#ifndef _URCU_H
#define _URCU_H
-/* The "volatile" is due to gcc bugs */
-#define barrier() __asm__ __volatile__("": : :"memory")
+/*
+ * urcu.h
+ *
+ * Userspace RCU header
+ *
+ * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (c) 2009 Paul E. McKenney, IBM Corporation.
+ *
+ * LGPL-compatible code should include this header with :
+ *
+ * #define _LGPL_SOURCE
+ * #include <urcu.h>
+ *
+ * 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.
+ */
-/* x86 32/64 specific */
-#define mb() asm volatile("mfence":::"memory")
-#define rmb() asm volatile("lfence":::"memory")
-#define wmb() asm volatile("sfence" ::: "memory")
+#include <stdlib.h>
+#include <pthread.h>
+/*
+ * See urcu-pointer.h and urcu-pointer-static.h for pointer publication headers.
+ */
+#include <urcu-pointer.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
-/* x86 32 */
-static inline void atomic_inc(int *v)
-{
- asm volatile("lock; incl %0"
- : "+m" (*v));
-}
+/*
+ * 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.
+ */
-/* Nop everywhere except on alpha. */
-#define smp_read_barrier_depends()
+#ifdef _LGPL_SOURCE
-#define SIGURCU SIGUSR1
+#include <urcu-static.h>
-/* Global quiescent period parity */
-extern int urcu_qparity;
+/*
+ * Mappings for static use of the userspace RCU library.
+ * Should only be used in LGPL-compatible code.
+ */
-extern int __thread urcu_active_readers[2];
+/*
+ * rcu_read_lock()
+ * rcu_read_unlock()
+ *
+ * Mark the beginning and end of a read-side critical section.
+ * DON'T FORGET TO USE RCU_REGISTER/UNREGISTER_THREAD() FOR EACH THREAD WITH
+ * READ-SIDE CRITICAL SECTION.
+ */
+#define rcu_read_lock() _rcu_read_lock()
+#define rcu_read_unlock() _rcu_read_unlock()
-static inline int get_urcu_qparity(void)
-{
- return urcu_qparity;
-}
+#else /* !_LGPL_SOURCE */
/*
- * returns urcu_parity.
+ * library wrappers to be used by non-LGPL compatible source code.
+ * See LGPL-only urcu-pointer-static.h for documentation.
*/
-static inline int rcu_read_lock(void)
-{
- int urcu_parity = get_urcu_qparity();
- urcu_active_readers[urcu_parity]++;
- /*
- * Increment active readers count before accessing the pointer.
- * See force_mb_all_threads().
- */
- barrier();
- return urcu_parity;
-}
-static inline void rcu_read_unlock(int urcu_parity)
-{
- barrier();
- /*
- * Finish using rcu before decrementing the pointer.
- * See force_mb_all_threads().
- */
- urcu_active_readers[urcu_parity]--;
-}
+extern void rcu_read_lock(void);
+extern void rcu_read_unlock(void);
+
+#endif /* !_LGPL_SOURCE */
-extern void *urcu_publish_content(void **ptr, void *new);
+extern void synchronize_rcu(void);
/*
* Reader thread registration.
*/
-extern void urcu_register_thread(void);
-extern void urcu_register_thread(void);
+extern void rcu_register_thread(void);
+extern void rcu_unregister_thread(void);
+
+/*
+ * Explicit rcu initialization, for "early" use within library constructors.
+ */
+extern void rcu_init(void);
+
+#ifdef __cplusplus
+}
+#endif
#endif /* _URCU_H */
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