started re-implementing route reservation

pom.xml

@@ -4,7 +4,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>de.srsoftware</groupId>
 	<artifactId>web4rail</artifactId>
-	<version>1.3.52</version>
+	<version>1.3.53</version>
 	<name>Web4Rail</name>
 	<packaging>jar</packaging>
 	<description>Java Model Railway Control</description>

resources/css/style.css

@@ -77,14 +77,20 @@ svg.Relay rect{
 	fill: white;
 }
 
+svg.allocated polygon,
+svg.allocated rect:not(.sig_a):not(.sig_b){
+	fill: yellow;
+}
+
 svg.locked polygon,
 svg.locked rect:not(.sig_a):not(.sig_b){
-	fill:lime;
+	fill: lime;
 }
 
+.occupied .block,
 svg.occupied polygon,
 svg.occupied rect:not(.sig_a):not(.sig_b){
-	fill:yellow;
+	fill: orange;
 }
 
 svg text{
@@ -232,10 +238,6 @@ svg.straight .right{
 	fill: #ddd !important;
 }
 
-.occupied .block{
-	fill: yellow;
-}
-
 .active circle{
 	fill: #f57900;
 }

resources/logback.xml

@@ -29,7 +29,7 @@
 		<appender-ref ref="STDOUT" />
 	</root>
 	
-	<logger name="de.srsoftware.web4rail" level="INFO" />
+	<logger name="de.srsoftware.web4rail" level="DEBUG" />
 	<logger name="de.srsoftware.web4rail.Application" level="DEBUG" />
 	<logger name="de.srsoftware.web4rail.Route" level="DEBUG" />
 	<logger name="de.srsoftware.web4rail.actions.Action" level="DEBUG" />

src/main/java/de/srsoftware/web4rail/Route.java

@@ -10,6 +10,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Stack;
 import java.util.Vector;
 
 import org.json.JSONArray;
@@ -44,6 +45,7 @@ import de.srsoftware.web4rail.tiles.Contact;
 import de.srsoftware.web4rail.tiles.Shadow;
 import de.srsoftware.web4rail.tiles.Signal;
 import de.srsoftware.web4rail.tiles.Tile;
+import de.srsoftware.web4rail.tiles.Tile.Status;
 import de.srsoftware.web4rail.tiles.Turnout;
 /**
  * A route is a vector of tiles that leads from one block to another.
@@ -53,9 +55,9 @@ import de.srsoftware.web4rail.tiles.Turnout;
  */
 public class Route extends BaseClass {
 	
-	public enum State {
+/*	public enum State {
 		FREE, LOCKED, PREPARED, STARTED;
-	}
+	}*/
 	public static final Logger LOG = LoggerFactory.getLogger(Route.class);
 
 	private static final String ACTIONS = "actions";
@@ -70,7 +72,7 @@ public class Route extends BaseClass {
 	static final String PATH     = "path";
 	static final String SIGNALS  = "signals";
 	static final String TURNOUTS = "turnouts";
-	private State state = State.FREE;
+	//private State state = State.FREE;
 	public static boolean freeBehindTrain = true;
 
 	private static final String ROUTE_START = "route_start";
@@ -79,11 +81,9 @@ public class Route extends BaseClass {
 
 	private static HashMap<Id, String> names = new HashMap<Id, String>(); // maps id to name. needed to keep names during plan.analyze()
 
-//	private BrakeProcessor				   brakeProcessor = null;
 	private HashMap<String,Integer>        brakeTimes = new HashMap<String, Integer>();
 	private ConditionList                  conditions;
 	private Vector<Contact>                contacts;
-	private Context                        context; // this context is passed to actions
 	private boolean                        disabled = false;
 	private Block                          endBlock = null;
 	public  Direction					   endDirection;
@@ -100,7 +100,7 @@ public class Route extends BaseClass {
 		conditions = new ConditionList();
 		conditions.parent(this);
 	}
-		
+	
 	/**
 	 * process commands from the client
 	 * @param params
@@ -121,12 +121,6 @@ public class Route extends BaseClass {
 				plan.stream(t("Removed {}.",route));				
 				return plan.properties(new HashMap<String,String>());
 			case ACTION_PROPS:
-				return route.properties();
-			case ACTION_START:
-				route.set(new Context(route));
-				route.prepare();
-				route.context.clear();
-				
 				return route.properties();
 			case ACTION_UPDATE:
 				return route.update(params,plan);
@@ -204,6 +198,10 @@ public class Route extends BaseClass {
 		turnouts.put(t, s);
 	}
 	
+	public boolean allocateFor(Train newTrain) {
+		return pathState(newTrain,Tile.Status.ALLOCATED);
+	}
+	
 	/**
 	 * checks, whether the route may be used in a given context
 	 * @param context
@@ -333,6 +331,7 @@ public class Route extends BaseClass {
 		ActionList actions = triggeredActions.get(contact.trigger());
 		LOG.debug("Contact has id {} / trigger {} and is assigned with {}",contact.id(),contact.trigger(),isNull(actions)?t("nothing"):actions);
 		if (isNull(actions)) return;
+		Context context = new Context(this).train(train);
 		actions.fire(context,"Route.Contact("+contact.addr()+")");
 	}
 
@@ -373,10 +372,6 @@ public class Route extends BaseClass {
 		return win;
 	}
 	
-	public Context context() {
-		return context.clone();
-	}
-	
 	public void dropBraketimes(String...brakeIds) {
 		for (String brakeId : brakeIds) brakeTimes.remove(brakeId);
 	}
@@ -416,10 +411,10 @@ public class Route extends BaseClass {
 		return disabled;
 	}
 		
