates that the first element of the list 528 * points back at 'head.' 529 */ 530 #define QMD_LIST_CHECK_HEAD(head, field) do { \ 531 if (LIST_FIRST((head)) != NULL && \ 532 LIST_FIRST((head))->field.le_prev != \ 533 &LIST_FIRST((head))) \ 534 panic("Bad list head %p first->prev != head", (head)); \ 535 } while (0) 536 537 /* 538 * QMD_LIST_CHECK_NEXT(TYPE *elm, LIST_ENTRY NAME) 539 * 540 * If an element follows 'elm' in the list, validates that the next element 541 * points back at 'elm.' 542 */ 543 #define QMD_LIST_CHECK_NEXT(elm, field) do { \ 544 if (LIST_NEXT((elm), field) != NULL && \ 545 LIST_NEXT((elm), field)->field.le_prev != \ 546 &((elm)->field.le_next)) \ 547 panic("Bad link elm %p next->prev != elm", (elm)); \ 548 } while (0) 549 550 /* 551 * QMD_LIST_CHECK_PREV(TYPE *elm, LIST_ENTRY NAME) 552 * 553 * Validates that the previous element (or head of the list) points to 'elm.' 554 */ 555 #define QMD_LIST_CHECK_PREV(elm, field) do { \ 556 if (*(elm)->field.le_prev != (elm)) \ 557 panic("Bad link elm %p prev->next != elm", (elm)); \ 558 } while (0) 559 #else 560 #define QMD_LIST_CHECK_HEAD(head, field) 561 #define QMD_LIST_CHECK_NEXT(elm, field) 562 #define QMD_LIST_CHECK_PREV(elm, field) 563 #endif /* (_KERNEL && INVARIANTS) */ 564 565 #define LIST_CONCAT(head1, head2, type, field) do { \ 566 QUEUE_TYPEOF(type) *curelm = LIST_FIRST(head1); \ 567 if (curelm == NULL) { \ 568 if ((LIST_FIRST(head1) = LIST_FIRST(head2)) != NULL) { \ 569 LIST_FIRST(head2)->field.le_prev = \ 570 &LIST_FIRST((head1)); \ 571 LIST_INIT(head2); \ 572 } \ 573 } else if (LIST_FIRST(head2) != NULL) { \ 574 while (LIST_NEXT(curelm, field) != NULL) \ 575 curelm = LIST_NEXT(curelm, field); \ 576 LIST_NEXT(curelm, field) = LIST_FIRST(head2); \ 577 LIST_FIRST(head2)->field.le_prev = &LIST_NEXT(curelm, field);\ 578 LIST_INIT(head2); \ 579 } \ 580 } while (0) 581 582 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 583 584 #define LIST_EMPTY_ATOMIC(head) \ 585 (atomic_load_ptr(&(head)->lh_first) == NULL) 586 587 #define LIST_FIRST(head) ((head)->lh_first) 588 589 #define LIST_FOREACH(var, head, field) \ 590 for ((var) = LIST_FIRST((head)); \ 591 (var); \ 592 (var) = LIST_NEXT((var), field)) 593 594 #define LIST_FOREACH_FROM(var, head, field) \ 595 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 596 (var); \ 597 (var) = LIST_NEXT((var), field)) 598 599 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 600 for ((var) = LIST_FIRST((head)); \ 601 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 602 (var) = (tvar)) 603 604 #define LIST_FOREACH_FROM_SAFE(var, head, field, tvar) \ 605 for ((var) = ((var) ? (var) : LIST_FIRST((head))); \ 606 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 607 (var) = (tvar)) 608 609 #define LIST_INIT(head) do { \ 610 LIST_FIRST((head)) = NULL; \ 611 } while (0) 612 613 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 614 QMD_LIST_CHECK_NEXT(listelm, field); \ 615 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 616 LIST_NEXT((listelm), field)->field.le_prev = \ 617 &LIST_NEXT((elm), field); \ 618 LIST_NEXT((listelm), field) = (elm); \ 619 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 620 } while (0) 621 622 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 623 QMD_LIST_CHECK_PREV(listelm, field); \ 624 (elm)->field.le_prev = (listelm)->field.le_prev; \ 625 LIST_NEXT((elm), field) = (listelm); \ 626 *(listelm)->field.le_prev = (elm); \ 627 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 628 } while (0) 629 630 #define LIST_INSERT_HEAD(head, elm, field) do { \ 631 QMD_LIST_CHECK_HEAD((head), field); \ 632 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 633 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 634 LIST_FIRST((head)) = (elm); \ 635 (elm)->field.le_prev = &LIST_FIRST((head)); \ 636 } while (0) 637 638 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 639 640 #define