From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 3 Feb 2015 21:47:17 +0000 (+0200)
Subject: Make route planning threaded
X-Git-Url: http://git.tdb.fi/?p=r2c2.git;a=commitdiff_plain;h=bf321305d7bf65aa5033a835f61370cd48f54619

Make route planning threaded

It can take several seconds in some cases, which would cause an
unacceptable pause in simulation and control.
---

diff --git a/source/libr2c2/trainrouteplanner.cpp b/source/libr2c2/trainrouteplanner.cpp
index 7ee655a..b4f01ab 100644
--- a/source/libr2c2/trainrouteplanner.cpp
+++ b/source/libr2c2/trainrouteplanner.cpp
@@ -14,7 +14,9 @@ using namespace Msp;
 namespace R2C2 {
 
 TrainRoutePlanner::TrainRoutePlanner(Layout &layout):
-	result(PENDING)
+	goal(0),
+	result(PENDING),
+	thread(0)
 {
 	const map<unsigned, Train *> &trains = layout.get_trains();
 	for(map<unsigned, Train *>::const_iterator i=trains.begin(); i!=trains.end(); ++i)
@@ -25,38 +27,40 @@ TrainRoutePlanner::TrainRoutePlanner(Layout &layout):
 	}
 }
 
-void TrainRoutePlanner::plan()
+TrainRoutePlanner::~TrainRoutePlanner()
 {
-	steps.clear();
-	queue.clear();
-	result = PENDING;
+	delete thread;
+}
 
-	queue.push_back(RoutingStep());
-	RoutingStep &start = queue.back();
-	for(vector<TrainRoutingInfo>::iterator i=routed_trains.begin(); i!=routed_trains.end(); ++i)
-		start.trains.push_back(TrainRoutingState(*i));
-	start.update_estimate();
+TrainRoutePlanner::Result TrainRoutePlanner::plan()
+{
+	prepare_plan();
+	create_plan();
+	if(result==PENDING)
+		finalize_plan();
 
-	const RoutingStep *goal = 0;
-	while(!queue.empty())
-	{
-		const RoutingStep &step = get_step();
-		if(step.is_goal())
-		{
-			goal = &step;
-			break;
-		}
+	return result;
+}
 
-		add_steps(step);
-	}
+void TrainRoutePlanner::plan_async()
+{
+	if(thread)
+		throw logic_error("already planning");
+
+	prepare_plan();
+	thread = new PlanningThread(*this);
+}
 
-	if(goal)
+TrainRoutePlanner::Result TrainRoutePlanner::check()
+{
+	if(result==PENDING && goal)
 	{
-		create_routes(*goal);
-		result = COMPLETE;
+		finalize_plan();
+		delete thread;
+		thread = 0;
 	}
-	else
-		result = FAILED;
+
+	return result;
 }
 
 const list<Route *> &TrainRoutePlanner::get_routes_for(const Train &train) const
@@ -84,6 +88,37 @@ const TrainRoutePlanner::RoutingStep &TrainRoutePlanner::get_step()
 	return steps.back();
 }
 
+void TrainRoutePlanner::prepare_plan()
+{
+	steps.clear();
+	queue.clear();
+	goal = 0;
+	result = PENDING;
+
+	queue.push_back(RoutingStep());
+	RoutingStep &start = queue.back();
+	for(vector<TrainRoutingInfo>::iterator i=routed_trains.begin(); i!=routed_trains.end(); ++i)
+		start.trains.push_back(TrainRoutingState(*i));
+	start.update_estimate();
+}
+
+void TrainRoutePlanner::create_plan()
+{
+	while(!queue.empty())
+	{
+		const RoutingStep &step = get_step();
+		if(step.is_goal())
+		{
+			goal = &step;
+			return;
+		}
+
+		add_steps(step);
+	}
+
+	result = FAILED;
+}
+
 void TrainRoutePlanner::add_steps(const RoutingStep &step)
 {
 	list<RoutingStep> new_steps;
@@ -92,7 +127,7 @@ void TrainRoutePlanner::add_steps(const RoutingStep &step)
 	queue.merge(new_steps);
 }
 
