queue.h (43459B) - Raw
1 /* 2 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 /*- 29 * Copyright (c) 1991, 1993 30 * The Regents of the University of California. All rights reserved. 31 * 32 * Redistribution and use in source and binary forms, with or without 33 * modification, are permitted provided that the following conditions 34 * are met: 35 * 1. Redistributions of source code must retain the above copyright 36 * notice, this list of conditions and the following disclaimer. 37 * 2. Redistributions in binary form must reproduce the above copyright 38 * notice, this list of conditions and the following disclaimer in the 39 * documentation and/or other materials provided with the distribution. 40 * 4. Neither the name of the University nor the names of its contributors 41 * may be used to endorse or promote products derived from this software 42 * without specific prior written permission. 43 * 44 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 45 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 46 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 47 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 48 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 49 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 50 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 51 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 52 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 53 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 54 * SUCH DAMAGE. 55 * 56 * @(#)queue.h 8.5 (Berkeley) 8/20/94 57 */ 58 59 #ifndef _SYS_QUEUE_H_ 60 #define _SYS_QUEUE_H_ 61 62 #ifndef __improbable 63 #define __improbable(x) (x) /* noop in userspace */ 64 #endif /* __improbable */ 65 66 /* 67 * This file defines five types of data structures: singly-linked lists, 68 * singly-linked tail queues, lists, tail queues, and circular queues. 69 * 70 * A singly-linked list is headed by a single forward pointer. The elements 71 * are singly linked for minimum space and pointer manipulation overhead at 72 * the expense of O(n) removal for arbitrary elements. New elements can be 73 * added to the list after an existing element or at the head of the list. 74 * Elements being removed from the head of the list should use the explicit 75 * macro for this purpose for optimum efficiency. A singly-linked list may 76 * only be traversed in the forward direction. Singly-linked lists are ideal 77 * for applications with large datasets and few or no removals or for 78 * implementing a LIFO queue. 79 * 80 * A singly-linked tail queue is headed by a pair of pointers, one to the 81 * head of the list and the other to the tail of the list. The elements are 82 * singly linked for minimum space and pointer manipulation overhead at the 83 * expense of O(n) removal for arbitrary elements. New elements can be added 84 * to the list after an existing element, at the head of the list, or at the 85 * end of the list. Elements being removed from the head of the tail queue 86 * should use the explicit macro for this purpose for optimum efficiency. 87 * A singly-linked tail queue may only be traversed in the forward direction. 88 * Singly-linked tail queues are ideal for applications with large datasets 89 * and few or no removals or for implementing a FIFO queue. 90 * 91 * A list is headed by a single forward pointer (or an array of forward 92 * pointers for a hash table header). The elements are doubly linked 93 * so that an arbitrary element can be removed without a need to 94 * traverse the list. New elements can be added to the list before 95 * or after an existing element or at the head of the list. A list 96 * may only be traversed in the forward direction. 