From: paulmck@linux.vnet.ibm.com (Paul E. McKenney)
Subject: [ltt-dev] [[PATCH URCU formal]] Restructure urcu_updater() to more accurately reflect actual failure scenario.
Date: Thu, 19 Feb 2009 17:57:47 -0800 [thread overview]
Message-ID: <20090220015747.GA19488@linux.vnet.ibm.com> (raw)
Restructure urcu_updater() to more accurately reflect actual failure
scenario.
This allows an easier transformation to force failure -- simple #ifdef
out the second counter flip out of urcu_updater()'s model of
"current synchronize_rcu()".
Signed-off-by: Paul E. McKenney <paulmck at linux.vnet.ibm.com>
---
formal-model/urcu.spin | 41 +++++++++++++++++++++++++++++++----------
1 files changed, 31 insertions(+), 10 deletions(-)
diff --git a/formal-model/urcu.spin b/formal-model/urcu.spin
index eea18e8..3e18457 100644
--- a/formal-model/urcu.spin
+++ b/formal-model/urcu.spin
@@ -187,10 +187,38 @@ proctype urcu_reader()
proctype urcu_updater()
{
+ /* prior synchronize_rcu(), second counter flip. */
+ need_mb = 1;
+ do
+ :: need_mb == 1 -> skip;
+ :: need_mb == 0 -> break;
+ od;
+ urcu_gp_ctr = urcu_gp_ctr + RCU_GP_CTR_BIT;
+ need_mb = 1;
+ do
+ :: need_mb == 1 -> skip;
+ :: need_mb == 0 -> break;
+ od;
+ do
+ :: 1 ->
+ if
+ :: (urcu_active_readers & RCU_GP_CTR_NEST_MASK) != 0 &&
+ (urcu_active_readers & ~RCU_GP_CTR_NEST_MASK) !=
+ (urcu_gp_ctr & ~RCU_GP_CTR_NEST_MASK) ->
+ skip;
+ :: else -> break;
+ fi;
+ od;
+ need_mb = 1;
+ do
+ :: need_mb == 1 -> skip;
+ :: need_mb == 0 -> break;
+ od;
+
/* Removal statement, e.g., list_del_rcu(). */
removed = 1;
- /* synchronize_rcu(), first counter flip. */
+ /* current synchronize_rcu(), first counter flip. */
need_mb = 1;
do
:: need_mb == 1 -> skip;
@@ -204,15 +232,13 @@ proctype urcu_updater()
od;
do
:: 1 ->
- printf("urcu_gp_ctr=%x urcu_active_readers=%x\n", urcu_gp_ctr, urcu_active_readers);
- printf("urcu_gp_ctr&0x7f=%x urcu_active_readers&0x7f=%x\n", urcu_gp_ctr & ~RCU_GP_CTR_NEST_MASK, urcu_active_readers & ~RCU_GP_CTR_NEST_MASK);
if
:: (urcu_active_readers & RCU_GP_CTR_NEST_MASK) != 0 &&
(urcu_active_readers & ~RCU_GP_CTR_NEST_MASK) !=
(urcu_gp_ctr & ~RCU_GP_CTR_NEST_MASK) ->
skip;
:: else -> break;
- fi
+ fi;
od;
need_mb = 1;
do
@@ -220,10 +246,7 @@ proctype urcu_updater()
:: need_mb == 0 -> break;
od;
- /* Erroneous removal statement, e.g., list_del_rcu(). */
- /* removed = 1; */
-
- /* synchronize_rcu(), second counter flip. */
+ /* current synchronize_rcu(), second counter flip. */
need_mb = 1;
do
:: need_mb == 1 -> skip;
@@ -237,8 +260,6 @@ proctype urcu_updater()
od;
do
:: 1 ->
- printf("urcu_gp_ctr=%x urcu_active_readers=%x\n", urcu_gp_ctr, urcu_active_readers);
- printf("urcu_gp_ctr&0x7f=%x urcu_active_readers&0x7f=%x\n", urcu_gp_ctr & ~RCU_GP_CTR_NEST_MASK, urcu_active_readers & ~RCU_GP_CTR_NEST_MASK);
if
:: (urcu_active_readers & RCU_GP_CTR_NEST_MASK) != 0 &&
(urcu_active_readers & ~RCU_GP_CTR_NEST_MASK) !=
--
1.5.2.5
next reply other threads:[~2009-02-20 1:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-20 1:57 Paul E. McKenney [this message]
2009-02-20 17:15 ` Mathieu Desnoyers
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