-	public boolean isFreeFor(Context context) {
-		PathFinder.LOG.debug("{}.isFreeFor({})",this,context);
+	public boolean isFreeFor(Train newTrain) {
+		PathFinder.LOG.debug("{}.isFreeFor({})",this,newTrain);
 		for (int i=1; i<path.size(); i++) {
-			if (!path.get(i).isFreeFor(context)) {
+			if (!path.get(i).canNeEnteredBy(newTrain)) {
 				PathFinder.LOG.debug("{}.isFreeFor(...) → false",this);
 				return false;
 			}
@@ -627,33 +622,7 @@ public class Route extends BaseClass {
 		}
 		fis.close();
 	}
-		
-	public boolean lock() {
-		return lockIgnoring(null);
-	}
-	
-	public boolean lockIgnoring(Route ignoredRoute) {
-		if (state == State.LOCKED || state == State.PREPARED || state == State.STARTED) return true;
-		LOG.debug("{}.lockIgnoring({})",this,ignoredRoute);
-		HashSet<Tile> ignoredPath = new HashSet<Tile>();
-		if (isSet(ignoredRoute)) ignoredPath.addAll(ignoredRoute.path);
-		for (Tile tile : path) {
-			if (ignoredPath.contains(tile)) continue;
-			try {
-				tile.setRoute(this);
-			} catch (IllegalStateException e) {
-				LOG.debug("{}.lockIgnoring(...) failed at {}, rolling back",this,tile);
-				for (Tile lockedTile : path) { // unlock the same tiles that have been locked before, until we encounter the unlockable tile
-					if (lockedTile == tile) return false;
-					lockedTile.unset(this);
-				}
-				return false;
-			}			
-		}
-		state = State.LOCKED;
-		return true;
-	}
-	
+			
 	public List<Route> multiply(int size) {
 		Vector<Route> routes = new Vector<Route>();
 		for (int i=0; i<size; i++) routes.add(i==0 ? this : this.clone());
@@ -681,12 +650,26 @@ public class Route extends BaseClass {
 		return result;
 	}
 	
-	public boolean prepare() {
-		if (state == State.PREPARED || state == State.STARTED) return true;
+	private boolean pathState(Train newTrain, Status newState) {
+		Stack<Tile> visited = new Stack<>();
+		for (Tile t : path) {
+			if (t.setState(newState,newTrain)) {
+				visited.push(t);
+			} else {
+				while (!visited.isEmpty()) visited.pop().free();
+				return false;
+			}
+		}
+		return true;
+	}
+	
+	public boolean prepareFor(Train newTrain) {
+//		if (state == State.PREPARED || state == State.STARTED) return true;
 		LOG.debug("{}.prepare()",this);
 		ActionList setupActions = triggeredActions.get(ROUTE_SETUP);
-		if (isSet(setupActions) && !setupActions.fire(context,this+".prepare()")) return false;
-		state = State.PREPARED;
+		if (isSet(setupActions) && !setupActions.fire(new Context(newTrain).route(this),this+".prepare()")) return false;
+//		state = State.PREPARED;
+		pathState(newTrain,Tile.Status.LOCKED);
 		return true;
 	}
 	
@@ -760,7 +743,6 @@ public class Route extends BaseClass {
 		LOG.debug("{}.reset()",this);
 		
 		// TODO
-		state = State.FREE;
 		return true;
 	}
 	
@@ -778,13 +760,6 @@ public class Route extends BaseClass {
 		file.close();
 	}
 	
-	public Context set(Context newContext) {
-		LOG.debug("{}.set({})",this,newContext);
-		context = newContext;
-		context.route(this);
-		return context;
-	}
-
 	public void setLast(Turnout.State state) {
 		if (isNull(state) || state == Turnout.State.UNDEF) return;
 		Tile lastTile = path.lastElement();
@@ -810,20 +785,21 @@ public class Route extends BaseClass {
 		return this;
 	}
 
-	public Route.State state(){
-		return state;
-	}
-	
 	public boolean start(Train newTrain) {
-		if (state == State.STARTED) return true;
+//		if (state == State.STARTED) return true;
 		LOG.debug("{}.start()",this);
 		if (isNull(newTrain)) return false; // can't set route's train to null
 		if (isSet(train)) {
 			if (newTrain != train) return false; // can't alter route's train
-		} else train = newTrain; // set new train 
+		} else train = newTrain.setRoute(this); // set new train
+		
 		ActionList startActions = triggeredActions.get(ROUTE_START);
-		if (isSet(startActions) && !startActions.fire(context,this+".start("+train.name()+")")) return false; // start actions failed
-		state = State.STARTED;
+		
+		if (isSet(startActions)) {
+			Context context = new Context(train).route(this);
+			if (!startActions.fire(context,this+".start("+train.name()+")")) return false; // start actions failed
+		}
+//		state = State.STARTED;
 		triggeredContacts.clear();
 		return true;
 	}
@@ -865,9 +841,8 @@ public class Route extends BaseClass {
 					newTrace.add(tile);
 					remainingLength -= tile.length();
 				} else if (Route.freeBehindTrain) {
-					try {
-						tile.unset(this);				
-					} catch (IllegalArgumentException e) {}
+					
+					// TODO
 				} else break;				
 			}
 		}		

src/main/java/de/srsoftware/web4rail/actions/ActionList.java

@@ -88,7 +88,10 @@ public class ActionList extends Action implements Iterable<Action>{
 		
 		for (Action action : actions) {
 			LOG.debug("firing \"{}\"",action);
-			if (!action.fire(context,cause)) return false;			
+			if (!action.fire(context,cause)) {
+				LOG.warn("{} failed",action);
+				return false;			
+			}
 		}
 		return true;
 	}

src/main/java/de/srsoftware/web4rail/conditions/BlockFree.java

@@ -25,7 +25,7 @@ public class BlockFree extends Condition {
 
 	@Override
 	public boolean fulfilledBy(Context context) {
-		return block.isFreeFor(null) != inverted;
+		return block.canNeEnteredBy(null) != inverted;
 	}
 	
