include/urcu/wfcqueue.h

   1 // SPDX-FileCopyrightText: 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   2 // SPDX-FileCopyrightText: 2011-2012 Lai Jiangshan <laijs@cn.fujitsu.com>
   3 //
   4 // SPDX-License-Identifier: LGPL-2.1-or-later
   5
   6 #ifndef _URCU_WFCQUEUE_H
   7 #define _URCU_WFCQUEUE_H
   8
   9 /*
  10  * Userspace RCU library - Concurrent Queue with Wait-Free Enqueue/Blocking Dequeue
  11  */
  12
  13 #include <pthread.h>
  14 #include <stdbool.h>
  15 #include <urcu/compiler.h>
  16 #include <urcu/arch.h>
  17
  18 #ifdef __cplusplus
  19 extern "C" {
  20 #endif
  21
  22 /*
  23  * Concurrent queue with wait-free enqueue/blocking dequeue.
  24  *
  25  * This queue has been designed and implemented collaboratively by
  26  * Mathieu Desnoyers and Lai Jiangshan. Inspired from
  27  * half-wait-free/half-blocking queue implementation done by Paul E.
  28  * McKenney.
  29  */
  30
  31 #define CDS_WFCQ_WOULDBLOCK     ((struct cds_wfcq_node *) -1UL)
  32
  33 enum cds_wfcq_ret {
  34         CDS_WFCQ_RET_WOULDBLOCK =       -1,
  35         CDS_WFCQ_RET_DEST_EMPTY =       0,
  36         CDS_WFCQ_RET_DEST_NON_EMPTY =   1,
  37         CDS_WFCQ_RET_SRC_EMPTY =        2,
  38 };
  39
  40 enum cds_wfcq_state {
  41         CDS_WFCQ_STATE_LAST =           (1U << 0),
  42 };
  43
  44 struct cds_wfcq_node {
  45         struct cds_wfcq_node *next;
  46 };
  47
  48 /*
  49  * Do not put head and tail on the same cache-line if concurrent
  50  * enqueue/dequeue are expected from many CPUs. This eliminates
  51  * false-sharing between enqueue and dequeue.
  52  */
  53 struct __cds_wfcq_head {
  54         struct cds_wfcq_node node;
  55 };
  56
  57 struct cds_wfcq_head {
  58         struct cds_wfcq_node node;
  59         pthread_mutex_t lock;
  60 };
  61
  62 /*
  63  * In C, the transparent union allows calling functions that work on both
  64  * struct cds_wfcq_head and struct __cds_wfcq_head on any of those two
  65  * types.
  66  *
  67  * In C++, implement static inline wrappers using function overloading
  68  * to obtain an API similar to C.
  69  *
  70  * Avoid complaints from clang++ not knowing the transparent union
  71  * attribute.
  72  */
  73 #if defined(__clang__)
  74 #pragma clang diagnostic push
  75 #pragma clang diagnostic ignored "-Wignored-attributes"
  76 #endif
  77 typedef union {
  78         struct __cds_wfcq_head *_h;
  79         struct cds_wfcq_head *h;
  80 } __attribute__((__transparent_union__)) cds_wfcq_head_ptr_t;
  81
  82 typedef union {
  83         const struct __cds_wfcq_head *_h;
  84         const struct cds_wfcq_head *h;
  85 } __attribute__((__transparent_union__)) cds_wfcq_head_const_ptr_t;
  86 #if defined(__clang__)
  87 #pragma clang diagnostic pop
  88 #endif
  89
  90 #ifndef __cplusplus
  91 /*
  92  * This static inline is only present for compatibility with C++. It is
  93  * effect-less in C.
  94  */
  95 static inline struct __cds_wfcq_head *__cds_wfcq_head_cast(struct __cds_wfcq_head *head)
  96 {
  97         return head;
  98 }
  99
 100 /*
 101  * This static inline is only present for compatibility with C++. It is
 102  * effect-less in C.
 103  */
 104 static inline struct cds_wfcq_head *cds_wfcq_head_cast(struct cds_wfcq_head *head)
 105 {
 106         return head;
 107 }
 108
 109 /*
 110  * This static inline is only present for compatibility with C++. It is
 111  * effect-less in C.
