queue.h (30075B)
1 /* $NetBSD: queue.h,v 1.70 2015/11/02 15:21:23 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)queue.h 8.5 (Berkeley) 8/20/94 32 */ 33 34 #ifndef _SYS_QUEUE_H_ 35 #define _SYS_QUEUE_H_ 36 37 /* 38 * This file defines five types of data structures: singly-linked lists, 39 * lists, simple queues, tail queues, and circular queues. 40 * 41 * A singly-linked list is headed by a single forward pointer. The 42 * elements are singly linked for minimum space and pointer manipulation 43 * overhead at the expense of O(n) removal for arbitrary elements. New 44 * elements can be added to the list after an existing element or at the 45 * head of the list. Elements being removed from the head of the list 46 * should use the explicit macro for this purpose for optimum 47 * efficiency. A singly-linked list may only be traversed in the forward 48 * direction. Singly-linked lists are ideal for applications with large 49 * datasets and few or no removals or for implementing a LIFO queue. 50 * 51 * A list is headed by a single forward pointer (or an array of forward 52 * pointers for a hash table header). The elements are doubly linked 53 * so that an arbitrary element can be removed without a need to 54 * traverse the list. New elements can be added to the list before 55 * or after an existing element or at the head of the list. A list 56 * may only be traversed in the forward direction. 57 * 58 * A simple queue is headed by a pair of pointers, one the head of the 59 * list and the other to the tail of the list. The elements are singly 60 * linked to save space, so elements can only be removed from the 61 * head of the list. New elements can be added to the list after 62 * an existing element, at the head of the list, or at the end of the 63 * list. A simple queue may only be traversed in the forward direction. 64 * 65 * A tail queue is headed by a pair of pointers, one to the head of the 66 * list and the other to the tail of the list. The elements are doubly 67 * linked so that an arbitrary element can be removed without a need to 68 * traverse the list. New elements can be added to the list before or 69 * after an existing element, at the head of the list, or at the end of 70 * the list. A tail queue may be traversed in either direction. 71 * 72 * A circle queue is headed by a pair of pointers, one to the head of the 73 * list and the other to the tail of the list. The elements are doubly 74 * linked so that an arbitrary element can be removed without a need to 75 * traverse the list. New elements can be added to the list before or after 76 * an existing element, at the head of the list, or at the end of the list. 77 * A circle queue may be traversed in either direction, but has a more 78 * complex end of list detection. 79 * 80 * For details on the use of these macros, see the queue(3) manual page. 81 */ 82 83 /* 84 * Include the definition of NULL only on NetBSD because sys/null.h 85 * is not available elsewhere. This conditional makes the header 86 * portable and it can simply be dropped verbatim into any system. 87 * The caveat is that on other systems some other header 88 * must provide NULL before the macros can be used. 89 */ 90 #ifdef __NetBSD__ 91 #include <sys/null.h> 92 #endif 93 94 #if defined(QUEUEDEBUG) 95 # if defined(_KERNEL) 96 # define QUEUEDEBUG_ABORT(...) panic(__VA_ARGS__) 97 # else 98 # include <err.h> 99 # define QUEUEDEBUG_ABORT(...) err(1, __VA_ARGS__) 100 # endif 101 #endif 102 103 /* 104 * Singly-linked List definitions. 