use new event loop callback to ensure that all surface/control protocol threads have tempo map ptr set

libs/surfaces/cc121/cc121.h

@@ -162,6 +162,8 @@ class CC121 : public ARDOUR::ControlProtocol, public AbstractUI<CC121Request> {
 
 	std::list<boost::shared_ptr<ARDOUR::Bundle> > bundles ();
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
   private:
 	boost::shared_ptr<ARDOUR::Stripable> _current_stripable;
 	boost::weak_ptr<ARDOUR::Stripable> pre_master_stripable;

libs/surfaces/contourdesign/contourdesign.h

@@ -128,6 +128,8 @@ public:
 	PBD::Signal1<void, unsigned short> ButtonPress;
 	PBD::Signal1<void, unsigned short> ButtonRelease;
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
 private:
 	void do_request (ContourDesignControlUIRequest*);
 	void start ();

libs/surfaces/control_protocol/control_protocol.cc

@@ -21,6 +21,7 @@
 
 #include "pbd/convert.h"
 #include "pbd/error.h"
+#include "pbd/pthread_utils.h"
 
 #include "temporal/superclock.h"
 #include "temporal/tempo.h"
@@ -65,6 +66,7 @@ const std::string ControlProtocol::state_node_name ("Protocol");
 ControlProtocol::ControlProtocol (Session& s, string str)
 	: BasicUI (s)
 	, _name (str)
+	, glib_event_callback (boost::bind (&ControlProtocol::event_loop_precall, this))
 	, _active (false)
 {
 	if (!selection_connected) {
@@ -78,6 +80,19 @@ ControlProtocol::~ControlProtocol ()
 {
 }
 
+void
+ControlProtocol::event_loop_precall ()
+{
+	/* reload the thread-local ptr to the tempo map */
+	Temporal::TempoMap::fetch ();
+}
+
+void
+ControlProtocol::install_precall_handler (Glib::RefPtr<Glib::MainContext> context)
+{
+	glib_event_callback.attach (context);
+}
+
 int
 ControlProtocol::set_active (bool yn)
 {

libs/surfaces/control_protocol/control_protocol/control_protocol.h

@@ -30,6 +30,7 @@
 
 #include "pbd/signals.h"
 #include "pbd/stateful.h"
+#include "pbd/glib_event_source.h"
 
 #include "control_protocol/basic_ui.h"
 #include "control_protocol/types.h"
@@ -147,6 +148,9 @@ protected:
 
 	std::vector<boost::shared_ptr<ARDOUR::Route> > route_table;
 	std::string _name;
+	GlibEventLoopCallback glib_event_callback;
+	virtual void event_loop_precall ();
+	void install_precall_handler (Glib::RefPtr<Glib::MainContext>);
 
 private:
 	LIBCONTROLCP_LOCAL ControlProtocol (const ControlProtocol&); /* noncopyable */
@@ -184,4 +188,17 @@ public:
 }
 }
 
+/* this is where the strange inheritance pattern hits the wall. A control
+   protocol thread/event loop is inherited from AbstractUI, but the precall
+   handler is inherited from ControlProtocol. When the AbstractUI sets up the
+   event loop, it will call attach_request_source() which will in turn pass a
+   Glib::MainContext to maybe_install_precall_handler(). We override the
+   definition of that method here to make it actuall install the
+   ControlProtocol's handler.
+*/
+
+#define CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL() \
+	void maybe_install_precall_handler (Glib::RefPtr<Glib::MainContext> ctxt) { install_precall_handler (ctxt); }
+
+
 #endif // ardour_control_protocols_h

libs/surfaces/faderport/faderport.h

@@ -162,6 +162,8 @@ class FaderPort : public ARDOUR::ControlProtocol, public AbstractUI<FaderPortReq
 
 	std::list<boost::shared_ptr<ARDOUR::Bundle> > bundles ();
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
   private:
 	boost::shared_ptr<ARDOUR::Stripable> _current_stripable;
 	boost::weak_ptr<ARDOUR::Stripable> pre_master_stripable;

libs/surfaces/faderport8/faderport8.h

@@ -108,6 +108,8 @@ public:
 
 	size_t tx_midi (std::vector<uint8_t> const&) const;
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
 private:
 	void close ();
 

libs/surfaces/generic_midi/generic_midi_control_protocol.h

@@ -128,6 +128,8 @@ public:
 
 	PBD::Signal0<void> ConnectionChange;
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
 private:
 	boost::shared_ptr<ARDOUR::Bundle> _input_bundle;
 	boost::shared_ptr<ARDOUR::Bundle> _output_bundle;

libs/surfaces/launch_control_xl/launch_control_xl.h

@@ -411,6 +411,8 @@ public:
 	void send_bank_switch(bool up);
 	int send_bank_base () const { return _send_bank_base; }
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
 private:
 	bool in_use;
 	TrackMode _track_mode;

libs/surfaces/mackie/mackie_control_protocol.h

@@ -276,6 +276,8 @@ class MackieControlProtocol
 
 	bool stripable_is_locked_to_strip (boost::shared_ptr<ARDOUR::Stripable>) const;
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
   private:
 
 	struct ButtonHandlers {

libs/surfaces/maschine2/maschine2.h

@@ -85,6 +85,8 @@ class Maschine2: public ARDOUR::ControlProtocol, public AbstractUI<Maschine2Requ
 			Studio
 		} Maschine2Type;
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
 	private:
 		void do_request (Maschine2Request*);
 

libs/surfaces/osc/osc.h

@@ -262,6 +262,8 @@ class OSC : public ARDOUR::ControlProtocol, public AbstractUI<OSCUIRequest>
 	std::string get_remote_port () { return remote_port; }
 	void set_remote_port (std::string pt) { remote_port = pt; }
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
   protected:
         void thread_init ();
 	void do_request (OSCUIRequest*);

libs/surfaces/push2/push2.h

@@ -362,6 +362,8 @@ class Push2 : public ARDOUR::ControlProtocol
 
 	libusb_device_handle* usb_handle() const { return handle; }
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
   private:
 	libusb_device_handle *handle;
 	bool in_use;

libs/surfaces/us2400/us2400_control_protocol.h

@@ -216,6 +216,8 @@ class US2400Protocol
 
 	int get_sends_bank ();
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
   protected:
 	// shut down the surface
 	void close();

libs/surfaces/websockets/ardour_websockets.h

@@ -85,6 +85,8 @@ public:
 	/* ControlProtocol */
 	void stripable_selection_changed () {}
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
 protected:
 	/* BaseUI */
 	void thread_init ();

libs/surfaces/wiimote/wiimote.h

@@ -55,6 +55,8 @@ public:
 
 	void stripable_selection_changed () {}
 
+	CONTROL_PROTOCOL_THREADS_NEED_TEMPO_MAP_DECL();
+
 protected:
 	void do_request (WiimoteControlUIRequest*);
 	int start ();