 112  */
 113 static inline const struct __cds_wfcq_head *__cds_wfcq_head_const_cast(const struct __cds_wfcq_head *head)
 114 {
 115         return head;
 116 }
 117
 118 /*
 119  * This static inline is only present for compatibility with C++. It is
 120  * effect-less in C.
 121  */
 122 static inline const struct cds_wfcq_head *cds_wfcq_head_const_cast(const struct cds_wfcq_head *head)
 123 {
 124         return head;
 125 }
 126
 127 #else /* #ifndef __cplusplus */
 128
 129 /*
 130  * This static inline is used by internally in the static inline
 131  * implementation of the API.
 132  */
 133 static inline cds_wfcq_head_ptr_t __cds_wfcq_head_cast(struct __cds_wfcq_head *head)
 134 {
 135         cds_wfcq_head_ptr_t ret = { ._h = head };
 136         return ret;
 137 }
 138
 139 /*
 140  * This static inline is used by internally in the static inline
 141  * implementation of the API.
 142  */
 143 static inline cds_wfcq_head_ptr_t cds_wfcq_head_cast(struct cds_wfcq_head *head)
 144 {
 145         cds_wfcq_head_ptr_t ret = { .h = head };
 146         return ret;
 147 }
 148
 149 /*
 150  * This static inline is used by internally in the static inline
 151  * implementation of the API.
 152  */
 153 static inline cds_wfcq_head_const_ptr_t __cds_wfcq_head_const_cast(const struct __cds_wfcq_head *head)
 154 {
 155         cds_wfcq_head_const_ptr_t ret = { ._h = head };
 156         return ret;
 157 }
 158
 159 /*
 160  * This static inline is used by internally in the static inline
 161  * implementation of the API.
 162  */
 163 static inline cds_wfcq_head_const_ptr_t cds_wfcq_head_const_cast(const struct cds_wfcq_head *head)
 164 {
 165         cds_wfcq_head_const_ptr_t ret = { .h = head };
 166         return ret;
 167 }
 168
 169 #endif /* #else #ifndef __cplusplus */
 170
 171 struct cds_wfcq_tail {
 172         struct cds_wfcq_node *p;
 173 };
 174
 175 #ifdef _LGPL_SOURCE
 176
 177 #include <urcu/static/wfcqueue.h>
 178
 179 #define cds_wfcq_node_init              _cds_wfcq_node_init
 180 #define cds_wfcq_init                   _cds_wfcq_init
 181 #define __cds_wfcq_init                 ___cds_wfcq_init
 182 #define cds_wfcq_destroy                _cds_wfcq_destroy
 183 #define cds_wfcq_empty                  _cds_wfcq_empty
 184 #define cds_wfcq_enqueue                _cds_wfcq_enqueue
 185
 186 /* Dequeue locking */
 187 #define cds_wfcq_dequeue_lock           _cds_wfcq_dequeue_lock
 188 #define cds_wfcq_dequeue_unlock         _cds_wfcq_dequeue_unlock
 189
 190 /* Locking performed within cds_wfcq calls. */
 191 #define cds_wfcq_dequeue_blocking       _cds_wfcq_dequeue_blocking
 192 #define cds_wfcq_dequeue_with_state_blocking    \
 193                                         _cds_wfcq_dequeue_with_state_blocking
 194 #define cds_wfcq_splice_blocking        _cds_wfcq_splice_blocking
 195 #define cds_wfcq_first_blocking         _cds_wfcq_first_blocking
 196 #define cds_wfcq_next_blocking          _cds_wfcq_next_blocking
 197
 198 /* Locking ensured by caller by holding cds_wfcq_dequeue_lock() */
 199 #define __cds_wfcq_dequeue_blocking     ___cds_wfcq_dequeue_blocking
 200 #define __cds_wfcq_dequeue_with_state_blocking  \
 201                                         ___cds_wfcq_dequeue_with_state_blocking
 202 #define __cds_wfcq_splice_blocking      ___cds_wfcq_splice_blocking
 203 #define __cds_wfcq_first_blocking       ___cds_wfcq_first_blocking
 204 #define __cds_wfcq_next_blocking        ___cds_wfcq_next_blocking
 205
 206 /*
 207  * Locking ensured by caller by holding cds_wfcq_dequeue_lock().