 	@Override

src/main/java/de/srsoftware/web4rail/moving/Train.java

@@ -38,12 +38,23 @@ import de.srsoftware.web4rail.tags.Table;
 import de.srsoftware.web4rail.tags.Window;
 import de.srsoftware.web4rail.threads.PathFinder;
 import de.srsoftware.web4rail.tiles.Block;
+import de.srsoftware.web4rail.tiles.Contact;
 import de.srsoftware.web4rail.tiles.Tile;
+import de.srsoftware.web4rail.tiles.Tile.Status;
 
 /**
  * @author Stephan Richter, SRSoftware 2020-2021 * 
  */
 public class Train extends BaseClass implements Comparable<Train> {
+	
+	public interface Listener {
+		enum Signal {
+			STOP
+		}
+		
+		public void on(Signal signal);
+	}
+
 	private static final Logger LOG = LoggerFactory.getLogger(Train.class);
 
 	private static final String CAR_ID  = "carId";
@@ -88,6 +99,8 @@ public class Train extends BaseClass implements Comparable<Train> {
 	private static final String SHUNTING = "shunting";
 	private boolean shunting = false;
 
+	private HashSet<Listener> listeners = new HashSet<Train.Listener>();
+
 	public static Object action(HashMap<String, String> params, Plan plan) throws IOException {
 		String action = params.get(ACTION);
 		if (isNull(action)) return t("No action passed to Train.action!");
@@ -147,10 +160,18 @@ public class Train extends BaseClass implements Comparable<Train> {
 		return t("Unknown action: {}",params.get(ACTION));
 	}
 	
+	public Train add(Car car) {
+		if (isSet(car)) {
+			cars.add(car);
+			car.train(this);
+		}
+		return this;		
+	}
+
 	public void addTag(String tag) {
 		tags.add(tag);
 	}
-
+	
 	private Object addCar(HashMap<String, String> params) {
 		LOG.debug("addCar({})",params);
 		String carId = params.get(CAR_ID);
@@ -161,12 +182,8 @@ public class Train extends BaseClass implements Comparable<Train> {
 		return properties();
 	}
 
-	public Train add(Car car) {
-		if (isSet(car)) {
-			cars.add(car);
-			car.train(this);
-		}
-		return this;		
+	public void addListener(Listener listener) {
+		listeners.add(listener);
 	}
 	
 	public boolean automatic() {
@@ -299,6 +316,11 @@ public class Train extends BaseClass implements Comparable<Train> {
 		return properties();
 	}
 	
+	public void contact(Contact contact) {
+		if (isSet(route)) route.contact(contact);
+	}
+
+	
 	public void coupleWith(Train parkingTrain,boolean swap) {
 		if (isSet(direction) && isSet(parkingTrain.direction) && parkingTrain.direction != direction) parkingTrain.turn();
 		if (swap) {
@@ -384,7 +406,7 @@ public class Train extends BaseClass implements Comparable<Train> {
 	}
 	
 	public void dropTrace() {
-		while (!trace.isEmpty()) trace.removeFirst().setTrain(null);
+		while (!trace.isEmpty()) trace.removeFirst().free();
 	}
 	
 	private Tag faster(int steps) {
@@ -485,8 +507,14 @@ public class Train extends BaseClass implements Comparable<Train> {
 		if (json.has(DIRECTION)) direction = Direction.valueOf(json.getString(DIRECTION));
 		if (json.has(NAME)) name = json.getString(NAME);
 		if (json.has(TAGS))  json.getJSONArray(TAGS ).forEach(elem -> {  tags.add(elem.toString()); });
-		if (json.has(TRACE)) json.getJSONArray(TRACE).forEach(elem -> {  trace.add(plan.get(new Id(elem.toString()), false).setTrain(this)); });
-		if (json.has(BLOCK)) currentBlock = (Block) plan.get(new Id(json.getString(BLOCK)), false).setTrain(this); // do not move this up! during set, other fields will be referenced!
+		if (json.has(TRACE)) json.getJSONArray(TRACE).forEach(elem -> {
+			Tile tile = plan.get(new Id(elem.toString()), false);
+			if (tile.setState(Status.OCCUPIED,this)) trace.add(tile);
+		});
+		if (json.has(BLOCK)) {// do not move this up! during set, other fields will be referenced!
+			currentBlock = (Block) plan.get(new Id(json.getString(BLOCK)), false);
+			currentBlock.setState(Status.OCCUPIED,this); 
+		}
 		if (json.has(LOCOS)) { // for downward compatibility
 			for (Object id : json.getJSONArray(LOCOS)) add(BaseClass.get(new Id(""+id)));	
 		}		
@@ -724,10 +752,10 @@ public class Train extends BaseClass implements Comparable<Train> {
 
 	public void set(Block newBlock) {
 		LOG.debug("{}.set({})",this,newBlock);
-		if (isSet(currentBlock)) currentBlock.setTrain(null);
+		if (isSet(currentBlock)) currentBlock.free();
 		currentBlock = newBlock;
 		if (isSet(currentBlock)) {
-			currentBlock.setTrain(this);
+			currentBlock.setState(Status.OCCUPIED,this);
 			lastBlocks.add(newBlock);
 			if (lastBlocks.size()>32) lastBlocks.remove(0);
 		}
@@ -776,9 +804,9 @@ public class Train extends BaseClass implements Comparable<Train> {
 		return properties();
 	}
 	
-	protected Route setRoute(Route newRoute) {
+	public Train setRoute(Route newRoute) {
 		route = newRoute;
-		return route;
+		return this;
 	}
 	
 	public void setSpeed(int newSpeed) {
@@ -794,9 +822,9 @@ public class Train extends BaseClass implements Comparable<Train> {
 		LOG.debug("old trace: {}",trace);
 
 		trace.removeAll(newTrace);			
-		for (Tile tile : trace) tile.setTrain(null);
+		for (Tile tile : trace) tile.free();
 		trace = newTrace;
-		for (Tile tile : trace) tile.setTrain(this);
+		for (Tile tile : trace) tile.setState(Status.OCCUPIED,this);
 		
