1/* 2 * Copyright 2012-2015 Samy Al Bahra. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27/*- 28 * Copyright (c) 1991, 1993 29 * The Regents of the University of California. All rights reserved. 30 * 31 * Redistribution and use in source and binary forms, with or without 32 * modification, are permitted provided that the following conditions 33 * are met: 34 * 1. Redistributions of source code must retain the above copyright 35 * notice, this list of conditions and the following disclaimer. 36 * 2. Redistributions in binary form must reproduce the above copyright 37 * notice, this list of conditions and the following disclaimer in the 38 * documentation and/or other materials provided with the distribution. 39 * 4. Neither the name of the University nor the names of its contributors 40 * may be used to endorse or promote products derived from this software 41 * without specific prior written permission. 42 * 43 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 44 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 45 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 46 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 47 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 48 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 49 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 50 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 51 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 52 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 53 * SUCH DAMAGE. 54 * 55 * @(#)queue.h 8.5 (Berkeley) 8/20/94 56 * $FreeBSD: stable/11/sys/contrib/ck/include/ck_queue.h 339650 2018-10-23 13:12:42Z avg $ 57 */ 58 59#ifndef CK_QUEUE_H 60#define CK_QUEUE_H 61 62#include <ck_pr.h> 63 64/* 65 * This file defines three types of data structures: singly-linked lists, 66 * singly-linked tail queues and lists. 67 * 68 * A singly-linked list is headed by a single forward pointer. The elements 69 * are singly linked for minimum space and pointer manipulation overhead at 70 * the expense of O(n) removal for arbitrary elements. New elements can be 71 * added to the list after an existing element or at the head of the list. 72 * Elements being removed from the head of the list should use the explicit 73 * macro for this purpose for optimum efficiency. A singly-linked list may 74 * only be traversed in the forward direction. Singly-linked lists are ideal 75 * for applications with large datasets and few or no removals or for 76 * implementing a LIFO queue. 77 * 78 * A singly-linked tail queue is headed by a pair of pointers, one to the 79 * head of the list and the other to the tail of the list. The elements are 80 * singly linked for minimum space and pointer manipulation overhead at the 81 * expense of O(n) removal for arbitrary elements. New elements can be added 82 * to the list after an existing element, at the head of the list, or at the 83 * end of the list. Elements being removed from the head of the tail queue 84 * should use the explicit macro for this purpose for optimum efficiency. 85 * A singly-linked tail queue may only be traversed in the forward direction. 86 * Singly-linked tail queues are ideal for applications with large datasets 87 * and few or no removals or for implementing a FIFO queue. 88 * 89 * A list is headed by a single forward pointer (or an array of forward 90 * pointers for a hash table header). The elements are doubly linked 91 * so that an arbitrary element can be removed without a need to 92 * traverse the list. New elements can be added to the list before 93 * or after an existing element or at the head of the list. A list 94 * may only be traversed in the forward direction. 