1 /* $NetBSD: queue.h,v 1.52 2009/04/20 09:56:08 mschuett Exp $ */ 2 3 /* 4 * QEMU version: Copy from netbsd, removed debug code, removed some of 5 * the implementations. Left in singly-linked lists, lists, simple 6 * queues, and tail queues. 7 */ 8 9 /* 10 * Copyright (c) 1991, 1993 11 * The Regents of the University of California. All rights reserved. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * @(#)queue.h 8.5 (Berkeley) 8/20/94 38 */ 39 40 #ifndef QEMU_SYS_QUEUE_H 41 #define QEMU_SYS_QUEUE_H 42 43 /* 44 * This file defines four types of data structures: singly-linked lists, 45 * lists, simple queues, and tail queues. 46 * 47 * A singly-linked list is headed by a single forward pointer. The 48 * elements are singly linked for minimum space and pointer manipulation 49 * overhead at the expense of O(n) removal for arbitrary elements. New 50 * elements can be added to the list after an existing element or at the 51 * head of the list. Elements being removed from the head of the list 52 * should use the explicit macro for this purpose for optimum 53 * efficiency. A singly-linked list may only be traversed in the forward 54 * direction. Singly-linked lists are ideal for applications with large 55 * datasets and few or no removals or for implementing a LIFO queue. 56 * 57 * A list is headed by a single forward pointer (or an array of forward 58 * pointers for a hash table header). The elements are doubly linked 59 * so that an arbitrary element can be removed without a need to 60 * traverse the list. New elements can be added to the list before 61 * or after an existing element or at the head of the list. A list 62 * may only be traversed in the forward direction. 63 * 64 * A simple queue is headed by a pair of pointers, one the head of the 65 * list and the other to the tail of the list. The elements are singly 66 * linked to save space, so elements can only be removed from the 67 * head of the list. New elements can be added to the list after 68 * an existing element, at the head of the list, or at the end of the 69 * list. A simple queue may only be traversed in the forward direction. 70 * 71 * A tail queue is headed by a pair of pointers, one to the head of the 72 * list and the other to the tail of the list. The elements are doubly 73 * linked so that an arbitrary element can be removed without a need to 74 * traverse the list. New elements can be added to the list before or 75 * after an existing element, at the head of the list, or at the end of 76 * the list. A tail queue may be traversed in either direction. 77 * 78 * For details on the use of these macros, see the queue(3) manual page. 79 */ 80 81 /* 82 * List definitions. 83 */ 84 #define QLIST_HEAD(name, type) \ 85 struct name { \ 86 struct type *lh_first; /* first element */ \ 87 } 88 89 #define QLIST_HEAD_INITIALIZER(head) \ 90 { NULL } 91 92 #define QLIST_ENTRY(type) \ 93 struct { \ 94 struct type *le_next; /* next element */ \ 95 struct type **le_prev; /* address of previous next element */ \ 96 } 97 98 /* 99 * List functions. 