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