 208  * Non-blocking: deque, first, next return CDS_WFCQ_WOULDBLOCK if they
 209  * need to block. splice returns nonzero if it needs to block.
 210  */
 211 #define __cds_wfcq_dequeue_nonblocking  ___cds_wfcq_dequeue_nonblocking
 212 #define __cds_wfcq_dequeue_with_state_nonblocking       \
 213                                 ___cds_wfcq_dequeue_with_state_nonblocking
 214 #define __cds_wfcq_splice_nonblocking   ___cds_wfcq_splice_nonblocking
 215 #define __cds_wfcq_first_nonblocking    ___cds_wfcq_first_nonblocking
 216 #define __cds_wfcq_next_nonblocking     ___cds_wfcq_next_nonblocking
 217
 218 #else /* !_LGPL_SOURCE */
 219
 220 /*
 221  * Mutual exclusion of cds_wfcq_* / __cds_wfcq_* API
 222  *
 223  * Synchronization table:
 224  *
 225  * External synchronization techniques described in the API below is
 226  * required between pairs marked with "X". No external synchronization
 227  * required between pairs marked with "-".
 228  *
 229  * Legend:
 230  * [1] cds_wfcq_enqueue
 231  * [2] __cds_wfcq_splice (destination queue)
 232  * [3] __cds_wfcq_dequeue
 233  * [4] __cds_wfcq_splice (source queue)
 234  * [5] __cds_wfcq_first
 235  * [6] __cds_wfcq_next
 236  *
 237  *     [1] [2] [3] [4] [5] [6]
 238  * [1]  -   -   -   -   -   -
 239  * [2]  -   -   -   -   -   -
 240  * [3]  -   -   X   X   X   X
 241  * [4]  -   -   X   -   X   X
 242  * [5]  -   -   X   X   -   -
 243  * [6]  -   -   X   X   -   -
 244  *
 245  * Mutual exclusion can be ensured by holding cds_wfcq_dequeue_lock().
 246  *
 247  * For convenience, cds_wfcq_dequeue_blocking() and
 248  * cds_wfcq_splice_blocking() hold the dequeue lock.
 249  *
 250  * Besides locking, mutual exclusion of dequeue, splice and iteration
 251  * can be ensured by performing all of those operations from a single
 252  * thread, without requiring any lock.
 253  */
 254
 255 /*
 256  * cds_wfcq_node_init: initialize wait-free queue node.
 257  */
 258 extern void cds_wfcq_node_init(struct cds_wfcq_node *node);
 259
 260 /*
 261  * cds_wfcq_init: initialize wait-free queue. Pair with
 262  * cds_wfcq_destroy().
 263  */
 264 extern void cds_wfcq_init(struct cds_wfcq_head *head,
 265                 struct cds_wfcq_tail *tail);
 266
 267 /*
 268  * cds_wfcq_destroy: destroy wait-free queue. Pair with
 269  * cds_wfcq_init().
 270  */
 271 extern void cds_wfcq_destroy(struct cds_wfcq_head *head,
 272                 struct cds_wfcq_tail *tail);
 273
 274 /*
 275  * __cds_wfcq_init: initialize wait-free queue (without lock). Don't
 276  * pair with any destroy function.
 277  */
 278 extern void __cds_wfcq_init(struct __cds_wfcq_head *head,
 279                 struct cds_wfcq_tail *tail);
 280
 281 /*
 282  * cds_wfcq_empty: return whether wait-free queue is empty.
 283  *
 284  * No memory barrier is issued. No mutual exclusion is required.
 285  */
 286 extern bool cds_wfcq_empty(cds_wfcq_head_const_ptr_t head,
 287                 const struct cds_wfcq_tail *tail);
 288
 289 /*
 290  * cds_wfcq_dequeue_lock: take the dequeue mutual exclusion lock.
 291  */
 292 extern void cds_wfcq_dequeue_lock(struct cds_wfcq_head *head,
 293                 struct cds_wfcq_tail *tail);
 294
 295 /*
 296  * cds_wfcq_dequeue_unlock: release the dequeue mutual exclusion lock.
 297  */
 298 extern void cds_wfcq_dequeue_unlock(struct cds_wfcq_head *head,
 299                 struct cds_wfcq_tail *tail);
 300
 301 /*
 302  * cds_wfcq_enqueue: enqueue a node into a wait-free queue.