100 */ 101 #define QLIST_INIT(head) do { \ 102 (head)->lh_first = NULL; \ 103 } while (/*CONSTCOND*/0) 104 105 #define QLIST_SWAP(dstlist, srclist, field) do { \ 106 void *tmplist; \ 107 tmplist = (srclist)->lh_first; \ 108 (srclist)->lh_first = (dstlist)->lh_first; \ 109 if ((srclist)->lh_first != NULL) { \ 110 (srclist)->lh_first->field.le_prev = &(srclist)->lh_first; \ 111 } \ 112 (dstlist)->lh_first = tmplist; \ 113 if ((dstlist)->lh_first != NULL) { \ 114 (dstlist)->lh_first->field.le_prev = &(dstlist)->lh_first; \ 115 } \ 116 } while (/*CONSTCOND*/0) 117 118 #define QLIST_INSERT_AFTER(listelm, elm, field) do { \ 119 if (((elm)->field.le_next = (listelm)->field.le_next) != NULL) \ 120 (listelm)->field.le_next->field.le_prev = \ 121 &(elm)->field.le_next; \ 122 (listelm)->field.le_next = (elm); \ 123 (elm)->field.le_prev = &(listelm)->field.le_next; \ 124 } while (/*CONSTCOND*/0) 125 126 #define QLIST_INSERT_BEFORE(listelm, elm, field) do { \ 127 (elm)->field.le_prev = (listelm)->field.le_prev; \ 128 (elm)->field.le_next = (listelm); \ 129 *(listelm)->field.le_prev = (elm); \ 130 (listelm)->field.le_prev = &(elm)->field.le_next; \ 131 } while (/*CONSTCOND*/0) 132 133 #define QLIST_INSERT_HEAD(head, elm, field) do { \ 134 if (((elm)->field.le_next = (head)->lh_first) != NULL) \ 135 (head)->lh_first->field.le_prev = &(elm)->field.le_next;\ 136 (head)->lh_first = (elm); \ 137 (elm)->field.le_prev = &(head)->lh_first; \ 138 } while (/*CONSTCOND*/0) 139 140 #define QLIST_REMOVE(elm, field) do { \ 141 if ((elm)->field.le_next != NULL) \ 142 (elm)->field.le_next->field.le_prev = \ 143 (elm)->field.le_prev; \ 144 *(elm)->field.le_prev = (elm)->field.le_next; \ 145 (elm)->field.le_next = NULL; \ 146 (elm)->field.le_prev = NULL; \ 147 } while (/*CONSTCOND*/0) 148 149 /* 150 * Like QLIST_REMOVE() but safe to call when elm is not in a list 151 */ 152 #define QLIST_SAFE_REMOVE(elm, field) do { \ 153 if ((elm)->field.le_prev != NULL) { \ 154 if ((elm)->field.le_next != NULL) \ 155 (elm)->field.le_next->field.le_prev = \ 156 (elm)->field.le_prev; \ 157 *(elm)->field.le_prev = (elm)->field.le_next; \ 158 (elm)->field.le_next = NULL; \ 159 (elm)->field.le_prev = NULL; \ 160 } \ 161 } while (/*CONSTCOND*/0) 162 163 /* Is elm in a list? */ 164 #define QLIST_IS_INSERTED(elm, field) ((elm)->field.le_prev != NULL) 165 166 #define QLIST_FOREACH(var, head, field) \ 167 for ((var) = ((head)->lh_first); \ 168 (var); \ 169 (var) = ((var)->field.le_next)) 170 171 #define QLIST_FOREACH_SAFE(var, head, field, next_var) \ 172 for ((var) = ((head)->lh_first); \ 173 (var) && ((next_var) = ((var)->field.le_next), 1); \ 174 (var) = (next_var)) 175 176 /* 177 * List access methods. 178 */ 179 #define QLIST_EMPTY(head) ((head)->lh_first == NULL) 180 #define QLIST_FIRST(head) ((head)->lh_first) 181 #define QLIST_NEXT(elm, field) ((elm)->field.le_next) 182 183 184 /* 185 * Singly-linked List definitions. 186 */ 187 #define QSLIST_HEAD(name, type) \ 188 struct name { \ 189 struct type *slh_first; /* first element */ \ 190 } 191 192 #define QSLIST_HEAD_INITIALIZER(head) \ 193 { NULL } 194 195 #define QSLIST_ENTRY(type) \ 196 struct { \ 197 struct type *sle_next; /* next element */ \ 198 } 199 200 /* 201 * Singly-linked List functions. 