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 <assert.h>
  28 #include <urcu/compiler.h>
  29
  30 #ifdef __cplusplus
  31 extern "C" {
  32 #endif
  33
  34 #ifndef CDS_WFQ_DEPRECATED
  35 #define CDS_WFQ_DEPRECATED      \
  36         CDS_DEPRECATED("urcu/wfqueue.h is deprecated. Please use urcu/wfcqueue.h instead.")
  37 #endif
  38
  39 /*
  40  * Queue with wait-free enqueue/blocking dequeue.
  41  * This implementation adds a dummy head node when the queue is empty to ensure
  42  * we can always update the queue locklessly.
  43  *
  44  * Inspired from half-wait-free/half-blocking queue implementation done by
  45  * Paul E. McKenney.
  46  */
  47
  48 struct cds_wfq_node {
  49         struct cds_wfq_node *next;
  50 };
  51
  52 struct cds_wfq_queue {
  53         struct cds_wfq_node *head, **tail;
  54         struct cds_wfq_node dummy;      /* Dummy node */
  55         pthread_mutex_t lock;
  56 };
  57
  58 #ifdef _LGPL_SOURCE
  59
  60 #include <urcu/static/wfqueue.h>
  61
  62 static inline CDS_WFQ_DEPRECATED
  63 void cds_wfq_node_init(struct cds_wfq_node *node)
  64 {
  65         _cds_wfq_node_init(node);
  66 }
  67
  68 static inline CDS_WFQ_DEPRECATED
  69 void cds_wfq_init(struct cds_wfq_queue *q)
  70 {
  71         _cds_wfq_init(q);
  72 }
  73
  74 static inline CDS_WFQ_DEPRECATED
  75 void cds_wfq_enqueue(struct cds_wfq_queue *q, struct cds_wfq_node *node)
  76 {
  77         _cds_wfq_enqueue(q, node);
  78 }
  79
  80 static inline CDS_WFQ_DEPRECATED
  81 struct cds_wfq_node *__cds_wfq_dequeue_blocking(struct cds_wfq_queue *q)
  82 {
  83         return ___cds_wfq_dequeue_blocking(q);
  84 }
  85
  86 static inline CDS_WFQ_DEPRECATED
  87 struct cds_wfq_node *cds_wfq_dequeue_blocking(struct cds_wfq_queue *q)
  88 {
  89         return _cds_wfq_dequeue_blocking(q);
  90 }
  91
  92 #else /* !_LGPL_SOURCE */
  93
  94 extern CDS_WFQ_DEPRECATED
  95 void cds_wfq_node_init(struct cds_wfq_node *node);
  96
  97 extern CDS_WFQ_DEPRECATED
  98 void cds_wfq_init(struct cds_wfq_queue *q);
  99
 100 extern CDS_WFQ_DEPRECATED
 101 void cds_wfq_enqueue(struct cds_wfq_queue *q, struct cds_wfq_node *node);
 102
 103 /* __cds_wfq_dequeue_blocking: caller ensures mutual exclusion between dequeues */
 104 extern CDS_WFQ_DEPRECATED
 105 struct cds_wfq_node *__cds_wfq_dequeue_blocking(struct cds_wfq_queue *q);
 106
 107 extern CDS_WFQ_DEPRECATED
 108 struct cds_wfq_node *cds_wfq_dequeue_blocking(struct cds_wfq_queue *q);
 109
 110 #endif /* !_LGPL_SOURCE */
 111
 112 #ifdef __cplusplus
 113 }
 114 #endif
 115
 116 #endif /* _URCU_WFQUEUE_H */