LIST_PREV(elm, head, type, field) \ 641 ((elm)->field.le_prev == &LIST_FIRST((head)) ? NULL : \ 642 __containerof((elm)->field.le_prev, \ 643 QUEUE_TYPEOF(type), field.le_next)) 644 645 #define LIST_REMOVE_HEAD(head, field) \ 646 LIST_REMOVE(LIST_FIRST(head), field) 647 648 #define LIST_REMOVE(elm, field) do { \ 649 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 650 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 651 QMD_LIST_CHECK_NEXT(elm, field); \ 652 QMD_LIST_CHECK_PREV(elm, field); \ 653 if (LIST_NEXT((elm), field) != NULL) \ 654 LIST_NEXT((elm), field)->field.le_prev = \ 655 (elm)->field.le_prev; \ 656 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 657 TRASHIT(*oldnext); \ 658 TRASHIT(*oldprev); \ 659 } while (0) 660 661 #define LIST_REPLACE(elm, elm2, field) do { \ 662 QMD_SAVELINK(oldnext, (elm)->field.le_next); \ 663 QMD_SAVELINK(oldprev, (elm)->field.le_prev); \ 664 QMD_LIST_CHECK_NEXT(elm, field); \ 665 QMD_LIST_CHECK_PREV(elm, field); \ 666 LIST_NEXT((elm2), field) = LIST_NEXT((elm), field); \ 667 if (LIST_NEXT((elm2), field) != NULL) \ 668 LIST_NEXT((elm2), field)->field.le_prev = \ 669 &(elm2)->field.le_next; \ 670 (elm2)->field.le_prev = (elm)->field.le_prev; \ 671 *(elm2)->field.le_prev = (elm2); \ 672 TRASHIT(*oldnext); \ 673 TRASHIT(*oldprev); \ 674 } while (0) 675 676 #define LIST_SWAP(head1, head2, type, field) do { \ 677 QUEUE_TYPEOF(type) *swap_tmp = LIST_FIRST(head1); \ 678 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 679 LIST_FIRST((head2)) = swap_tmp; \ 680 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 681 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 682 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 683 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 684 } while (0) 685 686 #define LIST_END(head) NULL 687 688 /* 689 * Tail queue declarations. 690 */ 691 #define TAILQ_HEAD(name, type) \ 692 struct name { \ 693 struct type *tqh_first; /* first element */ \ 694 struct type **tqh_last; /* addr of last next element */ \ 695 TRACEBUF \ 696 } 697 698 #define TAILQ_CLASS_HEAD(name, type) \ 699 struct name { \ 700 class type *tqh_first; /* first element */ \ 701 class type **tqh_last; /* addr of last next element */ \ 702 TRACEBUF \ 703 } 704 705 #define TAILQ_HEAD_INITIALIZER(head) \ 706 { NULL, &(head).tqh_first, TRACEBUF_INITIALIZER } 707 708 #define TAILQ_ENTRY(type) \ 709 struct { \ 710 struct type *tqe_next; /* next element */ \ 711 struct type **tqe_prev; /* address of previous next element */ \ 712 TRACEBUF \ 713 } 714 715 #define TAILQ_CLASS_ENTRY(type) \ 716 struct { \ 717 class type *tqe_next; /* next element */ \ 718 class type **tqe_prev; /* address of previous next element */ \ 719 TRACEBUF \ 720 } 721 722 /* 723 * Tail queue functions. 724 */ 725 #if (defined(_KERNEL) && defined(INVARIANTS)) 726 /* 727 * QMD_TAILQ_CHECK_HEAD(TAILQ_HEAD *head, TAILQ_ENTRY NAME) 728 * 729 * If the tailq is non-empty, validates that the first element of the tailq 730 * points back at 'head.' 731 */ 732 #define QMD_TAILQ_CHECK_HEAD(head, field) do { \ 733 if (!TAILQ_EMPTY(head) && \ 734 TAILQ_FIRST((head))->field.tqe_prev != \ 735 &TAILQ_FIRST((head))) \ 736 panic("Bad tailq head %p first->prev != head", (head)); \ 737 } while (0) 738 739 /* 740 * QMD_TAILQ_CHECK_TAIL(TAILQ_HEAD *head, TAILQ_ENTRY NAME) 741 * 742 * Validates that the tail of the tailq is a pointer to pointer to NULL. 743 */ 744 #define QMD_TAILQ_CHECK_TAIL(head, field) do { \ 745 if (*(head)->tqh_last != NULL) \ 746 panic("Bad tailq NEXT(%p->tqh_last) != NULL", (head)); \ 747 } while (0) 748 749 /* 750 * QMD_TAILQ_CHECK_NEXT(TYPE *elm, TAILQ_ENTRY NAME) 751 * 752 * If an element follows 'elm' in the tailq, validates that the next element 753 * points back at 'elm.' 754 */ 755 #define QMD_TAILQ_CHECK_NEXT(elm, field) do { \ 756 if (TAILQ_NEXT((elm), field) != NULL && \ 757 TAILQ_NEXT((elm), field)->field.tqe_prev != \ 758 &((elm)->field.tqe_next)) \ 759 panic("Bad link elm %p next->prev != elm", (elm)); \ 760 } while (0) 761 762 /* 763 * QMD_TAILQ_CHECK_PREV(TYPE *elm, TAILQ_ENTRY NAME) 764 * 765 * Validates that the previous element (or head of the tailq) points to 'elm.' 766 */ 767 #define QMD_TAILQ_CHECK_PREV(elm, field) do { \ 768 if (*(elm)->field.tqe_prev != (elm)) \ 769 panic("Bad link elm %p prev->next != elm", (elm)); \ 770 } while (0) 771 #else 772 #define QMD_TAILQ_CHECK_HEAD(head, field) 773 #define QMD_TAILQ_CHECK_TAIL(head, headname) 774 #define QMD_TAILQ_CHECK_NEXT(elm, field) 775 #define QMD_TAILQ_CHECK_PREV(elm, field) 776 #endif /* (_KERNEL && INVARIANTS) */ 777 778 #define TAILQ_CONCAT(head1, head2, field) do { \ 779 if (!TAILQ_EMPTY(head2)) { \ 780 *(head1)->tqh_last = (head2)->tqh_first; \ 781 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 782 (head1)->tqh_last = (head2)->tqh_last; \ 783 TAILQ_INIT((head2)); \ 784 QMD_TRACE_HEAD(head1); \ 785 QMD_TRACE_HEAD(head2); \ 786 } \ 787 } while (0) 788 789 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 790 791 #define TAILQ_EMPTY_ATOMIC(head) \ 792 (atomic_load_ptr(&(head)->tqh_first) == NULL) 793 794 #define TAILQ_FIRST(head) ((head)->tqh_first) 795 796 #define TAILQ_FOREACH(var, head, field) \ 797 for ((var) = TAILQ_FIRST((head)); \ 798 (var); \ 799 (var) = TAILQ_NEXT((var), field)) 800 801 #define TAILQ_FOREACH_FROM(var, head, field) \ 802 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 803 (var); \ 804 (var) = TAILQ_NEXT((var), field)) 805 806 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 807 for ((var) = TAILQ_FIRST((head)); \ 808 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 809 (var) = (tvar)) 810 811 #define TAILQ_FOREACH_FROM_SAFE(var, head, field, tvar) \ 812 for ((var) = ((var) ? (var) : TAILQ_FIRST((head))); \ 813 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 814 (var) = (tvar)) 815 816 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 817 for ((var) = TAILQ_LAST((head), headname); \ 818 (var); \ 819 (var) = TAILQ_PREV((var), headname, field)) 820 821 #define TAILQ_FOREACH_REVERSE_FROM(var, head, headname, field) \ 822 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 823 (var); \ 824 (var) = TAILQ_PREV((var), headname, field)) 825 826 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 827 for ((var) = TAILQ_LAST((head), headname); \ 828 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 829 (var) = (tvar)) 830 831 #define TAILQ_FOREACH_REVERSE_FROM_SAFE(var, head, headname, field, tvar)\ 832 for ((var) = ((var) ? (var) : TAILQ_LAST((head), headname)); \ 833 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 834 (var) = (tvar)) 835 836 #define TAILQ_INIT(head) do { \ 837 TAILQ_FIRST((head)) = NULL; \ 838 (head)->tqh_last = &TAILQ_FIRST((head)); \ 839 QMD_TRACE_HEAD(head); \ 840 } while (0) 841 842 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 843 QMD_TAILQ_CHECK_NEXT(listelm, field); \ 844 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 845 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 846 &TAILQ_NEXT((elm), field); \ 847 else { \ 848 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 849 QMD_TRACE_HEAD(head); \ 850 } \ 851 TAILQ_NEXT((listelm), field) = (elm); \ 852 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 853 QMD_TRACE_ELEM(&(elm)->field); \ 854 QMD_TRACE_ELEM(&(listelm)->field); \ 855 } while (0) 856 857 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 858 QMD_TAILQ_CHECK_PREV(listelm, field); \ 859 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 860 TAILQ_NEXT((elm), field) = (listelm); \ 861 *(listelm)->field.tqe_prev = (elm); \ 862 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 863 QMD_TRACE_ELEM(&(elm)->field); \ 864 QMD_TRACE_ELEM(&(listelm)->field); \ 865 } while (0) 866 867 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 868 QMD_TAILQ_CHECK_HEAD(head, field); \ 