FULL PRODUCT VERSION :
1.8.0_144

ADDITIONAL OS VERSION INFORMATION :
Darwin 17.3.0 Darwin Kernel Version 17.3.0; root:xnu-4570.31.3~1/RELEASE_X86_64 x86_64

Microsoft Windows [Version 6.3.9600]

A DESCRIPTION OF THE PROBLEM :
Memory usage increases non-stop when using a Timer and, inside the TimerTask, I change a button's Effect to show a DropShadow. The problem is worse when every time I call button.setEffect() I pass in 'new DropShadow()'. It consumes memory at a faster rate. If I do .setEffect() with only 1 object created beforehand, memory increases at a lower rate.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the program and monitor the memory usage for this app. It will increase while time passes.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Memory could increase, but it would decrease again after Garbage Collector runs.
ACTUAL -
Memory allocation is higher and keeps increasing over time and never decreases. (Consumption is higher on Mac)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
package blinkingmemoryleak;

import java.util.Timer;
import java.util.TimerTask;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.effect.DropShadow;
import javafx.scene.effect.Effect;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.stage.WindowEvent;

/**
 * Demonstrate a memory leak on macOS 10.13.2 and Windows 8.1 Pro (running
 * the same JDK [1.8.0_144]).
 * @author Melkis Espinal
 */
public class BlinkingMemoryLeak extends Application
{
    Timer timer;
    TimerTask timerTask;
    Button btn = new Button("Click To Stop Animation");
    DropShadow ds = new DropShadow();
    @Override
    public void start(Stage primaryStage)
    {
        primaryStage.setOnCloseRequest(new EventHandler<WindowEvent>()
        {
            @Override
            public void handle(WindowEvent event)
            {
                if(timer != null)
                {
                    timer.cancel();
                    primaryStage.close();
                    System.exit(0);
                }
            }
        });
        //add alarm.png image for the button icon
        //Image img = new Image(getClass().getResourceAsStream("alarm1.png"), 50, 50, true, true);
        //ImageView iv = new ImageView(img);
        //btn.setGraphic(iv);
        
        StackPane root = new StackPane();
        root.getChildren().add(btn);
        
        Scene scene = new Scene(root, 500, 500);
        
        primaryStage.setTitle("Blinking Memory Leak");
        primaryStage.setScene(scene);
        primaryStage.show();
        
        setupTimer();
    }
    
    /**
     * Sets up timer and button listener on action to start or stop the timer.
     */
    public void setupTimer()
    {
        timerTask = new TimerTask() {
            @Override
            public void run()
            {
                Effect effect = btn.getEffect();
                if(effect == null)
                {
                    btn.setEffect(ds);
                }
                else
                {
                    btn.setEffect(null);
                }
                effect = null;
            }
        };
        timer = new Timer();
        timer.scheduleAtFixedRate(timerTask, 0, 100);
        btn.setOnAction(new EventHandler<ActionEvent>()
        {
            @Override
            public void handle(ActionEvent event)
            {
                btn.setEffect(null);
                if(timer != null)
                {
                    timer.cancel();
                    timer = null;
                }
                if(timerTask != null)
                {
                    timerTask.cancel();
                    timerTask = null;
                }
            }
        });
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args)
    {
        launch(args);
    }
}
---------- END SOURCE ----------