97 * 98 * A tail queue is headed by a pair of pointers, one to the head of the 99 * list and the other to the tail of the list. The elements are doubly 100 * linked so that an arbitrary element can be removed without a need to 101 * traverse the list. New elements can be added to the list before or 102 * after an existing element, at the head of the list, or at the end of 103 * the list. A tail queue may be traversed in either direction. 104 * 105 * A circle queue is headed by a pair of pointers, one to the head of the 106 * list and the other to the tail of the list. The elements are doubly 107 * linked so that an arbitrary element can be removed without a need to 108 * traverse the list. New elements can be added to the list before or after 109 * an existing element, at the head of the list, or at the end of the list. 110 * A circle queue may be traversed in either direction, but has a more 111 * complex end of list detection. 112 * Note that circle queues are deprecated, because, as the removal log 113 * in FreeBSD states, "CIRCLEQs are a disgrace to everything Knuth taught 114 * us in Volume 1 Chapter 2. [...] Use TAILQ instead, it provides the same 115 * functionality." Code using them will continue to compile, but they 116 * are no longer documented on the man page. 117 * 118 * For details on the use of these macros, see the queue(3) manual page. 119 * 120 * 121 * SLIST LIST STAILQ TAILQ CIRCLEQ 122 * _HEAD + + + + + 123 * _HEAD_INITIALIZER + + + + - 124 * _ENTRY + + + + + 125 * _INIT + + + + + 126 * _EMPTY + + + + + 127 * _FIRST + + + + + 128 * _NEXT + + + + + 129 * _PREV - - - + + 130 * _LAST - - + + + 131 * _FOREACH + + + + + 132 * _FOREACH_SAFE + + + + - 133 * _FOREACH_REVERSE - - - + - 134 * _FOREACH_REVERSE_SAFE - - - + - 135 * _INSERT_HEAD + + + + + 136 * _INSERT_BEFORE - + - + + 137 * _INSERT_AFTER + + + + + 138 * _INSERT_TAIL - - + + + 139 * _CONCAT - - + + - 140 * _REMOVE_AFTER + - + - - 141 * _REMOVE_HEAD + - + - - 142 * _REMOVE_HEAD_UNTIL - - + - - 143 * _REMOVE + + + + + 144 * _SWAP - + + + - 145 * 146 */ 147 #ifdef QUEUE_MACRO_DEBUG 148 /* Store the last 2 places the queue element or head was altered */ 149 struct qm_trace { 150 char * lastfile; 151 int lastline; 152 char * prevfile; 153 int prevline; 154 }; 155 156 #define TRACEBUF struct qm_trace trace; 157 #define TRASHIT(x) do {(x) = (void *)-1;} while (0) 158 159 #define QMD_TRACE_HEAD(head) do { \ 160 (head)->trace.prevline = (head)->trace.lastline; \ 161 (head)->trace.prevfile = (head)->trace.lastfile; \ 162 (head)->trace.lastline = __LINE__; \ 163 (head)->trace.lastfile = __FILE__; \ 164 } while (0) 165 166 #define QMD_TRACE_ELEM(elem) do { \ 167 (elem)->trace.prevline = (elem)->trace.lastline; \ 168 (elem)->trace.prevfile = (elem)->trace.lastfile; \ 169 (elem)->trace.lastline = __LINE__; \ 170 (elem)->trace.lastfile = __FILE__; \ 171 } while (0) 172 173 #else 174 #define QMD_TRACE_ELEM(elem) 175 #define QMD_TRACE_HEAD(head) 176 #define TRACEBUF 177 #define TRASHIT(x) 178 #endif /* QUEUE_MACRO_DEBUG */ 179 180 /* 181 * Horrible macros to enable use of code that was meant to be C-specific 182 * (and which push struct onto type) in C++; without these, C++ code 183 * that uses these macros in the context of a class will blow up 184 * due to "struct" being preprended to "type" by the macros, causing 185 * inconsistent use of tags. 186 * 187 * This approach is necessary because these are macros; we have to use 188 * these on a per-macro basis (because the queues are implemented as 189 * macros, disabling this warning in the scope of the header file is 190 * insufficient), whuch means we can't use #pragma, and have to use 191 * _Pragma. We only need to use these for the queue macros that 192 * prepend "struct" to "type" and will cause C++ to blow up. 193 */ 194 #if defined(__clang__) && defined(__cplusplus) 195 #define __MISMATCH_TAGS_PUSH \ 196 _Pragma("clang diagnostic push") \ 197 _Pragma("clang diagnostic ignored \"-Wmismatched-tags\"") 198 #define __MISMATCH_TAGS_POP \ 199 _Pragma("clang diagnostic pop") 200 #else 201 #define __MISMATCH_TAGS_PUSH 202 #define __MISMATCH_TAGS_POP 203 #endif 204 205 /*! 