105 */ 106 #define SLIST_HEAD(name, type) \ 107 struct name { \ 108 struct type *slh_first; /* first element */ \ 109 } 110 111 #define SLIST_HEAD_INITIALIZER(head) \ 112 { NULL } 113 114 #define SLIST_ENTRY(type) \ 115 struct { \ 116 struct type *sle_next; /* next element */ \ 117 } 118 119 /* 120 * Singly-linked List access methods. 121 */ 122 #define SLIST_FIRST(head) ((head)->slh_first) 123 #define SLIST_END(head) NULL 124 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 125 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 126 127 #define SLIST_FOREACH(var, head, field) \ 128 for((var) = (head)->slh_first; \ 129 (var) != SLIST_END(head); \ 130 (var) = (var)->field.sle_next) 131 132 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 133 for ((var) = SLIST_FIRST((head)); \ 134 (var) != SLIST_END(head) && \ 135 ((tvar) = SLIST_NEXT((var), field), 1); \ 136 (var) = (tvar)) 137 138 /* 139 * Singly-linked List functions. 140 */ 141 #define SLIST_INIT(head) do { \ 142 (head)->slh_first = SLIST_END(head); \ 143 } while (/*CONSTCOND*/0) 144 145 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 146 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 147 (slistelm)->field.sle_next = (elm); \ 148 } while (/*CONSTCOND*/0) 149 150 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 151 (elm)->field.sle_next = (head)->slh_first; \ 152 (head)->slh_first = (elm); \ 153 } while (/*CONSTCOND*/0) 154 155 #define SLIST_REMOVE_AFTER(slistelm, field) do { \ 156 (slistelm)->field.sle_next = \ 157 SLIST_NEXT(SLIST_NEXT((slistelm), field), field); \ 158 } while (/*CONSTCOND*/0) 159 160 #define SLIST_REMOVE_HEAD(head, field) do { \ 161 (head)->slh_first = (head)->slh_first->field.sle_next; \ 162 } while (/*CONSTCOND*/0) 163 164 #define SLIST_REMOVE(head, elm, type, field) do { \ 165 if ((head)->slh_first == (elm)) { \ 166 SLIST_REMOVE_HEAD((head), field); \ 167 } \ 168 else { \ 169 struct type *curelm = (head)->slh_first; \ 170 while(curelm->field.sle_next != (elm)) \ 171 curelm = curelm->field.sle_next; \ 172 curelm->field.sle_next = \ 173 curelm->field.sle_next->field.sle_next; \ 174 } \ 175 } while (/*CONSTCOND*/0) 176 177 178 /* 179 * List definitions. 180 */ 181 #define LIST_HEAD(name, type) \ 182 struct name { \ 183 struct type *lh_first; /* first element */ \ 184 } 185 186 #define LIST_HEAD_INITIALIZER(head) \ 187 { NULL } 188 189 #define LIST_ENTRY(type) \ 190 struct { \ 191 struct type *le_next; /* next element */ \ 192 struct type **le_prev; /* address of previous next element */ \ 193 } 194 195 /* 196 * List access methods. 197 */ 198 #define LIST_FIRST(head) ((head)->lh_first) 199 #define LIST_END(head) NULL 200 #define LIST_EMPTY(head) ((head)->lh_first == LIST_END(head)) 201 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 202 203 #define LIST_FOREACH(var, head, field) \ 204 for ((var) = ((head)->lh_first); \ 205 (var) != LIST_END(head); \ 206 (var) = ((var)->field.le_next)) 207 208 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 209 for ((var) = LIST_FIRST((head)); \ 210 (var) != LIST_END(head) && \ 211 ((tvar) = LIST_NEXT((var), field), 1); \ 212 (var) = (tvar)) 213 214 #define LIST_MOVE(head1, head2) do { \ 215 LIST_INIT((head2)); \ 216 if (!LIST_EMPTY((head1))) { \ 217 (head2)->lh_first = (head1)->lh_first; \ 218 LIST_INIT((head1)); \ 219 } \ 220 } while (/*CONSTCOND*/0) 221 222 /* 223 * List functions. 