Towards fixing no_roll()

Currently ::roll() may actually be a ::no_roll() under some circumstances.

This can also happen during count-in:
  transport_stopped () == transport_rolling()

and during latency-preroll:
   Global session-transport speed != 0, some tracks already roll,
   read data from disk and feed latent plugins.
   but other non-latent tracks or busses don't roll and still have to
   behave like the switch from no_roll() to roll() has not yet happened.

This changes the game WRT to monitoring as well, previously, Route:roll()
called Route::no_roll_unlocked () for conditions outlined above.
Now Track::no_roll_unlocked is called and in some cases wrongly clears
the buffers before the signal hits the disk-writer. (more work is needed
related to 61f8e53b)

On the upside this also fixes an issue with MidiTrack::no_roll not keeping
a lock while pushing data into the step-edit-ringbuffer.

This is also a step towards consolidating all entry points:
::roll(), ::no_roll(), ::silent_roll() in the Route class.

1 files changed, 7 insertions, 9 deletions

diff --git a/libs/ardour/ardour/route.h b/libs/ardour/ardour/route.h
index c0f2048a18..5376635076 100644
--- a/libs/ardour/ardour/route.h
+++ b/libs/ardour/ardour/route.h
@@ -138,14 +138,11 @@ public:
 
 	virtual void filter_input (BufferSet &) {}
 
-	virtual int roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample,
-	                  int declick, bool& need_butler);
+	int roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample, int declick, bool& need_butler);
 
-	virtual int no_roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample,
-	                     bool state_changing);
+	int no_roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample, bool state_changing);
 
-	virtual int silent_roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample,
-	                         bool& need_butler);
+	int silent_roll (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample, bool& need_butler);
 
 	virtual bool can_record() { return false; }
 
@@ -589,8 +586,8 @@ public:
 
 	virtual void use_captured_sources (SourceList& srcs, CaptureInfos const &) {}
 
-  protected:
-        friend class Session;
+protected:
+	friend class Session;
 
 	void catch_up_on_solo_mute_override ();
 	void set_listen (bool);
@@ -598,6 +595,8 @@ public:
 	void curve_reallocate ();
 	virtual void set_block_size (pframes_t nframes);
 
+	virtual int no_roll_unlocked (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample, bool session_state_changing);
+
 	void fill_buffers_with_input (BufferSet& bufs, boost::shared_ptr<IO> io, pframes_t nframes);
 
 	void passthru (BufferSet&, samplepos_t start_sample, samplepos_t end_sample, pframes_t nframes, int declick, bool gain_automation_ok, bool run_disk_reader);
@@ -747,7 +746,6 @@ private:
 
 	void setup_invisible_processors ();
 
-	void no_roll_unlocked (pframes_t nframes, samplepos_t start_sample, samplepos_t end_sample);
 	pframes_t latency_preroll (pframes_t nframes, samplepos_t& start_sample, samplepos_t& end_sample);
 
 	void reset_instrument_info ();