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- package de.hems.trafficsim;
-
- import java.util.ArrayList;
- import java.util.LinkedList;
- import java.util.List;
- import java.util.Observable;
- import java.util.concurrent.Semaphore;
-
- /**
- * Main model class of TrafficSim. Represents a round course containing vehicles.
- */
- public class Track extends Observable {
- /**
- * list a vehicles on the track
- */
- final protected List<Vehicle> vehicles;
-
- /**
- * list of resulting time records of the simulation
- */
- final protected List<List<VehicleTimeRecord>> vtrList;
-
- /**
- * length of the track
- */
- final protected float trackLength;
-
- /**
- * sum of all vehicle speeds during the simulation, used for average calculation
- */
- protected float sumAvgMemory;
-
- /**
- * sum of all vehicle speeds during the simulation ignoring the first ten steps,
- * used for average calculation
- */
- protected float sumDelAvgMemory;
-
- /**
- * length of the history kept
- */
- final protected int historyLength;
-
- /**
- * average over all velocities in the simulation
- */
- protected float overallAvg;
-
- /**
- * average over all velocities in the simulation, ignoring the first ten steps
- */
- protected float delayedAvg;
-
- /**
- * average over all velocities in the last step
- */
- protected float lastAvg;
-
- /**
- * current configured wait time between two simulation steps
- */
- protected int waitTime;
-
- /**
- * currently configured max velocity for all vehicles
- */
- final protected float maxVelocity;
-
- /**
- * currently configured brake probability for all vehicles
- */
- final protected float brakeProb;
-
- /**
- * counter for executed simulation steps
- */
- protected long steps;
-
- /**
- * semaphore protecting the vtrlist
- */
- final protected Semaphore listSemaphore;
-
- /**
- * Constructor for a new Track.
- *
- * @param numberVehicles number of vehicles on the Track
- * @param trackLength length of the new Track
- * @param brakeProb probability of a vehicle to suddenly brake without reason
- * @param maxVelocity maxmimum velocity of the vehicles
- * @param waitTime time between two simulation steps to slow down the simulation artificially
- * @param historyLength length of the history to keep
- */
- public Track(int numberVehicles, float trackLength, float brakeProb, float maxVelocity, int waitTime, int historyLength) {
- this.trackLength = trackLength;
- this.brakeProb = brakeProb;
- this.maxVelocity = maxVelocity;
- this.vehicles = createVehiclesList(numberVehicles);
- this.vtrList = new LinkedList<>();
- this.sumAvgMemory = 0;
- this.sumDelAvgMemory = 0;
- this.overallAvg = 0;
- this.delayedAvg = 0;
- this.lastAvg = 0;
- this.historyLength = historyLength;
- this.waitTime = waitTime;
- this.steps = 0;
- this.listSemaphore = new Semaphore(1);
-
- }
-
- /**
- * Getter for vtrList
- *
- * @return vtrList
- */
- public List<List<VehicleTimeRecord>> getVtrList() {
- return vtrList;
- }
-
- /**
- * Getter for overallAvg
- *
- * @return overallAvg
- */
- public float getOverallAvg() {
- return overallAvg;
- }
-
- /**
- * Getter for lastAvg
- *
- * @return lastAvg
- */
- public float getLastAvg() {
- return lastAvg;
- }
-
- /**
- * Getter for delayedAvg
- *
- * @return delayedAvg
- */
- public float getDelayedAvg() {
- return delayedAvg;
- }
-
- /**
- * Getter for trackLength
- *
- * @return trackLength
- */
- public float getTrackLength() {
- return trackLength;
- }
-
- /**
- * Getter for steps
- *
- * @return steps
- */
- public long getSteps() {
- return steps;
- }
-
- /**
- * Getter for listSemaphore
- *
- * @return listSemaphore
- */
- public Semaphore getListSemaphore() {
- return listSemaphore;
- }
-
- /**
- * Getter for historyLength
- *
- * @return historyLength
- */
- public int getHistoryLength() {
- return historyLength;
- }
-
- /**
- * Utility function to add vehicles to the Track.
- *
- * @param numberVehicles number of vehicles to add
- * @return filled list with vehicles
- */
- protected List<Vehicle> createVehiclesList(int numberVehicles) {
- List<Vehicle> result = new ArrayList<>();
- for (int i = 0; i < numberVehicles; i++) {
- Vehicle vehicle = new Vehicle(i, i, this.maxVelocity, this.brakeProb, this.trackLength);
- result.add(vehicle);
- }
-
- return result;
- }
-
- /**
- * Update the wait time of the simulation.
- *
- * @param waitTime new wait time in ms
- */
- public void setWaitTime(int waitTime) {
- this.waitTime = waitTime;
- }
-
- /**
- * Update the brake probability of all vehicles.
- *
- * @param brakeProb new brake probability
- */
- public void setBrakeProb(float brakeProb) {
- for (Vehicle v : this.vehicles) {
- v.setBrakeProb(brakeProb);
- }
- }
-
- /**
- * Update the maximum velocity of all vehicles.
- *
- * @param maxVelocity new maximum velocity
- */
- public void setMaxVelocity(float maxVelocity) {
- for (Vehicle v : this.vehicles) {
- v.setMaxVelocity(maxVelocity);
- }
- }
-
- /**
- * Calculates on simulation step ahead and then waits for the configured wait time.
- */
- public void timeElapse() {
- for (int i = 0; i < vehicles.size(); i++) {
- Vehicle v = vehicles.get(i);
- int forerunnerIndex = i + 1;
- if (forerunnerIndex >= vehicles.size()) {
- forerunnerIndex -= vehicles.size();
- }
- Vehicle forerunner = vehicles.get(forerunnerIndex);
- float distanceForerunner = forerunner.getPosition() - v.getPosition() - 1;
- if (distanceForerunner < 0.0) {
- distanceForerunner += this.trackLength;
- }
- v.updateVelocity(distanceForerunner);
- }
-
- try {
- this.listSemaphore.acquire();
- } catch (InterruptedException ex) {return;}
- List <VehicleTimeRecord> records = new ArrayList<>(vehicles.size());
- this.vtrList.add(records);
- if (this.vtrList.size() > this.historyLength) {
- this.vtrList.remove(0);
- }
- for(Vehicle v: vehicles){
- v.timeElapse();
- VehicleTimeRecord vtr = new VehicleTimeRecord(v.position, v.curVelocity, v.maxVelocity);
- records.add(vtr);
- }
- steps++;
- this.listSemaphore.release();
-
- update_avg();
- try {
- Thread.sleep(waitTime);
- } catch (InterruptedException ignored) {
- }
- }
-
- /**
- * Returns the average velocity of the given simulation step.
- *
- * @param step index of the step in the history list
- * @return average velocity
- */
- public float avg_step(int step) {
- float sum_step = 0;
- for (VehicleTimeRecord r : vtrList.get(step)) {
- sum_step += r.velocity;
- }
- return sum_step / vehicles.size();
- }
-
- /**
- * Utility function which updates the averages values with the results from the last simulation
- * step.
- */
- protected void update_avg() {
- lastAvg = avg_step(vtrList.size() - 1);
- if (this.steps > 10) {
- sumDelAvgMemory += lastAvg;
- delayedAvg = sumDelAvgMemory / (this.steps - 10);
- }
- sumAvgMemory += lastAvg;
- overallAvg = sumAvgMemory / this.steps;
-
- }
- }
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