224 */ 225 #if defined(QUEUEDEBUG) 226 #define QUEUEDEBUG_LIST_INSERT_HEAD(head, elm, field) \ 227 if ((head)->lh_first && \ 228 (head)->lh_first->field.le_prev != &(head)->lh_first) \ 229 QUEUEDEBUG_ABORT("LIST_INSERT_HEAD %p %s:%d", (head), \ 230 __FILE__, __LINE__); 231 #define QUEUEDEBUG_LIST_OP(elm, field) \ 232 if ((elm)->field.le_next && \ 233 (elm)->field.le_next->field.le_prev != \ 234 &(elm)->field.le_next) \ 235 QUEUEDEBUG_ABORT("LIST_* forw %p %s:%d", (elm), \ 236 __FILE__, __LINE__); \ 237 if (*(elm)->field.le_prev != (elm)) \ 238 QUEUEDEBUG_ABORT("LIST_* back %p %s:%d", (elm), \ 239 __FILE__, __LINE__); 240 #define QUEUEDEBUG_LIST_POSTREMOVE(elm, field) \ 241 (elm)->field.le_next = (void *)1L; \ 242 (elm)->field.le_prev = (void *)1L; 243 #else 244 #define QUEUEDEBUG_LIST_INSERT_HEAD(head, elm, field) 245 #define QUEUEDEBUG_LIST_OP(elm, field) 246 #define QUEUEDEBUG_LIST_POSTREMOVE(elm, field) 247 #endif 248 249 #define LIST_INIT(head) do { \ 250 (head)->lh_first = LIST_END(head); \ 251 } while (/*CONSTCOND*/0) 252 253 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 254 QUEUEDEBUG_LIST_OP((listelm), field) \ 255 if (((elm)->field.le_next = (listelm)->field.le_next) != \ 256 LIST_END(head)) \ 257 (listelm)->field.le_next->field.le_prev = \ 258 &(elm)->field.le_next; \ 259 (listelm)->field.le_next = (elm); \ 260 (elm)->field.le_prev = &(listelm)->field.le_next; \ 261 } while (/*CONSTCOND*/0) 262 263 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 264 QUEUEDEBUG_LIST_OP((listelm), field) \ 265 (elm)->field.le_prev = (listelm)->field.le_prev; \ 266 (elm)->field.le_next = (listelm); \ 267 *(listelm)->field.le_prev = (elm); \ 268 (listelm)->field.le_prev = &(elm)->field.le_next; \ 269 } while (/*CONSTCOND*/0) 270 271 #define LIST_INSERT_HEAD(head, elm, field) do { \ 272 QUEUEDEBUG_LIST_INSERT_HEAD((head), (elm), field) \ 273 if (((elm)->field.le_next = (head)->lh_first) != LIST_END(head))\ 274 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 275 (head)->lh_first = (elm); \ 276 (elm)->field.le_prev = &(head)->lh_first; \ 277 } while (/*CONSTCOND*/0) 278 279 #define LIST_REMOVE(elm, field) do { \ 280 QUEUEDEBUG_LIST_OP((elm), field) \ 281 if ((elm)->field.le_next != NULL) \ 282 (elm)->field.le_next->field.le_prev = \ 283 (elm)->field.le_prev; \ 284 *(elm)->field.le_prev = (elm)->field.le_next; \ 285 QUEUEDEBUG_LIST_POSTREMOVE((elm), field) \ 286 } while (/*CONSTCOND*/0) 287 288 #define LIST_REPLACE(elm, elm2, field) do { \ 289 if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ 290 (elm2)->field.le_next->field.le_prev = \ 291 &(elm2)->field.le_next; \ 292 (elm2)->field.le_prev = (elm)->field.le_prev; \ 293 *(elm2)->field.le_prev = (elm2); \ 294 QUEUEDEBUG_LIST_POSTREMOVE((elm), field) \ 295 } while (/*CONSTCOND*/0) 296 297 /* 298 * Simple queue definitions. 299 */ 300 #define SIMPLEQ_HEAD(name, type) \ 301 struct name { \ 302 struct type *sqh_first; /* first element */ \ 303 struct type **sqh_last; /* addr of last next element */ \ 304 } 305 306 #define SIMPLEQ_HEAD_INITIALIZER(head) \ 307 { NULL, &(head).sqh_first } 308 309 #define SIMPLEQ_ENTRY(type) \ 310 struct { \ 311 struct type *sqe_next; /* next element */ \ 312 } 313 314 /* 315 * Simple queue access methods. 316 */ 317 #define SIMPLEQ_FIRST(head) ((head)->sqh_first) 318 #define SIMPLEQ_END(head) NULL 319 #define SIMPLEQ_EMPTY(head) ((head)->sqh_first == SIMPLEQ_END(head)) 320 #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 321 322 #define SIMPLEQ_FOREACH(var, head, field) \ 323 for ((var) = ((head)->sqh_first); \ 324 (var) != SIMPLEQ_END(head); \ 325 (var) = ((var)->field.sqe_next)) 326 327 #define SIMPLEQ_FOREACH_SAFE(var, head, field, next) \ 328 for ((var) = ((head)->sqh_first); \ 329 (var) != SIMPLEQ_END(head) && \ 330 ((next = ((var)->field.sqe_next)), 1); \ 331 (var) = (next)) 332 333 /* 334 * Simple queue functions. 