X-Git-Url: http://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu%2Fstatic%2Furcu.h;h=6c8b92602234b97d27a4cb462ec0ec06c56a62c7;hp=f32f300e599d95b922cbf043cc3a839e234190d5;hb=882f335739b978d1c55be2faeed077f315afe5d7;hpb=1de4df4b770e5e90440008becc5e14a15c75c6e0

diff --git a/urcu/static/urcu.h b/urcu/static/urcu.h
index f32f300..6c8b926 100644
--- a/urcu/static/urcu.h
+++ b/urcu/static/urcu.h
@@ -96,6 +96,12 @@ extern "C" {
 #define SIGRCU SIGUSR1
 #endif
 
+enum rcu_state {
+	RCU_READER_ACTIVE_CURRENT,
+	RCU_READER_ACTIVE_OLD,
+	RCU_READER_INACTIVE,
+};
+
 #ifdef DEBUG_RCU
 #define rcu_assert(args...)	assert(args)
 #else
@@ -239,7 +245,7 @@ static inline void wake_up_gp(void)
 	}
 }
 
-static inline int rcu_gp_ongoing(unsigned long *ctr)
+static inline enum rcu_state rcu_reader_state(unsigned long *ctr)
 {
 	unsigned long v;
 
@@ -248,8 +254,11 @@ static inline int rcu_gp_ongoing(unsigned long *ctr)
 	 * to insure consistency.
 	 */
 	v = CMM_LOAD_SHARED(*ctr);
-	return (v & RCU_GP_CTR_NEST_MASK) &&
-		 ((v ^ rcu_gp_ctr) & RCU_GP_CTR_PHASE);
+	if (!(v & RCU_GP_CTR_NEST_MASK))
+		return RCU_READER_INACTIVE;
+	if (!((v ^ rcu_gp_ctr) & RCU_GP_CTR_PHASE))
+		return RCU_READER_ACTIVE_CURRENT;
+	return RCU_READER_ACTIVE_OLD;
 }
 
 /*
@@ -320,6 +329,18 @@ static inline void _rcu_read_unlock(void)
 	cmm_barrier();	/* Ensure the compiler does not reorder us with mutex */
 }
 
+/*
+ * Returns whether within a RCU read-side critical section.
+ *
+ * This function is less than 10 lines long.  The intent is that this
+ * function meets the 10-line criterion for LGPL, allowing this function
+ * to be invoked directly from non-LGPL code.
+ */
+static inline int _rcu_read_ongoing(void)
+{
+	return URCU_TLS(rcu_reader).ctr & RCU_GP_CTR_NEST_MASK;
+}
+
 #ifdef __cplusplus
 }
 #endif