1 /* $OpenBSD: queue.h,v 1.45 2018/07/12 14:22:54 sashan Exp $ */ 2 /* $NetBSD: queue.h,v 1.11 1996/05/16 05:17:14 mycroft Exp $ */ 3 4 /* 5 * Copyright (c) 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)queue.h 8.5 (Berkeley) 8/20/94 33 */ 34 35 /* OPENBSD ORIGINAL: sys/sys/queue.h */ 36 37 #ifndef _FAKE_QUEUE_H_ 38 #define _FAKE_QUEUE_H_ 39 40 /* 41 * Require for OS/X and other platforms that have old/broken/incomplete 42 * <sys/queue.h>. 43 */ 44 #undef CIRCLEQ_EMPTY 45 #undef CIRCLEQ_END 46 #undef CIRCLEQ_ENTRY 47 #undef CIRCLEQ_FIRST 48 #undef CIRCLEQ_FOREACH 49 #undef CIRCLEQ_FOREACH_REVERSE 50 #undef CIRCLEQ_HEAD 51 #undef CIRCLEQ_HEAD_INITIALIZER 52 #undef CIRCLEQ_INIT 53 #undef CIRCLEQ_INSERT_AFTER 54 #undef CIRCLEQ_INSERT_BEFORE 55 #undef CIRCLEQ_INSERT_HEAD 56 #undef CIRCLEQ_INSERT_TAIL 57 #undef CIRCLEQ_LAST 58 #undef CIRCLEQ_NEXT 59 #undef CIRCLEQ_PREV 60 #undef CIRCLEQ_REMOVE 61 #undef CIRCLEQ_REPLACE 62 #undef LIST_EMPTY 63 #undef LIST_END 64 #undef LIST_ENTRY 65 #undef LIST_FIRST 66 #undef LIST_FOREACH 67 #undef LIST_FOREACH_SAFE 68 #undef LIST_HEAD 69 #undef LIST_HEAD_INITIALIZER 70 #undef LIST_INIT 71 #undef LIST_INSERT_AFTER 72 #undef LIST_INSERT_BEFORE 73 #undef LIST_INSERT_HEAD 74 #undef LIST_NEXT 75 #undef LIST_REMOVE 76 #undef LIST_REPLACE 77 #undef SIMPLEQ_CONCAT 78 #undef SIMPLEQ_EMPTY 79 #undef SIMPLEQ_END 80 #undef SIMPLEQ_ENTRY 81 #undef SIMPLEQ_FIRST 82 #undef SIMPLEQ_FOREACH 83 #undef SIMPLEQ_FOREACH_SAFE 84 #undef SIMPLEQ_HEAD 85 #undef SIMPLEQ_HEAD_INITIALIZER 86 #undef SIMPLEQ_INIT 87 #undef SIMPLEQ_INSERT_AFTER 88 #undef SIMPLEQ_INSERT_HEAD 89 #undef SIMPLEQ_INSERT_TAIL 90 #undef SIMPLEQ_NEXT 91 #undef SIMPLEQ_REMOVE_AFTER 92 #undef SIMPLEQ_REMOVE_HEAD 93 #undef SLIST_EMPTY 94 #undef SLIST_END 95 #undef SLIST_ENTRY 96 #undef SLIST_FIRST 97 #undef SLIST_FOREACH 98 #undef SLIST_FOREACH_PREVPTR 99 #undef SLIST_FOREACH_SAFE 100 #undef SLIST_HEAD 101 #undef SLIST_HEAD_INITIALIZER 102 #undef SLIST_INIT 103 #undef SLIST_INSERT_AFTER 104 #undef SLIST_INSERT_HEAD 105 #undef SLIST_NEXT 106 #undef SLIST_REMOVE 107 #undef SLIST_REMOVE_AFTER 108 #undef SLIST_REMOVE_HEAD 109 #undef SLIST_REMOVE_NEXT 110 #undef TAILQ_CONCAT 111 #undef TAILQ_EMPTY 112 #undef TAILQ_END 113 #undef TAILQ_ENTRY 114 #undef TAILQ_FIRST 115 #undef TAILQ_FOREACH 116 #undef TAILQ_FOREACH_REVERSE 117 #undef TAILQ_FOREACH_REVERSE_SAFE 118 #undef TAILQ_FOREACH_SAFE 119 #undef TAILQ_HEAD 120 #undef TAILQ_HEAD_INITIALIZER 121 #undef TAILQ_INIT 122 #undef TAILQ_INSERT_AFTER 123 #undef TAILQ_INSERT_BEFORE 124 #undef TAILQ_INSERT_HEAD 125 #undef TAILQ_INSERT_TAIL 126 #undef TAILQ_LAST 127 #undef TAILQ_NEXT 128 #undef TAILQ_PREV 129 #undef TAILQ_REMOVE 130 #undef TAILQ_REPLACE 131 132 /* 133 * This file defines five types of data structures: singly-linked lists, 134 * lists, simple queues, tail queues and XOR simple queues. 135 * 136 * 137 * A singly-linked list is headed by a single forward pointer. The elements 138 * are singly linked for minimum space and pointer manipulation overhead at 139 * the expense of O(n) removal for arbitrary elements. New elements can be 140 * added to the list after an existing element or at the head of the list. 141 * Elements being removed from the head of the list should use the explicit 142 * macro for this purpose for optimum efficiency. A singly-linked list may 143 * only be traversed in the forward direction. Singly-linked lists are ideal 144 * for applications with large datasets and few or no removals or for 145 * implementing a LIFO queue. 