335 */ 336 #define SIMPLEQ_INIT(head) do { \ 337 (head)->sqh_first = NULL; \ 338 (head)->sqh_last = &(head)->sqh_first; \ 339 } while (/*CONSTCOND*/0) 340 341 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 342 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ 343 (head)->sqh_last = &(elm)->field.sqe_next; \ 344 (head)->sqh_first = (elm); \ 345 } while (/*CONSTCOND*/0) 346 347 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 348 (elm)->field.sqe_next = NULL; \ 349 *(head)->sqh_last = (elm); \ 350 (head)->sqh_last = &(elm)->field.sqe_next; \ 351 } while (/*CONSTCOND*/0) 352 353 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 354 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ 355 (head)->sqh_last = &(elm)->field.sqe_next; \ 356 (listelm)->field.sqe_next = (elm); \ 357 } while (/*CONSTCOND*/0) 358 359 #define SIMPLEQ_REMOVE_HEAD(head, field) do { \ 360 if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \ 361 (head)->sqh_last = &(head)->sqh_first; \ 362 } while (/*CONSTCOND*/0) 363 364 #define SIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ 365 if (((elm)->field.sqe_next = (elm)->field.sqe_next->field.sqe_next) \ 366 == NULL) \ 367 (head)->sqh_last = &(elm)->field.sqe_next; \ 368 } while (/*CONSTCOND*/0) 369 370 #define SIMPLEQ_REMOVE(head, elm, type, field) do { \ 371 if ((head)->sqh_first == (elm)) { \ 372 SIMPLEQ_REMOVE_HEAD((head), field); \ 373 } else { \ 374 struct type *curelm = (head)->sqh_first; \ 375 while (curelm->field.sqe_next != (elm)) \ 376 curelm = curelm->field.sqe_next; \ 377 if ((curelm->field.sqe_next = \ 378 curelm->field.sqe_next->field.sqe_next) == NULL) \ 379 (head)->sqh_last = &(curelm)->field.sqe_next; \ 380 } \ 381 } while (/*CONSTCOND*/0) 382 383 #define SIMPLEQ_CONCAT(head1, head2) do { \ 384 if (!SIMPLEQ_EMPTY((head2))) { \ 385 *(head1)->sqh_last = (head2)->sqh_first; \ 386 (head1)->sqh_last = (head2)->sqh_last; \ 387 SIMPLEQ_INIT((head2)); \ 388 } \ 389 } while (/*CONSTCOND*/0) 390 391 #define SIMPLEQ_LAST(head, type, field) \ 392 (SIMPLEQ_EMPTY((head)) ? \ 393 NULL : \ 394 ((struct type *)(void *) \ 395 ((char *)((head)->sqh_last) - offsetof(struct type, field)))) 396 397 /* 398 * Tail queue definitions. 399 */ 400 #define _TAILQ_HEAD(name, type, qual) \ 401 struct name { \ 402 qual type *tqh_first; /* first element */ \ 403 qual type *qual *tqh_last; /* addr of last next element */ \ 404 } 405 #define TAILQ_HEAD(name, type) _TAILQ_HEAD(name, struct type,) 406 407 #define TAILQ_HEAD_INITIALIZER(head) \ 408 { TAILQ_END(head), &(head).tqh_first } 409 410 #define _TAILQ_ENTRY(type, qual) \ 411 struct { \ 412 qual type *tqe_next; /* next element */ \ 413 qual type *qual *tqe_prev; /* address of previous next element */\ 414 } 415 #define TAILQ_ENTRY(type) _TAILQ_ENTRY(struct type,) 416 417 /* 418 * Tail queue access methods. 419 */ 420 #define TAILQ_FIRST(head) ((head)->tqh_first) 421 #define TAILQ_END(head) (NULL) 422 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 423 #define TAILQ_LAST(head, headname) \ 424 (*(((struct headname *)(void *)((head)->tqh_last))->tqh_last)) 425 #define TAILQ_PREV(elm, headname, field) \ 426 (*(((struct headname *)(void *)((elm)->field.tqe_prev))->tqh_last)) 427 #define TAILQ_EMPTY(head) (TAILQ_FIRST(head) == TAILQ_END(head)) 428 429 430 #define TAILQ_FOREACH(var, head, field) \ 431 for ((var) = ((head)->tqh_first); \ 432 (var) != TAILQ_END(head); \ 433 (var) = ((var)->field.tqe_next)) 434 435 #define TAILQ_FOREACH_SAFE(var, head, field, next) \ 436 for ((var) = ((head)->tqh_first); \ 437 (var) != TAILQ_END(head) && \ 438 ((next) = TAILQ_NEXT(var, field), 1); (var) = (next)) 439 440 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 441 for ((var) = TAILQ_LAST((head), headname); \ 442 (var) != TAILQ_END(head); \ 443 (var) = TAILQ_PREV((var), headname, field)) 444 445 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, prev) \ 446 for ((var) = TAILQ_LAST((head), headname); \ 447 (var) != TAILQ_END(head) && \ 448 ((prev) = TAILQ_PREV((var), headname, field), 1); (var) = (prev)) 449 450 /* 451 * Tail queue functions. 