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