 303  *
 304  * Issues a full memory barrier before enqueue. No mutual exclusion is
 305  * required.
 306  *
 307  * Returns false if the queue was empty prior to adding the node.
 308  * Returns true otherwise.
 309  */
 310 extern bool cds_wfcq_enqueue(cds_wfcq_head_ptr_t head,
 311                 struct cds_wfcq_tail *tail,
 312                 struct cds_wfcq_node *node);
 313
 314 /*
 315  * cds_wfcq_dequeue_blocking: dequeue a node from a wait-free queue.
 316  *
 317  * Content written into the node before enqueue is guaranteed to be
 318  * consistent, but no other memory ordering is ensured.
 319  * It is valid to reuse and free a dequeued node immediately.
 320  * Mutual exclusion with cds_wfcq_dequeue_blocking and dequeue lock is
 321  * ensured.
 322  */
 323 extern struct cds_wfcq_node *cds_wfcq_dequeue_blocking(
 324                 struct cds_wfcq_head *head,
 325                 struct cds_wfcq_tail *tail);
 326
 327 /*
 328  * cds_wfcq_dequeue_with_state_blocking: dequeue with state.
 329  *
 330  * Same as cds_wfcq_dequeue_blocking, but saves whether dequeueing the
 331  * last node of the queue into state (CDS_WFCQ_STATE_LAST).
 332  */
 333 extern struct cds_wfcq_node *cds_wfcq_dequeue_with_state_blocking(
 334                 struct cds_wfcq_head *head,
 335                 struct cds_wfcq_tail *tail,
 336                 int *state);
 337
 338 /*
 339  * cds_wfcq_splice_blocking: enqueue all src_q nodes at the end of dest_q.
 340  *
 341  * Dequeue all nodes from src_q.
 342  * dest_q must be already initialized.
 343  * Content written into the node before enqueue is guaranteed to be
 344  * consistent, but no other memory ordering is ensured.
 345  * Mutual exclusion with cds_wfcq_dequeue_blocking and dequeue lock is
 346  * ensured.
 347  *
 348  * Returns enum cds_wfcq_ret which indicates the state of the src or
 349  * dest queue.
 350  */
 351 extern enum cds_wfcq_ret cds_wfcq_splice_blocking(
 352                 struct cds_wfcq_head *dest_q_head,
 353                 struct cds_wfcq_tail *dest_q_tail,
 354                 struct cds_wfcq_head *src_q_head,
 355                 struct cds_wfcq_tail *src_q_tail);
 356
 357 /*
 358  * __cds_wfcq_dequeue_blocking: dequeue a node from a wait-free queue.
 359  *
 360  * Content written into the node before enqueue is guaranteed to be
 361  * consistent, but no other memory ordering is ensured.
 362  * It is valid to reuse and free a dequeued node immediately.
 363  * Dequeue/splice/iteration mutual exclusion should be ensured by the
 364  * caller.
 365  */
 366 extern struct cds_wfcq_node *__cds_wfcq_dequeue_blocking(
 367                 cds_wfcq_head_ptr_t head,
 368                 struct cds_wfcq_tail *tail);
 369
 370 /*
 371  * __cds_wfcq_dequeue_with_state_blocking: dequeue with state.
 372  *
 373  * Same as __cds_wfcq_dequeue_blocking, but saves whether dequeueing the
 374  * last node of the queue into state (CDS_WFCQ_STATE_LAST).
 375  */
 376 extern struct cds_wfcq_node *__cds_wfcq_dequeue_with_state_blocking(
 377                 cds_wfcq_head_ptr_t head,
 378                 struct cds_wfcq_tail *tail,
 379                 int *state);
 380
 381 /*
 382  * __cds_wfcq_dequeue_nonblocking: dequeue a node from a wait-free queue.
 383  *
 384  * Same as __cds_wfcq_dequeue_blocking, but returns CDS_WFCQ_WOULDBLOCK
 385  * if it needs to block.
 386  */
 387 extern struct cds_wfcq_node *__cds_wfcq_dequeue_nonblocking(
 388                 cds_wfcq_head_ptr_t head,
 389                 struct cds_wfcq_tail *tail);
 390
 391 /*
 392  * __cds_wfcq_dequeue_with_state_blocking: dequeue with state.