95 * 96 * It is safe to use _FOREACH/_FOREACH_SAFE in the presence of concurrent 97 * modifications to the list. Writers to these lists must, on the other hand, 98 * implement writer-side synchronization. The _SWAP operations are not atomic. 99 * This facility is currently unsupported on architectures such as the Alpha 100 * which require load-depend memory fences. 101 * 102 * CK_SLIST CK_LIST CK_STAILQ 103 * _HEAD + + + 104 * _HEAD_INITIALIZER + + + 105 * _ENTRY + + + 106 * _INIT + + + 107 * _EMPTY + + + 108 * _FIRST + + + 109 * _NEXT + + + 110 * _FOREACH + + + 111 * _FOREACH_SAFE + + + 112 * _INSERT_HEAD + + + 113 * _INSERT_BEFORE - + - 114 * _INSERT_AFTER + + + 115 * _INSERT_TAIL - - + 116 * _REMOVE_AFTER + - + 117 * _REMOVE_HEAD + - + 118 * _REMOVE + + + 119 * _SWAP + + + 120 * _MOVE + + + 121 */ 122 123/* 124 * Singly-linked List declarations. 125 */ 126#define CK_SLIST_HEAD(name, type) \ 127struct name { \ 128 struct type *cslh_first; /* first element */ \ 129} 130 131#define CK_SLIST_HEAD_INITIALIZER(head) \ 132 { NULL } 133 134#define CK_SLIST_ENTRY(type) \ 135struct { \ 136 struct type *csle_next; /* next element */ \ 137} 138 139/* 140 * Singly-linked List functions. 141 */ 142#define CK_SLIST_EMPTY(head) \ 143 (ck_pr_load_ptr(&(head)->cslh_first) == NULL) 144 145#define CK_SLIST_FIRST(head) \ 146 (ck_pr_load_ptr(&(head)->cslh_first)) 147 148#define CK_SLIST_NEXT(elm, field) \ 149 ck_pr_load_ptr(&((elm)->field.csle_next)) 150 151#define CK_SLIST_FOREACH(var, head, field) \ 152 for ((var) = CK_SLIST_FIRST((head)); \ 153 (var) && (ck_pr_fence_load(), 1); \ 154 (var) = CK_SLIST_NEXT((var), field)) 155 156#define CK_SLIST_FOREACH_SAFE(var, head, field, tvar) \ 157 for ((var) = CK_SLIST_FIRST(head); \ 158 (var) && (ck_pr_fence_load(), (tvar) = CK_SLIST_NEXT(var, field), 1);\ 159 (var) = (tvar)) 160 161#define CK_SLIST_FOREACH_PREVPTR(var, varp, head, field) \ 162 for ((varp) = &(head)->cslh_first; \ 163 ((var) = ck_pr_load_ptr(varp)) != NULL && (ck_pr_fence_load(), 1); \ 164 (varp) = &(var)->field.csle_next) 165 166#define CK_SLIST_INIT(head) do { \ 167 ck_pr_store_ptr(&(head)->cslh_first, NULL); \ 168 ck_pr_fence_store(); \ 169} while (0) 170 171#define CK_SLIST_INSERT_AFTER(a, b, field) do { \ 172 (b)->field.csle_next = (a)->field.csle_next; \ 173 ck_pr_fence_store(); \ 174 ck_pr_store_ptr(&(a)->field.csle_next, b); \ 175} while (0) 176 177#define CK_SLIST_INSERT_HEAD(head, elm, field) do { \ 178 (elm)->field.csle_next = (head)->cslh_first; \ 179 ck_pr_fence_store(); \ 180 ck_pr_store_ptr(&(head)->cslh_first, elm); \ 181} while (0) 182 183#define CK_SLIST_INSERT_PREVPTR(prevp, slistelm, elm, field) do { \ 184 (elm)->field.csle_next = (slistelm); \ 185 ck_pr_fence_store(); \ 186 ck_pr_store_ptr(prevp, elm); \ 187} while (0) 188 189#define CK_SLIST_REMOVE_AFTER(elm, field) do { \ 190 ck_pr_store_ptr(&(elm)->field.csle_next, \ 191 (elm)->field.csle_next->field.csle_next); \ 192} while (0) 193 194#define CK_SLIST_REMOVE(head, elm, type, field) do { \ 195 if ((head)->cslh_first == (elm)) { \ 196 CK_SLIST_REMOVE_HEAD((head), field); \ 197 } else { \ 198 struct type *curelm = (head)->cslh_first; \ 199 while (curelm->field.csle_next != (elm)) \ 200 curelm = curelm->field.csle_next; \ 201 CK_SLIST_REMOVE_AFTER(curelm, field); \ 202 } \ 203} while (0) 204 205#define CK_SLIST_REMOVE_HEAD(head, field) do { \ 206 ck_pr_store_ptr(&(head)->cslh_first, \ 207 (head)->cslh_first->field.csle_next); \ 208} while (0) 209 210#define CK_SLIST_REMOVE_PREVPTR(prevp, elm, field) do { \ 211 ck_pr_store_ptr(prevptr, (elm)->field.csle_next); \ 212} while (0) 213 214#define CK_SLIST_MOVE(head1, head2, field) do { \ 215 ck_pr_store_ptr(&(head1)->cslh_first, (head2)->cslh_first); \ 216} while (0) 217 218/* 219 * This operation is not applied atomically. 