Memory leak with FXCanvas - javafx

Question

I'm working on Eclipse e4 RCP application where I have one SWT part. Using JavaFX interoperability with SWT I have added javafx.embed.swt.FXCanvas. After I create a javafx.scene.Scene with 50000 javafx.scene.control.Button and hook it to the canvas, application memory jumps to 1.5gb.
Problem starts when I close that part, application does not release a memory. When I open that part again, memory jumps to 2.something gb.
Part class:
import javax.annotation.PostConstruct;
import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import javafx.embed.swt.FXCanvas;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ScrollPane;
import javafx.scene.layout.Pane;
public class StressTestJavaFXPart
{
private Scene scene;
private FXCanvas canvas;
private final int columns = 100;
private final int rows = 500;
#PostConstruct
public void createComposite(final Composite parent)
{
parent.setLayout(new GridLayout(1, false));
canvas = new FXCanvas(parent, SWT.NONE);
GridDataFactory.fillDefaults().grab(true, true).span(0, 0).applyTo(canvas);
final Pane pane = new Pane();
for (int i = 0; i < columns ; i++)
{
for (int j = 0; j < rows ; j++)
{
final Button button = new Button(String.format("%s : %s", i, j));
pane.getChildren().add(button);
button.setLayoutX(100 * i);
button.setLayoutY(100 * j);
}
}
final ScrollPane sp = new ScrollPane(pane);
scene = new Scene(sp);
canvas.setScene(scene);
parent.addDisposeListener(new DisposeListener()
{
#Override
public void widgetDisposed(final DisposeEvent e)
{
canvas.dispose();
System.gc();
}
});
}
}
Any suggestions are very welcome! Thanks

Answer 1

I solved it using reflection:
parent.addDisposeListener(disposeEvent -> {
//release Pixel Buffer via Reflection -> prevents memory leak
try {
Field pixelBuffer = FXCanvas.class.getDeclaredField("pixelsBuf");
pixelBuffer.setAccessible(true);
pixelBuffer.set(this, null);
} catch (NoSuchFieldException | IllegalAccessException e) {
}
});
Worked well for me.