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Declarative Machine Learning
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.sysml.runtime.controlprogram.parfor.stat;
/**
* Helper class for encapsulated time measurements.
*
*
*/
public class Timing
{
private long _start = -1;
public Timing() {
//default constructor
}
public Timing(boolean start)
{
//init and start the timer
if( start ){
start();
}
}
/**
* Starts the time measurement.
*/
public void start()
{
_start = System.nanoTime();
}
/**
* Measures and returns the time since the last start() or stop() invocation and
* restarts the measurement.
*
* @return
*/
public double stop()
{
if( _start == -1 )
throw new RuntimeException("Stop time measurement without prior start is invalid.");
long end = System.nanoTime();
double duration = ((double)(end-_start))/1000000;
//carry end time over
_start = end;
return duration;
}
/**
* Measures and returns the time since the last start() or stop() invocation,
* restarts the measurement, and prints the last measurement to STDOUT.
*/
public void stopAndPrint()
{
double tmp = stop();
System.out.println("PARFOR: time = "+tmp+"ms");
}
}