 393  *
 394  * Same as __cds_wfcq_dequeue_nonblocking, but saves whether dequeueing
 395  * the last node of the queue into state (CDS_WFCQ_STATE_LAST).
 396  */
 397 extern struct cds_wfcq_node *__cds_wfcq_dequeue_with_state_nonblocking(
 398                 cds_wfcq_head_ptr_t head,
 399                 struct cds_wfcq_tail *tail,
 400                 int *state);
 401
 402 /*
 403  * __cds_wfcq_splice_blocking: enqueue all src_q nodes at the end of dest_q.
 404  *
 405  * Dequeue all nodes from src_q.
 406  * dest_q must be already initialized.
 407  * Mutual exclusion for src_q should be ensured by the caller as
 408  * specified in the "Synchronisation table".
 409  * Returns enum cds_wfcq_ret which indicates the state of the src or
 410  * dest queue. Never returns CDS_WFCQ_RET_WOULDBLOCK.
 411  */
 412 extern enum cds_wfcq_ret __cds_wfcq_splice_blocking(
 413                 cds_wfcq_head_ptr_t dest_q_head,
 414                 struct cds_wfcq_tail *dest_q_tail,
 415                 cds_wfcq_head_ptr_t src_q_head,
 416                 struct cds_wfcq_tail *src_q_tail);
 417
 418 /*
 419  * __cds_wfcq_splice_nonblocking: enqueue all src_q nodes at the end of dest_q.
 420  *
 421  * Same as __cds_wfcq_splice_blocking, but returns
 422  * CDS_WFCQ_RET_WOULDBLOCK if it needs to block.
 423  */
 424 extern enum cds_wfcq_ret __cds_wfcq_splice_nonblocking(
 425                 cds_wfcq_head_ptr_t dest_q_head,
 426                 struct cds_wfcq_tail *dest_q_tail,
 427                 cds_wfcq_head_ptr_t src_q_head,
 428                 struct cds_wfcq_tail *src_q_tail);
 429
 430 /*
 431  * __cds_wfcq_first_blocking: get first node of a queue, without dequeuing.
 432  *
 433  * Content written into the node before enqueue is guaranteed to be
 434  * consistent, but no other memory ordering is ensured.
 435  * Dequeue/splice/iteration mutual exclusion should be ensured by the
 436  * caller.
 437  *
 438  * Used by for-like iteration macros:
 439  * __cds_wfcq_for_each_blocking()
 440  * __cds_wfcq_for_each_blocking_safe()
 441  *
 442  * Returns NULL if queue is empty, first node otherwise.
 443  */
 444 extern struct cds_wfcq_node *__cds_wfcq_first_blocking(
 445                 cds_wfcq_head_ptr_t head,
 446                 struct cds_wfcq_tail *tail);
 447
 448 /*
 449  * __cds_wfcq_first_nonblocking: get first node of a queue, without dequeuing.
 450  *
 451  * Same as __cds_wfcq_first_blocking, but returns CDS_WFCQ_WOULDBLOCK if
 452  * it needs to block.
 453  */
 454 extern struct cds_wfcq_node *__cds_wfcq_first_nonblocking(
 455                 cds_wfcq_head_ptr_t head,
 456                 struct cds_wfcq_tail *tail);
 457
 458 /*
 459  * __cds_wfcq_next_blocking: get next node of a queue, without dequeuing.
 460  *
 461  * Content written into the node before enqueue is guaranteed to be
 462  * consistent, but no other memory ordering is ensured.
 463  * Dequeue/splice/iteration mutual exclusion should be ensured by the
 464  * caller.
 465  *
 466  * Used by for-like iteration macros:
 467  * __cds_wfcq_for_each_blocking()
 468  * __cds_wfcq_for_each_blocking_safe()
 469  *
 470  * Returns NULL if reached end of queue, non-NULL next queue node
 471  * otherwise.
 472  */
 473 extern struct cds_wfcq_node *__cds_wfcq_next_blocking(
 474                 cds_wfcq_head_ptr_t head,
 475                 struct cds_wfcq_tail *tail,
 476                 struct cds_wfcq_node *node);
 477
 478 /*
 479  * __cds_wfcq_next_blocking: get next node of a queue, without dequeuing.