146 * 147 * A list is headed by a single forward pointer (or an array of forward 148 * pointers for a hash table header). The elements are doubly linked 149 * so that an arbitrary element can be removed without a need to 150 * traverse the list. New elements can be added to the list before 151 * or after an existing element or at the head of the list. A list 152 * may only be traversed in the forward direction. 153 * 154 * A simple queue is headed by a pair of pointers, one to the head of the 155 * list and the other to the tail of the list. The elements are singly 156 * linked to save space, so elements can only be removed from the 157 * head of the list. New elements can be added to the list before or after 158 * an existing element, at the head of the list, or at the end of the 159 * list. A simple queue may only be traversed in the forward direction. 160 * 161 * A tail queue is headed by a pair of pointers, one to the head of the 162 * list and the other to the tail of the list. The elements are doubly 163 * linked so that an arbitrary element can be removed without a need to 164 * traverse the list. New elements can be added to the list before or 165 * after an existing element, at the head of the list, or at the end of 166 * the list. A tail queue may be traversed in either direction. 167 * 168 * An XOR simple queue is used in the same way as a regular simple queue. 169 * The difference is that the head structure also includes a "cookie" that 170 * is XOR'd with the queue pointer (first, last or next) to generate the 171 * real pointer value. 172 * 173 * For details on the use of these macros, see the queue(3) manual page. 174 */ 175 176 #if defined(QUEUE_MACRO_DEBUG) || (defined(_KERNEL) && defined(DIAGNOSTIC)) 177 #define _Q_INVALID ((void *)-1) 178 #define _Q_INVALIDATE(a) (a) = _Q_INVALID 179 #else 180 #define _Q_INVALIDATE(a) 181 #endif 182 183 /* 184 * Singly-linked List definitions. 185 */ 186 #define SLIST_HEAD(name, type) \ 187 struct name { \ 188 struct type *slh_first; /* first element */ \ 189 } 190 191 #define SLIST_HEAD_INITIALIZER(head) \ 192 { NULL } 193 194 #define SLIST_ENTRY(type) \ 195 struct { \ 196 struct type *sle_next; /* next element */ \ 197 } 198 199 /* 200 * Singly-linked List access methods. 201 */ 202 #define SLIST_FIRST(head) ((head)->slh_first) 203 #define SLIST_END(head) NULL 204 #define SLIST_EMPTY(head) (SLIST_FIRST(head) == SLIST_END(head)) 205 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 206 207 #define SLIST_FOREACH(var, head, field) \ 208 for((var) = SLIST_FIRST(head); \ 209 (var) != SLIST_END(head); \ 210 (var) = SLIST_NEXT(var, field)) 211 212 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 213 for ((var) = SLIST_FIRST(head); \ 214 (var) && ((tvar) = SLIST_NEXT(var, field), 1); \ 215 (var) = (tvar)) 216 217 /* 218 * Singly-linked List functions. 