X-Git-Url: http://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu%2Fstatic%2Furcu.h;h=6c8b92602234b97d27a4cb462ec0ec06c56a62c7;hp=c517693ff1cf187982882bf30f412e454ae8d26f;hb=15302e2854ad9f1377ec81e331c1bec7a54a5621;hpb=a5a9f428a238e790d6c97299bc214b5cca815cd7

diff --git a/urcu/static/urcu.h b/urcu/static/urcu.h
index c517693..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
@@ -108,8 +114,8 @@ extern "C" {
 #include <pthread.h>
 #include <unistd.h>
 
-#define YIELD_READ 	(1 << 0)
-#define YIELD_WRITE	(1 << 1)
+#define RCU_YIELD_READ 	(1 << 0)
+#define RCU_YIELD_WRITE	(1 << 1)
 
 /*
  * Updates with RCU_SIGNAL are much slower. Account this in the delay.
@@ -121,37 +127,37 @@ extern "C" {
 #define MAX_SLEEP 50
 #endif
 
-extern unsigned int yield_active;
-extern DECLARE_URCU_TLS(unsigned int, rand_yield);
+extern unsigned int rcu_yield_active;
+extern DECLARE_URCU_TLS(unsigned int, rcu_rand_yield);
 
-static inline void debug_yield_read(void)
+static inline void rcu_debug_yield_read(void)
 {
-	if (yield_active & YIELD_READ)
-		if (rand_r(&URCU_TLS(rand_yield)) & 0x1)
-			usleep(rand_r(&URCU_TLS(rand_yield)) % MAX_SLEEP);
+	if (rcu_yield_active & RCU_YIELD_READ)
+		if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
+			usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
 }
 
-static inline void debug_yield_write(void)
+static inline void rcu_debug_yield_write(void)
 {
-	if (yield_active & YIELD_WRITE)
-		if (rand_r(&URCU_TLS(rand_yield)) & 0x1)
-			usleep(rand_r(&URCU_TLS(rand_yield)) % MAX_SLEEP);
+	if (rcu_yield_active & RCU_YIELD_WRITE)
+		if (rand_r(&URCU_TLS(rcu_rand_yield)) & 0x1)
+			usleep(rand_r(&URCU_TLS(rcu_rand_yield)) % MAX_SLEEP);
 }
 
-static inline void debug_yield_init(void)
+static inline void rcu_debug_yield_init(void)
 {
-	URCU_TLS(rand_yield) = time(NULL) ^ (unsigned long) pthread_self();
+	URCU_TLS(rcu_rand_yield) = time(NULL) ^ (unsigned long) pthread_self();
 }
 #else
-static inline void debug_yield_read(void)
+static inline void rcu_debug_yield_read(void)
 {
 }
 
-static inline void debug_yield_write(void)
+static inline void rcu_debug_yield_write(void)
 {
 }
 
-static inline void debug_yield_init(void)
+static inline void rcu_debug_yield_init(void)
 {
 
 }
@@ -173,11 +179,11 @@ static inline void debug_yield_init(void)
 #define RCU_MB_GROUP		MB_GROUP_ALL
 
 #ifdef RCU_MEMBARRIER
-extern int has_sys_membarrier;
+extern int rcu_has_sys_membarrier;
 
 static inline void smp_mb_slave(int group)
 {
-	if (caa_likely(has_sys_membarrier))
+	if (caa_likely(rcu_has_sys_membarrier))
 		cmm_barrier();
 	else
 		cmm_smp_mb();
@@ -225,21 +231,21 @@ struct rcu_reader {
 
 extern DECLARE_URCU_TLS(struct rcu_reader, rcu_reader);
 
-extern int32_t gp_futex;
+extern int32_t rcu_gp_futex;
 
 /*
  * Wake-up waiting synchronize_rcu(). Called from many concurrent threads.
  */
 static inline void wake_up_gp(void)
 {
-	if (caa_unlikely(uatomic_read(&gp_futex) == -1)) {
-		uatomic_set(&gp_futex, 0);
-		futex_async(&gp_futex, FUTEX_WAKE, 1,
+	if (caa_unlikely(uatomic_read(&rcu_gp_futex) == -1)) {
+		uatomic_set(&rcu_gp_futex, 0);
+		futex_async(&rcu_gp_futex, FUTEX_WAKE, 1,
 		      NULL, NULL, 0);
 	}
 }
 
-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