Railsim: Moving blocks & Deadlock avoidance (#3075)

* first step to move reroute and link request into one method

* prepare test and enum for moving blocks

* start restructure rail resources

* add approved dist to state, prepare some restructuring

* change reservation logic to be based on distance, no exceptions for now, but slight difference in some tests still need fixing

* disposition can now give an approved speed, update speed calculation to include approved speed from disposition, fixes the failing tests

* overhaul of the resource management, removed completely from RailLink and put into separate classes

* change resource interfaces to be distance based as well

* use current train position for checking reservation distance

* worked on moving block implementation, still WIP

* worked on moving block implementation, still WIP

* worked on moving block implementation, still WIP

* add track number to reservation interface, this will allow for more fine-grained control by disposition

* reworked track assignment in moving block

* worked on resources, test partially working now

* moving block train following test now working, prepare to add more tests and scenarion

* add a multi-track test for moving block

* add case when dist is 0 to calc target speed

* adding another network and test case

* small fixed, more complex mixed test case now working

* fixed situation where train blocks a link that has the same length as itself, all moving block tests now working

* prepare interfaces and network for deadlock tests

* worked on DeadlockAvoidance interface and tests

* allow to specify if one track for the opposite direction always needs to be reserved

* implemented non blocking reserve mode for fixed blocks as well, improved interfaces, update tests

* improved interfaces, first draft for simple deadlock avoidance

* tests for simple deadlock avoidance

* update deadlock tests, improve network

* added events for stuck trains, reworked dead lock avoidance interface and simple strategy

* update test cases, improve deadlock avoidance

* fixed dead lock avoidance for moving blocks, enabled re-routing again, but still wip

* deadlock avoidance checks for re-routing, fixed remaining issues in tests

* add two more deadlock tests

* update to junit5

contribs/railsim/pom.xml

@@ -12,6 +12,11 @@
 	<artifactId>railsim</artifactId>
 	<dependencies>
 
+		<dependency>
+			<groupId>it.unimi.dsi</groupId>
+			<artifactId>fastutil</artifactId>
+		</dependency>
+
 		<dependency>
 			<groupId>org.assertj</groupId>
 			<artifactId>assertj-core</artifactId>

contribs/railsim/src/main/java/ch/sbb/matsim/contrib/railsim/RailsimUtils.java

@@ -20,12 +20,14 @@
 package ch.sbb.matsim.contrib.railsim;
 
 import ch.sbb.matsim.contrib.railsim.config.RailsimConfigGroup;
+import ch.sbb.matsim.contrib.railsim.qsimengine.resources.ResourceType;
 import org.matsim.api.core.v01.network.Link;
 import org.matsim.vehicles.VehicleType;
 
 import java.math.BigDecimal;
 import java.math.RoundingMode;
 
+
 /**
  * Utility class for working with Railsim and its specific attributes.
  *
@@ -40,6 +42,7 @@ public final class RailsimUtils {
 	public static final String LINK_ATTRIBUTE_MINIMUM_TIME = "railsimMinimumTime";
 	public static final String VEHICLE_ATTRIBUTE_ACCELERATION = "railsimAcceleration";
 	public static final String VEHICLE_ATTRIBUTE_DECELERATION = "railsimDeceleration";
+	public static final String RESOURCE_TYPE = "railsimResourceType";
 
 	private RailsimUtils() {
 	}
@@ -155,4 +158,19 @@ public static void setTrainAcceleration(VehicleType vehicle, double acceleration
 		vehicle.getAttributes().putAttribute(VEHICLE_ATTRIBUTE_ACCELERATION, acceleration);
 	}
 