 		LOG.debug("new trace of {}: {}",this,trace);
 	}
@@ -835,27 +863,33 @@ public class Train extends BaseClass implements Comparable<Train> {
 
 
 	public void start() {
-		Context context = new Context(this).block(currentBlock).direction(direction);
-		new PathFinder(context) {
+		new PathFinder(this,currentBlock,direction) {
 			
 			@Override
-			public void found(Route r) {
-				// TODO Auto-generated method stub
-				LOG.debug("Route {} prepared for {}",r,Train.this);
+			public void aborted() {
+				LOG.debug("Aborted");
 			}
 			
 			@Override
-			public void locked(Route r) {
+			public void found(Route newRoute) {
 				// TODO Auto-generated method stub
-				LOG.debug("Route {} locked for {}",r,Train.this);
+				LOG.debug("Found route {} for {}",newRoute,Train.this);
+			}
+
+			@Override
+			public void locked(Route newRoute) {
+				// TODO Auto-generated method stub
+				LOG.debug("Locked route {} for {}",newRoute,Train.this);
 			}
 			
 			@Override
-			public void prepared(Route r) {
-				LOG.debug("Route {} prepared for {}",r,Train.this);
-				setRoute(r).start(Train.this);
+			public void prepared(Route newRoute) {
+				LOG.debug("Prepared route {} for {}",newRoute,Train.this);
+				newRoute.start(Train.this);
 			}
-		};
+
+	
+		}.start();
 	}
 
 	public static void startAll() {
@@ -869,7 +903,8 @@ public class Train extends BaseClass implements Comparable<Train> {
 	}
 
 	public Object stopNow() {
-		
+		setSpeed(0);
+		listeners.forEach(listener -> listener.on(Listener.Signal.STOP));
 		return properties();
 	}
 
@@ -911,6 +946,7 @@ public class Train extends BaseClass implements Comparable<Train> {
 	 */
 	public Train turn() {
 		LOG.debug("{}.turn()",this);
+		setSpeed(0);
 		for (Car car : cars) car.turn();
 		Collections.reverse(cars);
 		return reverse();

src/main/java/de/srsoftware/web4rail/threads/ControlUnit.java

@@ -321,7 +321,9 @@ public class ControlUnit extends Thread implements Constants{
 								Thread thread = new Thread() {
 									@Override
 									public void run() {
-										ControlUnit.this.plan.sensor(addr,active);
+										set(false);
+										plan.sensor(addr,active);
+										set(true);
 									}
 								};			
 								thread.setName(Application.threadName("CU.FeedBack("+addr+")"));

src/main/java/de/srsoftware/web4rail/threads/PathFinder.java

@@ -18,71 +18,76 @@ import de.srsoftware.web4rail.tiles.Block;
 /**
  * @author Stephan Richter, SRSoftware 2020-2021 
  */
-public abstract class PathFinder extends BaseClass implements Runnable{
+public abstract class PathFinder extends BaseClass implements Runnable, Train.Listener{
 	public static final Logger LOG = LoggerFactory.getLogger(PathFinder.class);
-	private Context context;
+//	private Context context;
 	private boolean aborted = false;
+	private Direction direction;
+	private Block startBlock;
+	private Train train;
 	
-	public PathFinder(Context context) {
-		this.context = context;
+	public PathFinder(Train train, Block start, Direction direction) {
+		this.train = train;		
+		this.startBlock = start;
+		this.direction = direction;
 	}
 	
 	public void abort() {
 		aborted = true;
+		aborted();
+		LOG.debug("aborted {}",this);
 	}
 
-	private static TreeMap<Integer,List<Route>> availableRoutes(Context context,HashSet<Route> visitedRoutes){
+	private static TreeMap<Integer,List<Route>> availableRoutes(Train train, Block start, Direction startDir, HashSet<Route> visitedRoutes){
 		String inset = "";
 		for (int i=0; i<visitedRoutes.size(); i++) inset+="    ";
 
-		LOG.debug(inset+"PathFinder.availableRoutes({})",context);
-		TreeMap<Integer,List<Route>> availableRoutes = new TreeMap<Integer, List<Route>>();
+		LOG.debug(inset+"PathFinder.availableRoutes({})",visitedRoutes);
 		
 		boolean error = false;
-		Block block = context.block();		
-		if (isNull(block)) {
-			LOG.warn("{} → {}.availableRoutes called without context.block!",inset,Train.class.getSimpleName());
+		if (isNull(start)) {
+			LOG.warn("{} → {}.availableRoutes called without start block!",inset,Train.class.getSimpleName());
 			error = true;
 		}
-		Train train = context.train();
 		if (isNull(train)) {
-			LOG.warn("{}→ {}.availableRoutes called without context.train!",inset,Train.class.getSimpleName());
+			LOG.warn("{}→ {}.availableRoutes called without train!",inset,Train.class.getSimpleName());
 			error = true;
 		}
-		if (error) return availableRoutes;
+		if (error) return new TreeMap<Integer, List<Route>>();
 		
-		Block destination = train.destination();
-		Direction direction = context.direction();
-		if (isSet(direction)) {
-			LOG.debug("{}Looking for {}-bound routes from {}",inset,direction,block);
+		if (isSet(startDir)) {
+			LOG.debug("{}Looking for {}-bound routes from {}",inset,startDir,start);
 		} else {
-			LOG.debug("{}Looking for all routes from {}",inset,block);
+			LOG.debug("{}Looking for all routes from {}",inset,start);
 		}//*/
+		Block destination = train.destination();
 		if (isSet(destination) && visitedRoutes.isEmpty())	LOG.debug("{}- Destination: {}",inset,destination);
 