220 */ 221#define CK_SLIST_SWAP(a, b, type) do { \ 222 struct type *swap_first = (a)->cslh_first; \ 223 (a)->cslh_first = (b)->cslh_first; \ 224 (b)->cslh_first = swap_first; \ 225} while (0) 226 227/* 228 * Singly-linked Tail queue declarations. 229 */ 230#define CK_STAILQ_HEAD(name, type) \ 231struct name { \ 232 struct type *cstqh_first;/* first element */ \ 233 struct type **cstqh_last;/* addr of last next element */ \ 234} 235 236#define CK_STAILQ_HEAD_INITIALIZER(head) \ 237 { NULL, &(head).cstqh_first } 238 239#define CK_STAILQ_ENTRY(type) \ 240struct { \ 241 struct type *cstqe_next; /* next element */ \ 242} 243 244/* 245 * Singly-linked Tail queue functions. 246 */ 247#define CK_STAILQ_CONCAT(head1, head2) do { \ 248 if ((head2)->cstqh_first != NULL) { \ 249 ck_pr_store_ptr((head1)->cstqh_last, (head2)->cstqh_first); \ 250 ck_pr_fence_store(); \ 251 (head1)->cstqh_last = (head2)->cstqh_last; \ 252 CK_STAILQ_INIT((head2)); \ 253 } \ 254} while (0) 255 256#define CK_STAILQ_EMPTY(head) (ck_pr_load_ptr(&(head)->cstqh_first) == NULL) 257 258#define CK_STAILQ_FIRST(head) (ck_pr_load_ptr(&(head)->cstqh_first)) 259 260#define CK_STAILQ_FOREACH(var, head, field) \ 261 for((var) = CK_STAILQ_FIRST((head)); \ 262 (var) && (ck_pr_fence_load(), 1); \ 263 (var) = CK_STAILQ_NEXT((var), field)) 264 265#define CK_STAILQ_FOREACH_SAFE(var, head, field, tvar) \ 266 for ((var) = CK_STAILQ_FIRST((head)); \ 267 (var) && (ck_pr_fence_load(), (tvar) = \ 268 CK_STAILQ_NEXT((var), field), 1); \ 269 (var) = (tvar)) 270 271#define CK_STAILQ_INIT(head) do { \ 272 ck_pr_store_ptr(&(head)->cstqh_first, NULL); \ 273 ck_pr_fence_store(); \ 274 (head)->cstqh_last = &(head)->cstqh_first; \ 275} while (0) 276 277#define CK_STAILQ_INSERT_AFTER(head, tqelm, elm, field) do { \ 278 (elm)->field.cstqe_next = (tqelm)->field.cstqe_next; \ 279 ck_pr_fence_store(); \ 280 ck_pr_store_ptr(&(tqelm)->field.cstqe_next, elm); \ 281 if ((elm)->field.cstqe_next == NULL) \ 282 (head)->cstqh_last = &(elm)->field.cstqe_next; \ 283} while (0) 284 285#define CK_STAILQ_INSERT_HEAD(head, elm, field) do { \ 286 (elm)->field.cstqe_next = (head)->cstqh_first; \ 287 ck_pr_fence_store(); \ 288 ck_pr_store_ptr(&(head)->cstqh_first, elm); \ 289 if ((elm)->field.cstqe_next == NULL) \ 290 (head)->cstqh_last = &(elm)->field.cstqe_next; \ 291} while (0) 292 293#define CK_STAILQ_INSERT_TAIL(head, elm, field) do { \ 294 (elm)->field.cstqe_next = NULL; \ 295 ck_pr_fence_store(); \ 296 ck_pr_store_ptr((head)->cstqh_last, (elm)); \ 297 (head)->cstqh_last = &(elm)->field.cstqe_next; \ 298} while (0) 299 300#define CK_STAILQ_NEXT(elm, field) \ 301 (ck_pr_load_ptr(&(elm)->field.cstqe_next)) 302 303#define CK_STAILQ_REMOVE(head, elm, type, field) do { \ 304 if ((head)->cstqh_first == (elm)) { \ 305 CK_STAILQ_REMOVE_HEAD((head), field); \ 306 } else { \ 307 struct type *curelm = (head)->cstqh_first; \ 308 while (curelm->field.cstqe_next != (elm)) \ 309 curelm = curelm->field.cstqe_next; \ 310 CK_STAILQ_REMOVE_AFTER(head, curelm, field); \ 311 } \ 312} while (0) 313 314#define CK_STAILQ_REMOVE_AFTER(head, elm, field) do { \ 315 ck_pr_store_ptr(&(elm)->field.cstqe_next, \ 316 (elm)->field.cstqe_next->field.cstqe_next); \ 317 if ((elm)->field.cstqe_next == NULL) \ 318 (head)->cstqh_last = &(elm)->field.cstqe_next; \ 319} while (0) 320 321#define CK_STAILQ_REMOVE_HEAD(head, field) do { \ 322 ck_pr_store_ptr(&(head)->cstqh_first, \ 323 (head)->cstqh_first->field.cstqe_next); \ 324 if ((head)->cstqh_first == NULL) \ 325 (head)->cstqh_last = &(head)->cstqh_first; \ 326} while (0) 327 328#define CK_STAILQ_MOVE(head1, head2, field) do { \ 329 ck_pr_store_ptr(&(head1)->cstqh_first, (head2)->cstqh_first); \ 330 (head1)->cstqh_last = (head2)->cstqh_last; \ 331 if ((head2)->cstqh_last == &(head2)->cstqh_first) \ 332 (head1)->cstqh_last = &(head1)->cstqh_first; \ 333} while (0) 334 335/* 336 * This operation is not applied atomically. 