 480  *
 481  * Same as __cds_wfcq_next_blocking, but returns CDS_WFCQ_WOULDBLOCK if
 482  * it needs to block.
 483  */
 484 extern struct cds_wfcq_node *__cds_wfcq_next_nonblocking(
 485                 cds_wfcq_head_ptr_t head,
 486                 struct cds_wfcq_tail *tail,
 487                 struct cds_wfcq_node *node);
 488
 489 #endif /* !_LGPL_SOURCE */
 490
 491 /*
 492  * __cds_wfcq_for_each_blocking: Iterate over all nodes in a queue,
 493  * without dequeuing them.
 494  * @head: head of the queue (struct cds_wfcq_head or __cds_wfcq_head pointer).
 495  * @tail: tail of the queue (struct cds_wfcq_tail pointer).
 496  * @node: iterator on the queue (struct cds_wfcq_node pointer).
 497  *
 498  * Content written into each node before enqueue is guaranteed to be
 499  * consistent, but no other memory ordering is ensured.
 500  * Dequeue/splice/iteration mutual exclusion should be ensured by the
 501  * caller.
 502  */
 503 #define __cds_wfcq_for_each_blocking(head, tail, node)          \
 504         for (node = __cds_wfcq_first_blocking(head, tail);      \
 505                 node != NULL;                                   \
 506                 node = __cds_wfcq_next_blocking(head, tail, node))
 507
 508 /*
 509  * __cds_wfcq_for_each_blocking_safe: Iterate over all nodes in a queue,
 510  * without dequeuing them. Safe against deletion.
 511  * @head: head of the queue (struct cds_wfcq_head or __cds_wfcq_head pointer).
 512  * @tail: tail of the queue (struct cds_wfcq_tail pointer).
 513  * @node: iterator on the queue (struct cds_wfcq_node pointer).
 514  * @n: struct cds_wfcq_node pointer holding the next pointer (used
 515  *     internally).
 516  *
 517  * Content written into each node before enqueue is guaranteed to be
 518  * consistent, but no other memory ordering is ensured.
 519  * Dequeue/splice/iteration mutual exclusion should be ensured by the
 520  * caller.
 521  */
 522 #define __cds_wfcq_for_each_blocking_safe(head, tail, node, n)                 \
 523         for (node = __cds_wfcq_first_blocking(head, tail),                     \
 524                         n = (node ? __cds_wfcq_next_blocking(head, tail, node) : NULL); \
 525                 node != NULL;                                                  \
 526                 node = n, n = (node ? __cds_wfcq_next_blocking(head, tail, node) : NULL))
 527
 528 #ifdef __cplusplus
 529 }
 530
 531 /*
 532  * In C++, implement static inline wrappers using function overloading
 533  * to obtain an API similar to C.
 534  */
 535
 536 static inline cds_wfcq_head_ptr_t cds_wfcq_head_cast_cpp(struct __cds_wfcq_head *head)
 537 {
 538         cds_wfcq_head_ptr_t ret = { ._h = head };
 539         return ret;
 540 }
 541
 542 static inline cds_wfcq_head_ptr_t cds_wfcq_head_cast_cpp(struct cds_wfcq_head *head)
 543 {
 544         cds_wfcq_head_ptr_t ret = { .h = head };
 545         return ret;
 546 }
 547
 548 static inline cds_wfcq_head_const_ptr_t cds_wfcq_head_const_cast_cpp(const struct __cds_wfcq_head *head)
 549 {
 550         cds_wfcq_head_const_ptr_t ret = { ._h = head };
 551         return ret;
 552 }
 553
 554 static inline cds_wfcq_head_const_ptr_t cds_wfcq_head_const_cast_cpp(const struct cds_wfcq_head *head)
 555 {
 556         cds_wfcq_head_const_ptr_t ret = { .h = head };
 557         return ret;
 558 }
 559
 560 template<typename T> static inline bool cds_wfcq_empty(T head,
 561                 const struct cds_wfcq_tail *tail)
 562 {
 563         return cds_wfcq_empty(cds_wfcq_head_const_cast_cpp(head), tail);
 564 }
 565
 566 template<typename T> static inline bool cds_wfcq_enqueue(T head,
