X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=urcu.h;h=0b0d232311a58666c8b41a9c3162b4efb8caaed4;hb=121a5d44c8cc7197116df73854cb94c6cfbad0b0;hp=363021d7832927e288705e42f7c31f4d36486d72;hpb=f69f195a06af55b7501ed2f59ed719970727ce5b;p=urcu.git

diff --git a/urcu.h b/urcu.h
index 363021d..0b0d232 100644
--- a/urcu.h
+++ b/urcu.h
@@ -1,69 +1,78 @@
 #ifndef _URCU_H
 #define _URCU_H
 
-/* The "volatile" is due to gcc bugs */
-#define barrier() __asm__ __volatile__("": : :"memory")
-
-/* x86 32/64 specific */
-#define mb()    asm volatile("mfence":::"memory")
-#define rmb()   asm volatile("lfence":::"memory")
-#define wmb()   asm volatile("sfence" ::: "memory")
-
+/*
+ * urcu.h
+ *
+ * Userspace RCU header
+ *
+ * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ *
+ * Credits for Paul E. McKenney <paulmck@linux.vnet.ibm.com>
+ * for inspiration coming from the Linux kernel RCU and rcu-preempt.
+ *
+ * LGPL-compatible code should include this header with :
+ *
+ * #define _LGPL_SOURCE
+ * #include <urcu.h>
+ *
+ * Distributed under LGPLv2.1
+ *
+ * IBM's contributions to this file may be relicensed under LGPLv2 or later.
+ */
 
+#include <stdlib.h>
+#include <pthread.h>
 
-/* x86 32 */
-static inline void atomic_inc(int *v)
-{
-	asm volatile("lock; incl %0"
-		     : "+m" (*v));
-}
+#ifdef _LGPL_SOURCE
 
-/* Nop everywhere except on alpha. */
-#define smp_read_barrier_depends()
+#include <urcu-static.h>
 
-#define SIGURCU SIGUSR1
+/*
+ * Mappings for static use of the userspace RCU library.
+ * Should only be used in LGPL-compatible code.
+ */
 
-/* Global quiescent period parity */
-extern int urcu_qparity;
+#define rcu_dereference		_rcu_dereference
+#define rcu_read_lock		_rcu_read_lock
+#define rcu_read_unlock		_rcu_read_unlock
 
-extern int __thread urcu_active_readers[2];
+#define rcu_assign_pointer	_rcu_assign_pointer
+#define rcu_xchg_pointer	_rcu_xchg_pointer
+#define rcu_publish_content	_rcu_publish_content
 
-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.
  */
-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 *urcu_publish_content(void **ptr, void *new);
+
+extern void rcu_read_lock(void);
+extern void rcu_read_unlock(void);
+
+extern void *rcu_dereference(void *p);
+
+extern void *rcu_assign_pointer_sym(void **p, void *v);
+
+#define rcu_assign_pointer(p, v)			\
+	rcu_assign_pointer_sym((void **)(p), (v))
+
+extern void *rcu_xchg_pointer_sym(void **p, void *v);
+#define rcu_xchg_pointer(p, v)				\
+	rcu_xchg_pointer_sym((void **)(p), (v))
+
+extern void *rcu_publish_content_sym(void **p, void *v);
+#define rcu_publish_content(p, v)			\
+	rcu_publish_content_sym((void **)(p), (v))
+
+#endif /* !_LGPL_SOURCE */
+
+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);
 
 #endif /* _URCU_H */