452 */ 453 #if defined(QUEUEDEBUG) 454 #define QUEUEDEBUG_TAILQ_INSERT_HEAD(head, elm, field) \ 455 if ((head)->tqh_first && \ 456 (head)->tqh_first->field.tqe_prev != &(head)->tqh_first) \ 457 QUEUEDEBUG_ABORT("TAILQ_INSERT_HEAD %p %s:%d", (head), \ 458 __FILE__, __LINE__); 459 #define QUEUEDEBUG_TAILQ_INSERT_TAIL(head, elm, field) \ 460 if (*(head)->tqh_last != NULL) \ 461 QUEUEDEBUG_ABORT("TAILQ_INSERT_TAIL %p %s:%d", (head), \ 462 __FILE__, __LINE__); 463 #define QUEUEDEBUG_TAILQ_OP(elm, field) \ 464 if ((elm)->field.tqe_next && \ 465 (elm)->field.tqe_next->field.tqe_prev != \ 466 &(elm)->field.tqe_next) \ 467 QUEUEDEBUG_ABORT("TAILQ_* forw %p %s:%d", (elm), \ 468 __FILE__, __LINE__); \ 469 if (*(elm)->field.tqe_prev != (elm)) \ 470 QUEUEDEBUG_ABORT("TAILQ_* back %p %s:%d", (elm), \ 471 __FILE__, __LINE__); 472 #define QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field) \ 473 if ((elm)->field.tqe_next == NULL && \ 474 (head)->tqh_last != &(elm)->field.tqe_next) \ 475 QUEUEDEBUG_ABORT("TAILQ_PREREMOVE head %p elm %p %s:%d",\ 476 (head), (elm), __FILE__, __LINE__); 477 #define QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field) \ 478 (elm)->field.tqe_next = (void *)1L; \ 479 (elm)->field.tqe_prev = (void *)1L; 480 #else 481 #define QUEUEDEBUG_TAILQ_INSERT_HEAD(head, elm, field) 482 #define QUEUEDEBUG_TAILQ_INSERT_TAIL(head, elm, field) 483 #define QUEUEDEBUG_TAILQ_OP(elm, field) 484 #define QUEUEDEBUG_TAILQ_PREREMOVE(head, elm, field) 485 #define QUEUEDEBUG_TAILQ_POSTREMOVE(elm, field) 486 #endif 487 488 #define TAILQ_INIT(head) do { \ 489 (head)->tqh_first = TAILQ_END(head); \ 490 (head)->tqh_last = &(head)->tqh_first; \ 491 } while (/*CONSTCOND*/0) 492 493 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 494 QUEUEDEBUG_TAILQ_INSERT_HEAD((head), (elm), field) \ 495 if (((elm)->field.tqe_next = (head)->tqh_first) != TAILQ_END(head))\ 496 (head)->tqh_first->field.tqe_prev = \ 497 &(elm)->field.tqe_next; \ 498 else \ 499 (head)->tqh_last = &(elm)->field.tqe_next; \ 500 (head)->tqh_first = (elm); \ 501 (elm)->field.tqe_prev = &(head)->tqh_first; \ 502 } while (/*CONSTCOND*/0) 503 504 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 505 QUEUEDEBUG_TAILQ_INSERT_TAIL((head), (elm), field) \ 506 (elm)->field.tqe_next = TAILQ_END(head); \ 507 (elm)->field.tqe_prev = (head)->tqh_last; \ 508 *(head)->tqh_last = (elm); \ 509 (head)->tqh_last = &(elm)->field.tqe_next; \ 510 } while (/*CONSTCOND*/0) 511 512 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 513 QUEUEDEBUG_TAILQ_OP((listelm), field) \ 514 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != \ 515 TAILQ_END(head)) \ 516 (elm)->field.tqe_next->field.tqe_prev = \ 517 &(elm)->field.tqe_next; \ 518 else \ 519 (head)->tqh_last = &(elm)->field.tqe_next; \ 520 (listelm)->field.tqe_next = (elm); \ 521 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 522 } while (/*CONSTCOND*/0) 523 524 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 525 QUEUEDEBUG_TAILQ_OP((listelm), field) \ 526 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 527 (elm)->field.tqe_next = (listelm); \ 528 *(listelm)->field.tqe_prev = (elm); \ 529 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 530 } while (/*CONSTCOND*/0) 531 532 #define TAILQ_REMOVE(head, elm, field) do { \ 533 QUEUEDEBUG_TAILQ_PREREMOVE((head), (elm), field) \ 534 QUEUEDEBUG_TAILQ_OP((elm), field) \ 535 if (((elm)->field.tqe_next) != TAILQ_END(head)) \ 536 (elm)->field.tqe_next->field.tqe_prev = \ 537 (elm)->field.tqe_prev; \ 538 else \ 539 (head)->tqh_last = (elm)->field.tqe_prev; \ 540 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 541 QUEUEDEBUG_TAILQ_POSTREMOVE((elm), field); \ 542 } while (/*CONSTCOND*/0) 543 544 #define TAILQ_REPLACE(head, elm, elm2, field) do { \ 545 if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != \ 546 TAILQ_END(head)) \ 547 (elm2)->field.tqe_next->field.tqe_prev = \ 548 &(elm2)->field.tqe_next; \ 549 else \ 550 (head)->tqh_last = &(elm2)->field.tqe_next; \ 551 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ 552 *(elm2)->field.tqe_prev = (elm2); \ 553 QUEUEDEBUG_TAILQ_POSTREMOVE((elm), field); \ 554 } while (/*CONSTCOND*/0) 555 556 #define TAILQ_CONCAT(head1, head2, field) do { \ 557 if (!TAILQ_EMPTY(head2)) { \ 558 *(head1)->tqh_last = (head2)->tqh_first; \ 559 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 560 (head1)->tqh_last = (head2)->tqh_last; \ 561 TAILQ_INIT((head2)); \ 562 } \ 563 } while (/*CONSTCOND*/0) 564 565 /* 566 * Singly-linked Tail queue declarations. 567 */ 568 #define STAILQ_HEAD(name, type) \ 569 struct name { \ 570 struct type *stqh_first; /* first element */ \ 571 struct type **stqh_last; /* addr of last next element */ \ 572 } 573 574 #define STAILQ_HEAD_INITIALIZER(head) \ 575 { NULL, &(head).stqh_first } 576 577 #define STAILQ_ENTRY(type) \ 578 struct { \ 579 struct type *stqe_next; /* next element */ \ 580 } 581 582 /* 583 * Singly-linked Tail queue access methods. 584 */ 585 #define STAILQ_FIRST(head) ((head)->stqh_first) 586 #define STAILQ_END(head) NULL 587 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 588 #define STAILQ_EMPTY(head) (STAILQ_FIRST(head) == STAILQ_END(head)) 589 590 /* 591 * Singly-linked Tail queue functions. 592 */ 593 #define STAILQ_INIT(head) do { \ 594 (head)->stqh_first = NULL; \ 595 (head)->stqh_last = &(head)->stqh_first; \ 596 } while (/*CONSTCOND*/0) 597 598 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 599 if (((elm)->field.stqe_next = (head)->stqh_first) == NULL) \ 600 (head)->stqh_last = &(elm)->field.stqe_next; \ 601 (head)->stqh_first = (elm); \ 602 } while (/*CONSTCOND*/0) 603 604 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 605 (elm)->field.stqe_next = NULL; \ 606 *(head)->stqh_last = (elm); \ 607 (head)->stqh_last = &(elm)->field.stqe_next; \ 608 } while (/*CONSTCOND*/0) 609 610 #define STAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 611 if (((elm)->field.stqe_next = (listelm)->field.stqe_next) == NULL)\ 612 (head)->stqh_last = &(elm)->field.stqe_next; \ 613 (listelm)->field.stqe_next = (elm); \ 614 } while (/*CONSTCOND*/0) 615 616 #define STAILQ_REMOVE_HEAD(head, field) do { \ 617 if (((head)->stqh_first = (head)->stqh_first->field.stqe_next) == NULL) \ 618 (head)->stqh_last = &(head)->stqh_first; \ 619 } while (/*CONSTCOND*/0) 620 621 #define STAILQ_REMOVE(head, elm, type, field) do { \ 622 if ((head)->stqh_first == (elm)) { \ 623 STAILQ_REMOVE_HEAD((head), field); \ 624 } else { \ 625 struct type *curelm = (head)->stqh_first; \ 626 while (curelm->field.stqe_next != (elm)) \ 627 curelm = curelm->field.stqe_next; \ 628 if ((curelm->field.stqe_next = \ 629 curelm->field.stqe_next->field.stqe_next) == NULL) \ 630 (head)->stqh_last = &(curelm)->field.stqe_next; \ 631 } \ 632 } while (/*CONSTCOND*/0) 633 634 #define STAILQ_FOREACH(var, head, field) \ 635 for ((var) = ((head)->stqh_first); \ 636 (var); \ 637 (var) = ((var)->field.stqe_next)) 638 639 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 640 for ((var) = STAILQ_FIRST((head)); \ 641 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 642 (var) = (tvar)) 643 644 #define STAILQ_CONCAT(head1, head2) do { \ 645 if (!STAILQ_EMPTY((head2))) { \ 