 567                 struct cds_wfcq_tail *tail,
 568                 struct cds_wfcq_node *node)
 569 {
 570         return cds_wfcq_enqueue(cds_wfcq_head_cast_cpp(head), tail, node);
 571 }
 572
 573 template<typename T> static inline struct cds_wfcq_node *__cds_wfcq_dequeue_blocking(
 574                 T head, struct cds_wfcq_tail *tail)
 575 {
 576         return __cds_wfcq_dequeue_blocking(cds_wfcq_head_cast_cpp(head), tail);
 577 }
 578
 579 template<typename T> static inline struct cds_wfcq_node *__cds_wfcq_dequeue_with_state_blocking(
 580                 T head, struct cds_wfcq_tail *tail, int *state)
 581 {
 582         return __cds_wfcq_dequeue_with_state_blocking(cds_wfcq_head_cast_cpp(head),
 583                         tail, state);
 584 }
 585
 586 template<typename T> static inline struct cds_wfcq_node *__cds_wfcq_dequeue_nonblocking(
 587                 T head, struct cds_wfcq_tail *tail)
 588 {
 589         return __cds_wfcq_dequeue_nonblocking(cds_wfcq_head_cast_cpp(head), tail);
 590 }
 591
 592 template<typename T> static inline struct cds_wfcq_node *__cds_wfcq_dequeue_with_state_nonblocking(
 593                 T head, struct cds_wfcq_tail *tail, int *state)
 594 {
 595         return __cds_wfcq_dequeue_with_state_nonblocking(cds_wfcq_head_cast_cpp(head),
 596                         tail, state);
 597 }
 598
 599 template<typename T, typename U> static inline enum cds_wfcq_ret __cds_wfcq_splice_blocking(
 600                 T dest_q_head,
 601                 struct cds_wfcq_tail *dest_q_tail,
 602                 U src_q_head,
 603                 struct cds_wfcq_tail *src_q_tail)
 604 {
 605         return __cds_wfcq_splice_blocking(cds_wfcq_head_cast_cpp(dest_q_head),
 606                         dest_q_tail,
 607                         cds_wfcq_head_cast_cpp(src_q_head),
 608                         src_q_tail);
 609 }
 610
 611 template<typename T, typename U> static inline enum cds_wfcq_ret __cds_wfcq_splice_nonblocking(
 612                 T dest_q_head,
 613                 struct cds_wfcq_tail *dest_q_tail,
 614                 U *src_q_head,
 615                 struct cds_wfcq_tail *src_q_tail)
 616 {
 617         return __cds_wfcq_splice_nonblocking(cds_wfcq_head_cast_cpp(dest_q_head),
 618                         dest_q_tail,
 619                         cds_wfcq_head_cast_cpp(src_q_head),
 620                         src_q_tail);
 621 }
 622
 623 template<typename T> static inline struct cds_wfcq_node *__cds_wfcq_first_blocking(
 624                 T head, struct cds_wfcq_tail *tail)
 625 {
 626         return __cds_wfcq_first_blocking(cds_wfcq_head_cast_cpp(head), tail);
 627 }
 628
 629 template<typename T> static inline struct cds_wfcq_node *__cds_wfcq_first_nonblocking(
 630                 T head, struct cds_wfcq_tail *tail)
 631 {
 632         return __cds_wfcq_first_nonblocking(cds_wfcq_head_cast_cpp(head), tail);
 633 }
 634
 635 template<typename T> static inline struct cds_wfcq_node *__cds_wfcq_next_blocking(
 636                 T head,
 637                 struct cds_wfcq_tail *tail,
 638                 struct cds_wfcq_node *node)
 639 {
 640         return __cds_wfcq_next_blocking(cds_wfcq_head_cast_cpp(head), tail, node);
 641 }
 642
 643 template<typename T> static inline struct cds_wfcq_node *__cds_wfcq_next_nonblocking(
 644                 T head,
 645                 struct cds_wfcq_tail *tail,
 646                 struct cds_wfcq_node *node)
 647 {
 648         return __cds_wfcq_next_nonblocking(cds_wfcq_head_cast_cpp(head), tail, node);
 649 }
 650
 651 #endif
 652
 653 #endif /* _URCU_WFCQUEUE_H */