X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=formal-model%2Furcu%2Furcu.spin;h=f4d3ea78ade593788bf9d97710e7c8bda5ace2ff;hb=a570e118a8f9ed38d5eaebf8d21b65d2b6f5cf40;hp=e9271f82bb58e3acdef1db13aa7226e011d48200;hpb=89674313b5ff1209dc090e3b2c48680d222e81cd;p=urcu.git

diff --git a/formal-model/urcu/urcu.spin b/formal-model/urcu/urcu.spin
index e9271f8..f4d3ea7 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 */
@@ -148,6 +212,7 @@ inline wait_for_reader(tmp, id, i)
 	:: 1 ->
 		ooo_mem(i);
 		tmp = READ_CACHED_VAR(urcu_active_readers_one);
+		ooo_mem(i);
 		if
 		:: (tmp & RCU_GP_CTR_NEST_MASK)
 			&& ((tmp ^ READ_CACHED_VAR(urcu_gp_ctr))
@@ -176,26 +241,11 @@ inline wait_for_quiescent_state(tmp, i, j)
 
 /* Model the RCU read-side critical section. */
 
-active [NR_READERS] proctype urcu_reader()
+inline urcu_one_read(i, nest_i, tmp, tmp2)
 {
-	byte i;
-	byte tmp, tmp2;
-
-	assert(get_pid() < NR_PROCS);
-
-end_reader:
+	nest_i = 0;
 	do
-	:: 1 ->
-		/*
-		 * We do not test reader's progress here, because we are mainly
-		 * interested in writer's progress. The reader never blocks
-		 * anyway. We have to test for reader/writer's progress
-		 * separately, otherwise we could think the writer is doing
-		 * progress when it's blocked by an always progressing reader.
-		 */
-#ifdef READER_PROGRESS
-progress_reader:
-#endif
+	:: nest_i < READER_NEST_LEVEL ->
 		ooo_mem(i);
 		tmp = READ_CACHED_VAR(urcu_active_readers_one);
 		ooo_mem(i);
@@ -206,27 +256,61 @@ progress_reader:
 			ooo_mem(i);
 			WRITE_CACHED_VAR(urcu_active_readers_one, tmp2);
 		:: else	->
-			WRITE_CACHED_VAR(urcu_active_readers_one, tmp + 1);
+			WRITE_CACHED_VAR(urcu_active_readers_one,
+					 tmp + 1);
 		fi;
 		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++;
+	:: 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);
-		ooo_mem(i);
-		//wakeup_all(i);
-		//smp_mc(i);	/* added */
+		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;
+	byte tmp, tmp2;
+
+	assert(get_pid() < NR_PROCS);
+
+end_reader:
+	do
+	:: 1 ->
+		/*
+		 * We do not test reader's progress here, because we are mainly
+		 * interested in writer's progress. The reader never blocks
+		 * anyway. We have to test for reader/writer's progress
+		 * separately, otherwise we could think the writer is doing
+		 * progress when it's blocked by an always progressing reader.
+		 */
+#ifdef READER_PROGRESS
+progress_reader:
+#endif
+		urcu_one_read(i, nest_i, tmp, tmp2);
+	od;
+}
 
 /* Model the RCU update process. */
 
@@ -271,7 +355,7 @@ 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 +363,7 @@ 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);