/*
* 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.
*/
:: 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 {
#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 */
{
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))
#ifndef GEN_ERROR_WRITER_PROGRESS
smp_mb(i);
#else
- skip;
+ ooo_mem(i);
#endif
:: else ->
break;
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;
/* 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);
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;
- ooo_mem(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);
- 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. */
}
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);
//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);
//smp_mc(i);
ooo_mem(i);
wait_for_quiescent_state(tmp, i, j);
- #endif
- ooo_mem(i);
+#endif
smp_mb(i);
- ooo_mem(i);
write_lock = 0;
/* free-up step, e.g., kfree(). */
atomic {
projects / urcu.git / blobdiff