646 *(head1)->stqh_last = (head2)->stqh_first; \ 647 (head1)->stqh_last = (head2)->stqh_last; \ 648 STAILQ_INIT((head2)); \ 649 } \ 650 } while (/*CONSTCOND*/0) 651 652 #define STAILQ_LAST(head, type, field) \ 653 (STAILQ_EMPTY((head)) ? \ 654 NULL : \ 655 ((struct type *)(void *) \ 656 ((char *)((head)->stqh_last) - offsetof(struct type, field)))) 657 658 659 #ifndef _KERNEL 660 /* 661 * Circular queue definitions. Do not use. We still keep the macros 662 * for compatibility but because of pointer aliasing issues their use 663 * is discouraged! 664 */ 665 666 /* 667 * __launder_type(): We use this ugly hack to work around the the compiler 668 * noticing that two types may not alias each other and elide tests in code. 669 * We hit this in the CIRCLEQ macros when comparing 'struct name *' and 670 * 'struct type *' (see CIRCLEQ_HEAD()). Modern compilers (such as GCC 671 * 4.8) declare these comparisons as always false, causing the code to 672 * not run as designed. 673 * 674 * This hack is only to be used for comparisons and thus can be fully const. 675 * Do not use for assignment. 676 * 677 * If we ever choose to change the ABI of the CIRCLEQ macros, we could fix 678 * this by changing the head/tail sentinal values, but see the note above 679 * this one. 680 */ 681 static __inline const void * __launder_type(const void *); 682 static __inline const void * 683 __launder_type(const void *__x) 684 { 685 __asm __volatile("" : "+r" (__x)); 686 return __x; 687 } 688 689 #if defined(QUEUEDEBUG) 690 #define QUEUEDEBUG_CIRCLEQ_HEAD(head, field) \ 691 if ((head)->cqh_first != CIRCLEQ_ENDC(head) && \ 692 (head)->cqh_first->field.cqe_prev != CIRCLEQ_ENDC(head)) \ 693 QUEUEDEBUG_ABORT("CIRCLEQ head forw %p %s:%d", (head), \ 694 __FILE__, __LINE__); \ 695 if ((head)->cqh_last != CIRCLEQ_ENDC(head) && \ 696 (head)->cqh_last->field.cqe_next != CIRCLEQ_ENDC(head)) \ 697 QUEUEDEBUG_ABORT("CIRCLEQ head back %p %s:%d", (head), \ 698 __FILE__, __LINE__); 699 #define QUEUEDEBUG_CIRCLEQ_ELM(head, elm, field) \ 700 if ((elm)->field.cqe_next == CIRCLEQ_ENDC(head)) { \ 701 if ((head)->cqh_last != (elm)) \ 702 QUEUEDEBUG_ABORT("CIRCLEQ elm last %p %s:%d", \ 703 (elm), __FILE__, __LINE__); \ 704 } else { \ 705 if ((elm)->field.cqe_next->field.cqe_prev != (elm)) \ 706 QUEUEDEBUG_ABORT("CIRCLEQ elm forw %p %s:%d", \ 707 (elm), __FILE__, __LINE__); \ 708 } \ 709 if ((elm)->field.cqe_prev == CIRCLEQ_ENDC(head)) { \ 710 if ((head)->cqh_first != (elm)) \ 711 QUEUEDEBUG_ABORT("CIRCLEQ elm first %p %s:%d", \ 712 (elm), __FILE__, __LINE__); \ 713 } else { \ 714 if ((elm)->field.cqe_prev->field.cqe_next != (elm)) \ 715 QUEUEDEBUG_ABORT("CIRCLEQ elm prev %p %s:%d", \ 716 (elm), __FILE__, __LINE__); \ 717 } 718 #define QUEUEDEBUG_CIRCLEQ_POSTREMOVE(elm, field) \ 719 (elm)->field.cqe_next = (void *)1L; \ 720 (elm)->field.cqe_prev = (void *)1L; 721 #else 722 #define QUEUEDEBUG_CIRCLEQ_HEAD(head, field) 723 #define QUEUEDEBUG_CIRCLEQ_ELM(head, elm, field) 724 #define QUEUEDEBUG_CIRCLEQ_POSTREMOVE(elm, field) 725 #endif 726 727 #define CIRCLEQ_HEAD(name, type) \ 728 struct name { \ 729 struct type *cqh_first; /* first element */ \ 730 struct type *cqh_last; /* last element */ \ 731 } 732 733 #define CIRCLEQ_HEAD_INITIALIZER(head) \ 734 { CIRCLEQ_END(&head), CIRCLEQ_END(&head) } 735 736 #define CIRCLEQ_ENTRY(type) \ 737 struct { \ 738 struct type *cqe_next; /* next element */ \ 739 struct type *cqe_prev; /* previous element */ \ 740 } 741 742 /* 743 * Circular queue functions. 