337 */ 338#define CK_STAILQ_SWAP(head1, head2, type) do { \ 339 struct type *swap_first = CK_STAILQ_FIRST(head1); \ 340 struct type **swap_last = (head1)->cstqh_last; \ 341 CK_STAILQ_FIRST(head1) = CK_STAILQ_FIRST(head2); \ 342 (head1)->cstqh_last = (head2)->cstqh_last; \ 343 CK_STAILQ_FIRST(head2) = swap_first; \ 344 (head2)->cstqh_last = swap_last; \ 345 if (CK_STAILQ_EMPTY(head1)) \ 346 (head1)->cstqh_last = &(head1)->cstqh_first; \ 347 if (CK_STAILQ_EMPTY(head2)) \ 348 (head2)->cstqh_last = &(head2)->cstqh_first; \ 349} while (0) 350 351/* 352 * List declarations. 353 */ 354#define CK_LIST_HEAD(name, type) \ 355struct name { \ 356 struct type *clh_first; /* first element */ \ 357} 358 359#define CK_LIST_HEAD_INITIALIZER(head) \ 360 { NULL } 361 362#define CK_LIST_ENTRY(type) \ 363struct { \ 364 struct type *cle_next; /* next element */ \ 365 struct type **cle_prev; /* address of previous next element */ \ 366} 367 368#define CK_LIST_FIRST(head) ck_pr_load_ptr(&(head)->clh_first) 369#define CK_LIST_EMPTY(head) (CK_LIST_FIRST(head) == NULL) 370#define CK_LIST_NEXT(elm, field) ck_pr_load_ptr(&(elm)->field.cle_next) 371 372#define CK_LIST_FOREACH(var, head, field) \ 373 for ((var) = CK_LIST_FIRST((head)); \ 374 (var) && (ck_pr_fence_load(), 1); \ 375 (var) = CK_LIST_NEXT((var), field)) 376 377#define CK_LIST_FOREACH_SAFE(var, head, field, tvar) \ 378 for ((var) = CK_LIST_FIRST((head)); \ 379 (var) && (ck_pr_fence_load(), (tvar) = CK_LIST_NEXT((var), field), 1);\ 380 (var) = (tvar)) 381 382#define CK_LIST_INIT(head) do { \ 383 ck_pr_store_ptr(&(head)->clh_first, NULL); \ 384 ck_pr_fence_store(); \ 385} while (0) 386 387#define CK_LIST_INSERT_AFTER(listelm, elm, field) do { \ 388 (elm)->field.cle_next = (listelm)->field.cle_next; \ 389 (elm)->field.cle_prev = &(listelm)->field.cle_next; \ 390 ck_pr_fence_store(); \ 391 if ((listelm)->field.cle_next != NULL) \ 392 (listelm)->field.cle_next->field.cle_prev = &(elm)->field.cle_next;\ 393 ck_pr_store_ptr(&(listelm)->field.cle_next, elm); \ 394} while (0) 395 396#define CK_LIST_INSERT_BEFORE(listelm, elm, field) do { \ 397 (elm)->field.cle_prev = (listelm)->field.cle_prev; \ 398 (elm)->field.cle_next = (listelm); \ 399 ck_pr_fence_store(); \ 400 ck_pr_store_ptr((listelm)->field.cle_prev, (elm)); \ 401 (listelm)->field.cle_prev = &(elm)->field.cle_next; \ 402} while (0) 403 404#define CK_LIST_INSERT_HEAD(head, elm, field) do { \ 405 (elm)->field.cle_next = (head)->clh_first; \ 406 ck_pr_fence_store(); \ 407 if ((elm)->field.cle_next != NULL) \ 408 (head)->clh_first->field.cle_prev = &(elm)->field.cle_next; \ 409 ck_pr_store_ptr(&(head)->clh_first, elm); \ 410 (elm)->field.cle_prev = &(head)->clh_first; \ 411} while (0) 412 413#define CK_LIST_REMOVE(elm, field) do { \ 414 ck_pr_store_ptr((elm)->field.cle_prev, (elm)->field.cle_next); \ 415 if ((elm)->field.cle_next != NULL) \ 416 (elm)->field.cle_next->field.cle_prev = (elm)->field.cle_prev; \ 417} while (0) 418 419#define CK_LIST_MOVE(head1, head2, field) do { \ 420 ck_pr_store_ptr(&(head1)->clh_first, (head2)->clh_first); \ 421 if ((head1)->clh_first != NULL) \ 422 (head1)->clh_first->field.cle_prev = &(head1)->clh_first; \ 423} while (0) 424 425/* 426 * This operation is not applied atomically. 427 */ 428#define CK_LIST_SWAP(head1, head2, type, field) do { \ 429 struct type *swap_tmp = (head1)->clh_first; \ 430 (head1)->clh_first = (head2)->clh_first; \ 431 (head2)->clh_first = swap_tmp; \ 432 if ((swap_tmp = (head1)->clh_first) != NULL) \ 433 swap_tmp->field.cle_prev = &(head1)->clh_first; \ 434 if ((swap_tmp = (head2)->clh_first) != NULL) \ 435 swap_tmp->field.cle_prev = &(head2)->clh_first; \ 436} while (0) 437 438#endif /* CK_QUEUE_H */ 439