urcu: avoid false sharing for rcu_gp_ctr
[urcu.git] / urcu-qsbr.h
... / ...
CommitLineData
1#ifndef _URCU_QSBR_H
2#define _URCU_QSBR_H
3
4/*
5 * urcu-qsbr.h
6 *
7 * Userspace RCU QSBR header.
8 *
9 * LGPL-compatible code should include this header with :
10 *
11 * #define _LGPL_SOURCE
12 * #include <urcu.h>
13 *
14 * This library is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU Lesser General Public
16 * License as published by the Free Software Foundation; either
17 * version 2.1 of the License, or (at your option) any later version.
18 *
19 * This library is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 * Lesser General Public License for more details.
23 *
24 * You should have received a copy of the GNU Lesser General Public
25 * License along with this library; if not, write to the Free Software
26 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 *
28 * IBM's contributions to this file may be relicensed under LGPLv2 or later.
29 */
30
31#include <stdlib.h>
32#include <pthread.h>
33
34/*
35 * See urcu-pointer.h and urcu/static/urcu-pointer.h for pointer
36 * publication headers.
37 */
38#include <urcu-pointer.h>
39
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44#include <urcu/map/urcu-qsbr.h>
45
46/*
47 * Important !
48 *
49 * Each thread containing read-side critical sections must be registered
50 * with rcu_register_thread() before calling rcu_read_lock().
51 * rcu_unregister_thread() should be called before the thread exits.
52 */
53
54#ifdef _LGPL_SOURCE
55
56#include <urcu/static/urcu-qsbr.h>
57
58/*
59 * Mappings for static use of the userspace RCU library.
60 * Should only be used in LGPL-compatible code.
61 */
62
63/*
64 * rcu_read_lock()
65 * rcu_read_unlock()
66 *
67 * Mark the beginning and end of a read-side critical section.
68 * DON'T FORGET TO USE rcu_register_thread/rcu_unregister_thread()
69 * FOR EACH THREAD WITH READ-SIDE CRITICAL SECTION.
70 */
71#define rcu_read_lock_qsbr _rcu_read_lock
72#define rcu_read_unlock_qsbr _rcu_read_unlock
73#define rcu_read_ongoing_qsbr _rcu_read_ongoing
74
75#define rcu_quiescent_state_qsbr _rcu_quiescent_state
76#define rcu_thread_offline_qsbr _rcu_thread_offline
77#define rcu_thread_online_qsbr _rcu_thread_online
78
79#else /* !_LGPL_SOURCE */
80
81/*
82 * library wrappers to be used by non-LGPL compatible source code.
83 */
84
85/*
86 * QSBR read lock/unlock are guaranteed to be no-ops. Therefore, we expose them
87 * in the LGPL header for any code to use. However, the debug version is not
88 * nops and may contain sanity checks. To activate it, applications must be
89 * recompiled with -DRCU_DEBUG (even non-LGPL/GPL applications). This is the
90 * best trade-off between license/performance/code triviality and
91 * library debugging & tracing features we could come up with.
92 */
93
94#if (!defined(BUILD_QSBR_LIB) && defined(RCU_DEBUG))
95
96static inline void rcu_read_lock(void)
97{
98}
99
100static inline void rcu_read_unlock(void)
101{
102}
103
104#else /* !RCU_DEBUG */
105
106extern void rcu_read_lock(void);
107extern void rcu_read_unlock(void);
108
109#endif /* !RCU_DEBUG */
110
111extern int rcu_read_ongoing(void);
112extern void rcu_quiescent_state(void);
113extern void rcu_thread_offline(void);
114extern void rcu_thread_online(void);
115
116#endif /* !_LGPL_SOURCE */
117
118extern void synchronize_rcu(void);
119
120/*
121 * Reader thread registration.
122 */
123extern void rcu_register_thread(void);
124extern void rcu_unregister_thread(void);
125
126#ifdef __cplusplus
127}
128#endif
129
130#include <urcu-call-rcu.h>
131#include <urcu-defer.h>
132#include <urcu-flavor.h>
133
134#endif /* _URCU_QSBR_H */
This page took 0.022103 seconds and 4 git commands to generate.