869 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 870 TAILQ_FIRST((head))->field.tqe_prev = \ 871 &TAILQ_NEXT((elm), field); \ 872 else \ 873 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 874 TAILQ_FIRST((head)) = (elm); \ 875 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 876 QMD_TRACE_HEAD(head); \ 877 QMD_TRACE_ELEM(&(elm)->field); \ 878 } while (0) 879 880 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 881 QMD_TAILQ_CHECK_TAIL(head, field); \ 882 TAILQ_NEXT((elm), field) = NULL; \ 883 (elm)->field.tqe_prev = (head)->tqh_last; \ 884 *(head)->tqh_last = (elm); \ 885 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 886 QMD_TRACE_HEAD(head); \ 887 QMD_TRACE_ELEM(&(elm)->field); \ 888 } while (0) 889 890 #define TAILQ_LAST(head, headname) \ 891 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 892 893 /* 894 * The FAST function is fast in that it causes no data access other 895 * then the access to the head. The standard LAST function above 896 * will cause a data access of both the element you want and 897 * the previous element. FAST is very useful for instances when 898 * you may want to prefetch the last data element. 899 */ 900 #define TAILQ_LAST_FAST(head, type, field) \ 901 (TAILQ_EMPTY(head) ? NULL : __containerof((head)->tqh_last, QUEUE_TYPEOF(type), field.tqe_next)) 902 903 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 904 905 #define TAILQ_PREV(elm, headname, field) \ 906 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 907 908 #define TAILQ_PREV_FAST(elm, head, type, field) \ 909 ((elm)->field.tqe_prev == &(head)->tqh_first ? NULL : \ 910 __containerof((elm)->field.tqe_prev, QUEUE_TYPEOF(type), field.tqe_next)) 911 912 #define TAILQ_REMOVE_HEAD(head, field) \ 913 TAILQ_REMOVE(head, TAILQ_FIRST(head), field) 914 915 #define TAILQ_REMOVE(head, elm, field) do { \ 916 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 917 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 918 QMD_TAILQ_CHECK_NEXT(elm, field); \ 919 QMD_TAILQ_CHECK_PREV(elm, field); \ 920 if ((TAILQ_NEXT((elm), field)) != NULL) \ 921 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 922 (elm)->field.tqe_prev; \ 923 else { \ 924 (head)->tqh_last = (elm)->field.tqe_prev; \ 925 QMD_TRACE_HEAD(head); \ 926 } \ 927 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 928 TRASHIT(*oldnext); \ 929 TRASHIT(*oldprev); \ 930 QMD_TRACE_ELEM(&(elm)->field); \ 931 } while (0) 932 933 #define TAILQ_REPLACE(head, elm, elm2, field) do { \ 934 QMD_SAVELINK(oldnext, (elm)->field.tqe_next); \ 935 QMD_SAVELINK(oldprev, (elm)->field.tqe_prev); \ 936 QMD_TAILQ_CHECK_NEXT(elm, field); \ 937 QMD_TAILQ_CHECK_PREV(elm, field); \ 938 TAILQ_NEXT((elm2), field) = TAILQ_NEXT((elm), field); \ 939 if (TAILQ_NEXT((elm2), field) != TAILQ_END(head)) \ 940 TAILQ_NEXT((elm2), field)->field.tqe_prev = \ 941 &(elm2)->field.tqe_next; \ 942 else \ 943 (head)->tqh_last = &(elm2)->field.tqe_next; \ 944 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ 945 *(elm2)->field.tqe_prev = (elm2); \ 946 TRASHIT(*oldnext); \ 947 TRASHIT(*oldprev); \ 948 QMD_TRACE_ELEM(&(elm)->field); \ 949 } while (0) 950 951 #define TAILQ_SWAP(head1, head2, type, field) do { \ 952 QUEUE_TYPEOF(type) *swap_first = (head1)->tqh_first; \ 953 QUEUE_TYPEOF(type) **swap_last = (head1)->tqh_last; \ 954 (head1)->tqh_first = (head2)->tqh_first; \ 955 (head1)->tqh_last = (head2)->tqh_last; \ 956 (head2)->tqh_first = swap_first; \ 957 (head2)->tqh_last = swap_last; \ 958 if ((swap_first = (head1)->tqh_first) != NULL) \ 959 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 960 else \ 961 (head1)->tqh_last = &(head1)->tqh_first; \ 962 if ((swap_first = (head2)->tqh_first) != NULL) \ 963 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 964 else \ 965 (head2)->tqh_last = &(head2)->tqh_first; \ 966 } while (0) 967 968 #define TAILQ_END(head) NULL 969 970 #endif /* !_SYS_QUEUE_H_ */ 971