-		Route currentRoute = context.route();
-		
-		for (Route routeCandidate : block.routes()) {
-			if (routeCandidate.path().firstElement() != block) continue; // Routen, die nicht vom aktuellen Block starten sind bubu
+		//Route currentRoute = context.route();
+		TreeMap<Integer,List<Route>> availableRoutes = new TreeMap<Integer, List<Route>>();
+				
+		for (Route routeCandidate : start.routes()) {
+			if (routeCandidate.path().firstElement() != start) continue; // Routen, die nicht vom aktuellen Block starten sind bubu
 			if (visitedRoutes.contains(routeCandidate)) {
 				LOG.debug("{}→ Candidate {}  would create loop, skipping",inset,routeCandidate.shortName());
 				continue;
 			}
-			if (!routeCandidate.allowed(context)) { 
+			Context c = new Context(train).block(start).direction(startDir);
+			if (!routeCandidate.allowed(c)) { 
 				if (routeCandidate.endBlock() != destination) { // allowance may be overridden by destination
-					LOG.debug("{} not allowed for {}",routeCandidate,context);
+					LOG.debug("{} not allowed for {}",routeCandidate,c);
 					continue; // Zug darf auf Grund einer nicht erfüllten Bedingung nicht auf die Route
 				}
-				LOG.debug("{} not allowed for {} – overridden by selected destination",routeCandidate,context);
+				LOG.debug("{} not allowed for {} – overridden by selected destination",routeCandidate,c);
 			}
 
 			int priority = 0;
-			if (isSet(direction) && routeCandidate.startDirection != direction) { // Route startet entgegen der aktuellen Fahrtrichtung des Zuges 
+			if (isSet(startDir) && routeCandidate.startDirection != startDir) { // Route startet entgegen der aktuellen Fahrtrichtung des Zuges 
 				if (!train.pushPull) continue; // Zug kann nicht wenden
-				if (!block.turnAllowed) continue; // Wenden im Block nicht gestattet
+				if (!start.turnAllowed) continue; // Wenden im Block nicht gestattet
 				priority -= 5;
 			}
-			if (routeCandidate == currentRoute) priority-=10; // möglichst andere Route als zuvor wählen // TODO: den Routen einen "last-used" Zeitstempel hinzufügen, und diesen mit in die Priorisierung einbeziehen
+			//if (routeCandidate == currentRoute) priority-=10; // möglichst andere Route als zuvor wählen // TODO: den Routen einen "last-used" Zeitstempel hinzufügen, und diesen mit in die Priorisierung einbeziehen
 
 			if (isSet(destination)) {
 				if (routeCandidate.endBlock() == destination) { // route goes directly to destination
@@ -90,9 +95,8 @@ public abstract class PathFinder extends BaseClass implements Runnable{
 					priority = 1_000_000;
 				} else {
 					LOG.debug("{}- Candidate: {}",inset,routeCandidate.shortName());
-					Context forwardContext = new Context(train).block(routeCandidate.endBlock()).route(null).direction(routeCandidate.endDirection);
 					visitedRoutes.add(routeCandidate);
-					TreeMap<Integer, List<Route>> forwardRoutes = availableRoutes(forwardContext,visitedRoutes);
+					TreeMap<Integer, List<Route>> forwardRoutes = availableRoutes(train, routeCandidate.endBlock(), routeCandidate.endDirection, visitedRoutes);
 					visitedRoutes.remove(routeCandidate);
 					if (forwardRoutes.isEmpty()) continue; // the candidate does not lead to a block, from which routes to the destination exist
 					Entry<Integer, List<Route>> entry = forwardRoutes.lastEntry();
@@ -110,7 +114,7 @@ public abstract class PathFinder extends BaseClass implements Runnable{
 			routeSet.add(routeCandidate);
 			if (routeCandidate.endBlock() == destination) break; // direct connection to destination discovered, quit search
 		}
-		if (!availableRoutes.isEmpty())	LOG.debug("{}→ Routes from {}: {}",inset,block,availableRoutes.isEmpty()?"none":"");
+		if (!availableRoutes.isEmpty())	LOG.debug("{}→ Routes from {}: {}",inset,start,availableRoutes.isEmpty()?"none":"");
 		for (Entry<Integer, List<Route>> entry : availableRoutes.entrySet()) {
 			LOG.debug("{} - Priority {}:",inset,entry.getKey());
 			for (Route r : entry.getValue()) {
@@ -122,19 +126,20 @@ public abstract class PathFinder extends BaseClass implements Runnable{
 	
 	public Route chooseRoute() {
 		LOG.debug("PathFinder.chooseRoute()");
-		TreeMap<Integer, List<Route>> availableRoutes = availableRoutes(context,new HashSet<Route>());
+		HashSet<Route> visitedRoutes = new HashSet<Route>();
+		TreeMap<Integer, List<Route>> availableRoutes = availableRoutes(train, startBlock, direction,visitedRoutes);
 		while (!availableRoutes.isEmpty()) {
 			LOG.debug("availableRoutes: {}",availableRoutes);
 			Entry<Integer, List<Route>> entry = availableRoutes.lastEntry();
 			List<Route> preferredRoutes = entry.getValue();
 			LOG.debug("preferredRoutes: {}",preferredRoutes);
 			Route selectedRoute = preferredRoutes.get(random.nextInt(preferredRoutes.size()));
-			if (selectedRoute.isFreeFor(context.route(selectedRoute))) {
+			if (selectedRoute.isFreeFor(train)) {
 				LOG.debug("Chose \"{}\" with priority {}.",selectedRoute,entry.getKey());
 				return selectedRoute;
 			}
 		
-			LOG.debug("Selected route \"{}\" is not free for {}",selectedRoute,context);
+			LOG.debug("Selected route \"{}\" is not free for {}",selectedRoute,train);
 			preferredRoutes.remove(selectedRoute);
 			if (preferredRoutes.isEmpty()) availableRoutes.remove(availableRoutes.lastKey());
 		}
@@ -142,17 +147,17 @@ public abstract class PathFinder extends BaseClass implements Runnable{
 	}
 
