X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=formal-model%2Furcu%2Furcu.spin;h=2282407ce5aa6c16a4891748df3923d4b492cc57;hb=cc76fd1df9192f5bf2e10113bda65e25251075c8;hp=e9271f82bb58e3acdef1db13aa7226e011d48200;hpb=89674313b5ff1209dc090e3b2c48680d222e81cd;p=urcu.git

diff --git a/formal-model/urcu/urcu.spin b/formal-model/urcu/urcu.spin
index e9271f8..2282407 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 */
@@ -178,7 +242,7 @@ inline wait_for_quiescent_state(tmp, i, j)
 
 active [NR_READERS] proctype urcu_reader()
 {
-	byte i;
+	byte i, nest_i;
 	byte tmp, tmp2;
 
 	assert(get_pid() < NR_PROCS);
@@ -196,33 +260,48 @@ end_reader:
 #ifdef READER_PROGRESS
 progress_reader:
 #endif
-		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);
+		nest_i = 0;
+		do
+		:: nest_i < READER_NEST_LEVEL ->
 			ooo_mem(i);
-			WRITE_CACHED_VAR(urcu_active_readers_one, tmp2);
-		:: else	->
-			WRITE_CACHED_VAR(urcu_active_readers_one, tmp + 1);
-		fi;
+			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);
-		smp_mb(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_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);
-		ooo_mem(i);
-		//wakeup_all(i);
 		//smp_mc(i);	/* added */
 	od;
 }
@@ -271,7 +350,7 @@ progress_writer1:
 		//smp_mc(i);
 		wait_for_quiescent_state(tmp, i, j);
 		//smp_mc(i);
-	#ifndef SINGLE_FLIP
+#ifndef SINGLE_FLIP
 		ooo_mem(i);
 		tmp = READ_CACHED_VAR(urcu_gp_ctr);
 		ooo_mem(i);
@@ -279,7 +358,7 @@ progress_writer1:
 		//smp_mc(i);
 		ooo_mem(i);
 		wait_for_quiescent_state(tmp, i, j);
-	#endif
+#endif
 		ooo_mem(i);
 		smp_mb(i);
 		ooo_mem(i);