add missing ooo_mem() to writer model

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

diff --git a/formal-model/urcu/urcu.spin b/formal-model/urcu/urcu.spin
index e9271f82bb58e3acdef1db13aa7226e011d48200..f4d3ea78ade593788bf9d97710e7c8bda5ace2ff 100644 (file)
--- 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);