use a lock to set/get AutomationList automation state

It isn't 100% clear that we should use the list's data lock, but it seems quite likely
that this is the correct design, because of the interlock between data being present
and automation state

1 files changed, 18 insertions, 7 deletions

diff --git a/libs/ardour/automation_list.cc b/libs/ardour/automation_list.cc
index d92e65288f..3ffc040b62 100644
--- a/libs/ardour/automation_list.cc
+++ b/libs/ardour/automation_list.cc
@@ -192,16 +192,28 @@ AutomationList::maybe_signal_changed ()
 	}
 }
 
+AutoState
+AutomationList::automation_state() const
+{
+	Glib::Threads::RWLock::ReaderLock lm (Evoral::ControlList::_lock);
+	return _state;
+}
+
 void
 AutomationList::set_automation_state (AutoState s)
 {
-	if (s == _state) {
-		return;
-	}
-	_state = s;
-	if (s == Write && _desc.toggled) {
-		snapshot_history (true);
+	{
+		Glib::Threads::RWLock::ReaderLock lm (Evoral::ControlList::_lock);
+
+		if (s == _state) {
+			return;
+		}
+		_state = s;
+		if (s == Write && _desc.toggled) {
+			snapshot_history (true);
+		}
 	}
+
 	automation_state_changed (s); /* EMIT SIGNAL */
 }
 
@@ -588,4 +600,3 @@ AutomationListProperty::clone () const
 		boost::shared_ptr<AutomationList> (new AutomationList (*this->_current.get()))
 		);
 }
-