[Boost-commit] svn:boost r65323 - trunk/boost/msm/back

Subject: [Boost-commit] svn:boost r65323 - trunk/boost/msm/back
From: christophe.j.henry_at_[hidden]
Date: 2010-09-06 16:17:09

Author: chenry
Date: 2010-09-06 16:17:01 EDT (Mon, 06 Sep 2010)
New Revision: 65323
URL: http://svn.boost.org/trac/boost/changeset/65323

Log:
bugfix: guard always returning false with an anonymous transition causes stack overflow
Text files modified: 
   trunk/boost/msm/back/state_machine.hpp |    31 ++++++++++++++++++++++++++-----         
   1 files changed, 26 insertions(+), 5 deletions(-)

Modified: trunk/boost/msm/back/state_machine.hpp
==============================================================================
--- trunk/boost/msm/back/state_machine.hpp	(original)
+++ trunk/boost/msm/back/state_machine.hpp	2010-09-06 16:17:01 EDT (Mon, 06 Sep 2010)
@@ -991,6 +991,11 @@
             {
                 ret_handled = HANDLED_TRUE;
             }
+
+            // process completion transitions BEFORE any other event in the pool (UML Standard 2.3 §15.3.14)
+            handle_eventless_transitions_helper<library_sm> eventless_helper(this,(handled == HANDLED_TRUE));
+            eventless_helper.process_completion_event();
+
             // after handling, take care of the deferred events
             defer_helper.do_post_handle_deferred(handled);
 
@@ -998,15 +1003,31 @@
             // because of another processing, and if yes, start handling them
             do_post_msg_queue_helper(::boost::mpl::bool_<is_no_message_queue<library_sm>::type::value>());
 
-            // event can be handled, processing
-            // handle with lowest priority event-less transitions
-            handle_eventless_transitions_helper<library_sm> eventless_helper(this,(handled!=HANDLED_FALSE));
-            eventless_helper.process_completion_event();
-
             return ret_handled;
         }       
     }
 
+    // Tries to process a completion event (useful if a previous one was rejected by a guard).
+    execute_return process_completion()
+    {
+        typedef typename ::boost::mpl::deref<
+                    typename ::boost::mpl::begin<
+                        typename find_completion_events<library_sm>::type
+                    >::type
+            >::type first_completion_event;
+
+        // if the state machine has terminate or interrupt flags, check them, otherwise skip
+        if (is_event_handling_blocked_helper<first_completion_event>
+                ( ::boost::mpl::bool_<has_fsm_blocking_states<library_sm>::type::value>() ) )
+            return HANDLED_TRUE;
+
+        // process completion transitions BEFORE any other event in the pool (UML Standard 2.3 §15.3.14)
+        handle_eventless_transitions_helper<library_sm> eventless_helper(this,true);
+        eventless_helper.process_completion_event();
+
+        return HANDLED_TRUE;
+    }
+
     // Getter that returns the current state of the FSM
     const int* current_state() const
     {