urcu-bp.h

   1 #ifndef _URCU_BP_H
   2 #define _URCU_BP_H
   3
   4 /*
   5  * urcu-bp.h
   6  *
   7  * Userspace RCU header, "bulletproof" version.
   8  *
   9  * Slower RCU read-side adapted for tracing library. Does not require thread
  10  * registration nor unregistration. Also signal-safe.
  11  *
  12  * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
  13  * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
  14  *
  15  * LGPL-compatible code should include this header with :
  16  *
  17  * #define _LGPL_SOURCE
  18  * #include <urcu.h>
  19  *
  20  * This library is free software; you can redistribute it and/or
  21  * modify it under the terms of the GNU Lesser General Public
  22  * License as published by the Free Software Foundation; either
  23  * version 2.1 of the License, or (at your option) any later version.
  24  *
  25  * This library is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  28  * Lesser General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU Lesser General Public
  31  * License along with this library; if not, write to the Free Software
  32  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  33  *
  34  * IBM's contributions to this file may be relicensed under LGPLv2 or later.
  35  */
  36
  37 #include <stdlib.h>
  38 #include <pthread.h>
  39
  40 /*
  41  * See urcu-pointer.h and urcu-pointer-static.h for pointer publication headers.
  42  */
  43 #include <urcu-pointer.h>
  44
  45 /*
  46  * Important !
  47  *
  48  * Each thread containing read-side critical sections must be registered
  49  * with rcu_register_thread() before calling rcu_read_lock().
  50  * rcu_unregister_thread() should be called before the thread exits.
  51  */
  52
  53 #ifdef _LGPL_SOURCE
  54
  55 #include <urcu-bp-static.h>
  56
  57 /*
  58  * Mappings for static use of the userspace RCU library.
  59  * Should only be used in LGPL-compatible code.
  60  */
  61
  62 /*
  63  * rcu_read_lock()
  64  * rcu_read_unlock()
  65  *
  66  * Mark the beginning and end of a read-side critical section.
  67  */
  68 #define rcu_read_lock()         _rcu_read_lock()
  69 #define rcu_read_unlock()       _rcu_read_unlock()
  70
  71 #else /* !_LGPL_SOURCE */
  72
  73 /*
  74  * library wrappers to be used by non-LGPL compatible source code.
  75  * See LGPL-only urcu-pointer-static.h for documentation.
  76  */
  77
  78 extern void rcu_read_lock(void);
  79 extern void rcu_read_unlock(void);
  80
  81 #endif /* !_LGPL_SOURCE */
  82
  83 extern void synchronize_rcu(void);
  84
  85 /*
  86  * In the bulletproof version, the following functions are no-ops.
  87  */
  88 static inline void rcu_register_thread(void)
  89 {
  90 }
  91
  92 static inline void rcu_unregister_thread(void)
  93 {
  94 }
  95
  96 static inline void urcu_init(void)
  97 {
  98 }
  99
 100 #endif /* _URCU_BP_H */