projects / urcu.git / blame
| Commit | Line | Data |
|---|---|---|
| 4afee0a7 MD |
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 | ||
| 4afee0a7 MD |
34 | /* |
| 35 | * Queue with wait-free enqueue/blocking dequeue. | |
| 36 | * This implementation adds a dummy head node when the queue is empty to ensure | |
| 37 | * we can always update the queue locklessly. | |
| 38 | * | |
| 39 | * Inspired from half-wait-free/half-blocking queue implementation done by | |
| 40 | * Paul E. McKenney. | |
| 41 | */ | |
| 42 | ||
| 43 | struct wfq_node { | |
| 44 | struct wfq_node *next; | |
| 45 | }; | |
| 46 | ||
| 47 | struct wfq_queue { | |
| 48 | struct wfq_node *head, **tail; | |
| 49 | struct wfq_node dummy; /* Dummy node */ | |
| 50 | pthread_mutex_t lock; | |
| 51 | }; | |
| 52 | ||
| 4d001e96 | 53 | #ifdef _LGPL_SOURCE |
| 4afee0a7 | 54 | |
| 4d001e96 | 55 | #include <urcu/wfqueue-static.h> |
| 4afee0a7 | 56 | |
| 4d001e96 MD |
57 | #define wfq_node_init _wfq_node_init |
| 58 | #define wfq_init _wfq_init | |
| 59 | #define wfq_enqueue _wfq_enqueue | |
| b0dd35e2 | 60 | #define __wfq_dequeue_blocking ___wfq_dequeue_blocking |
| 4d001e96 | 61 | #define wfq_dequeue_blocking _wfq_dequeue_blocking |
| 4afee0a7 | 62 | |
| 4d001e96 | 63 | #else /* !_LGPL_SOURCE */ |
| 4afee0a7 | 64 | |
| 4d001e96 MD |
65 | extern void wfq_node_init(struct wfq_node *node); |
| 66 | extern void wfq_init(struct wfq_queue *q); | |
| 67 | extern void wfq_enqueue(struct wfq_queue *q, struct wfq_node *node); | |
| b0dd35e2 MD |
68 | /* __wfq_dequeue_blocking: caller ensures mutual exclusion between dequeues */ |
| 69 | extern struct wfq_node *__wfq_dequeue_blocking(struct wfq_queue *q); | |
| 4d001e96 | 70 | extern struct wfq_node *wfq_dequeue_blocking(struct wfq_queue *q); |
| 4afee0a7 | 71 | |
| 4d001e96 | 72 | #endif /* !_LGPL_SOURCE */ |
| 4afee0a7 MD |
73 | |
| 74 | #ifdef __cplusplus | |
| 75 | } | |
| 76 | #endif | |
| 77 | ||
| 78 | #endif /* _URCU_WFQUEUE_H */ |