#ifndef _URCU_QSBR_H #define _URCU_QSBR_H /* * urcu-qsbr.h * * Userspace RCU QSBR header. * * LGPL-compatible code should include this header with : * * #define _LGPL_SOURCE * #include * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * IBM's contributions to this file may be relicensed under LGPLv2 or later. */ #include #include /* * See urcu-pointer.h and urcu/static/urcu-pointer.h for pointer * publication headers. */ #include #ifdef __cplusplus extern "C" { #endif #include #ifdef RCU_DEBUG /* For backward compatibility */ #define DEBUG_RCU #endif /* * Important ! * * Each thread containing read-side critical sections must be registered * with rcu_register_thread() before calling rcu_read_lock(). * rcu_unregister_thread() should be called before the thread exits. */ #ifdef _LGPL_SOURCE #include /* * Mappings for static use of the userspace RCU library. * Should only be used in LGPL-compatible code. */ /* * rcu_read_lock() * rcu_read_unlock() * * Mark the beginning and end of a read-side critical section. * DON'T FORGET TO USE rcu_register_thread/rcu_unregister_thread() * FOR EACH THREAD WITH READ-SIDE CRITICAL SECTION. */ #define rcu_read_lock_qsbr _rcu_read_lock #define rcu_read_unlock_qsbr _rcu_read_unlock #define rcu_read_ongoing_qsbr _rcu_read_ongoing #define rcu_quiescent_state_qsbr _rcu_quiescent_state #define rcu_thread_offline_qsbr _rcu_thread_offline #define rcu_thread_online_qsbr _rcu_thread_online #else /* !_LGPL_SOURCE */ /* * library wrappers to be used by non-LGPL compatible source code. */ /* * QSBR read lock/unlock are guaranteed to be no-ops. Therefore, we expose them * in the LGPL header for any code to use. However, the debug version is not * nops and may contain sanity checks. To activate it, applications must be * recompiled with -DDEBUG_RCU (even non-LGPL/GPL applications). This is the * best trade-off between license/performance/code triviality and * library debugging & tracing features we could come up with. */ #if (!defined(BUILD_QSBR_LIB) && !defined(DEBUG_RCU)) static inline void rcu_read_lock(void) { } static inline void rcu_read_unlock(void) { } #else /* !DEBUG_RCU */ extern void rcu_read_lock(void); extern void rcu_read_unlock(void); #endif /* !DEBUG_RCU */ extern int rcu_read_ongoing(void); extern void rcu_quiescent_state(void); extern void rcu_thread_offline(void); extern void rcu_thread_online(void); #endif /* !_LGPL_SOURCE */ extern void synchronize_rcu(void); /* * Reader thread registration. */ extern void rcu_register_thread(void); extern void rcu_unregister_thread(void); #ifdef __cplusplus } #endif #include #include #include #endif /* _URCU_QSBR_H */