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