219 */ 220 #define SLIST_INIT(head) { \ 221 SLIST_FIRST(head) = SLIST_END(head); \ 222 } 223 224 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 225 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 226 (slistelm)->field.sle_next = (elm); \ 227 } while (0) 228 229 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 230 (elm)->field.sle_next = (head)->slh_first; \ 231 (head)->slh_first = (elm); \ 232 } while (0) 233 234 #define SLIST_REMOVE_AFTER(elm, field) do { \ 235 (elm)->field.sle_next = (elm)->field.sle_next->field.sle_next; \ 236 } while (0) 237 238 #define SLIST_REMOVE_HEAD(head, field) do { \ 239 (head)->slh_first = (head)->slh_first->field.sle_next; \ 240 } while (0) 241 242 #define SLIST_REMOVE(head, elm, type, field) do { \ 243 if ((head)->slh_first == (elm)) { \ 244 SLIST_REMOVE_HEAD((head), field); \ 245 } else { \ 246 struct type *curelm = (head)->slh_first; \ 247 \ 248 while (curelm->field.sle_next != (elm)) \ 249 curelm = curelm->field.sle_next; \ 250 curelm->field.sle_next = \ 251 curelm->field.sle_next->field.sle_next; \ 252 } \ 253 _Q_INVALIDATE((elm)->field.sle_next); \ 254 } while (0) 255 256 /* 257 * List definitions. 258 */ 259 #define LIST_HEAD(name, type) \ 260 struct name { \ 261 struct type *lh_first; /* first element */ \ 262 } 263 264 #define LIST_HEAD_INITIALIZER(head) \ 265 { NULL } 266 267 #define LIST_ENTRY(type) \ 268 struct { \ 269 struct type *le_next; /* next element */ \ 270 struct type **le_prev; /* address of previous next element */ \ 271 } 272 273 /* 274 * List access methods. 275 */ 276 #define LIST_FIRST(head) ((head)->lh_first) 277 #define LIST_END(head) NULL 278 #define LIST_EMPTY(head) (LIST_FIRST(head) == LIST_END(head)) 279 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 280 281 #define LIST_FOREACH(var, head, field) \ 282 for((var) = LIST_FIRST(head); \ 283 (var)!= LIST_END(head); \ 284 (var) = LIST_NEXT(var, field)) 285 286 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 287 for ((var) = LIST_FIRST(head); \ 288 (var) && ((tvar) = LIST_NEXT(var, field), 1); \ 289 (var) = (tvar)) 290 291 /* 292 * List functions. 293 */ 294 #define LIST_INIT(head) do { \ 295 LIST_FIRST(head) = LIST_END(head); \ 296 } while (0) 297 298 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 299 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 300 (listelm)->field.le_next->field.le_prev = \ 301 &(elm)->field.le_next; \ 302 (listelm)->field.le_next = (elm); \ 303 (elm)->field.le_prev = &(listelm)->field.le_next; \ 304 } while (0) 305 306 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 307 (elm)->field.le_prev = (listelm)->field.le_prev; \ 308 (elm)->field.le_next = (listelm); \ 309 *(listelm)->field.le_prev = (elm); \ 310 (listelm)->field.le_prev = &(elm)->field.le_next; \ 311 } while (0) 312 313 #define LIST_INSERT_HEAD(head, elm, field) do { \ 314 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 315 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 316 (head)->lh_first = (elm); \ 317 (elm)->field.le_prev = &(head)->lh_first; \ 318 } while (0) 319 320 #define LIST_REMOVE(elm, field) do { \ 321 if ((elm)->field.le_next != NULL) \ 322 (elm)->field.le_next->field.le_prev = \ 323 (elm)->field.le_prev; \ 324 *(elm)->field.le_prev = (elm)->field.le_next; \ 325 _Q_INVALIDATE((elm)->field.le_prev); \ 326 _Q_INVALIDATE((elm)->field.le_next); \ 327 } while (0) 328 329 #define LIST_REPLACE(elm, elm2, field) do { \ 330 if (((elm2)->field.le_next = (elm)->field.le_next) != NULL) \ 331 (elm2)->field.le_next->field.le_prev = \ 332 &(elm2)->field.le_next; \ 333 (elm2)->field.le_prev = (elm)->field.le_prev; \ 334 *(elm2)->field.le_prev = (elm2); \ 335 _Q_INVALIDATE((elm)->field.le_prev); \ 336 _Q_INVALIDATE((elm)->field.le_next); \ 337 } while (0) 338 339 /* 340 * Simple queue definitions. 