X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=formal-model%2Furcu%2Furcu.spin;h=324ee3945bd21507b11b49d9ab151230dcf0f0ed;hb=a5b558b0c4655e98f7d8f43b900b6e3350a74f86;hp=903782b352ee6a5f8a1d58af29b78fbfea46f355;hpb=d4e437ba8e99a9cd38c4ccb1c243427935c8f293;p=urcu.git

diff --git a/formal-model/urcu/urcu.spin b/formal-model/urcu/urcu.spin
index 903782b..324ee39 100644
--- a/formal-model/urcu/urcu.spin
+++ b/formal-model/urcu/urcu.spin
@@ -29,7 +29,7 @@
 
 /*
  * Each process have its own data in cache. Caches are randomly updated.
- * smp_wmb and smp_rmb forces cache updates (write and read), wmb_mb forces
+ * smp_wmb and smp_rmb forces cache updates (write and read), smp_mb forces
  * both.
  */
 
@@ -80,6 +80,72 @@
 	:: 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
+#ifdef NO_WMB
+#ifdef NO_RMB
+		ooo_mem(i);
+#endif
+#endif
+	}
+}
+
+/*
+ * 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 {
@@ -107,10 +173,16 @@ inline smp_mb(i)
 #ifndef NO_RMB
 		smp_rmb(i);
 #endif
-		skip;
+#ifdef NO_WMB
+#ifdef NO_RMB
+		ooo_mem(i);
+#endif
+#endif
 	}
 }
 
+#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 */
@@ -146,8 +218,8 @@ inline wait_for_reader(tmp, id, i)
 {
 	do
 	:: 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))
@@ -155,7 +227,7 @@ inline wait_for_reader(tmp, id, i)
 #ifndef GEN_ERROR_WRITER_PROGRESS
 			smp_mb(i);
 #else
-			skip;
+			ooo_mem(i);
 #endif
 		:: else	->
 			break;
@@ -169,6 +241,12 @@ inline wait_for_quiescent_state(tmp, i, j)
 	do
 	:: i < NR_READERS ->
 		wait_for_reader(tmp, i, j);
+		if
+		:: (NR_READERS > 1) && (i < NR_READERS - 1)
+			-> ooo_mem(j);
+		:: else
+			-> skip;
+		fi;
 		i++
 	:: i >= NR_READERS -> break
 	od;
@@ -176,6 +254,50 @@ 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;
+		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 ->
+		smp_mb(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 +318,10 @@ 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()
@@ -278,7 +357,6 @@ progress_writer1:
 			}
 		od;
 		smp_mb(i);
-		ooo_mem(i);
 		tmp = READ_CACHED_VAR(urcu_gp_ctr);
 		ooo_mem(i);
 		WRITE_CACHED_VAR(urcu_gp_ctr, tmp ^ RCU_GP_CTR_BIT);
@@ -295,9 +373,7 @@ progress_writer1:
 		ooo_mem(i);
 		wait_for_quiescent_state(tmp, i, j);
 #endif
-		ooo_mem(i);
 		smp_mb(i);
-		ooo_mem(i);
 		write_lock = 0;
 		/* free-up step, e.g., kfree(). */
 		atomic {