Timing.java

/*******************************************************************************
 * Copyright (c) 2009-2013 CWI
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:

 *   * Jurgen J. Vinju - Jurgen.Vinju@cwi.nl - CWI
 *   * Arnold Lankamp - Arnold.Lankamp@cwi.nl
*******************************************************************************/
package org.rascalmpl.interpreter.utils;

import java.lang.management.ManagementFactory;
import java.lang.management.ThreadMXBean;

public final class Timing {
	private long start;
	
	public Timing(){
		super();
	}
	
	public void start() {
		start = getCpuTime();
	}
	
	public long duration() {
		long now = getCpuTime();
		long diff = now - start;
		start = now;
		return diff;
	}
	
	public static long getCpuTime( ) {
	    ThreadMXBean bean = ManagementFactory.getThreadMXBean( );
	    return bean.isCurrentThreadCpuTimeSupported( ) ?
	        bean.getCurrentThreadCpuTime( ) : 0L;
	}
	 
	/** Get user time in nanoseconds. */
	public static long getUserTime( ) {
	    ThreadMXBean bean = ManagementFactory.getThreadMXBean( );
	    return bean.isCurrentThreadCpuTimeSupported( ) ?
	        bean.getCurrentThreadUserTime( ) : 0L;
	}

	/** Get system time in nanoseconds. */
	public static long getSystemTime( ) {
	    ThreadMXBean bean = ManagementFactory.getThreadMXBean( );
	    return bean.isCurrentThreadCpuTimeSupported( ) ?
	        (bean.getCurrentThreadCpuTime( ) - bean.getCurrentThreadUserTime( )) : 0L;
	}
}