X-Git-Url: http://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu-qsbr-static.h;h=22a93b2fd7a823d21c76cbbd1ad5c6bf3b0495e4;hp=752d4b9aced8630a94fca3bcf1e6338b012d0e36;hb=13ba7e6d703b58b0c9d9d872e12930385af087a8;hpb=7ac06cef7a7d9394332837edc5c0e9595286a5fc

diff --git a/urcu-qsbr-static.h b/urcu-qsbr-static.h
index 752d4b9..22a93b2 100644
--- a/urcu-qsbr-static.h
+++ b/urcu-qsbr-static.h
@@ -32,6 +32,7 @@
 #include <stdlib.h>
 #include <pthread.h>
 #include <assert.h>
+#include <limits.h>
 
 #include <compiler.h>
 #include <arch.h>
@@ -160,26 +161,43 @@ static inline void reader_barrier()
 	smp_mb();
 }
 
+#define RCU_GP_ONLINE		(1UL << 0)
+#define RCU_GP_CTR		(1UL << 1)
+
 /*
  * Global quiescent period counter with low-order bits unused.
  * Using a int rather than a char to eliminate false register dependencies
  * causing stalls on some architectures.
  */
-extern long urcu_gp_ctr;
+extern unsigned long urcu_gp_ctr;
 
-extern long __thread rcu_reader_qs_gp;
+extern unsigned long __thread rcu_reader_qs_gp;
 
-static inline int rcu_gp_ongoing(long *value)
+#if (BITS_PER_LONG < 64)
+static inline int rcu_gp_ongoing(unsigned long *value)
 {
+	unsigned long reader_gp;
+
 	if (value == NULL)
 		return 0;
+	reader_gp = LOAD_SHARED(*value);
+	return reader_gp && ((reader_gp ^ urcu_gp_ctr) & RCU_GP_CTR);
+}
+#else /* !(BITS_PER_LONG < 64) */
+static inline int rcu_gp_ongoing(unsigned long *value)
+{
+	unsigned long reader_gp;
 
-	return LOAD_SHARED(*value) & 1;
+	if (value == NULL)
+		return 0;
+	reader_gp = LOAD_SHARED(*value);
+	return reader_gp && (reader_gp - urcu_gp_ctr > ULONG_MAX / 2);
 }
+#endif  /* !(BITS_PER_LONG < 64) */
 
 static inline void _rcu_read_lock(void)
 {
-	rcu_assert(rcu_reader_qs_gp & 1);
+	rcu_assert(rcu_reader_qs_gp);
 }
 
 static inline void _rcu_read_unlock(void)
@@ -189,19 +207,19 @@ static inline void _rcu_read_unlock(void)
 static inline void _rcu_quiescent_state(void)
 {
 	smp_mb();	
-	rcu_reader_qs_gp = ACCESS_ONCE(urcu_gp_ctr) + 1;
+	_STORE_SHARED(rcu_reader_qs_gp, _LOAD_SHARED(urcu_gp_ctr));
 	smp_mb();
 }
 
 static inline void _rcu_thread_offline(void)
 {
 	smp_mb();
-	rcu_reader_qs_gp = ACCESS_ONCE(urcu_gp_ctr);
+	STORE_SHARED(rcu_reader_qs_gp, 0);
 }
 
 static inline void _rcu_thread_online(void)
 {
-	rcu_reader_qs_gp = ACCESS_ONCE(urcu_gp_ctr) + 1;
+	_STORE_SHARED(rcu_reader_qs_gp, LOAD_SHARED(urcu_gp_ctr));
 	smp_mb();
 }