remove duplicate ooo_mem statements

[urcu.git] / formal-model / urcu / urcu.spin

diff --git a/formal-model/urcu/urcu.spin b/formal-model/urcu/urcu.spin
index 903782b352ee6a5f8a1d58af29b78fbfea46f355..324ee3945bd21507b11b49d9ab151230dcf0f0ed 100644 (file)
--- 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 {