 	@Override
-	public void run() {
+	public void run() {		
 		while (true) {
-			Route route = chooseRoute();
 			if (aborted) return;
+			Route route = chooseRoute();
 			if (isSet(route)) {
 				found(route);
 				if (aborted) return;
-				if (route.lock()) {
+				if (route.allocateFor(train)) {
 					locked(route);
 					if (aborted) return;
-					if (route.prepare()) {
+					if (route.prepareFor(train)) {
 						prepared(route);
 						return;
 					}
@@ -162,7 +167,24 @@ public abstract class PathFinder extends BaseClass implements Runnable{
 		}
 	}
 	
+	public abstract void aborted();
 	public abstract void locked(Route r);
 	public abstract void found(Route r);
 	public abstract void prepared(Route r);
+	
+	@Override
+	public void on(Signal signal) {
+		switch (signal) {
+		case STOP:
+			abort();
+			break;
+		}
+	}
+	
+	public void start() {
+		train.addListener(this);
+		Thread thread = new Thread(this);
+		thread.setName("Pathfinder("+train+")");
+		thread.start();
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/Block.java

@@ -146,10 +146,17 @@ public abstract class Block extends StretchableTile{
 		return t("Trigger contact to learn new contact");
 	}
 	
+	@Override
+	public boolean canNeEnteredBy(Train newTrain) {
+		if (!super.canNeEnteredBy(newTrain)) return false;
+		if (parkedTrains.isEmpty()) return true;
+		return isNull(newTrain) ? false : newTrain.isShunting(); // block contains train(s), thus it is only free for shunting train
+	}
+	
 	@Override
 	protected HashSet<String> classes() {
 		HashSet<String> classes = super.classes();
-		if (!parkedTrains.isEmpty()) classes.add(OCCUPIED);
+		if (!parkedTrains.isEmpty()) classes.add(Status.OCCUPIED.toString());
 		return classes;
 	}
 	
@@ -229,14 +236,6 @@ public abstract class Block extends StretchableTile{
 		return 1+internalContacts.indexOf(contact);
 	}
 	
-	@Override
-	public boolean isFreeFor(Context context) {
-		if (!super.isFreeFor(context)) return false;
-		if (parkedTrains.isEmpty()) return true;
-		Train t = isSet(context) ? context.train() : null;
-		return isSet(t) ? t.isShunting() : false; // block contains train(s), thus it is olny free for shunting train
-	}
-		
 	@Override
 	public JSONObject json() {
 		JSONObject json = super.json();
@@ -358,7 +357,6 @@ public abstract class Block extends StretchableTile{
 		super.removeChild(child);
 		internalContacts.remove(child);
 		if (parkedTrains.remove(child)) plan.place(this);		
-		if (train == child) setTrain(null);
 	}
 	
 	public void removeContact(BlockContact blockContact) {

src/main/java/de/srsoftware/web4rail/tiles/BlockContact.java

@@ -27,11 +27,6 @@ public class BlockContact extends Contact {
 		return new Id(block.name+":"+block.indexOf(this));
 	}
 		
-	@Override
-	public Route route() {
-		return ((Block)parent()).route();
-	}
-	
 	@Override
 	public Tag tag(Map<String, Object> replacements) throws IOException {
 		return ((Block)parent()).tag(replacements);

src/main/java/de/srsoftware/web4rail/tiles/Bridge.java

@@ -9,7 +9,6 @@ import org.json.JSONObject;
 import de.srsoftware.tools.Tag;
 import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
-import de.srsoftware.web4rail.Route;
 import de.srsoftware.web4rail.moving.Train;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Window;
@@ -42,6 +41,12 @@ public abstract class Bridge extends Tile {
 	
 	protected abstract Connector connector();
 	
+	@Override
+	public void free() {
+		if (isSet(counterpart) && counterpart.train != null) counterpart.free();
+		super.free();
+	}
+	
 	@Override
 	public JSONObject json() {
 		JSONObject json = super.json();
@@ -63,16 +68,10 @@ public abstract class Bridge extends Tile {
 	}
 	
 	@Override
-	public Tile setRoute(Route route) {
-		super.setRoute(route);
-		if (isSet(counterpart) && counterpart.route != route) counterpart.setRoute(route);
-		return this;
-	}
-	
-	public Tile setTrain(Train train) {
-		super.setTrain(train);
-		if (isSet(counterpart) && counterpart.train != train) counterpart.setTrain(train);
-		return this;
+	public boolean setState(Status newState, Train newTrain) {
+		if (train == newTrain && is(newState)) return true;
+		if (!super.setState(newState,newTrain)) return false;		
+		return isNull(counterpart) ? true : counterpart.setState(newState,newTrain);		
 	}
 	
 	@Override
@@ -109,11 +108,4 @@ public abstract class Bridge extends Tile {
 		if (isNull(counterpart)) tag.clazz(tag.get("class")+" disconnected");
 		return tag;
 	}
-	
-	@Override
-	public Tile unset(Route oldRoute) {
-		super.unset(oldRoute);
-		if (isSet(counterpart) && isSet(counterpart.route)) counterpart.unset(oldRoute);
-		return this;
-	}
 }

src/main/java/de/srsoftware/web4rail/tiles/Contact.java

@@ -16,7 +16,6 @@ import org.slf4j.LoggerFactory;
 import de.srsoftware.tools.Tag;
 import de.srsoftware.web4rail.Application;
 import de.srsoftware.web4rail.BaseClass;
-import de.srsoftware.web4rail.Route;
 import de.srsoftware.web4rail.actions.Action;
 import de.srsoftware.web4rail.actions.ActionList;
 import de.srsoftware.web4rail.tags.Fieldset;
@@ -85,12 +84,12 @@ public class Contact extends Tile{
 			LOG.debug("{} activated.",this);
 			state = true;
 			if (isSet(timer)) timer.abort();
-			Route route = route();
-			Context context = isSet(route) ? route.context().contact(this) : new Context(this);
-			
-			if (isSet(route)) route.traceTrainFrom(this);
+			Context context = new Context(this);
+			if (isSet(train)) {
+				train.contact(this);
+				context.train(train);
+			}
 			actions.fire(context,"Contact("+addr+")");
-			if (isSet(route)) route.contact(this);
 			