744 */ 745 #define CIRCLEQ_INIT(head) do { \ 746 (head)->cqh_first = CIRCLEQ_END(head); \ 747 (head)->cqh_last = CIRCLEQ_END(head); \ 748 } while (/*CONSTCOND*/0) 749 750 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 751 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 752 QUEUEDEBUG_CIRCLEQ_ELM((head), (listelm), field) \ 753 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 754 (elm)->field.cqe_prev = (listelm); \ 755 if ((listelm)->field.cqe_next == CIRCLEQ_ENDC(head)) \ 756 (head)->cqh_last = (elm); \ 757 else \ 758 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 759 (listelm)->field.cqe_next = (elm); \ 760 } while (/*CONSTCOND*/0) 761 762 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 763 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 764 QUEUEDEBUG_CIRCLEQ_ELM((head), (listelm), field) \ 765 (elm)->field.cqe_next = (listelm); \ 766 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 767 if ((listelm)->field.cqe_prev == CIRCLEQ_ENDC(head)) \ 768 (head)->cqh_first = (elm); \ 769 else \ 770 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 771 (listelm)->field.cqe_prev = (elm); \ 772 } while (/*CONSTCOND*/0) 773 774 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 775 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 776 (elm)->field.cqe_next = (head)->cqh_first; \ 777 (elm)->field.cqe_prev = CIRCLEQ_END(head); \ 778 if ((head)->cqh_last == CIRCLEQ_ENDC(head)) \ 779 (head)->cqh_last = (elm); \ 780 else \ 781 (head)->cqh_first->field.cqe_prev = (elm); \ 782 (head)->cqh_first = (elm); \ 783 } while (/*CONSTCOND*/0) 784 785 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 786 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 787 (elm)->field.cqe_next = CIRCLEQ_END(head); \ 788 (elm)->field.cqe_prev = (head)->cqh_last; \ 789 if ((head)->cqh_first == CIRCLEQ_ENDC(head)) \ 790 (head)->cqh_first = (elm); \ 791 else \ 792 (head)->cqh_last->field.cqe_next = (elm); \ 793 (head)->cqh_last = (elm); \ 794 } while (/*CONSTCOND*/0) 795 796 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 797 QUEUEDEBUG_CIRCLEQ_HEAD((head), field) \ 798 QUEUEDEBUG_CIRCLEQ_ELM((head), (elm), field) \ 799 if ((elm)->field.cqe_next == CIRCLEQ_ENDC(head)) \ 800 (head)->cqh_last = (elm)->field.cqe_prev; \ 801 else \ 802 (elm)->field.cqe_next->field.cqe_prev = \ 803 (elm)->field.cqe_prev; \ 804 if ((elm)->field.cqe_prev == CIRCLEQ_ENDC(head)) \ 805 (head)->cqh_first = (elm)->field.cqe_next; \ 806 else \ 807 (elm)->field.cqe_prev->field.cqe_next = \ 808 (elm)->field.cqe_next; \ 809 QUEUEDEBUG_CIRCLEQ_POSTREMOVE((elm), field) \ 810 } while (/*CONSTCOND*/0) 811 812 #define CIRCLEQ_FOREACH(var, head, field) \ 813 for ((var) = ((head)->cqh_first); \ 814 (var) != CIRCLEQ_ENDC(head); \ 815 (var) = ((var)->field.cqe_next)) 816 817 #define CIRCLEQ_FOREACH_REVERSE(var, head, field) \ 818 for ((var) = ((head)->cqh_last); \ 819 (var) != CIRCLEQ_ENDC(head); \ 820 (var) = ((var)->field.cqe_prev)) 821 822 /* 823 * Circular queue access methods. 824 */ 825 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 826 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 827 /* For comparisons */ 828 #define CIRCLEQ_ENDC(head) (__launder_type(head)) 829 /* For assignments */ 830 #define CIRCLEQ_END(head) ((void *)(head)) 831 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) 832 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) 833 #define CIRCLEQ_EMPTY(head) \ 834 (CIRCLEQ_FIRST(head) == CIRCLEQ_ENDC(head)) 835 836 #define CIRCLEQ_LOOP_NEXT(head, elm, field) \ 837 (((elm)->field.cqe_next == CIRCLEQ_ENDC(head)) \ 838 ? ((head)->cqh_first) \ 839 : (elm->field.cqe_next)) 840 #define CIRCLEQ_LOOP_PREV(head, elm, field) \ 841 (((elm)->field.cqe_prev == CIRCLEQ_ENDC(head)) \ 842 ? ((head)->cqh_last) \ 843 : (elm->field.cqe_prev)) 844 #endif /* !_KERNEL */ 845 846 #endif /* !_SYS_QUEUE_H_ */