Add history length constant

Optimize view update
Add semaphore to TimeRecordList
Add waiting timer to model update

app/src/main/java/de/hems/trafficsim/MainActivity.java

@@ -18,6 +18,7 @@ public class MainActivity extends AppCompatActivity implements Observer, SeekBar
     public static final float defaultBrakeProb = 0.3f;
     public static final float defaultMaxVelocity = 5.0f;
     public static final int defaultDelay = 0;
+    public static final int defaultHistoryLength = 50;
     protected Track track;
     protected TimeRecordView trackView;
     protected Worker worker;
@@ -28,9 +29,11 @@ public class MainActivity extends AppCompatActivity implements Observer, SeekBar
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         this.track = new Track(defaultNoOfVehicles, defaultTrackLength, defaultBrakeProb,
-                defaultMaxVelocity, defaultDelay);
+                defaultMaxVelocity, defaultDelay, defaultHistoryLength);
         this.track.addObserver(this);
         this.viewStack = (LinearLayout) findViewById(R.id.trackViewStack);
+        this.trackView = new TimeRecordView(this, track, defaultHistoryLength);
+        viewStack.addView(this.trackView);
 
         SeekBar trackLengthSeekBar = (SeekBar) findViewById(R.id.trackLengthSeekBar);
         trackLengthSeekBar.setOnSeekBarChangeListener(this);
@@ -73,18 +76,22 @@ public class MainActivity extends AppCompatActivity implements Observer, SeekBar
         final TextView overallAvgView = (TextView) findViewById(R.id.avgVeloOverallView);
         final TextView delayedAvgView = (TextView) findViewById(R.id.delayedAvgTextView);
         final TextView stepsView = (TextView) findViewById(R.id.stepsTextView);
+        final TimeRecordView view = this.trackView;
         runOnUiThread(new Runnable() {
             @Override
             public void run() {
-                TimeRecordView newTrView = new TimeRecordView(mainActivity, trackRef);
-                if (viewStackRef.getChildCount() > 0)
-                    viewStackRef.removeViewAt(0);
-                viewStackRef.addView(newTrView);
+
+                //TimeRecordView newTrView = new TimeRecordView(mainActivity, trackRef);
+                trackView.invalidate();
+                //if (viewStackRef.getChildCount() > 0)
+                //    viewStackRef.removeViewAt(0);
+                //viewStackRef.addView(newTrView);
                 lastAvgView.setText(String.valueOf(round(trackRef.getLastAvg(), 2)));
                 overallAvgView.setText(String.valueOf(round(trackRef.getOverallAvg(), 2)));
-                stepsView.setText(String.valueOf(trackRef.getVtrList().size()));
+                stepsView.setText(String.valueOf(trackRef.getSteps()));
                 delayedAvgView.setText(String.valueOf(round(trackRef.getDelayedAvg(), 2)));
 
+
             }
         });
     }
@@ -172,7 +179,8 @@ public class MainActivity extends AppCompatActivity implements Observer, SeekBar
 
         int newDelay = ((SeekBar)(findViewById(R.id.simDelaySeekBar))).getProgress();
 
-        this.track = new Track(newNoOfVehicles, newTrackLength, newBrakeProb, newMaxVelocity, newDelay);
+        this.track = new Track(newNoOfVehicles, newTrackLength, newBrakeProb, newMaxVelocity, newDelay, defaultHistoryLength);
+        this.trackView.setTrack(this.track);
         this.track.addObserver(this);
         if (this.worker != null) { // There was a simulation running already
             this.stopWorker();

app/src/main/java/de/hems/trafficsim/TimeRecordView.java

@@ -14,11 +14,13 @@ public class TimeRecordView extends View {
     protected Track track;
     protected int pixelPerVehicle;
     protected float tooShortPerTrackLength;
+    protected int historyLength;
 
-    public TimeRecordView(Context context, Track track) {
+    public TimeRecordView(Context context, Track track, int historyLength) {
         super(context);
         this.track = track;
         this.paint = new Paint();
+        this.historyLength = historyLength;
         paint.setColor(Color.BLACK);
         paint.setStyle(Paint.Style.FILL_AND_STROKE);
         this.setBackgroundColor(Color.BLACK);
@@ -26,6 +28,10 @@ public class TimeRecordView extends View {
         this.tooShortPerTrackLength = (this.getWidth() - this.pixelPerVehicle*this.track.getTrackLength())/this.track.getTrackLength();
     }
 