202 */ 203 #define QSLIST_INIT(head) do { \ 204 (head)->slh_first = NULL; \ 205 } while (/*CONSTCOND*/0) 206 207 #define QSLIST_INSERT_AFTER(slistelm, elm, field) do { \ 208 (elm)->field.sle_next = (slistelm)->field.sle_next; \ 209 (slistelm)->field.sle_next = (elm); \ 210 } while (/*CONSTCOND*/0) 211 212 #define QSLIST_INSERT_HEAD(head, elm, field) do { \ 213 (elm)->field.sle_next = (head)->slh_first; \ 214 (head)->slh_first = (elm); \ 215 } while (/*CONSTCOND*/0) 216 217 #define QSLIST_INSERT_HEAD_ATOMIC(head, elm, field) do { \ 218 typeof(elm) save_sle_next; \ 219 do { \ 220 save_sle_next = (elm)->field.sle_next = (head)->slh_first; \ 221 } while (qatomic_cmpxchg(&(head)->slh_first, save_sle_next, (elm)) !=\ 222 save_sle_next); \ 223 } while (/*CONSTCOND*/0) 224 225 #define QSLIST_MOVE_ATOMIC(dest, src) do { \ 226 (dest)->slh_first = qatomic_xchg(&(src)->slh_first, NULL); \ 227 } while (/*CONSTCOND*/0) 228 229 #define QSLIST_REMOVE_HEAD(head, field) do { \ 230 typeof((head)->slh_first) elm = (head)->slh_first; \ 231 (head)->slh_first = elm->field.sle_next; \ 232 elm->field.sle_next = NULL; \ 233 } while (/*CONSTCOND*/0) 234 235 #define QSLIST_REMOVE_AFTER(slistelm, field) do { \ 236 typeof(slistelm) next = (slistelm)->field.sle_next; \ 237 (slistelm)->field.sle_next = next->field.sle_next; \ 238 next->field.sle_next = NULL; \ 239 } while (/*CONSTCOND*/0) 240 241 #define QSLIST_REMOVE(head, elm, type, field) do { \ 242 if ((head)->slh_first == (elm)) { \ 243 QSLIST_REMOVE_HEAD((head), field); \ 244 } else { \ 245 struct type *curelm = (head)->slh_first; \ 246 while (curelm->field.sle_next != (elm)) \ 247 curelm = curelm->field.sle_next; \ 248 curelm->field.sle_next = curelm->field.sle_next->field.sle_next; \ 249 (elm)->field.sle_next = NULL; \ 250 } \ 251 } while (/*CONSTCOND*/0) 252 253 #define QSLIST_FOREACH(var, head, field) \ 254 for((var) = (head)->slh_first; (var); (var) = (var)->field.sle_next) 255 256 #define QSLIST_FOREACH_SAFE(var, head, field, tvar) \ 257 for ((var) = QSLIST_FIRST((head)); \ 258 (var) && ((tvar) = QSLIST_NEXT((var), field), 1); \ 259 (var) = (tvar)) 260 261 /* 262 * Singly-linked List access methods. 263 */ 264 #define QSLIST_EMPTY(head) ((head)->slh_first == NULL) 265 #define QSLIST_FIRST(head) ((head)->slh_first) 266 #define QSLIST_NEXT(elm, field) ((elm)->field.sle_next) 267 268 269 /* 270 * Simple queue definitions. 271 */ 272 #define QSIMPLEQ_HEAD(name, type) \ 273 struct name { \ 274 struct type *sqh_first; /* first element */ \ 275 struct type **sqh_last; /* addr of last next element */ \ 276 } 277 278 #define QSIMPLEQ_HEAD_INITIALIZER(head) \ 279 { NULL, &(head).sqh_first } 280 281 #define QSIMPLEQ_ENTRY(type) \ 282 struct { \ 283 struct type *sqe_next; /* next element */ \ 284 } 285 286 /* 287 * Simple queue functions. 288 */ 289 #define QSIMPLEQ_INIT(head) do { \ 290 (head)->sqh_first = NULL; \ 291 (head)->sqh_last = &(head)->sqh_first; \ 292 } while (/*CONSTCOND*/0) 293 294 #define QSIMPLEQ_INSERT_HEAD(head, elm, field) do { \ 295 if (((elm)->field.sqe_next = (head)->sqh_first) == NULL) \ 296 (head)->sqh_last = &(elm)->field.sqe_next; \ 297 (head)->sqh_first = (elm); \ 298 } while (/*CONSTCOND*/0) 299 300 #define QSIMPLEQ_INSERT_TAIL(head, elm, field) do { \ 301 (elm)->field.sqe_next = NULL; \ 302 *(head)->sqh_last = (elm); \ 303 (head)->sqh_last = &(elm)->field.sqe_next; \ 304 } while (/*CONSTCOND*/0) 305 306 #define