include/urcu/rculfqueue.h

   1 // SPDX-FileCopyrightText: 2010 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   2 //
   3 // SPDX-License-Identifier: LGPL-2.1-or-later
   4
   5 #ifndef _URCU_RCULFQUEUE_H
   6 #define _URCU_RCULFQUEUE_H
   7
   8 /*
   9  * Userspace RCU library - Lock-Free RCU Queue
  10  */
  11
  12
  13 #ifdef __cplusplus
  14 extern "C" {
  15 #endif
  16
  17 struct cds_lfq_queue_rcu;
  18 struct rcu_head;
  19
  20 struct cds_lfq_node_rcu {
  21         struct cds_lfq_node_rcu *next;
  22         int dummy;
  23 };
  24
  25 struct cds_lfq_queue_rcu {
  26         struct cds_lfq_node_rcu *head, *tail;
  27         void (*queue_call_rcu)(struct rcu_head *head,
  28                 void (*func)(struct rcu_head *head));
  29 };
  30
  31 #ifdef _LGPL_SOURCE
  32
  33 #include <urcu/static/rculfqueue.h>
  34
  35 #define cds_lfq_node_init_rcu           _cds_lfq_node_init_rcu
  36 #define cds_lfq_init_rcu                _cds_lfq_init_rcu
  37 #define cds_lfq_destroy_rcu             _cds_lfq_destroy_rcu
  38 #define cds_lfq_enqueue_rcu             _cds_lfq_enqueue_rcu
  39 #define cds_lfq_dequeue_rcu             _cds_lfq_dequeue_rcu
  40
  41 #else /* !_LGPL_SOURCE */
  42
  43 extern void cds_lfq_node_init_rcu(struct cds_lfq_node_rcu *node);
  44 extern void cds_lfq_init_rcu(struct cds_lfq_queue_rcu *q,
  45                              void queue_call_rcu(struct rcu_head *head,
  46                                         void (*func)(struct rcu_head *head)));
  47 /*
  48  * The queue should be emptied before calling destroy.
  49  *
  50  * Return 0 on success, -EPERM if queue is not empty.
  51  */
  52 extern int cds_lfq_destroy_rcu(struct cds_lfq_queue_rcu *q);
  53
  54 /*
  55  * Should be called under rcu read lock critical section.
  56  */
  57 extern void cds_lfq_enqueue_rcu(struct cds_lfq_queue_rcu *q,
  58                                 struct cds_lfq_node_rcu *node);
  59
  60 /*
  61  * Should be called under rcu read lock critical section.
  62  *
  63  * The caller must wait for a grace period to pass before freeing the returned
  64  * node or modifying the cds_lfq_node_rcu structure.
  65  * Returns NULL if queue is empty.
  66  */
  67 extern
  68 struct cds_lfq_node_rcu *cds_lfq_dequeue_rcu(struct cds_lfq_queue_rcu *q);
  69
  70 #endif /* !_LGPL_SOURCE */
  71
  72 #ifdef __cplusplus
  73 }
  74 #endif
  75
  76 #endif /* _URCU_RCULFQUEUE_H */