206 * Ensures that these macros can safely be used in structs when compiling with 207 * clang. The macros do not allow for nullability attributes to be specified due 208 * to how they are expanded. For example: 209 * 210 * SLIST_HEAD(, foo _Nullable) bar; 211 * 212 * expands to 213 * 214 * struct { 215 * struct foo _Nullable *slh_first; 216 * } 217 * 218 * which is not valid because the nullability specifier has to apply to the 219 * pointer. So just ignore nullability completeness in all the places where this 220 * is an issue. 221 */ 222 #if defined(__clang__) 223 #define __NULLABILITY_COMPLETENESS_PUSH \ 224 _Pragma("clang diagnostic push") \ 225 _Pragma("clang diagnostic ignored \"-Wnullability-completeness\"") 226 #define __NULLABILITY_COMPLETENESS_POP \ 227 _Pragma("clang diagnostic pop") 228 #else 229 #define __NULLABILITY_COMPLETENESS_PUSH 230 #define __NULLABILITY_COMPLETENESS_POP 231 #endif 232 233 /* 234 * Singly-linked List declarations. 235 */ 236 #define SLIST_HEAD(name, type) \ 237 __MISMATCH_TAGS_PUSH \ 238 __NULLABILITY_COMPLETENESS_PUSH \ 239 struct name { \ 240 struct type *slh_first; /* first element */ \ 241 } \ 242 __NULLABILITY_COMPLETENESS_POP \ 243 __MISMATCH_TAGS_POP 244 245 #define SLIST_HEAD_INITIALIZER(head) \ 246 { NULL } 247 248 #define SLIST_ENTRY(type) \ 249 __MISMATCH_TAGS_PUSH \ 250 __NULLABILITY_COMPLETENESS_PUSH \ 251 struct { \ 252 struct type *sle_next; /* next element */ \ 253 } \ 254 __NULLABILITY_COMPLETENESS_POP \ 255 __MISMATCH_TAGS_POP 256 257 /* 258 * Singly-linked List functions. 259 */ 260 #define SLIST_EMPTY(head) ((head)->slh_first == NULL) 261 262 #define SLIST_FIRST(head) ((head)->slh_first) 263 264 #define SLIST_FOREACH(var, head, field) \ 265 for ((var) = SLIST_FIRST((head)); \ 266 (var); \ 267 (var) = SLIST_NEXT((var), field)) 268 269 #define SLIST_FOREACH_SAFE(var, head, field, tvar) \ 270 for ((var) = SLIST_FIRST((head)); \ 271 (var) && ((tvar) = SLIST_NEXT((var), field), 1); \ 272 (var) = (tvar)) 273 274 #define SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 275 for ((varp) = &SLIST_FIRST((head)); \ 276 ((var) = *(varp)) != NULL; \ 277 (varp) = &SLIST_NEXT((var), field)) 278 279 #define SLIST_INIT(head) do { \ 280 SLIST_FIRST((head)) = NULL; \ 281 } while (0) 282 283 #define SLIST_INSERT_AFTER(slistelm, elm, field) do { \ 284 SLIST_NEXT((elm), field) = SLIST_NEXT((slistelm), field); \ 285 SLIST_NEXT((slistelm), field) = (elm); \ 286 } while (0) 287 288 #define SLIST_INSERT_HEAD(head, elm, field) do { \ 289 SLIST_NEXT((elm), field) = SLIST_FIRST((head)); \ 290 SLIST_FIRST((head)) = (elm); \ 291 } while (0) 292 293 #define SLIST_NEXT(elm, field) ((elm)->field.sle_next) 294 295 #define SLIST_REMOVE(head, elm, type, field) \ 296 __MISMATCH_TAGS_PUSH \ 297 __NULLABILITY_COMPLETENESS_PUSH \ 298 do { \ 299 if (SLIST_FIRST((head)) == (elm)) { \ 300 SLIST_REMOVE_HEAD((head), field); \ 301 } \ 302 else { \ 303 struct type *curelm = SLIST_FIRST((head)); \ 304 while (SLIST_NEXT(curelm, field) != (elm)) \ 305 curelm = SLIST_NEXT(curelm, field); \ 306 SLIST_REMOVE_AFTER(curelm, field); \ 307 } \ 308 TRASHIT((elm)->field.sle_next); \ 309 } while (0) \ 310 __NULLABILITY_COMPLETENESS_POP \ 311 __MISMATCH_TAGS_POP 312 313 #define SLIST_REMOVE_AFTER(elm, field) do { \ 314 SLIST_NEXT(elm, field) = \ 315 SLIST_NEXT(SLIST_NEXT(elm, field), field); \ 316 } while (0) 317 318 #define SLIST_REMOVE_HEAD(head, field) do { \ 319 SLIST_FIRST((head)) = SLIST_NEXT(SLIST_FIRST((head)), field); \ 320 } while (0) 321 322 /* 323 * Singly-linked Tail queue declarations. 