Clean up TMM at exit

libs/ardour/ardour/transport_master_manager.h

@@ -41,6 +41,7 @@ class LIBARDOUR_API TransportMasterManager : public boost::noncopyable
 	void engine_stopped ();
 
 	static TransportMasterManager& instance();
+	static void destroy();
 	/* this method is not thread-safe and is intended to be used only
 	 * very early in application-lifetime to check if the TMM has
 	 * been created yet. Do not use in other code.

libs/ardour/globals.cc

@@ -654,6 +654,7 @@ ARDOUR::cleanup ()
 
 	delete &ControlProtocolManager::instance ();
 	ARDOUR::AudioEngine::destroy ();
+	ARDOUR::TransportMasterManager::destroy ();
 
 	delete Library;
 #ifdef HAVE_LRDF

libs/ardour/transport_master_manager.cc

@@ -47,7 +47,9 @@ TransportMasterManager::TransportMasterManager()
 
 TransportMasterManager::~TransportMasterManager ()
 {
-	clear ();
+	Glib::Threads::RWLock::WriterLock lm (lock);
+	_current_master.reset ();
+	_transport_masters.clear ();
 }
 
 TransportMasterManager&
@@ -139,6 +141,13 @@ TransportMasterManager::instance()
 	return *_instance;
 }
 
+void
+TransportMasterManager::destroy()
+{
+	delete _instance;
+	_instance = 0;
+}
+
 // Called from AudioEngine::process_callback() BEFORE Session::process() is called. Each transport master has processed any incoming data for this cycle,
 // and this method computes the transport speed that Ardour should use to get into and remain in sync with the master.
 //