341 */ 342 #define SIMPLEQ_HEAD(name, type) \ 343 struct name { \ 344 struct type *sqh_first; /* first element */ \ 345 struct type **sqh_last; /* addr of last next element */ \ 346 } 347 348 #define SIMPLEQ_HEAD_INITIALIZER(head) \ 349 { NULL, &(head).sqh_first } 350 351 #define SIMPLEQ_ENTRY(type) \ 352 struct { \ 353 struct type *sqe_next; /* next element */ \ 354 } 355 356 /* 357 * Simple queue access methods. 358 */ 359 #define SIMPLEQ_FIRST(head) ((head)->sqh_first) 360 #define SIMPLEQ_END(head) NULL 361 #define SIMPLEQ_EMPTY(head) (SIMPLEQ_FIRST(head) == SIMPLEQ_END(head)) 362 #define SIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 363 364 #define SIMPLEQ_FOREACH(var, head, field) \ 365 for((var) = SIMPLEQ_FIRST(head); \ 366 (var) != SIMPLEQ_END(head); \ 367 (var) = SIMPLEQ_NEXT(var, field)) 368 369 #define SIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \ 370 for ((var) = SIMPLEQ_FIRST(head); \ 371 (var) && ((tvar) = SIMPLEQ_NEXT(var, field), 1); \ 372 (var) = (tvar)) 373 374 /* 375 * Simple queue functions. 376 */ 377 #define SIMPLEQ_INIT(head) do { \ 378 (head)->sqh_first = NULL; \ 379 (head)->sqh_last = &(head)->sqh_first; \ 380 } while (0) 381 382 #define SIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 383 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ 384 (head)->sqh_last = &(elm)->field.sqe_next; \ 385 (head)->sqh_first = (elm); \ 386 } while (0) 387 388 #define SIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 389 (elm)->field.sqe_next = NULL; \ 390 *(head)->sqh_last = (elm); \ 391 (head)->sqh_last = &(elm)->field.sqe_next; \ 392 } while (0) 393 394 #define SIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 395 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL)\ 396 (head)->sqh_last = &(elm)->field.sqe_next; \ 397 (listelm)->field.sqe_next = (elm); \ 398 } while (0) 399 400 #define SIMPLEQ_REMOVE_HEAD(head, field) do { \ 401 if (((head)->sqh_first = (head)->sqh_first->field.sqe_next) == NULL) \ 402 (head)->sqh_last = &(head)->sqh_first; \ 403 } while (0) 404 405 #define SIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ 406 if (((elm)->field.sqe_next = (elm)->field.sqe_next->field.sqe_next) \ 407 == NULL) \ 408 (head)->sqh_last = &(elm)->field.sqe_next; \ 409 } while (0) 410 411 #define SIMPLEQ_CONCAT(head1, head2) do { \ 412 if (!SIMPLEQ_EMPTY((head2))) { \ 413 *(head1)->sqh_last = (head2)->sqh_first; \ 414 (head1)->sqh_last = (head2)->sqh_last; \ 415 SIMPLEQ_INIT((head2)); \ 416 } \ 417 } while (0) 418 419 /* 420 * XOR Simple queue definitions. 421 */ 422 #define XSIMPLEQ_HEAD(name, type) \ 423 struct name { \ 424 struct type *sqx_first; /* first element */ \ 425 struct type **sqx_last; /* addr of last next element */ \ 426 unsigned long sqx_cookie; \ 427 } 428 429 #define XSIMPLEQ_ENTRY(type) \ 430 struct { \ 431 struct type *sqx_next; /* next element */ \ 432 } 433 434 /* 435 * XOR Simple queue access methods. 