324 */ 325 #define STAILQ_HEAD(name, type) \ 326 __MISMATCH_TAGS_PUSH \ 327 __NULLABILITY_COMPLETENESS_PUSH \ 328 struct name { \ 329 struct type *stqh_first;/* first element */ \ 330 struct type **stqh_last;/* addr of last next element */ \ 331 } \ 332 __NULLABILITY_COMPLETENESS_POP \ 333 __MISMATCH_TAGS_POP 334 335 #define STAILQ_HEAD_INITIALIZER(head) \ 336 { NULL, &(head).stqh_first } 337 338 #define STAILQ_ENTRY(type) \ 339 __MISMATCH_TAGS_PUSH \ 340 __NULLABILITY_COMPLETENESS_PUSH \ 341 struct { \ 342 struct type *stqe_next; /* next element */ \ 343 } \ 344 __NULLABILITY_COMPLETENESS_POP \ 345 __MISMATCH_TAGS_POP 346 347 /* 348 * Singly-linked Tail queue functions. 349 */ 350 #define STAILQ_CONCAT(head1, head2) do { \ 351 if (!STAILQ_EMPTY((head2))) { \ 352 *(head1)->stqh_last = (head2)->stqh_first; \ 353 (head1)->stqh_last = (head2)->stqh_last; \ 354 STAILQ_INIT((head2)); \ 355 } \ 356 } while (0) 357 358 #define STAILQ_EMPTY(head) ((head)->stqh_first == NULL) 359 360 #define STAILQ_FIRST(head) ((head)->stqh_first) 361 362 #define STAILQ_FOREACH(var, head, field) \ 363 for((var) = STAILQ_FIRST((head)); \ 364 (var); \ 365 (var) = STAILQ_NEXT((var), field)) 366 367 368 #define STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 369 for ((var) = STAILQ_FIRST((head)); \ 370 (var) && ((tvar) = STAILQ_NEXT((var), field), 1); \ 371 (var) = (tvar)) 372 373 #define STAILQ_INIT(head) do { \ 374 STAILQ_FIRST((head)) = NULL; \ 375 (head)->stqh_last = &STAILQ_FIRST((head)); \ 376 } while (0) 377 378 #define STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 379 if ((STAILQ_NEXT((elm), field) = STAILQ_NEXT((tqelm), field)) == NULL)\ 380 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 381 STAILQ_NEXT((tqelm), field) = (elm); \ 382 } while (0) 383 384 #define STAILQ_INSERT_HEAD(head, elm, field) do { \ 385 if ((STAILQ_NEXT((elm), field) = STAILQ_FIRST((head))) == NULL) \ 386 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 387 STAILQ_FIRST((head)) = (elm); \ 388 } while (0) 389 390 #define STAILQ_INSERT_TAIL(head, elm, field) do { \ 391 STAILQ_NEXT((elm), field) = NULL; \ 392 *(head)->stqh_last = (elm); \ 393 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 394 } while (0) 395 396 #define STAILQ_LAST(head, type, field) \ 397 __MISMATCH_TAGS_PUSH \ 398 __NULLABILITY_COMPLETENESS_PUSH \ 399 (STAILQ_EMPTY((head)) ? \ 400 NULL : \ 401 ((struct type *)(void *) \ 402 ((char *)((head)->stqh_last) - __offsetof(struct type, field))))\ 403 __NULLABILITY_COMPLETENESS_POP \ 404 __MISMATCH_TAGS_POP 405 406 #define STAILQ_NEXT(elm, field) ((elm)->field.stqe_next) 407 408 #define STAILQ_REMOVE(head, elm, type, field) \ 409 __MISMATCH_TAGS_PUSH \ 410 __NULLABILITY_COMPLETENESS_PUSH \ 411 do { \ 412 if (STAILQ_FIRST((head)) == (elm)) { \ 413 STAILQ_REMOVE_HEAD((head), field); \ 414 } \ 415 else { \ 416 struct type *curelm = STAILQ_FIRST((head)); \ 417 while (STAILQ_NEXT(curelm, field) != (elm)) \ 418 curelm = STAILQ_NEXT(curelm, field); \ 419 STAILQ_REMOVE_AFTER(head, curelm, field); \ 420 } \ 421 TRASHIT((elm)->field.stqe_next); \ 422 } while (0) \ 423 __NULLABILITY_COMPLETENESS_POP \ 424 __MISMATCH_TAGS_POP 425 426 #define STAILQ_REMOVE_HEAD(head, field) do { \ 427 if ((STAILQ_FIRST((head)) = \ 428 STAILQ_NEXT(STAILQ_FIRST((head)), field)) == NULL) \ 429 (head)->stqh_last = &STAILQ_FIRST((head)); \ 430 } while (0) 431 432 #define STAILQ_REMOVE_HEAD_UNTIL(head, elm, field) do { \ 433 if ((STAILQ_FIRST((head)) = STAILQ_NEXT((elm), field)) == NULL) \ 434 (head)->stqh_last = &STAILQ_FIRST((head)); \ 