Netty event latency simulator

LatencySimulatorHandler.java

import org.jboss.netty.channel.*;
import org.jboss.netty.util.HashedWheelTimer;
import org.jboss.netty.util.Timeout;
import org.jboss.netty.util.Timer;
import org.jboss.netty.util.TimerTask;

import java.util.concurrent.TimeUnit;

/**
 * Simulates latency of Netty events
 * 
 * Useful when debugging race conditions.
 */
public class LatencySimulatorHandler extends SimpleChannelHandler
{
    private static final Timer timer = new HashedWheelTimer();

    @Override
    public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {
        delayUpstream(ctx, e);
    }

    @Override
    public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
        delayUpstream(ctx, e);
    }

    @Override
    public void channelDisconnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
        delayUpstream(ctx, e);
    }

    @Override
    public void writeRequested(final ChannelHandlerContext ctx, final MessageEvent e) throws Exception {
        delayDownstream(ctx, e);
    }

    @Override
    public void closeRequested(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
        delayDownstream(ctx, e);
    }

    private void delayDownstream(final ChannelHandlerContext ctx, final ChannelEvent e) {
        timer.newTimeout(new TimerTask() {
            public void run(Timeout timeout) throws Exception {
                ctx.sendDownstream(e);
            }
        }, 500, TimeUnit.MILLISECONDS);
    }

    private void delayUpstream(final ChannelHandlerContext ctx, final ChannelEvent e) {
        timer.newTimeout(new TimerTask() {
            public void run(Timeout timeout) throws Exception {
                ctx.sendUpstream(e);
            }
        }, 500, TimeUnit.MILLISECONDS);
    }
}