include/urcu/wfqueue.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_WFQUEUE_H
   6 #define _URCU_WFQUEUE_H
   7
   8 /*
   9  * Userspace RCU library - Queue with Wait-Free Enqueue/Blocking Dequeue
  10  */
  11
  12 #include <pthread.h>
  13 #include <urcu/compiler.h>
  14
  15 #ifdef __cplusplus
  16 extern "C" {
  17 #endif
  18
  19 #ifndef CDS_WFQ_DEPRECATED
  20 #define CDS_WFQ_DEPRECATED      \
  21         CDS_DEPRECATED("urcu/wfqueue.h is deprecated. Please use urcu/wfcqueue.h instead.")
  22 #endif
  23
  24 /*
  25  * Queue with wait-free enqueue/blocking dequeue.
  26  * This implementation adds a dummy head node when the queue is empty to ensure
  27  * we can always update the queue locklessly.
  28  *
  29  * Inspired from half-wait-free/half-blocking queue implementation done by
  30  * Paul E. McKenney.
  31  */
  32
  33 struct cds_wfq_node {
  34         struct cds_wfq_node *next;
  35 };
  36
  37 struct cds_wfq_queue {
  38         struct cds_wfq_node *head, **tail;
  39         struct cds_wfq_node dummy;      /* Dummy node */
  40         pthread_mutex_t lock;
  41 };
  42
  43 #ifdef _LGPL_SOURCE
  44
  45 #include <urcu/static/wfqueue.h>
  46
  47 static inline CDS_WFQ_DEPRECATED
  48 void cds_wfq_node_init(struct cds_wfq_node *node)
  49 {
  50         _cds_wfq_node_init(node);
  51 }
  52
  53 static inline CDS_WFQ_DEPRECATED
  54 void cds_wfq_init(struct cds_wfq_queue *q)
  55 {
  56         _cds_wfq_init(q);
  57 }
  58
  59 static inline CDS_WFQ_DEPRECATED
  60 void cds_wfq_destroy(struct cds_wfq_queue *q)
  61 {
  62         _cds_wfq_destroy(q);
  63 }
  64
  65 static inline CDS_WFQ_DEPRECATED
  66 void cds_wfq_enqueue(struct cds_wfq_queue *q, struct cds_wfq_node *node)
  67 {
  68         _cds_wfq_enqueue(q, node);
  69 }
  70
  71 static inline CDS_WFQ_DEPRECATED
  72 struct cds_wfq_node *__cds_wfq_dequeue_blocking(struct cds_wfq_queue *q)
  73 {
  74         return ___cds_wfq_dequeue_blocking(q);
  75 }
  76
  77 static inline CDS_WFQ_DEPRECATED
  78 struct cds_wfq_node *cds_wfq_dequeue_blocking(struct cds_wfq_queue *q)
  79 {
  80         return _cds_wfq_dequeue_blocking(q);
  81 }
  82
  83 #else /* !_LGPL_SOURCE */
  84
  85 extern CDS_WFQ_DEPRECATED
  86 void cds_wfq_node_init(struct cds_wfq_node *node);
  87
  88 extern CDS_WFQ_DEPRECATED
  89 void cds_wfq_init(struct cds_wfq_queue *q);
  90
  91 extern CDS_WFQ_DEPRECATED
  92 void cds_wfq_destroy(struct cds_wfq_queue *q);
  93
  94 extern CDS_WFQ_DEPRECATED
  95 void cds_wfq_enqueue(struct cds_wfq_queue *q, struct cds_wfq_node *node);
  96
  97 /* __cds_wfq_dequeue_blocking: caller ensures mutual exclusion between dequeues */
  98 extern CDS_WFQ_DEPRECATED
  99 struct cds_wfq_node *__cds_wfq_dequeue_blocking(struct cds_wfq_queue *q);
 100
 101 extern CDS_WFQ_DEPRECATED
 102 struct cds_wfq_node *cds_wfq_dequeue_blocking(struct cds_wfq_queue *q);
 103
 104 #endif /* !_LGPL_SOURCE */
 105
 106 #ifdef __cplusplus
 107 }
 108 #endif
 109
 110 #endif /* _URCU_WFQUEUE_H */