435 } while (0) 436 437 #define STAILQ_REMOVE_AFTER(head, elm, field) do { \ 438 if ((STAILQ_NEXT(elm, field) = \ 439 STAILQ_NEXT(STAILQ_NEXT(elm, field), field)) == NULL) \ 440 (head)->stqh_last = &STAILQ_NEXT((elm), field); \ 441 } while (0) 442 443 #define STAILQ_SWAP(head1, head2, type) \ 444 __MISMATCH_TAGS_PUSH \ 445 __NULLABILITY_COMPLETENESS_PUSH \ 446 do { \ 447 struct type *swap_first = STAILQ_FIRST(head1); \ 448 struct type **swap_last = (head1)->stqh_last; \ 449 STAILQ_FIRST(head1) = STAILQ_FIRST(head2); \ 450 (head1)->stqh_last = (head2)->stqh_last; \ 451 STAILQ_FIRST(head2) = swap_first; \ 452 (head2)->stqh_last = swap_last; \ 453 if (STAILQ_EMPTY(head1)) \ 454 (head1)->stqh_last = &STAILQ_FIRST(head1); \ 455 if (STAILQ_EMPTY(head2)) \ 456 (head2)->stqh_last = &STAILQ_FIRST(head2); \ 457 } while (0) \ 458 __NULLABILITY_COMPLETENESS_POP \ 459 __MISMATCH_TAGS_POP 460 461 462 /* 463 * List declarations. 464 */ 465 #define LIST_HEAD(name, type) \ 466 __MISMATCH_TAGS_PUSH \ 467 __NULLABILITY_COMPLETENESS_PUSH \ 468 struct name { \ 469 struct type *lh_first; /* first element */ \ 470 } \ 471 __NULLABILITY_COMPLETENESS_POP \ 472 __MISMATCH_TAGS_POP 473 474 #define LIST_HEAD_INITIALIZER(head) \ 475 { NULL } 476 477 #define LIST_ENTRY(type) \ 478 __MISMATCH_TAGS_PUSH \ 479 __NULLABILITY_COMPLETENESS_PUSH \ 480 struct { \ 481 struct type *le_next; /* next element */ \ 482 struct type **le_prev; /* address of previous next element */ \ 483 } \ 484 __NULLABILITY_COMPLETENESS_POP \ 485 __MISMATCH_TAGS_POP 486 487 /* 488 * List functions. 489 */ 490 491 #define LIST_CHECK_HEAD(head, field) 492 #define LIST_CHECK_NEXT(elm, field) 493 #define LIST_CHECK_PREV(elm, field) 494 495 #define LIST_EMPTY(head) ((head)->lh_first == NULL) 496 497 #define LIST_FIRST(head) ((head)->lh_first) 498 499 #define LIST_FOREACH(var, head, field) \ 500 for ((var) = LIST_FIRST((head)); \ 501 (var); \ 502 (var) = LIST_NEXT((var), field)) 503 504 #define LIST_FOREACH_SAFE(var, head, field, tvar) \ 505 for ((var) = LIST_FIRST((head)); \ 506 (var) && ((tvar) = LIST_NEXT((var), field), 1); \ 507 (var) = (tvar)) 508 509 #define LIST_INIT(head) do { \ 510 LIST_FIRST((head)) = NULL; \ 511 } while (0) 512 513 #define LIST_INSERT_AFTER(listelm, elm, field) do { \ 514 LIST_CHECK_NEXT(listelm, field); \ 515 if ((LIST_NEXT((elm), field) = LIST_NEXT((listelm), field)) != NULL)\ 516 LIST_NEXT((listelm), field)->field.le_prev = \ 517 &LIST_NEXT((elm), field); \ 518 LIST_NEXT((listelm), field) = (elm); \ 519 (elm)->field.le_prev = &LIST_NEXT((listelm), field); \ 520 } while (0) 521 522 #define LIST_INSERT_BEFORE(listelm, elm, field) do { \ 523 LIST_CHECK_PREV(listelm, field); \ 524 (elm)->field.le_prev = (listelm)->field.le_prev; \ 525 LIST_NEXT((elm), field) = (listelm); \ 526 *(listelm)->field.le_prev = (elm); \ 527 (listelm)->field.le_prev = &LIST_NEXT((elm), field); \ 528 } while (0) 529 530 #define LIST_INSERT_HEAD(head, elm, field) do { \ 531 LIST_CHECK_HEAD((head), field); \ 532 if ((LIST_NEXT((elm), field) = LIST_FIRST((head))) != NULL) \ 533 LIST_FIRST((head))->field.le_prev = &LIST_NEXT((elm), field);\ 534 LIST_FIRST((head)) = (elm); \ 535 (elm)->field.le_prev = &LIST_FIRST((head)); \ 536 } while (0) 537 538 #define LIST_NEXT(elm, field) ((elm)->field.le_next) 539 540 #define LIST_REMOVE(elm, field) do { \ 541 LIST_CHECK_NEXT(elm, field); \ 542 LIST_CHECK_PREV(elm, field); \ 543 if (LIST_NEXT((elm), field) != NULL) \ 544 LIST_NEXT((elm), field)->field.le_prev = \ 545 (elm)->field.le_prev; \ 546 *(elm)->field.le_prev = LIST_NEXT((elm), field); \ 547 TRASHIT((elm)->field.le_next); \ 548 TRASHIT((elm)->field.le_prev); \ 549 } while (0) 550 551 #define LIST_SWAP(head1, head2, type, field) \ 552 __MISMATCH_TAGS_PUSH \ 553 __NULLABILITY_COMPLETENESS_PUSH \ 554 do { \ 555 struct type *swap_tmp = LIST_FIRST((head1)); \ 556 LIST_FIRST((head1)) = LIST_FIRST((head2)); \ 557 LIST_FIRST((head2)) = swap_tmp; \ 558 if ((swap_tmp = LIST_FIRST((head1))) != NULL) \ 559 swap_tmp->field.le_prev = &LIST_FIRST((head1)); \ 560 if ((swap_tmp = LIST_FIRST((head2))) != NULL) \ 561 swap_tmp->field.le_prev = &LIST_FIRST((head2)); \ 562 } while (0) \ 563 __NULLABILITY_COMPLETENESS_POP \ 564 __MISMATCH_TAGS_POP 565 566 /* 567 * Tail queue declarations. 