more rational handling of silence when (a) running freeze/export/bounce (b) during sync start

git-svn-id: svn://localhost/ardour2/branches/2.0-ongoing@4864 d708f5d6-7413-0410-9779-e7cbd77b26cf

3 files changed, 16 insertions, 14 deletions

diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 8ca3714666..cba51e2ce3 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -1065,7 +1065,11 @@ class Session : public PBD::StatefulDestructible
 	void process_with_events    (nframes_t);
 	void process_audition       (nframes_t);
 	int  process_export         (nframes_t, ARDOUR::AudioExportSpecification*);
-	
+
+	void block_processing() { g_atomic_int_set (&processing_prohibited, 1); }
+	void unblock_processing() { g_atomic_int_set (&processing_prohibited, 0); }
+	bool processing_blocked() const { return g_atomic_int_get (&processing_prohibited); }
+
 	/* slave tracking */
 
 	static const int delta_accumulator_size = 25;
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index e0221b53cc..567c16d142 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -4135,7 +4135,9 @@ Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t en
 	// any bigger than this seems to cause stack overflows in called functions
 	const nframes_t chunk_size = (128 * 1024)/4;
 
-	g_atomic_int_set (&processing_prohibited, 1);
+	// block all process callback handling
+
+	block_processing ();
 	
 	/* call tree *MUST* hold route_lock */
 	
@@ -4270,7 +4272,7 @@ Session::write_one_audio_track (AudioTrack& track, nframes_t start, nframes_t en
 		free (*i);
 	}
 
-	g_atomic_int_set (&processing_prohibited, 0);
+	unblock_processing ();
 
 	itt.done = true;
 
diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc
index 99615a08b3..31cf3a930d 100644
--- a/libs/ardour/session_process.cc
+++ b/libs/ardour/session_process.cc
@@ -47,12 +47,17 @@ Session::process (nframes_t nframes)
 {
 	_silent = false;
 
+	if (processing_blocked()) {
+		_silent = true;
+		return;
+	}
+
 	if (non_realtime_work_pending()) {
 		if (!transport_work_requested ()) {
 			post_transport ();
 		} 
 	} 
-	
+
 	(this->*process_function) (nframes);
 	
 	{
@@ -82,13 +87,6 @@ Session::no_roll (nframes_t nframes, nframes_t offset)
 		_click_io->silence (nframes, offset);
 	}
 
-	if (g_atomic_int_get (&processing_prohibited)) {
-		for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
-			(*i)->silence (nframes, offset);
-		}
-		return 0;
-	}
-
 	for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
 		
 		if ((*i)->hidden()) {
@@ -866,9 +864,7 @@ Session::maybe_sync_start (nframes_t& nframes, nframes_t& offset)
 		   with any fancy stuff here, just the minimal silence.
 		*/
 
-		g_atomic_int_inc (&processing_prohibited);
-		no_roll (nframes, 0);
-		g_atomic_int_dec_and_test (&processing_prohibited);
+		_silent = true;
 
 		if (Config->get_locate_while_waiting_for_sync()) {
 			if (micro_locate (nframes)) {