include/urcu/urcu-qsbr.h

   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 #include <stdbool.h>
  34
  35 #include <urcu/config.h>
  36
  37 /*
  38  * See urcu/pointer.h and urcu/static/pointer.h for pointer
  39  * publication headers.
  40  */
  41 #include <urcu/pointer.h>
  42 #include <urcu/urcu-poll.h>
  43
  44 #ifdef __cplusplus
  45 extern "C" {
  46 #endif
  47
  48 #include <urcu/map/urcu-qsbr.h>
  49
  50 #ifdef RCU_DEBUG        /* For backward compatibility */
  51 #define DEBUG_RCU
  52 #endif
  53
  54 /*
  55  * Important !
  56  *
  57  * Each thread containing read-side critical sections must be registered
  58  * with rcu_register_thread() before calling rcu_read_lock().
  59  * rcu_unregister_thread() should be called before the thread exits.
  60  */
  61
  62 #ifdef _LGPL_SOURCE
  63
  64 #include <urcu/static/urcu-qsbr.h>
  65
  66 /*
  67  * Mappings for static use of the userspace RCU library.
  68  * Should only be used in LGPL-compatible code.
  69  */
  70
  71 /*
  72  * rcu_read_lock()
  73  * rcu_read_unlock()
  74  *
  75  * Mark the beginning and end of a read-side critical section.
  76  * DON'T FORGET TO USE rcu_register_thread/rcu_unregister_thread()
  77  * FOR EACH THREAD WITH READ-SIDE CRITICAL SECTION.
  78  */
  79 #define urcu_qsbr_read_lock             _urcu_qsbr_read_lock
  80 #define urcu_qsbr_read_unlock           _urcu_qsbr_read_unlock
  81 #define urcu_qsbr_read_ongoing          _urcu_qsbr_read_ongoing
  82
  83 #define urcu_qsbr_quiescent_state       _urcu_qsbr_quiescent_state
  84 #define urcu_qsbr_thread_offline        _urcu_qsbr_thread_offline
  85 #define urcu_qsbr_thread_online         _urcu_qsbr_thread_online
  86
  87 #else /* !_LGPL_SOURCE */
  88
  89 /*
  90  * library wrappers to be used by non-LGPL compatible source code.
  91  */
  92
  93 /*
  94  * QSBR read lock/unlock are guaranteed to be no-ops. Therefore, we expose them
  95  * in the LGPL header for any code to use. However, the debug version is not
  96  * nops and may contain sanity checks. To activate it, applications must be
  97  * recompiled with -DDEBUG_RCU (even non-LGPL/GPL applications), or
  98  * compiled against a urcu/config.h that has CONFIG_RCU_DEBUG defined.
  99  * This is the best trade-off between license/performance/code
 100  * triviality and library debugging & tracing features we could come up
 101  * with.
 102  */
 103
 104 #if (!defined(BUILD_QSBR_LIB) && !defined(DEBUG_RCU) && !defined(CONFIG_RCU_DEBUG))
 105
 106 static inline void urcu_qsbr_read_lock(void)
 107 {
 108 }
 109
 110 static inline void urcu_qsbr_read_unlock(void)
 111 {
 112 }
 113
 114 #else /* #if (!defined(BUILD_QSBR_LIB) && !defined(DEBUG_RCU) && !defined(CONFIG_RCU_DEBUG)) */
 115
 116 extern void urcu_qsbr_read_lock(void);
 117 extern void urcu_qsbr_read_unlock(void);
 118
 119 #endif /* #else #if (!defined(BUILD_QSBR_LIB) && !defined(DEBUG_RCU) && !defined(CONFIG_RCU_DEBUG)) */
 120
 121 extern int urcu_qsbr_read_ongoing(void);
 122 extern void urcu_qsbr_quiescent_state(void);
 123 extern void urcu_qsbr_thread_offline(void);
 124 extern void urcu_qsbr_thread_online(void);
 125
 126 #endif /* !_LGPL_SOURCE */
 127
 128 extern void urcu_qsbr_synchronize_rcu(void);
 129
 130 /*
 131  * RCU grace period polling API.
 132  */
 133 extern struct urcu_gp_poll_state urcu_qsbr_start_poll_synchronize_rcu(void);
 134 extern bool urcu_qsbr_poll_state_synchronize_rcu(struct urcu_gp_poll_state state);
 135
 136 /*
 137  * Reader thread registration.
 138  */
 139 extern void urcu_qsbr_register_thread(void);
 140 extern void urcu_qsbr_unregister_thread(void);
 141
 142 #ifdef __cplusplus
 143 }
 144 #endif
 145
 146 #include <urcu/call-rcu.h>
 147 #include <urcu/defer.h>
 148 #include <urcu/flavor.h>
 149
 150 #ifndef URCU_API_MAP
 151 #include <urcu/map/clear.h>
 152 #endif
 153
 154 #endif /* _URCU_QSBR_H */