436 */ 437 #define XSIMPLEQ_XOR(head, ptr) ((__typeof(ptr))((head)->sqx_cookie ^ \ 438 (unsigned long)(ptr))) 439 #define XSIMPLEQ_FIRST(head) XSIMPLEQ_XOR(head, ((head)->sqx_first)) 440 #define XSIMPLEQ_END(head) NULL 441 #define XSIMPLEQ_EMPTY(head) (XSIMPLEQ_FIRST(head) == XSIMPLEQ_END(head)) 442 #define XSIMPLEQ_NEXT(head, elm, field) XSIMPLEQ_XOR(head, ((elm)->field.sqx_next)) 443 444 445 #define XSIMPLEQ_FOREACH(var, head, field) \ 446 for ((var) = XSIMPLEQ_FIRST(head); \ 447 (var) != XSIMPLEQ_END(head); \ 448 (var) = XSIMPLEQ_NEXT(head, var, field)) 449 450 #define XSIMPLEQ_FOREACH_SAFE(var, head, field, tvar) \ 451 for ((var) = XSIMPLEQ_FIRST(head); \ 452 (var) && ((tvar) = XSIMPLEQ_NEXT(head, var, field), 1); \ 453 (var) = (tvar)) 454 455 /* 456 * XOR Simple queue functions. 457 */ 458 #define XSIMPLEQ_INIT(head) do { \ 459 arc4random_buf(&(head)->sqx_cookie, sizeof((head)->sqx_cookie)); \ 460 (head)->sqx_first = XSIMPLEQ_XOR(head, NULL); \ 461 (head)->sqx_last = XSIMPLEQ_XOR(head, &(head)->sqx_first); \ 462 } while (0) 463 464 #define XSIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 465 if (((elm)->field.sqx_next = (head)->sqx_first) == \ 466 XSIMPLEQ_XOR(head, NULL)) \ 467 (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ 468 (head)->sqx_first = XSIMPLEQ_XOR(head, (elm)); \ 469 } while (0) 470 471 #define XSIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 472 (elm)->field.sqx_next = XSIMPLEQ_XOR(head, NULL); \ 473 *(XSIMPLEQ_XOR(head, (head)->sqx_last)) = XSIMPLEQ_XOR(head, (elm)); \ 474 (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ 475 } while (0) 476 477 #define XSIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 478 if (((elm)->field.sqx_next = (listelm)->field.sqx_next) == \ 479 XSIMPLEQ_XOR(head, NULL)) \ 480 (head)->sqx_last = XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ 481 (listelm)->field.sqx_next = XSIMPLEQ_XOR(head, (elm)); \ 482 } while (0) 483 484 #define XSIMPLEQ_REMOVE_HEAD(head, field) do { \ 485 if (((head)->sqx_first = XSIMPLEQ_XOR(head, \ 486 (head)->sqx_first)->field.sqx_next) == XSIMPLEQ_XOR(head, NULL)) \ 487 (head)->sqx_last = XSIMPLEQ_XOR(head, &(head)->sqx_first); \ 488 } while (0) 489 490 #define XSIMPLEQ_REMOVE_AFTER(head, elm, field) do { \ 491 if (((elm)->field.sqx_next = XSIMPLEQ_XOR(head, \ 492 (elm)->field.sqx_next)->field.sqx_next) \ 493 == XSIMPLEQ_XOR(head, NULL)) \ 494 (head)->sqx_last = \ 495 XSIMPLEQ_XOR(head, &(elm)->field.sqx_next); \ 496 } while (0) 497 498 499 /* 500 * Tail queue definitions. 501 */ 502 #define TAILQ_HEAD(name, type) \ 503 struct name { \ 504 struct type *tqh_first; /* first element */ \ 505 struct type **tqh_last; /* addr of last next element */ \ 506 } 507 508 #define TAILQ_HEAD_INITIALIZER(head) \ 509 { NULL, &(head).tqh_first } 510 511 #define TAILQ_ENTRY(type) \ 512 struct { \ 513 struct type *tqe_next; /* next element */ \ 514 struct type **tqe_prev; /* address of previous next element */ \ 515 } 516 517 /* 518 * Tail queue access methods. 