+	/**
+	 * Return the resource type for a link, if not set, fixed block is assumed.
+	 */
+	public static ResourceType getResourceType(Link link) {
+		Object attr = link.getAttributes().getAttribute(RESOURCE_TYPE);
+		return attr != null ? ResourceType.valueOf(attr.toString()) : ResourceType.fixedBlock;
+	}
+
+	/**
+	 * Sets the resource type for the link.
+	 */
+	public static void setResourceType(Link link, ResourceType type) {
+		link.getAttributes().putAttribute(RESOURCE_TYPE, type.toString());
+	}
+
 }

contribs/railsim/src/main/java/ch/sbb/matsim/contrib/railsim/analysis/RailsimCsvWriter.java

@@ -45,15 +45,14 @@ private RailsimCsvWriter() {
 	 * Write {@link RailsimLinkStateChangeEvent} to a csv file.
 	 */
 	public static void writeLinkStatesCsv(List<RailsimLinkStateChangeEvent> events, String filename) throws UncheckedIOException {
-		String[] header = {"link", "time", "state", "vehicle", "track"};
+		String[] header = {"link", "time", "state", "vehicle"};
 
 		try (CSVPrinter csv = new CSVPrinter(IOUtils.getBufferedWriter(filename), CSVFormat.DEFAULT.builder().setHeader(header).build())) {
 			for (RailsimLinkStateChangeEvent event : events) {
 				csv.print(event.getLinkId().toString());
 				csv.print(event.getTime());
 				csv.print(event.getState().toString());
 				csv.print(event.getVehicleId() != null ? event.getVehicleId().toString() : "");
-				csv.print(event.getTrack());
 				csv.println();
 			}
 		} catch (IOException e) {

contribs/railsim/src/main/java/ch/sbb/matsim/contrib/railsim/eventmappers/RailsimLinkStateChangeEventMapper.java

@@ -20,7 +20,7 @@
 package ch.sbb.matsim.contrib.railsim.eventmappers;
 
 import ch.sbb.matsim.contrib.railsim.events.RailsimLinkStateChangeEvent;
-import ch.sbb.matsim.contrib.railsim.qsimengine.TrackState;
+import ch.sbb.matsim.contrib.railsim.qsimengine.resources.ResourceState;
 import org.matsim.api.core.v01.Id;
 import org.matsim.api.core.v01.events.GenericEvent;
 import org.matsim.api.core.v01.network.Link;
@@ -38,8 +38,7 @@ public RailsimLinkStateChangeEvent apply(GenericEvent event) {
 			event.getTime(),
 			asId(attributes.get(RailsimLinkStateChangeEvent.ATTRIBUTE_LINK), Link.class),
 			asId(attributes.get(RailsimLinkStateChangeEvent.ATTRIBUTE_VEHICLE), Vehicle.class),
-			TrackState.valueOf(attributes.get(RailsimLinkStateChangeEvent.ATTRIBUTE_STATE)),
-			Integer.parseInt(attributes.get(RailsimLinkStateChangeEvent.ATTRIBUTE_TRACK))
+			ResourceState.valueOf(attributes.get(RailsimLinkStateChangeEvent.ATTRIBUTE_STATE))
 		);
 	}
 

contribs/railsim/src/main/java/ch/sbb/matsim/contrib/railsim/events/RailsimDetourEvent.java

@@ -39,17 +39,17 @@ public class RailsimDetourEvent extends Event implements HasVehicleId {
 	public static final String EVENT_TYPE = "railsimDetourEvent";
 
 	private final Id<Vehicle> vehicleId;
-	private final Id<Link> entry;
-	private final Id<Link> exit;
+	private final Id<Link> start;
+	private final Id<Link> end;
 	private final List<Id<Link>> detour;
 	private final Id<TransitStopFacility> newStop;
 
