include/urcu/wfqueue.h

   1 #ifndef _URCU_WFQUEUE_H
   2 #define _URCU_WFQUEUE_H
   3
   4 /*
   5  * wfqueue.h
   6  *
   7  * Userspace RCU library - Queue with Wait-Free Enqueue/Blocking Dequeue
   8  *
   9  * Copyright 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  *
  11  * This library is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public
  13  * License as published by the Free Software Foundation; either
  14  * version 2.1 of the License, or (at your option) any later version.
  15  *
  16  * This library is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public
  22  * License along with this library; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  24  */
  25
  26 #include <pthread.h>
  27 #include <urcu/compiler.h>
  28
  29 #ifdef __cplusplus
  30 extern "C" {
  31 #endif
  32
  33 #ifndef CDS_WFQ_DEPRECATED
  34 #define CDS_WFQ_DEPRECATED      \
  35         CDS_DEPRECATED("urcu/wfqueue.h is deprecated. Please use urcu/wfcqueue.h instead.")
  36 #endif
  37
  38 /*
  39  * Queue with wait-free enqueue/blocking dequeue.
  40  * This implementation adds a dummy head node when the queue is empty to ensure
  41  * we can always update the queue locklessly.
  42  *
  43  * Inspired from half-wait-free/half-blocking queue implementation done by
  44  * Paul E. McKenney.
  45  */
  46
  47 struct cds_wfq_node {
  48         struct cds_wfq_node *next;
  49 };
  50
  51 struct cds_wfq_queue {
  52         struct cds_wfq_node *head, **tail;
  53         struct cds_wfq_node dummy;      /* Dummy node */
  54         pthread_mutex_t lock;
  55 };
  56
  57 #ifdef _LGPL_SOURCE
  58
  59 #include <urcu/static/wfqueue.h>
  60
  61 static inline CDS_WFQ_DEPRECATED
  62 void cds_wfq_node_init(struct cds_wfq_node *node)
  63 {
  64         _cds_wfq_node_init(node);
  65 }
  66
  67 static inline CDS_WFQ_DEPRECATED
  68 void cds_wfq_init(struct cds_wfq_queue *q)
  69 {
  70         _cds_wfq_init(q);
  71 }
  72
  73 static inline CDS_WFQ_DEPRECATED
  74 void cds_wfq_destroy(struct cds_wfq_queue *q)
  75 {
  76         _cds_wfq_destroy(q);
  77 }
  78
  79 static inline CDS_WFQ_DEPRECATED
  80 void cds_wfq_enqueue(struct cds_wfq_queue *q, struct cds_wfq_node *node)
  81 {
  82         _cds_wfq_enqueue(q, node);
  83 }
  84
  85 static inline CDS_WFQ_DEPRECATED
  86 struct cds_wfq_node *__cds_wfq_dequeue_blocking(struct cds_wfq_queue *q)
  87 {
  88         return ___cds_wfq_dequeue_blocking(q);
  89 }
  90
  91 static inline CDS_WFQ_DEPRECATED
  92 struct cds_wfq_node *cds_wfq_dequeue_blocking(struct cds_wfq_queue *q)
  93 {
  94         return _cds_wfq_dequeue_blocking(q);
  95 }
  96
  97 #else /* !_LGPL_SOURCE */
  98
  99 extern CDS_WFQ_DEPRECATED
 100 void cds_wfq_node_init(struct cds_wfq_node *node);
 101
 102 extern CDS_WFQ_DEPRECATED
 103 void cds_wfq_init(struct cds_wfq_queue *q);
 104
 105 extern CDS_WFQ_DEPRECATED
 106 void cds_wfq_destroy(struct cds_wfq_queue *q);
 107
 108 extern CDS_WFQ_DEPRECATED
 109 void cds_wfq_enqueue(struct cds_wfq_queue *q, struct cds_wfq_node *node);
 110
 111 /* __cds_wfq_dequeue_blocking: caller ensures mutual exclusion between dequeues */
 112 extern CDS_WFQ_DEPRECATED
 113 struct cds_wfq_node *__cds_wfq_dequeue_blocking(struct cds_wfq_queue *q);
 114
 115 extern CDS_WFQ_DEPRECATED
 116 struct cds_wfq_node *cds_wfq_dequeue_blocking(struct cds_wfq_queue *q);
 117
 118 #endif /* !_LGPL_SOURCE */
 119
 120 #ifdef __cplusplus
 121 }
 122 #endif
 123
 124 #endif /* _URCU_WFQUEUE_H */