+    public void setTrack(Track track) {
+        this.track = track;
+    }
+
     protected int getColor(float curVelocity, float maxVelocity) {
         float perc = curVelocity / maxVelocity;
         perc = 1 - perc;
@@ -60,18 +66,25 @@ public class TimeRecordView extends View {
     protected void onDraw(Canvas canvas) {
         int y = 0;
         List<List<VehicleTimeRecord>> stepList = this.track.getVtrList();
-        for (int curStepIdx = stepList.size()-1; curStepIdx >= stepList.size()-1-50 && curStepIdx >= 0; curStepIdx--) {
+        for (int curStepIdx = this.historyLength-1;
+             curStepIdx >= 0 && stepList.size() >= curStepIdx;
+             curStepIdx--) {
             try {
+                try {
+                    track.getListSemaphore().acquire();
+                } catch (InterruptedException ex) { return; }
                 List<VehicleTimeRecord> step = stepList.get(curStepIdx);
                 int i = 0;
                 for (VehicleTimeRecord r : step) {
                     int left = (int) (this.pixelPerVehicle * r.getPosition());
                     int compensate = Math.round(r.getPosition()*this.tooShortPerTrackLength);
                     this.paint.setColor(getColor(r.getVelocity(), r.getMaxVelocity()));
-                    canvas.drawRect(left+compensate, y, left + this.pixelPerVehicle - 1+compensate,
+                    canvas.drawRect(left+compensate, y,
+                            left + this.pixelPerVehicle - 1+compensate,
                             y + 10, this.paint);
                     i++;
                 }
+                track.getListSemaphore().release();
                 y += 10;
             } catch (ConcurrentModificationException ex) {
                 System.out.println("Concurrent Exception occured, skipping record");

app/src/main/java/de/hems/trafficsim/Track.java

@@ -4,6 +4,8 @@ import java.util.ArrayList;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Observable;
+import java.util.concurrent.Semaphore;
+import java.util.concurrent.locks.LockSupport;
 
 public class Track extends Observable {
     protected List<Vehicle> vehicles;
@@ -18,6 +20,8 @@ public class Track extends Observable {
     protected int waitTime;
     protected float maxVelocity;
     protected float brakeProb;
+    protected long steps;
+    protected Semaphore listSemaphore;
 
     public List<List<VehicleTimeRecord>> getVtrList() { return vtrList; }
     public float getOverallAvg() {
@@ -33,8 +37,10 @@ public class Track extends Observable {
     public float getTrackLength() {
         return trackLength;
     }
+    public long getSteps() { return steps; }
+    public Semaphore getListSemaphore() { return listSemaphore; }
 
-    public Track(int numberVehicles, float trackLength, float brakeProb, float maxVelocity, int waitTime) {
+    public Track(int numberVehicles, float trackLength, float brakeProb, float maxVelocity, int waitTime, int historyLength) {
         this.trackLength = trackLength;
         this.brakeProb = brakeProb;
         this.maxVelocity = maxVelocity;
@@ -45,8 +51,10 @@ public class Track extends Observable {
         this.overallAvg = 0;
         this.delayedAvg = 0;
         this.lastAvg = 0;
-        this.historyLength = 25;
+        this.historyLength = historyLength;
         this.waitTime = waitTime;
+        this.steps = 0;
+        this.listSemaphore = new Semaphore(1);
 
     }
 
@@ -90,17 +98,28 @@ public class Track extends Observable {
             }
             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.id, v.position, v.curVelocity, v.maxVelocity);
             records.add(vtr);
         }
+        steps++;
+        this.listSemaphore.release();
+
         update_avg();
         this.setChanged();
         this.notifyObservers();
         this.clearChanged();
+        LockSupport.parkNanos(1);
         try  {
             Thread.sleep(waitTime);
         } catch (InterruptedException ex) { }
@@ -116,12 +135,12 @@ public class Track extends Observable {
 
     protected void update_avg(){
         lastAvg = avg_step(vtrList.size()-1);
-        if (this.vtrList.size() > 10) {
+        if (this.steps > 10) {
             sumDelAvgMemory += lastAvg;
-            delayedAvg = sumDelAvgMemory / (vtrList.size() - 10);
+            delayedAvg = sumDelAvgMemory / (this.steps - 10);
         }
         sumAvgMemory += lastAvg;
-        overallAvg = sumAvgMemory / vtrList.size();
+        overallAvg = sumAvgMemory / this.steps;
 
     }
 

app/src/main/java/de/hems/trafficsim/Vehicle.java

@@ -46,7 +46,6 @@ public class Vehicle {
             curVelocity = curVelocity + 1;
         }
         if (r < brakeProb && curVelocity > 0) {
-            System.out.println("vehicle: "+brakeProb);
             curVelocity = curVelocity - 1;
         }
         if (curVelocity > distanceForerunner) {