/* If the headers do not support SYS_membarrier, statically use RCU_MB */
#ifdef SYS_membarrier
-# define MEMBARRIER_EXPEDITED (1 << 0)
-# define MEMBARRIER_DELAYED (1 << 1)
+# define MEMBARRIER_EXPEDITED (1 << 0)
+# define MEMBARRIER_DELAYED (1 << 1)
+# define MEMBARRIER_QUERY (1 << 16)
# define membarrier(...) syscall(__NR_membarrier, __VA_ARGS__)
#else
# undef RCU_MEMBARRIER
/*
* The signal number used by the RCU library can be overridden with
* -DSIGRCU= when compiling the library.
+ * Provide backward compatibility for liburcu 0.3.x SIGURCU.
*/
+#ifdef SIGURCU
+#define SIGRCU SIGURCU
+#endif
+
#ifndef SIGRCU
#define SIGRCU SIGUSR1
#endif
}
#endif
+/*
+ * RCU memory barrier broadcast group. Currently, only broadcast to all process
+ * threads is supported (group 0).
+ *
+ * Slave barriers are only guaranteed to be ordered wrt master barriers.
+ *
+ * The pair ordering is detailed as (O: ordered, X: not ordered) :
+ * slave master
+ * slave X O
+ * master O O
+ */
+
+#define MB_GROUP_ALL 0
+#define RCU_MB_GROUP MB_GROUP_ALL
+
#ifdef RCU_MEMBARRIER
extern int has_sys_membarrier;
-static inline void smp_mb_light()
+static inline void smp_mb_slave(int group)
{
if (likely(has_sys_membarrier))
barrier();
#endif
#ifdef RCU_MB
-static inline void smp_mb_light()
+static inline void smp_mb_slave(int group)
{
smp_mb();
}
#endif
#ifdef RCU_SIGNAL
-static inline void smp_mb_light()
+static inline void smp_mb_slave(int group)
{
barrier();
}
_STORE_SHARED(rcu_reader.ctr, _LOAD_SHARED(rcu_gp_ctr));
/*
* Set active readers count for outermost nesting level before
- * accessing the pointer. See smp_mb_heavy().
+ * accessing the pointer. See smp_mb_master().
*/
- smp_mb_light();
+ smp_mb_slave(RCU_MB_GROUP);
} else {
_STORE_SHARED(rcu_reader.ctr, tmp + RCU_GP_COUNT);
}
tmp = rcu_reader.ctr;
/*
* Finish using rcu before decrementing the pointer.
- * See smp_mb_heavy().
+ * See smp_mb_master().
*/
if (likely((tmp & RCU_GP_CTR_NEST_MASK) == RCU_GP_COUNT)) {
- smp_mb_light();
+ smp_mb_slave(RCU_MB_GROUP);
_STORE_SHARED(rcu_reader.ctr, rcu_reader.ctr - RCU_GP_COUNT);
/* write rcu_reader.ctr before read futex */
- smp_mb_light();
+ smp_mb_slave(RCU_MB_GROUP);
wake_up_gp();
} else {
_STORE_SHARED(rcu_reader.ctr, rcu_reader.ctr - RCU_GP_COUNT);