519 */ 520 #define TAILQ_FIRST(head) ((head)->tqh_first) 521 #define TAILQ_END(head) NULL 522 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 523 #define TAILQ_LAST(head, headname) \ 524 (*(((struct headname *)((head)->tqh_last))->tqh_last)) 525 /* XXX */ 526 #define TAILQ_PREV(elm, headname, field) \ 527 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) 528 #define TAILQ_EMPTY(head) \ 529 (TAILQ_FIRST(head) == TAILQ_END(head)) 530 531 #define TAILQ_FOREACH(var, head, field) \ 532 for((var) = TAILQ_FIRST(head); \ 533 (var) != TAILQ_END(head); \ 534 (var) = TAILQ_NEXT(var, field)) 535 536 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 537 for ((var) = TAILQ_FIRST(head); \ 538 (var) != TAILQ_END(head) && \ 539 ((tvar) = TAILQ_NEXT(var, field), 1); \ 540 (var) = (tvar)) 541 542 543 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 544 for((var) = TAILQ_LAST(head, headname); \ 545 (var) != TAILQ_END(head); \ 546 (var) = TAILQ_PREV(var, headname, field)) 547 548 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 549 for ((var) = TAILQ_LAST(head, headname); \ 550 (var) != TAILQ_END(head) && \ 551 ((tvar) = TAILQ_PREV(var, headname, field), 1); \ 552 (var) = (tvar)) 553 554 /* 555 * Tail queue functions. 556 */ 557 #define TAILQ_INIT(head) do { \ 558 (head)->tqh_first = NULL; \ 559 (head)->tqh_last = &(head)->tqh_first; \ 560 } while (0) 561 562 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 563 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 564 (head)->tqh_first->field.tqe_prev = \ 565 &(elm)->field.tqe_next; \ 566 else \ 567 (head)->tqh_last = &(elm)->field.tqe_next; \ 568 (head)->tqh_first = (elm); \ 569 (elm)->field.tqe_prev = &(head)->tqh_first; \ 570 } while (0) 571 572 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 573 (elm)->field.tqe_next = NULL; \ 574 (elm)->field.tqe_prev = (head)->tqh_last; \ 575 *(head)->tqh_last = (elm); \ 576 (head)->tqh_last = &(elm)->field.tqe_next; \ 577 } while (0) 578 579 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 580 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 581 (elm)->field.tqe_next->field.tqe_prev = \ 582 &(elm)->field.tqe_next; \ 583 else \ 584 (head)->tqh_last = &(elm)->field.tqe_next; \ 585 (listelm)->field.tqe_next = (elm); \ 586 (elm)->field.tqe_prev = &(listelm)->field.tqe_next; \ 587 } while (0) 588 589 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 590 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 591 (elm)->field.tqe_next = (listelm); \ 592 *(listelm)->field.tqe_prev = (elm); \ 593 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 594 } while (0) 595 596 #define TAILQ_REMOVE(head, elm, field) do { \ 597 if (((elm)->field.tqe_next) != NULL) \ 598 (elm)->field.tqe_next->field.tqe_prev = \ 599 (elm)->field.tqe_prev; \ 600 else \ 601 (head)->tqh_last = (elm)->field.tqe_prev; \ 602 *(elm)->field.tqe_prev = (elm)->field.tqe_next; \ 603 _Q_INVALIDATE((elm)->field.tqe_prev); \ 604 _Q_INVALIDATE((elm)->field.tqe_next); \ 605 } while (0) 606 607 #define TAILQ_REPLACE(head, elm, elm2, field) do { \ 608 if (((elm2)->field.tqe_next = (elm)->field.tqe_next) != NULL) \ 609 (elm2)->field.tqe_next->field.tqe_prev = \ 610 &(elm2)->field.tqe_next; \ 611 else \ 612 (head)->tqh_last = &(elm2)->field.tqe_next; \ 613 (elm2)->field.tqe_prev = (elm)->field.tqe_prev; \ 614 *(elm2)->field.tqe_prev = (elm2); \ 615 _Q_INVALIDATE((elm)->field.tqe_prev); \ 616 _Q_INVALIDATE((elm)->field.tqe_next); \ 617 } while (0) 618 619 #define TAILQ_CONCAT(head1, head2, field) do { \ 620 if (!TAILQ_EMPTY(head2)) { \ 621 *(head1)->tqh_last = (head2)->tqh_first; \ 622 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 623 (head1)->tqh_last = (head2)->tqh_last; \ 624 TAILQ_INIT((head2)); \ 625 } \ 626 } while (0) 627 628 #endif /* !_SYS_QUEUE_H_ */ 629