QSIMPLEQ_INSERT_AFTER(head, listelm, elm, field) do { \ 307 if (((elm)->field.sqe_next = (listelm)->field.sqe_next) == NULL) \ 308 (head)->sqh_last = &(elm)->field.sqe_next; \ 309 (listelm)->field.sqe_next = (elm); \ 310 } while (/*CONSTCOND*/0) 311 312 #define QSIMPLEQ_REMOVE_HEAD(head, field) do { \ 313 typeof((head)->sqh_first) elm = (head)->sqh_first; \ 314 if (((head)->sqh_first = elm->field.sqe_next) == NULL) \ 315 (head)->sqh_last = &(head)->sqh_first; \ 316 elm->field.sqe_next = NULL; \ 317 } while (/*CONSTCOND*/0) 318 319 #define QSIMPLEQ_SPLIT_AFTER(head, elm, field, removed) do { \ 320 QSIMPLEQ_INIT(removed); \ 321 if (((removed)->sqh_first = (head)->sqh_first) != NULL) { \ 322 if (((head)->sqh_first = (elm)->field.sqe_next) == NULL) { \ 323 (head)->sqh_last = &(head)->sqh_first; \ 324 } \ 325 (removed)->sqh_last = &(elm)->field.sqe_next; \ 326 (elm)->field.sqe_next = NULL; \ 327 } \ 328 } while (/*CONSTCOND*/0) 329 330 #define QSIMPLEQ_REMOVE(head, elm, type, field) do { \ 331 if ((head)->sqh_first == (elm)) { \ 332 QSIMPLEQ_REMOVE_HEAD((head), field); \ 333 } else { \ 334 struct type *curelm = (head)->sqh_first; \ 335 while (curelm->field.sqe_next != (elm)) \ 336 curelm = curelm->field.sqe_next; \ 337 if ((curelm->field.sqe_next = \ 338 curelm->field.sqe_next->field.sqe_next) == NULL) \ 339 (head)->sqh_last = &(curelm)->field.sqe_next; \ 340 (elm)->field.sqe_next = NULL; \ 341 } \ 342 } while (/*CONSTCOND*/0) 343 344 #define QSIMPLEQ_FOREACH(var, head, field) \ 345 for ((var) = ((head)->sqh_first); \ 346 (var); \ 347 (var) = ((var)->field.sqe_next)) 348 349 #define QSIMPLEQ_FOREACH_SAFE(var, head, field, next) \ 350 for ((var) = ((head)->sqh_first); \ 351 (var) && ((next = ((var)->field.sqe_next)), 1); \ 352 (var) = (next)) 353 354 #define QSIMPLEQ_CONCAT(head1, head2) do { \ 355 if (!QSIMPLEQ_EMPTY((head2))) { \ 356 *(head1)->sqh_last = (head2)->sqh_first; \ 357 (head1)->sqh_last = (head2)->sqh_last; \ 358 QSIMPLEQ_INIT((head2)); \ 359 } \ 360 } while (/*CONSTCOND*/0) 361 362 #define QSIMPLEQ_PREPEND(head1, head2) do { \ 363 if (!QSIMPLEQ_EMPTY((head2))) { \ 364 *(head2)->sqh_last = (head1)->sqh_first; \ 365 (head1)->sqh_first = (head2)->sqh_first; \ 366 QSIMPLEQ_INIT((head2)); \ 367 } \ 368 } while (/*CONSTCOND*/0) 369 370 #define QSIMPLEQ_LAST(head, type, field) \ 371 (QSIMPLEQ_EMPTY((head)) ? \ 372 NULL : \ 373 ((struct type *)(void *) \ 374 ((char *)((head)->sqh_last) - offsetof(struct type, field)))) 375 376 /* 377 * Simple queue access methods. 378 */ 379 #define QSIMPLEQ_EMPTY_ATOMIC(head) \ 380 (qatomic_read(&((head)->sqh_first)) == NULL) 381 #define QSIMPLEQ_EMPTY(head) ((head)->sqh_first == NULL) 382 #define QSIMPLEQ_FIRST(head) ((head)->sqh_first) 383 #define QSIMPLEQ_NEXT(elm, field) ((elm)->field.sqe_next) 384 385 typedef struct QTailQLink { 386 void *tql_next; 387 struct QTailQLink *tql_prev; 388 } QTailQLink; 389 390 /* 391 * Tail queue definitions. The union acts as a poor man template, as if 392 * it were QTailQLink<type>. 