568 */ 569 #define TAILQ_HEAD(name, type) \ 570 __MISMATCH_TAGS_PUSH \ 571 __NULLABILITY_COMPLETENESS_PUSH \ 572 struct name { \ 573 struct type *tqh_first; /* first element */ \ 574 struct type **tqh_last; /* addr of last next element */ \ 575 TRACEBUF \ 576 } \ 577 __NULLABILITY_COMPLETENESS_POP \ 578 __MISMATCH_TAGS_POP 579 580 #define TAILQ_HEAD_INITIALIZER(head) \ 581 { NULL, &(head).tqh_first } 582 583 #define TAILQ_ENTRY(type) \ 584 __MISMATCH_TAGS_PUSH \ 585 __NULLABILITY_COMPLETENESS_PUSH \ 586 struct { \ 587 struct type *tqe_next; /* next element */ \ 588 struct type **tqe_prev; /* address of previous next element */ \ 589 TRACEBUF \ 590 } \ 591 __NULLABILITY_COMPLETENESS_POP \ 592 __MISMATCH_TAGS_POP 593 594 /* 595 * Tail queue functions. 596 */ 597 #define TAILQ_CHECK_HEAD(head, field) 598 #define TAILQ_CHECK_NEXT(elm, field) 599 #define TAILQ_CHECK_PREV(elm, field) 600 601 #define TAILQ_CONCAT(head1, head2, field) do { \ 602 if (!TAILQ_EMPTY(head2)) { \ 603 *(head1)->tqh_last = (head2)->tqh_first; \ 604 (head2)->tqh_first->field.tqe_prev = (head1)->tqh_last; \ 605 (head1)->tqh_last = (head2)->tqh_last; \ 606 TAILQ_INIT((head2)); \ 607 QMD_TRACE_HEAD(head1); \ 608 QMD_TRACE_HEAD(head2); \ 609 } \ 610 } while (0) 611 612 #define TAILQ_EMPTY(head) ((head)->tqh_first == NULL) 613 614 #define TAILQ_FIRST(head) ((head)->tqh_first) 615 616 #define TAILQ_FOREACH(var, head, field) \ 617 for ((var) = TAILQ_FIRST((head)); \ 618 (var); \ 619 (var) = TAILQ_NEXT((var), field)) 620 621 #define TAILQ_FOREACH_SAFE(var, head, field, tvar) \ 622 for ((var) = TAILQ_FIRST((head)); \ 623 (var) && ((tvar) = TAILQ_NEXT((var), field), 1); \ 624 (var) = (tvar)) 625 626 #define TAILQ_FOREACH_REVERSE(var, head, headname, field) \ 627 for ((var) = TAILQ_LAST((head), headname); \ 628 (var); \ 629 (var) = TAILQ_PREV((var), headname, field)) 630 631 #define TAILQ_FOREACH_REVERSE_SAFE(var, head, headname, field, tvar) \ 632 for ((var) = TAILQ_LAST((head), headname); \ 633 (var) && ((tvar) = TAILQ_PREV((var), headname, field), 1); \ 634 (var) = (tvar)) 635 636 637 #define TAILQ_INIT(head) do { \ 638 TAILQ_FIRST((head)) = NULL; \ 639 (head)->tqh_last = &TAILQ_FIRST((head)); \ 640 QMD_TRACE_HEAD(head); \ 641 } while (0) 642 643 644 #define TAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 645 TAILQ_CHECK_NEXT(listelm, field); \ 646 if ((TAILQ_NEXT((elm), field) = TAILQ_NEXT((listelm), field)) != NULL)\ 647 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 648 &TAILQ_NEXT((elm), field); \ 649 else { \ 650 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 651 QMD_TRACE_HEAD(head); \ 652 } \ 653 TAILQ_NEXT((listelm), field) = (elm); \ 654 (elm)->field.tqe_prev = &TAILQ_NEXT((listelm), field); \ 655 QMD_TRACE_ELEM(&(elm)->field); \ 656 QMD_TRACE_ELEM(&listelm->field); \ 657 } while (0) 658 659 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 660 TAILQ_CHECK_PREV(listelm, field); \ 661 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 662 TAILQ_NEXT((elm), field) = (listelm); \ 663 *(listelm)->field.tqe_prev = (elm); \ 664 (listelm)->field.tqe_prev = &TAILQ_NEXT((elm), field); \ 665 QMD_TRACE_ELEM(&(elm)->field); \ 666 QMD_TRACE_ELEM(&listelm->field); \ 667 } while (0) 668 669 #define TAILQ_INSERT_HEAD(head, elm, field) do { \ 670 TAILQ_CHECK_HEAD(head, field); \ 671 if ((TAILQ_NEXT((elm), field) = TAILQ_FIRST((head))) != NULL) \ 672 TAILQ_FIRST((head))->field.tqe_prev = \ 673 &TAILQ_NEXT((elm), field); \ 674 else \ 675 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 676 TAILQ_FIRST((head)) = (elm); \ 677 (elm)->field.tqe_prev = &TAILQ_FIRST((head)); \ 678 QMD_TRACE_HEAD(head); \ 679 QMD_TRACE_ELEM(&(elm)->field); \ 680 } while (0) 681 682 #define TAILQ_INSERT_TAIL(head, elm, field) do { \ 683 TAILQ_NEXT((elm), field) = NULL; \ 684 (elm)->field.tqe_prev = (head)->tqh_last; \ 685 *(head)->tqh_last = (elm); \ 686 (head)->tqh_last = &TAILQ_NEXT((elm), field); \ 687 QMD_TRACE_HEAD(head); \ 688 QMD_TRACE_ELEM(&(elm)->field); \ 689 } while (0) 690 691 #define TAILQ_LAST(head, headname) \ 692 __MISMATCH_TAGS_PUSH \ 693 __NULLABILITY_COMPLETENESS_PUSH \ 694 (*(((struct headname *)((head)->tqh_last))->tqh_last)) \ 695 __NULLABILITY_COMPLETENESS_POP \ 696 __MISMATCH_TAGS_POP 697 698 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 699 700 #define TAILQ_PREV(elm, headname, field) \ 701 __MISMATCH_TAGS_PUSH \ 702 __NULLABILITY_COMPLETENESS_PUSH \ 703 (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) \ 704 __NULLABILITY_COMPLETENESS_POP \ 705 __MISMATCH_TAGS_POP 706 707 #define TAILQ_REMOVE(head, elm, field) do { \ 708 TAILQ_CHECK_NEXT(elm, field); \ 709 TAILQ_CHECK_PREV(elm, field); \ 710 if ((TAILQ_NEXT((elm), field)) != NULL) \ 711 TAILQ_NEXT((elm), field)->field.tqe_prev = \ 712 (elm)->field.tqe_prev; \ 713 else { \ 714 (head)->tqh_last = (elm)->field.tqe_prev; \ 715 QMD_TRACE_HEAD(head); \ 716 } \ 717 *(elm)->field.tqe_prev = TAILQ_NEXT((elm), field); \ 718 TRASHIT((elm)->field.tqe_next); \ 719 TRASHIT((elm)->field.tqe_prev); \ 720 QMD_TRACE_ELEM(&(elm)->field); \ 721 } while (0) 722 723 /* 724 * Why did they switch to spaces for this one macro? 725 */ 726 #define TAILQ_SWAP(head1, head2, type, field) \ 727 __MISMATCH_TAGS_PUSH \ 728 __NULLABILITY_COMPLETENESS_PUSH \ 729 do { \ 730 struct type *swap_first = (head1)->tqh_first; \ 731 struct type **swap_last = (head1)->tqh_last; \ 732 (head1)->tqh_first = (head2)->tqh_first; \ 733 (head1)->tqh_last = (head2)->tqh_last; \ 734 (head2)->tqh_first = swap_first; \ 735 (head2)->tqh_last = swap_last; \ 736 if ((swap_first = (head1)->tqh_first) != NULL) \ 737 swap_first->field.tqe_prev = &(head1)->tqh_first; \ 738 else \ 739 (head1)->tqh_last = &(head1)->tqh_first; \ 740 if ((swap_first = (head2)->tqh_first) != NULL) \ 741 swap_first->field.tqe_prev = &(head2)->tqh_first; \ 742 else \ 743 (head2)->tqh_last = &(head2)->tqh_first; \ 744 } while (0) \ 745 __NULLABILITY_COMPLETENESS_POP \ 746 __MISMATCH_TAGS_POP 747 748 /* 749 * Circular queue definitions. 750 */ 751 #define CIRCLEQ_HEAD(name, type) \ 752 __MISMATCH_TAGS_PUSH \ 753 __NULLABILITY_COMPLETENESS_PUSH \ 754 struct name { \ 755 struct type *cqh_first; /* first element */ \ 756 struct type *cqh_last; /* last element */ \ 757 } \ 758 __NULLABILITY_COMPLETENESS_POP \ 759 __MISMATCH_TAGS_POP 760 761 #define CIRCLEQ_ENTRY(type) \ 762 __MISMATCH_TAGS_PUSH \ 763 __NULLABILITY_COMPLETENESS_PUSH \ 764 struct { \ 765 struct type *cqe_next; /* next element */ \ 766 struct type *cqe_prev; /* previous element */ \ 767 } \ 768 __NULLABILITY_COMPLETENESS_POP \ 769 __MISMATCH_TAGS_POP 770 771 /* 772 * Circular queue functions. 