triggerbox: flesh out Request mechanism

Still no actually active requests

libs/ardour/ardour/triggerbox.h

@@ -28,6 +28,7 @@
 #include <glibmm/threads.h>
 
 #include "pbd/pcg_rand.h"
+#include "pbd/pool.h"
 #include "pbd/properties.h"
 #include "pbd/ringbuffer.h"
 #include "pbd/stateful.h"
@@ -366,6 +367,9 @@ class LIBARDOUR_API TriggerBox : public Processor
 
 	void add_midi_sidechain (std::string const & name);
 
+	void request_reload (int32_t slot);
+	void request_use (int32_t slot, Trigger&);
+
 	enum TriggerMidiMapMode {
 		AbletonPush,
 		SequentialNote,
@@ -386,6 +390,8 @@ class LIBARDOUR_API TriggerBox : public Processor
 	static void scene_bang (uint32_t scene_number);
 	static void scene_unbang (uint32_t scene_number);
 
+	static void init_pool();
+
 	static const int32_t default_triggers_per_box;
 
   private:
@@ -441,11 +447,26 @@ class LIBARDOUR_API TriggerBox : public Processor
 		union {
 			Trigger* trigger;
 		};
+
+		union {
+			int32_t slot;
+		};
+
+		Request (Type t) : type (t) {}
+
+		static MultiAllocSingleReleasePool* pool;
+		static void init_pool();
+
+		void* operator new (size_t);
+		void  operator delete (void* ptr, size_t);
 	};
 
-	typedef PBD::RingBuffer<Request> RequestBuffer;
+	typedef PBD::RingBuffer<Request*> RequestBuffer;
 	RequestBuffer requests;
 
+	void process_requests ();
+	void process_request (Request*);
+
 };
 
 namespace Properties {

libs/ardour/globals.cc

@@ -551,6 +551,7 @@ ARDOUR::init (bool try_optimization, const char* localedir, bool with_gui)
 
 	SessionEvent::init_event_pool ();
 	TransportFSM::Event::init_pool ();
+	TriggerBox::init_pool ();
 
 	Operations::make_operations_quarks ();
 	SessionObject::make_property_quarks ();

libs/ardour/triggerbox.cc

@@ -2214,3 +2214,73 @@ TriggerBox::reconnect_to_default ()
 	_sidechain->input()->nth (0)->disconnect_all ();
 	_sidechain->input()->nth (0)->connect (Config->get_default_trigger_input_port());
 }
+
+MultiAllocSingleReleasePool* TriggerBox::Request::pool;
+
+void
+TriggerBox::init_pool ()
+{
+	/* "indirection" is because the Request struct is private, and so
+	   nobody else can call its ::init_pool() static method.
+	*/
+
+	Request::init_pool ();
+}
+
+void
+TriggerBox::Request::init_pool ()
+{
+	pool = new MultiAllocSingleReleasePool (X_("TriggerBoxRequests"), sizeof (TriggerBox::Request), 1024);
+}
+
+void*
+TriggerBox::Request::operator new (size_t)
+{
+	return pool->alloc();
+ }
+
+void
+TriggerBox::Request::operator delete (void *ptr, size_t /*size*/)
+{
+	return pool->release (ptr);
+}
+
+void
+TriggerBox::request_reload (int32_t slot)
+{
+	Request* r = new Request (Request::Use);
+	r->slot = slot;
+	requests.write (&r, 1);
+}
+
+void
+TriggerBox::request_use (int32_t slot, Trigger& t)
+{
+	Request* r = new Request (Request::Use);
+	r->slot = slot;
+	r->trigger = &t;
+	requests.write (&r, 1);
+}
+
+void
+TriggerBox::process_requests ()
+{
+	Request* r;
+
+	while (requests.read (&r, 1) == 1) {
+		process_request (r);
+	}
+}
+
+void
+TriggerBox::process_request (Request* req)
+{
+	switch (req->type) {
+	case Request::Use:
+		break;
+	case Request::Reload:
+		break;
+	}
+
+	delete req; /* back to the pool, RT-safe */
+}