X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=formal-model%2Furcu%2Furcu.spin;h=570da40231773d139e2c80166b584b0585136da3;hb=6ae334b09959594326f5d85f76e0427c03a64995;hp=903782b352ee6a5f8a1d58af29b78fbfea46f355;hpb=d4e437ba8e99a9cd38c4ccb1c243427935c8f293;p=urcu.git

diff --git a/formal-model/urcu/urcu.spin b/formal-model/urcu/urcu.spin
index 903782b..570da40 100644
--- a/formal-model/urcu/urcu.spin
+++ b/formal-model/urcu/urcu.spin
@@ -80,6 +80,68 @@
 	:: 1 -> skip			\
 	fi;
 
+/*
+ * Remote barriers tests the scheme where a signal (or IPI) is sent to all
+ * reader threads to promote their compiler barrier to a smp_mb().
+ */
+#ifdef REMOTE_BARRIERS
+
+inline smp_rmb_pid(i)
+{
+	atomic {
+		CACHE_READ_FROM_MEM(urcu_gp_ctr, i);
+		CACHE_READ_FROM_MEM(urcu_active_readers_one, i);
+		CACHE_READ_FROM_MEM(generation_ptr, i);
+	}
+}
+
+inline smp_wmb_pid(i)
+{
+	atomic {
+		CACHE_WRITE_TO_MEM(urcu_gp_ctr, i);
+		CACHE_WRITE_TO_MEM(urcu_active_readers_one, i);
+		CACHE_WRITE_TO_MEM(generation_ptr, i);
+	}
+}
+
+inline smp_mb_pid(i)
+{
+	atomic {
+#ifndef NO_WMB
+		smp_wmb_pid(i);
+#endif
+#ifndef NO_RMB
+		smp_rmb_pid(i);
+#endif
+		skip;
+	}
+}
+
+/*
+ * Readers do a simple barrier(), writers are doing a smp_mb() _and_ sending a
+ * signal or IPI to have all readers execute a smp_mb.
+ * We are not modeling the whole rendez-vous between readers and writers here,
+ * we just let the writer update each reader's caches remotely.
+ */
+inline smp_mb(i)
+{
+	if
+	:: get_pid() >= NR_READERS ->
+		smp_mb_pid(get_pid());
+		i = 0;
+		do
+		:: i < NR_READERS ->
+			smp_mb_pid(i);
+			i++;
+		:: i >= NR_READERS -> break
+		od;
+		smp_mb_pid(get_pid());
+	:: else -> skip;
+	fi;
+}
+
+#else
+
 inline smp_rmb(i)
 {
 	atomic {
@@ -111,6 +173,8 @@ inline smp_mb(i)
 	}
 }
 
+#endif
+
 /* Keep in sync manually with smp_rmb, wmp_wmb and ooo_mem */
 DECLARE_CACHED_VAR(byte, urcu_gp_ctr, 1);
 /* Note ! currently only one reader */
@@ -176,6 +240,53 @@ inline wait_for_quiescent_state(tmp, i, j)
 
 /* Model the RCU read-side critical section. */
 
+inline urcu_one_read(i, nest_i, tmp, tmp2)
+{
+	nest_i = 0;
+	do
+	:: nest_i < READER_NEST_LEVEL ->
+		ooo_mem(i);
+		tmp = READ_CACHED_VAR(urcu_active_readers_one);
+		ooo_mem(i);
+		if
+		:: (!(tmp & RCU_GP_CTR_NEST_MASK))
+			->
+			tmp2 = READ_CACHED_VAR(urcu_gp_ctr);
+			ooo_mem(i);
+			WRITE_CACHED_VAR(urcu_active_readers_one, tmp2);
+		:: else	->
+			WRITE_CACHED_VAR(urcu_active_readers_one,
+					 tmp + 1);
+		fi;
+		ooo_mem(i);
+		smp_mb(i);
+		nest_i++;
+	:: nest_i >= READER_NEST_LEVEL -> break;
+	od;
+
+	ooo_mem(i);
+	read_generation = READ_CACHED_VAR(generation_ptr);
+	ooo_mem(i);
+	data_access = 1;
+	ooo_mem(i);
+	data_access = 0;
+
+	nest_i = 0;
+	do
+	:: nest_i < READER_NEST_LEVEL ->
+		ooo_mem(i);
+		smp_mb(i);
+		ooo_mem(i);
+		tmp2 = READ_CACHED_VAR(urcu_active_readers_one);
+		ooo_mem(i);
+		WRITE_CACHED_VAR(urcu_active_readers_one, tmp2 - 1);
+		nest_i++;
+	:: nest_i >= READER_NEST_LEVEL -> break;
+	od;
+	ooo_mem(i);
+	//smp_mc(i);	/* added */
+}
+
 active [NR_READERS] proctype urcu_reader()
 {
 	byte i, nest_i;
@@ -196,53 +307,10 @@ end_reader:
 #ifdef READER_PROGRESS
 progress_reader:
 #endif
-		nest_i = 0;
-		do
-		:: nest_i < READER_NEST_LEVEL ->
-			ooo_mem(i);
-			tmp = READ_CACHED_VAR(urcu_active_readers_one);
-			ooo_mem(i);
-			if
-			:: (!(tmp & RCU_GP_CTR_NEST_MASK))
-				->
-				tmp2 = READ_CACHED_VAR(urcu_gp_ctr);
-				ooo_mem(i);
-				WRITE_CACHED_VAR(urcu_active_readers_one, tmp2);
-			:: else	->
-				WRITE_CACHED_VAR(urcu_active_readers_one,
-						 tmp + 1);
-			fi;
-			ooo_mem(i);
-			smp_mb(i);
-			nest_i++;
-		:: nest_i >= READER_NEST_LEVEL -> break;
-		od;
-
-		ooo_mem(i);
-		read_generation = READ_CACHED_VAR(generation_ptr);
-		ooo_mem(i);
-		data_access = 1;
-		ooo_mem(i);
-		data_access = 0;
-
-		nest_i = 0;
-		do
-		:: nest_i < READER_NEST_LEVEL ->
-			ooo_mem(i);
-			smp_mb(i);
-			ooo_mem(i);
-			tmp2 = READ_CACHED_VAR(urcu_active_readers_one);
-			ooo_mem(i);
-			WRITE_CACHED_VAR(urcu_active_readers_one, tmp2 - 1);
-			nest_i++;
-		:: nest_i >= READER_NEST_LEVEL -> break;
-		od;
-		ooo_mem(i);
-		//smp_mc(i);	/* added */
+		urcu_one_read(i, nest_i, tmp, tmp2);
 	od;
 }
 
-
 /* Model the RCU update process. */
 
 active [NR_WRITERS] proctype urcu_writer()