 			for (Listener listener : listeners) listener.fired("Contact("+addr+")");
 			

src/main/java/de/srsoftware/web4rail/tiles/Tile.java

@@ -40,12 +40,27 @@ import de.srsoftware.web4rail.threads.PathFinder;
  *
  */
 public abstract class Tile extends BaseClass implements Comparable<Tile>{
+	public enum Status{
+		FREE("free"),
+		ALLOCATED("allocated"),
+		LOCKED("locked"),
+		OCCUPIED("occupied");
+
+		private String tx;
+
+		Status(String s) {
+			tx = s;
+		}
+		
+		@Override
+		public String toString() {
+			return tx;
+		}
+	}
 	protected static Logger LOG = LoggerFactory.getLogger(Tile.class);	
 	private static int DEFAUT_LENGTH = 100; // 10cm
 	
 	private   static final String LENGTH     = "length";
-	private   static final String LOCKED     = "locked";
-	protected static final String OCCUPIED   = "occupied";
 	private   static final String ONEW_WAY   = "one_way";
 	private   static final String POS        = "pos";
 	private   static final String TYPE       = "type";
@@ -56,8 +71,8 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 	private   boolean         isTrack   = true;
 	private   int             length    = DEFAUT_LENGTH;
 	protected Direction       oneWay    = null;
-	protected Route           route     = null;
 	private   TreeSet<Route>  routes    = new TreeSet<>((r1,r2)->r1.toString().compareTo(r2.toString()));
+	private   Status		  status 	= Status.FREE;
 	protected Train           train     = null;	
 	public    Integer         x         = null;
 	public    Integer         y         = null;
@@ -65,13 +80,38 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 	public void add(Route route) {
 		this.routes.add(route);
 	}
+	
+	public boolean canNeEnteredBy(Train newTrain) {
+		PathFinder.LOG.debug("{}.canNeEnteredBy({})",this,newTrain);
+		if (disabled) {
+			PathFinder.LOG.debug("{} is disabled!",this);
+			return false;
+		}
+		
+		if (isNull(train)) {
+			PathFinder.LOG.debug("→ free");
+			return true;
+		}
+
+		if (newTrain == train) { // during train.reserveNext, we may encounter, parts, that are already reserved by the respective train, but having another route. do not compare routes in that case!
+			PathFinder.LOG.debug("already reserved by {} → true",train);
+			return true;
+		}
+
+		if (isSet(newTrain) && newTrain.isShunting()) {
+			PathFinder.LOG.debug("occupied by {}. Allowed for shunting {}",train,newTrain);
+			return true;
+		}
+			
+		PathFinder.LOG.debug("occupied by {} → false",train);				
+		return false;
+	}
 
 	protected HashSet<String> classes(){
 		HashSet<String> classes = new HashSet<String>();
 		classes.add("tile");
-		classes.add(getClass().getSimpleName());
-		if (isSet(route)) classes.add(LOCKED);
-		if (isSet(train)) classes.add(OCCUPIED);
+		classes.add(getClass().getSimpleName());		
+		if (!is(Status.FREE)) classes.add(status.toString());
 		if (disabled)     classes.add(DISABLED);
 		return classes;
 	}
@@ -96,6 +136,11 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 		return new HashMap<>();
 	}
 	
+	public void free() {
+		train = null;
+		status = Status.FREE;
+	}
+	
 	public int height() {
 		return 1;
 	}
@@ -115,58 +160,18 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 		if (tile instanceof TileWithShadow) ((TileWithShadow)tile).placeShadows();
 		plan.place(tile);
 	}
-
-	public boolean isFreeFor(Context context) {
-		PathFinder.LOG.debug("{}.isFreeFor({})",this,context);
-		if (disabled) {
-			PathFinder.LOG.debug("{} is disabled!",this);
-			return false;
-		}
-		if (isNull(context)) {
-			if (isSet(train)) {
-				PathFinder.LOG.debug("{} is occupied by {}",this,train);
-				return false;
-			}
-			if (isSet(route)) {
-				PathFinder.LOG.debug("{} is occupied by {}",this,route);
-				return false;				
-			}
-		}
-		if (isSet(train)) {
-			Train contextTrain = context.train();
-			boolean free = train == contextTrain; // during train.reserveNext, we may encounter, parts, that are already reserved by the respective train, but having another route. do not compare routes in that case!
-			if (free) {
-				PathFinder.LOG.debug("already reserved by {} → true",train);
-			} else {
-				if (isSet(contextTrain) && contextTrain.isShunting()) {
-					PathFinder.LOG.debug("occupied by {}. Allowed for shunting {}",train,contextTrain);
-					free = true;
-				} else PathFinder.LOG.debug("occupied by {} → false",train);				
-			}
-			return free;
-		}
-		
-		// if we get here, the tile is not occupied by a train, but reserved by a route, yet. thus, the tile is not available for another route
-		if (isSet(route) && route != context.route()) {
-			PathFinder.LOG.debug("reserved by other route: {}",route);
-			if (isSet(route.train())) {				
-				if (route.train() == context.train()) {
-					PathFinder.LOG.debug("that route is used by {}, which is also requesting this tile → true",route.train());
-					return true;
-				}
-			}
-			PathFinder.LOG.debug("{}.route.train = {} → false",this,route.train());
-			return false;
+	
+	public boolean is(Status...states) {
+		for (Status s: states) {
+			if (status == s) return true;
 		}
-		PathFinder.LOG.debug("free");
-		return true;
+		return false;
 	}
-		
+
 	public JSONObject json() {
 		JSONObject json = super.json();
 		json.put(TYPE, getClass().getSimpleName());
 		if (isSet(x) && isSet(y)) json.put(POS, new JSONObject(Map.of(X,x,Y,y)));
-		if (isSet(route))     json.put(ROUTE, route.id());
 		if (isSet(oneWay))    json.put(ONEW_WAY, oneWay);
 		if (disabled)         json.put(DISABLED, true);
 		if (isSet(train))     json.put(REALM_TRAIN, train.id());
@@ -242,7 +247,7 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 	protected void noTrack() {
 		isTrack  = false;
 	}
-		
+	
 	public Tile position(int x, int y) {
 		this.x = x;
 		this.y = y;
@@ -256,16 +261,9 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 	@Override
 	protected Window properties(List<Fieldset> preForm, FormInput formInputs, List<Fieldset> postForm) {
 		Fieldset fieldset = null;
-
-		if (isSet(route)) {
-			fieldset = new Fieldset(t("Route"));
-			route.link("p",t("Locked by {}",route)).addTo(fieldset);
-		}
 		