-void TrainRoutePlanner::create_routes(const RoutingStep &goal)
+void TrainRoutePlanner::finalize_plan()
 {
 	for(vector<TrainRoutingInfo>::iterator i=routed_trains.begin(); i!=routed_trains.end(); ++i)
 	{
@@ -104,7 +139,7 @@ void TrainRoutePlanner::create_routes(const RoutingStep &goal)
 
 	map<Track *, TrainRouter::SequencePoint *> sequenced_tracks;
 	unsigned sequence = steps.size();
-	for(const RoutingStep *i=&goal; i; i=i->prev)
+	for(const RoutingStep *i=goal; i; i=i->prev)
 		for(vector<TrainRoutingState>::const_iterator j=i->trains.begin(); j!=i->trains.end(); ++j)
 		{
 			Track **history = j->info->track_history;
@@ -166,6 +201,8 @@ void TrainRoutePlanner::create_routes(const RoutingStep &goal)
 				--sequence;
 			}
 		}
+
+	result = COMPLETE;
 }
 
 
@@ -548,4 +585,16 @@ bool TrainRoutePlanner::RoutingStep::operator<(const RoutingStep &other) const
 	return cost_estimate<other.cost_estimate;
 }
 
+
+TrainRoutePlanner::PlanningThread::PlanningThread(TrainRoutePlanner &p):
+	planner(p)
+{
+	launch();
+}
+
+void TrainRoutePlanner::PlanningThread::main()
+{
+	planner.create_plan();
+}
+
 } // namespace R2C2
diff --git a/source/libr2c2/trainrouteplanner.h b/source/libr2c2/trainrouteplanner.h
index f5bbf57..54ecadb 100644
--- a/source/libr2c2/trainrouteplanner.h
+++ b/source/libr2c2/trainrouteplanner.h
@@ -3,6 +3,7 @@
 
 #include <list>
 #include <vector>
+#include <msp/core/thread.h>
 #include <msp/time/timedelta.h>
 #include "trackiter.h"
 #include "trainrouter.h"
@@ -112,23 +113,42 @@ private:
 		bool operator<(const RoutingStep &) const;
 	};
 
+	class PlanningThread: public Msp::Thread
+	{
+	private:
+		TrainRoutePlanner &planner;
+
+	public:
+		PlanningThread(TrainRoutePlanner &);
+
+	private:
+		virtual void main();
+	};
+
 	std::vector<TrainRoutingInfo> routed_trains;
 	std::list<RoutingStep> steps;
 	std::list<RoutingStep> queue;
+	const RoutingStep *goal;
 	Result result;
+	PlanningThread *thread;
 
 public:
 	TrainRoutePlanner(Layout &);
+	~TrainRoutePlanner();
 
-	void plan();
+	Result plan();
+	void plan_async();
+	Result check();
 	Result get_result() { return result; }
 	const std::list<Route *> &get_routes_for(const Train &) const;
 	const std::list<TrainRouter::SequencePoint> &get_sequence_for(const Train &) const;
 private:
 	const TrainRoutingInfo &get_train_info(const Train &) const;
 	const RoutingStep &get_step();
+	void prepare_plan();
+	void create_plan();
 	void add_steps(const RoutingStep &);
-	void create_routes(const RoutingStep &);
+	void finalize_plan();
 };
 
 } // namespace R2C2
diff --git a/source/libr2c2/trainrouter.cpp b/source/libr2c2/trainrouter.cpp
index 1c05f82..bbb87ea 100644
--- a/source/libr2c2/trainrouter.cpp
+++ b/source/libr2c2/trainrouter.cpp
@@ -222,7 +222,7 @@ void TrainRouter::tick(const Time::TimeDelta &dt)
 	if(destination_changed && !planner)
 		start_planning(train.get_layout());
 
-	if(planner && planner->get_result()!=TrainRoutePlanner::PENDING)
+	if(planner && planner->check()!=TrainRoutePlanner::PENDING)
 	{
 		destination_changed = false;
 		if(planner->get_result()==TrainRoutePlanner::COMPLETE)
@@ -494,7 +494,7 @@ void TrainRouter::start_planning(Layout &layout)
 			router->planner = planner;
 		}
 
-	planner->plan();
+	planner->plan_async();
 }