773 */ 774 #define CIRCLEQ_CHECK_HEAD(head, field) 775 #define CIRCLEQ_CHECK_NEXT(head, elm, field) 776 #define CIRCLEQ_CHECK_PREV(head, elm, field) 777 778 #define CIRCLEQ_EMPTY(head) ((head)->cqh_first == (void *)(head)) 779 780 #define CIRCLEQ_FIRST(head) ((head)->cqh_first) 781 782 #define CIRCLEQ_FOREACH(var, head, field) \ 783 for((var) = (head)->cqh_first; \ 784 (var) != (void *)(head); \ 785 (var) = (var)->field.cqe_next) 786 787 #define CIRCLEQ_INIT(head) do { \ 788 (head)->cqh_first = (void *)(head); \ 789 (head)->cqh_last = (void *)(head); \ 790 } while (0) 791 792 #define CIRCLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 793 CIRCLEQ_CHECK_NEXT(head, listelm, field); \ 794 (elm)->field.cqe_next = (listelm)->field.cqe_next; \ 795 (elm)->field.cqe_prev = (listelm); \ 796 if ((listelm)->field.cqe_next == (void *)(head)) \ 797 (head)->cqh_last = (elm); \ 798 else \ 799 (listelm)->field.cqe_next->field.cqe_prev = (elm); \ 800 (listelm)->field.cqe_next = (elm); \ 801 } while (0) 802 803 #define CIRCLEQ_INSERT_BEFORE(head, listelm, elm, field) do { \ 804 CIRCLEQ_CHECK_PREV(head, listelm, field); \ 805 (elm)->field.cqe_next = (listelm); \ 806 (elm)->field.cqe_prev = (listelm)->field.cqe_prev; \ 807 if ((listelm)->field.cqe_prev == (void *)(head)) \ 808 (head)->cqh_first = (elm); \ 809 else \ 810 (listelm)->field.cqe_prev->field.cqe_next = (elm); \ 811 (listelm)->field.cqe_prev = (elm); \ 812 } while (0) 813 814 #define CIRCLEQ_INSERT_HEAD(head, elm, field) do { \ 815 CIRCLEQ_CHECK_HEAD(head, field); \ 816 (elm)->field.cqe_next = (head)->cqh_first; \ 817 (elm)->field.cqe_prev = (void *)(head); \ 818 if ((head)->cqh_last == (void *)(head)) \ 819 (head)->cqh_last = (elm); \ 820 else \ 821 (head)->cqh_first->field.cqe_prev = (elm); \ 822 (head)->cqh_first = (elm); \ 823 } while (0) 824 825 #define CIRCLEQ_INSERT_TAIL(head, elm, field) do { \ 826 (elm)->field.cqe_next = (void *)(head); \ 827 (elm)->field.cqe_prev = (head)->cqh_last; \ 828 if ((head)->cqh_first == (void *)(head)) \ 829 (head)->cqh_first = (elm); \ 830 else \ 831 (head)->cqh_last->field.cqe_next = (elm); \ 832 (head)->cqh_last = (elm); \ 833 } while (0) 834 835 #define CIRCLEQ_LAST(head) ((head)->cqh_last) 836 837 #define CIRCLEQ_NEXT(elm, field) ((elm)->field.cqe_next) 838 839 #define CIRCLEQ_PREV(elm, field) ((elm)->field.cqe_prev) 840 841 #define CIRCLEQ_REMOVE(head, elm, field) do { \ 842 CIRCLEQ_CHECK_NEXT(head, elm, field); \ 843 CIRCLEQ_CHECK_PREV(head, elm, field); \ 844 if ((elm)->field.cqe_next == (void *)(head)) \ 845 (head)->cqh_last = (elm)->field.cqe_prev; \ 846 else \ 847 (elm)->field.cqe_next->field.cqe_prev = \ 848 (elm)->field.cqe_prev; \ 849 if ((elm)->field.cqe_prev == (void *)(head)) \ 850 (head)->cqh_first = (elm)->field.cqe_next; \ 851 else \ 852 (elm)->field.cqe_prev->field.cqe_next = \ 853 (elm)->field.cqe_next; \ 854 } while (0) 855 856 #ifdef _KERNEL 857 858 #if NOTFB31 859 860 /* 861 * XXX insque() and remque() are an old way of handling certain queues. 862 * They bogusly assumes that all queue heads look alike. 863 */ 864 865 struct quehead { 866 struct quehead *qh_link; 867 struct quehead *qh_rlink; 868 }; 869 870 #ifdef __GNUC__ 871 #define chkquenext(a) 872 #define chkqueprev(a) 873 874 static __inline void 875 insque(void *a, void *b) 876 { 877 struct quehead *element = (struct quehead *)a, 878 *head = (struct quehead *)b; 879 chkquenext(head); 880 881 element->qh_link = head->qh_link; 882 element->qh_rlink = head; 883 head->qh_link = element; 884 element->qh_link->qh_rlink = element; 885 } 886 887 static __inline void 888 remque(void *a) 889 { 890 struct quehead *element = (struct quehead *)a; 891 chkquenext(element); 892 chkqueprev(element); 893 894 element->qh_link->qh_rlink = element->qh_rlink; 895 element->qh_rlink->qh_link = element->qh_link; 896 element->qh_rlink = 0; 897 } 898 899 #else /* !__GNUC__ */ 900 901 void insque(void *a, void *b); 902 void remque(void *a); 903 904 #endif /* __GNUC__ */ 905 906 #endif /* NOTFB31 */ 907 #endif /* _KERNEL */ 908 909 #endif /* !_SYS_QUEUE_H_ */