393 */ 394 #define QTAILQ_HEAD(name, type) \ 395 union name { \ 396 struct type *tqh_first; /* first element */ \ 397 QTailQLink tqh_circ; /* link for circular backwards list */ \ 398 } 399 400 #define QTAILQ_HEAD_INITIALIZER(head) \ 401 { .tqh_circ = { NULL, &(head).tqh_circ } } 402 403 #define QTAILQ_ENTRY(type) \ 404 union { \ 405 struct type *tqe_next; /* next element */ \ 406 QTailQLink tqe_circ; /* link for circular backwards list */ \ 407 } 408 409 /* 410 * Tail queue functions. 411 */ 412 #define QTAILQ_INIT(head) do { \ 413 (head)->tqh_first = NULL; \ 414 (head)->tqh_circ.tql_prev = &(head)->tqh_circ; \ 415 } while (/*CONSTCOND*/0) 416 417 #define QTAILQ_INSERT_HEAD(head, elm, field) do { \ 418 if (((elm)->field.tqe_next = (head)->tqh_first) != NULL) \ 419 (head)->tqh_first->field.tqe_circ.tql_prev = \ 420 &(elm)->field.tqe_circ; \ 421 else \ 422 (head)->tqh_circ.tql_prev = &(elm)->field.tqe_circ; \ 423 (head)->tqh_first = (elm); \ 424 (elm)->field.tqe_circ.tql_prev = &(head)->tqh_circ; \ 425 } while (/*CONSTCOND*/0) 426 427 #define QTAILQ_INSERT_TAIL(head, elm, field) do { \ 428 (elm)->field.tqe_next = NULL; \ 429 (elm)->field.tqe_circ.tql_prev = (head)->tqh_circ.tql_prev; \ 430 (head)->tqh_circ.tql_prev->tql_next = (elm); \ 431 (head)->tqh_circ.tql_prev = &(elm)->field.tqe_circ; \ 432 } while (/*CONSTCOND*/0) 433 434 #define QTAILQ_INSERT_AFTER(head, listelm, elm, field) do { \ 435 if (((elm)->field.tqe_next = (listelm)->field.tqe_next) != NULL)\ 436 (elm)->field.tqe_next->field.tqe_circ.tql_prev = \ 437 &(elm)->field.tqe_circ; \ 438 else \ 439 (head)->tqh_circ.tql_prev = &(elm)->field.tqe_circ; \ 440 (listelm)->field.tqe_next = (elm); \ 441 (elm)->field.tqe_circ.tql_prev = &(listelm)->field.tqe_circ; \ 442 } while (/*CONSTCOND*/0) 443 444 #define QTAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 445 (elm)->field.tqe_circ.tql_prev = (listelm)->field.tqe_circ.tql_prev; \ 446 (elm)->field.tqe_next = (listelm); \ 447 (listelm)->field.tqe_circ.tql_prev->tql_next = (elm); \ 448 (listelm)->field.tqe_circ.tql_prev = &(elm)->field.tqe_circ; \ 449 } while (/*CONSTCOND*/0) 450 451 #define QTAILQ_REMOVE(head, elm, field) do { \ 452 if (((elm)->field.tqe_next) != NULL) \ 453 (elm)->field.tqe_next->field.tqe_circ.tql_prev = \ 454 (elm)->field.tqe_circ.tql_prev; \ 455 else \ 456 (head)->tqh_circ.tql_prev = (elm)->field.tqe_circ.tql_prev; \ 457 (elm)->field.tqe_circ.tql_prev->tql_next = (elm)->field.tqe_next; \ 458 (elm)->field.tqe_circ.tql_prev = NULL; \ 459 (elm)->field.tqe_circ.tql_next = NULL; \ 460 (elm)->field.tqe_next = NULL; \ 461 } while (/*CONSTCOND*/0) 462 463 /* remove @left, @right and all elements in between from @head */ 464 #define QTAILQ_REMOVE_SEVERAL(head, left, right, field) do { \ 465 if (((right)->field.tqe_next) != NULL) \ 466 (right)->field.tqe_next->field.tqe_circ.tql_prev = \ 467 (left)->field.tqe_circ.tql_prev; \ 468 else \ 469 (head)->tqh_circ.tql_prev = (left)->field.tqe_circ.tql_prev; \ 470 (left)->field.tqe_circ.tql_prev->tql_next = (right)->field.tqe_next; \ 471 } while (/*CONSTCOND*/0) 472 473 #define QTAILQ_FOREACH(var, head, field) \ 474 for ((var) = ((head)->tqh_first); \ 475 (var); \ 476 (var) = ((var)->field.tqe_next)) 477 478 #define QTAILQ_FOREACH_SAFE(var, head, field, next_var) \ 479 for ((var) = ((head)->tqh_first); \ 480 (var) && ((next_var) = ((var)->field.tqe_next), 1); \ 481 (var) = (next_var)) 482 483 #define QTAILQ_FOREACH_REVERSE(var, head, field) \ 484 for ((var) = QTAILQ_LAST(head); \ 485 (var); \ 486 (var) = QTAILQ_PREV(var, field)) 487 488 #define QTAILQ_FOREACH_REVERSE_SAFE(var, head, field, prev_var) \ 489 for ((var) = QTAILQ_LAST(head); \ 490 (var) && ((prev_var) = QTAILQ_PREV(var, field), 1); \ 491 (var) = (prev_var)) 492 493 /* 494 * Tail queue access methods. 