Re.: CHA ignores default methods during analysis leading to incorrect code generation (original) (raw)

Yann Le Tallec ylt at letallec.org
Fri Feb 28 12:27:40 PST 2014

Original message: http://mail.openjdk.java.net/pipermail/hotspot-dev/2014-January/012252.html

The test (DefaultAndConcreteMethodsCHA.java) passes as expected on b129.

However a post on Stackoverflow reports a very similar bug that can still be reproduced on b129: http://stackoverflow.com/q/22096052/829571

Code copied below for reference - I get the erroneous output for i ~ 260, i.e. after approximately 25 seconds.

Yann

public class IsolatedBug { static int i = 0; private final Box box;

private final List<Drawable> drawables;

public IsolatedBug() {
    this.box = new Box();
    this.drawables = new ArrayList<>();

    drawables.add(box);
    drawables.forEach(drawable -> System.out.println(++i + " " +

drawable + " C=" + drawable.isShadowCaster() + "/R=" + drawable.isShadowReceiver())); }

private void init() throws InterruptedException {
    while (true) {
        drawables.forEach(drawable -> System.out.println(++i + " " +

drawable + " C=" + drawable.isShadowCaster() + "/R=" + drawable.isShadowReceiver())); Thread.sleep(100); } }

public static void main(String[] args) throws InterruptedException {
    new IsolatedBug().init();
}

}

abstract class Drawable implements DrawableInterface {}

interface DrawableInterface { default public boolean isShadowReceiver() { return false; } default public boolean isShadowCaster() { return false; } }

interface ShadowDrawable extends DrawableInterface { @Override default public boolean isShadowReceiver() { return true; } @Override default public boolean isShadowCaster() { return true; } }

class Box extends Drawable implements ShadowDrawable {}

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