 		if (isSet(train)) {
-			if (isSet(fieldset)) {
-				fieldset.children().firstElement().content(" / "+t("Train"));
-			} else fieldset = new Fieldset(t("Train"));
+			fieldset = new Fieldset(t("Train"));
 			train.link("span", t("Train")+":"+NBSP+train+NBSP).addTo(fieldset);
 			if (isSet(train.route())) {
 				train.button(t("stop"), Map.of(ACTION,ACTION_STOP)).addTo(fieldset);
@@ -352,10 +350,6 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 		}
 		return line;
 	}
-
-	public Route route() {
-		return route;
-	}
 	
 	public TreeSet<Route> routes() {
 		return routes;
@@ -370,24 +364,16 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 		file.close();
 	}
 	
-	public Tile setTrain(Train newTrain) {
-		LOG.debug("{}.setTrain({})",this,newTrain);
-		if (newTrain == train) return this; // nothing to update
-		this.train = newTrain;		
-		return plan.place(this);
-	}	
-
-	public Tile setRoute(Route lockingRoute) {
-		LOG.debug("{}.setRoute({})",this,lockingRoute);
-		if (isNull(lockingRoute)) throw new NullPointerException();
-		if (isSet(route)) {
-			if (route == lockingRoute) return this; // nothing changed
-			throw new IllegalStateException(this.toString()); // tile already locked by other route
-		}
-		route = lockingRoute;
-		return plan.place(this);
+	public boolean setState(Status newState,Train newTrain) {
+		if (isNull(newTrain)) return false;
+		if (isSet(train) && newTrain != train) return false; // already locked by other train		
+		if (is(Status.OCCUPIED,newState)) return true; // do not downgrade occupied tiles, accept current state
+		train = newTrain;
+		status = newState;
+		plan.place(this);
+		return true;
 	}
-
+	
 	public Tag tag(Map<String,Object> replacements) throws IOException {
 		int width = 100*width();
 		int height = 100*height();
@@ -477,7 +463,6 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 		if (child instanceof Route) routes.remove(child);
 		
 		if (child == train) train = null;
-		if (child == route) route = null;
 		super.removeChild(child);
 		plan.place(this);
 	}
@@ -487,22 +472,6 @@ public abstract class Tile extends BaseClass implements Comparable<Tile>{
 		plan.place(this);
 	}
 	
-	public void unlock() {
-		route = null;
-		train = null;
-		plan.place(this);
-	}
-	
-	public Tile unset(Route oldRoute) {
-		LOG.debug("{}.unset({})",this,oldRoute);
-		if (route == null) return this;
-		if (route == oldRoute) {
-			route = null;			
-			return plan.place(this);
-		}
-		throw new IllegalArgumentException(t("{} not occupied by {}!",this,oldRoute));
-	}
-
 	public Tile update(HashMap<String, String> params) {
 		LOG.debug("{}.update({})",getClass().getSimpleName(),params);
 		String oneWayDir = params.get("oneway");

src/main/java/de/srsoftware/web4rail/tiles/Turnout.java

@@ -159,7 +159,7 @@ public abstract class Turnout extends Tile implements Device{
 	}
 	
 	public Reply state(State newState) {
-		if (train != null && newState != state) return new Reply(415, t("{} locked by {}!",this,train));
+		if (is(Status.LOCKED,Status.OCCUPIED) && newState != state) return new Reply(415, t("{} locked by {}!",this,train));
 		if (address == 0) { 
 			state = newState;
 			plan.place(this);

src/main/java/de/srsoftware/web4rail/tiles/TurnoutL.java

@@ -16,8 +16,8 @@ public abstract class TurnoutL extends Turnout {
 	public Object click(boolean shift) throws IOException {
 		Object o = super.click(shift);
 		if (!shift) {
-			if (route != null) {
-				plan.stream(t("{} is locked by {}!",this,route)); 
+			if (isSet(train)) {
+				plan.stream(t("{} is locked by {}!",this,train)); 
 			} else state(state == State.STRAIGHT ? State.LEFT : State.STRAIGHT);
 		}
 		return o;

src/main/java/de/srsoftware/web4rail/tiles/TurnoutR.java

@@ -16,8 +16,8 @@ public abstract class TurnoutR extends Turnout {
 	public Object click(boolean shift) throws IOException {
 		Object o = super.click(shift);
 		if (!shift) {
-			if (route != null) {
-				plan.stream(t("{} is locked by {}!",this,route)); 
+			if (isSet(train)) {
+				plan.stream(t("{} is locked by {}!",this,train)); 
 			} else state(state == State.STRAIGHT ? State.RIGHT : State.STRAIGHT);
 		}
 		return o;