495 */ 496 #define QTAILQ_EMPTY(head) ((head)->tqh_first == NULL) 497 #define QTAILQ_FIRST(head) ((head)->tqh_first) 498 #define QTAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 499 #define QTAILQ_IN_USE(elm, field) ((elm)->field.tqe_circ.tql_prev != NULL) 500 501 #define QTAILQ_LINK_PREV(link) \ 502 ((link).tql_prev->tql_prev->tql_next) 503 #define QTAILQ_LAST(head) \ 504 ((typeof((head)->tqh_first)) QTAILQ_LINK_PREV((head)->tqh_circ)) 505 #define QTAILQ_PREV(elm, field) \ 506 ((typeof((elm)->field.tqe_next)) QTAILQ_LINK_PREV((elm)->field.tqe_circ)) 507 508 #define field_at_offset(base, offset, type) \ 509 ((type *) (((char *) (base)) + (offset))) 510 511 /* 512 * Raw access of elements of a tail queue head. Offsets are all zero 513 * because it's a union. 514 */ 515 #define QTAILQ_RAW_FIRST(head) \ 516 field_at_offset(head, 0, void *) 517 #define QTAILQ_RAW_TQH_CIRC(head) \ 518 field_at_offset(head, 0, QTailQLink) 519 520 /* 521 * Raw access of elements of a tail entry 522 */ 523 #define QTAILQ_RAW_NEXT(elm, entry) \ 524 field_at_offset(elm, entry, void *) 525 #define QTAILQ_RAW_TQE_CIRC(elm, entry) \ 526 field_at_offset(elm, entry, QTailQLink) 527 /* 528 * Tail queue traversal using pointer arithmetic. 529 */ 530 #define QTAILQ_RAW_FOREACH(elm, head, entry) \ 531 for ((elm) = *QTAILQ_RAW_FIRST(head); \ 532 (elm); \ 533 (elm) = *QTAILQ_RAW_NEXT(elm, entry)) 534 /* 535 * Tail queue insertion using pointer arithmetic. 536 */ 537 #define QTAILQ_RAW_INSERT_TAIL(head, elm, entry) do { \ 538 *QTAILQ_RAW_NEXT(elm, entry) = NULL; \ 539 QTAILQ_RAW_TQE_CIRC(elm, entry)->tql_prev = QTAILQ_RAW_TQH_CIRC(head)->tql_prev; \ 540 QTAILQ_RAW_TQH_CIRC(head)->tql_prev->tql_next = (elm); \ 541 QTAILQ_RAW_TQH_CIRC(head)->tql_prev = QTAILQ_RAW_TQE_CIRC(elm, entry); \ 542 } while (/*CONSTCOND*/0) 543 544 #define QLIST_RAW_FIRST(head) \ 545 field_at_offset(head, 0, void *) 546 547 #define QLIST_RAW_NEXT(elm, entry) \ 548 field_at_offset(elm, entry, void *) 549 550 #define QLIST_RAW_PREVIOUS(elm, entry) \ 551 field_at_offset(elm, entry + sizeof(void *), void *) 552 553 #define QLIST_RAW_FOREACH(elm, head, entry) \ 554 for ((elm) = *QLIST_RAW_FIRST(head); \ 555 (elm); \ 556 (elm) = *QLIST_RAW_NEXT(elm, entry)) 557 558 #define QLIST_RAW_INSERT_AFTER(head, prev, elem, entry) do { \ 559 *QLIST_RAW_NEXT(prev, entry) = elem; \ 560 *QLIST_RAW_PREVIOUS(elem, entry) = QLIST_RAW_NEXT(prev, entry); \ 561 *QLIST_RAW_NEXT(elem, entry) = NULL; \ 562 } while (0) 563 564 #define QLIST_RAW_INSERT_HEAD(head, elm, entry) do { \ 565 void *first = *QLIST_RAW_FIRST(head); \ 566 *QLIST_RAW_FIRST(head) = elm; \ 567 *QLIST_RAW_PREVIOUS(elm, entry) = QLIST_RAW_FIRST(head); \ 568 if (first) { \ 569 *QLIST_RAW_NEXT(elm, entry) = first; \ 570 *QLIST_RAW_PREVIOUS(first, entry) = QLIST_RAW_NEXT(elm, entry); \ 571 } else { \ 572 *QLIST_RAW_NEXT(elm, entry) = NULL; \ 573 } \ 574 } while (0) 575 576 #endif /* QEMU_SYS_QUEUE_H */ 577