I'm designing a stopwatch using JavaFX. The code runs well. Except for enormous cumulative memory leaks over time. The leak increases whenever I increase the Timeline
's framerate
. I'm currently on Ubuntu 16.04 with 4gigs of RAM, and the leak is happening at a speed of 300MB/min at 30fps. That's 5MBps. I can understand that this may happen due to the repetitive drawing over the Scene
, but why would it be cumulative? Shouldn't the JVM take care of this?
Main.java :
package UI;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ButtonBar;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception{
primaryStage.setTitle("StopWatch");
primaryStage.setScene(new Scene(getPane(), 400, 400));
primaryStage.show();
}
private BorderPane getPane(){
BorderPane pane = new BorderPane();
ClockUI clockUI = new ClockUI();
clockUI.setMinSize(200,200);
pane.setCenter(clockUI);
ButtonBar buttonBar = new ButtonBar();
Button startButton = new Button("Start");
startButton.setOnAction(e->clockUI.startClock());
Button pauseButton = new Button("Stop");
pauseButton.setOnAction(e->clockUI.stopClock());
Button resetButton = new Button("Reset");
resetButton.setOnAction(e->clockUI.resetClock());
buttonBar.getButtons().addAll(startButton, pauseButton, resetButton);
pane.setBottom(buttonBar);
return pane;
}
public static void main(String[] args) {
System.setProperty("prism.lcdtext","false");
launch(args);
}
}
ClockUI.java :
package UI;
import javafx.animation.*;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.scene.paint.Paint;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Line;
import javafx.scene.transform.Rotate;
import javafx.util.Duration;
/**
* Created by subhranil on 23/6/17.
*/
public class ClockUI extends StackPane {
private final Rotate hourRotate;
private final Rotate minuteRotate;
private final Rotate secondRotate;
private final Timeline hourTimeline;
private final Timeline minuteTimeline;
private final Timeline secondTimeline;
private final ParallelTransition clockTransition;
public ClockUI() {
super();
Line hourHand = getHand(80, Color.WHITE);
hourRotate = getRotate(hourHand);
hourTimeline = createRotateTimeline(Duration.hours(12), hourRotate);
Line minuteHand = getHand(100, Color.WHITE);
minuteRotate = getRotate(minuteHand);
minuteTimeline = createRotateTimeline(Duration.minutes(60), minuteRotate);
Line secondHand = getHand(90, Color.WHITE);
secondRotate = getRotate(secondHand);
secondTimeline = createRotateTimeline(Duration.seconds(60), secondRotate);
clockTransition = new ParallelTransition(hourTimeline, minuteTimeline, secondTimeline);
Circle back = new Circle(120);
back.centerXProperty().bind(widthProperty().divide(2));
back.centerYProperty().bind(heightProperty().divide(2));
back.setStyle("-fx-fill: #555555");
setStyle("-fx-background-color: #333333;");
getChildren().addAll(back, hourHand, minuteHand, secondHand);
}
private Timeline createRotateTimeline(Duration duration, Rotate rotate) {
Timeline timeline = new Timeline(30);
timeline.getKeyFrames().add(new KeyFrame(duration, new KeyValue(rotate.angleProperty(), 360)));
timeline.setCycleCount(Animation.INDEFINITE);
return timeline;
}
public void startClock() {
if (clockTransition.getStatus() != Animation.Status.RUNNING) {
clockTransition.play();
}
}
public void stopClock() {
if (clockTransition.getStatus() == Animation.Status.RUNNING) {
clockTransition.pause();
}
}
public void resetClock() {
stopClock();
clockTransition.stop();
}
private Rotate getRotate(Line line){
Rotate r = new Rotate(0);
r.pivotXProperty().bind(line.startXProperty());
r.pivotYProperty().bind(line.startYProperty());
line.getTransforms().add(r);
return r;
}
private Line getHand(int size, Paint color) {
Line hand = new Line();
hand.startXProperty().bind(widthProperty().divide(2));
hand.startYProperty().bind(heightProperty().divide(2));
hand.endXProperty().bind(widthProperty().divide(2));
hand.endYProperty().bind(heightProperty().divide(2).subtract(size));
hand.setStroke(color);
hand.setStrokeWidth(3);
return hand;
}
}
INFO : I've tried various other methods, like running an ExecutorService
, using Task
and Thread
, but all yield same results.