From 8dbbc1df5479a27d930df24991a14495931e5bbe Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Fri, 27 Nov 2020 22:13:41 -0700
Subject: [PATCH] library changes to get libtemporal setup at application
 startup

---
 libs/ardour/graph.cc           |  2 ++
 libs/ardour/session_state.cc   | 26 ++++++++++++++------------
 libs/pbd/pbd/rcu.h             | 12 ++++++++++--
 libs/temporal/enums.cc         | 18 +++++++++++++++++-
 libs/temporal/tempo.cc         |  8 ++++++++
 libs/temporal/temporal/tempo.h |  2 ++
 6 files changed, 53 insertions(+), 15 deletions(-)

diff --git a/libs/ardour/graph.cc b/libs/ardour/graph.cc
index d1b1e27c9c..5a08e2c787 100644
--- a/libs/ardour/graph.cc
+++ b/libs/ardour/graph.cc
@@ -28,6 +28,7 @@
 #include "pbd/pthread_utils.h"
 
 #include "temporal/superclock.h"
+#include "temporal/tempo.h"
 
 #include "ardour/audioengine.h"
 #include "ardour/debug.h"
@@ -535,6 +536,7 @@ void
 Graph::setup_thread_local_variables ()
 {
 	Temporal::_thread_sample_rate = _session.sample_rate ();
+	Temporal::TempoMap::fetch ();
 }
 
 void
diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index 9a69f6408f..b998cfa09a 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -1557,6 +1557,20 @@ Session::set_state (const XMLNode& node, int version)
 		goto out;
 	}
 
+	/* need the tempo map setup ASAP */
+
+	if ((child = find_named_node (node, "TempoMap")) == 0) {
+		error << _("Session: XML state has no Tempo Map section") << endmsg;
+		goto out;
+	} else {
+		try {
+			TempoMap::SharedPtr new_map (new TempoMap (*child, version));
+			TempoMap::update (new_map);
+		} catch (...) {
+			goto out;
+		}
+	}
+
 	node.get_property ("name", _name);
 
 	if (node.get_property (X_("sample-rate"), _base_sample_rate)) {
@@ -1645,18 +1659,6 @@ Session::set_state (const XMLNode& node, int version)
 		goto out;
 	}
 
-	if ((child = find_named_node (node, "TempoMap")) == 0) {
-		error << _("Session: XML state has no Tempo Map section") << endmsg;
-		goto out;
-	} else {
-		try {
-			TempoMap::SharedPtr new_map (new TempoMap (*child, version));
-			TempoMap::update (new_map);
-		} catch (...) {
-			goto out;
-		}
-	}
-
 	if ((child = find_named_node (node, "Locations")) == 0) {
 		error << _("Session: XML state has no locations section") << endmsg;
 		goto out;
diff --git a/libs/pbd/pbd/rcu.h b/libs/pbd/pbd/rcu.h
index cdad78325c..8d544a8176 100644
--- a/libs/pbd/pbd/rcu.h
+++ b/libs/pbd/pbd/rcu.h
@@ -144,11 +144,19 @@ template <class T>
 class /*LIBPBD_API*/ SerializedRCUManager : public RCUManager<T>
 {
 public:
-	SerializedRCUManager (T* new_rcu_value)
-	    : RCUManager<T> (new_rcu_value)
+	SerializedRCUManager(T* new_rcu_value)
+		: RCUManager<T>(new_rcu_value)
+		, current_write_old (0)
 	{
 	}
 
+	void init (boost::shared_ptr<T> new_rcu_value) {
+		assert  (*RCUManager<T>::x.m_rcu_value == boost::shared_ptr<T> ());
+
+		boost::shared_ptr<T>* new_spp = new boost::shared_ptr<T> (new_rcu_value);
+		g_atomic_pointer_set (&RCUManager<T>::x.gptr, new_spp);
+	}
+
 	boost::shared_ptr<T> write_copy ()
 	{
 		_lock.lock ();
diff --git a/libs/temporal/enums.cc b/libs/temporal/enums.cc
index 8acb7429a6..0405efd881 100644
--- a/libs/temporal/enums.cc
+++ b/libs/temporal/enums.cc
@@ -27,6 +27,8 @@ using namespace PBD;
 using namespace Temporal;
 using namespace std;
 
+static bool libtemporal_initialized = false;
+
 void
 setup_libtemporal_enums ()
 {
@@ -62,5 +64,19 @@ setup_libtemporal_enums ()
 
 void Temporal::init ()
 {
-	setup_libtemporal_enums ();
+	if (!libtemporal_initialized) {
+		setup_libtemporal_enums ();
+
+
+		/* this should be the main (typically GUI) thread. Normally
+		 * this will be done by some
+		 * Gtkmm2ext::UI::event_loop_precall() but we need to make sure
+		 * that things are set up for this thread before we get started
+		 */
+
+		Temporal::_thread_sample_rate = 44100;
+		TempoMap::init ();
+
+		libtemporal_initialized = true;
+	}
 }
diff --git a/libs/temporal/tempo.cc b/libs/temporal/tempo.cc
index 74763bc0d6..ec065d46cc 100644
--- a/libs/temporal/tempo.cc
+++ b/libs/temporal/tempo.cc
@@ -2877,3 +2877,11 @@ TempoMap::MementoBinder::set_state (XMLNode const & node, int version) const
 	/* now update this thread's view of the current tempo map */
 	fetch ();
 }
+
+void
+TempoMap::init ()
+{
+	SharedPtr new_map (new TempoMap (Tempo (120), Meter (4, 4)));
+	_map_mgr.init (new_map);
+	fetch ();
+}
diff --git a/libs/temporal/temporal/tempo.h b/libs/temporal/temporal/tempo.h
index 50e4b5e39a..79c7a85542 100644
--- a/libs/temporal/temporal/tempo.h
+++ b/libs/temporal/temporal/tempo.h
@@ -619,6 +619,8 @@ class LIBTEMPORAL_API TempoMap : public PBD::StatefulDestructible
 	static thread_local SharedPtr _tempo_map_p;
 	static SerializedRCUManager<TempoMap> _map_mgr;
   public:
+	static void init ();
+
 	static void update_thread_tempo_map() { _tempo_map_p = _map_mgr.reader(); }
 	static SharedPtr use() { assert (_tempo_map_p); return _tempo_map_p; }
 	static SharedPtr fetch() { update_thread_tempo_map(); return use(); }