-	public RailsimDetourEvent(double time, Id<Vehicle> vehicleId, Id<Link> entry, Id<Link> exit, List<Id<Link>> detour,
+	public RailsimDetourEvent(double time, Id<Vehicle> vehicleId, Id<Link> start, Id<Link> end, List<Id<Link>> detour,
 							  Id<TransitStopFacility> newStop) {
 		super(time);
 		this.vehicleId = vehicleId;
-		this.entry = entry;
-		this.exit = exit;
+		this.start = start;
+		this.end = end;
 		this.detour = detour;
 		this.newStop = newStop;
 	}
@@ -70,8 +70,8 @@ public Map<String, String> getAttributes() {
 		Map<String, String> attributes = super.getAttributes();
 
 		attributes.put(HasVehicleId.ATTRIBUTE_VEHICLE, vehicleId.toString());
-		attributes.put("entry", entry.toString());
-		attributes.put("exit", exit.toString());
+		attributes.put("start", start.toString());
+		attributes.put("end", end.toString());
 		attributes.put("detour", detour.stream().map(Object::toString).collect(Collectors.joining(",")));
 		attributes.put("newStop", Objects.toString(newStop));
 

contribs/railsim/src/main/java/ch/sbb/matsim/contrib/railsim/events/RailsimLinkStateChangeEvent.java

@@ -19,7 +19,7 @@
 
 package ch.sbb.matsim.contrib.railsim.events;
 
-import ch.sbb.matsim.contrib.railsim.qsimengine.TrackState;
+import ch.sbb.matsim.contrib.railsim.qsimengine.resources.ResourceState;
 import org.matsim.api.core.v01.Id;
 import org.matsim.api.core.v01.events.Event;
 import org.matsim.api.core.v01.events.HasLinkId;
@@ -30,26 +30,23 @@
 import java.util.Map;
 
 /**
- * Event thrown when the {@link ch.sbb.matsim.contrib.railsim.qsimengine.TrackState} of a {@link Link} changes.
+ * Event thrown when the {@link ResourceState} of a {@link Link} changes.
  */
 public final class RailsimLinkStateChangeEvent extends Event implements HasLinkId, HasVehicleId {
 
 	public static final String EVENT_TYPE = "railsimLinkStateChangeEvent";
 
 	public static final String ATTRIBUTE_STATE = "state";
-	public static final String ATTRIBUTE_TRACK = "track";
 
 	private final Id<Link> linkId;
 	private final Id<Vehicle> vehicleId;
-	private final TrackState state;
-	private final int track;
+	private final ResourceState state;
 
-	public RailsimLinkStateChangeEvent(double time, Id<Link> linkId, Id<Vehicle> vehicleId, TrackState state, int track) {
+	public RailsimLinkStateChangeEvent(double time, Id<Link> linkId, Id<Vehicle> vehicleId, ResourceState state) {
 		super(time);
 		this.linkId = linkId;
 		this.vehicleId = vehicleId;
 		this.state = state;
-		this.track = track;
 	}
 
 	@Override
@@ -67,21 +64,16 @@ public Id<Vehicle> getVehicleId() {
 		return this.vehicleId;
 	}
 
-	public TrackState getState() {
+	public ResourceState getState() {
 		return state;
 	}
 
-	public int getTrack() {
-		return track;
-	}
-
 	@Override
 	public Map<String, String> getAttributes() {
 		Map<String, String> attr = super.getAttributes();
 		attr.put(ATTRIBUTE_LINK, this.linkId.toString());
 		attr.put(ATTRIBUTE_VEHICLE, this.vehicleId.toString());
 		attr.put(ATTRIBUTE_STATE, this.state.toString());
-		attr.put(ATTRIBUTE_TRACK, String.valueOf(track));
 		return attr;
 	}
 }

contribs/railsim/src/main/java/ch/sbb/matsim/contrib/railsim/qsimengine/FuzzyUtils.java

@@ -24,7 +24,12 @@
  */
 final class FuzzyUtils {
 
-	private static final double EPSILON = 1E-5;
+	/**
+	 * The allowed deviation for small numbers to be considered equal.
+	 * Contrary to intuition, this value should not be too large.
+	 * It might happen that trains are moved too earlier over links.
+	 */
+	private static final double EPSILON = 1E-6;
 
 	private FuzzyUtils() {
 	}