/* The contents of this file are subject to the terms
* of the Common Development and Distribution License
* (the License). You may not use this file except in
* compliance with the License.
*
* You can obtain a copy of the License at
* http://www.sun.com/cddl/cddl.html or
* install_dir/legal/LICENSE
* See the License for the specific language governing
* permission and limitations under the License.
*
* When distributing Covered Code, include this CDDL
* Header Notice in each file and include the License file
* at install_dir/legal/LICENSE.
* If applicable, add the following below the CDDL Header,
* with the fields enclosed by brackets [] replaced by
* your own identifying information:
* "Portions Copyrighted [year] [name of copyright owner]"
*
* $Id$
*
* Copyright 2005-2009 Sun Microsystems Inc. All Rights Reserved
*/
package com.sun.faban.driver.engine;
import com.sun.faban.common.Utilities;
import com.sun.faban.driver.util.Random;
import com.sun.faban.driver.ConfigurationException;
import com.sun.faban.driver.CycleType;
import com.sun.faban.driver.DefinitionException;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import java.lang.annotation.Annotation;
/**
* Implements the negative exponential distribution/selection.
*
* @author Akara Sucharitakul
*/
public class NegativeExponential extends Cycle {
private static final long serialVersionUID = 1L;
long cycleMin = 0;
long cycleMean = 1000 * Utilities.TO_NANOS;
long cycleMax = 5000 * Utilities.TO_NANOS;
boolean truncate = true;
/**
* Initializes this cycle according to the annotation.
* @param a The annotation
* @throws DefinitionException If there is an error in the annotation
*/
public void init(Annotation a) throws DefinitionException {
com.sun.faban.driver.NegativeExponential cycleDef =
(com.sun.faban.driver.NegativeExponential) a;
cycleType = cycleDef.cycleType();
cycleDeviation = cycleDef.cycleDeviation();
cycleMin = cycleDef.cycleMin();
cycleMean = cycleDef.cycleMean();
cycleMax = cycleDef.cycleMax();
truncate = cycleDef.truncateAtMin();
if (cycleMax == -1) {
cycleMax = 5 * cycleMean;
}
// Now check parameters for validity.
if (cycleMin < 0) {
throw new DefinitionException("@NegativeExponential cycleMin < 0");
}
if (cycleMean < 0) {
throw new DefinitionException("@NegativeExponential cycleMean < 0");
}
if (cycleMax < 0) {
throw new DefinitionException("@NegativeExponential cycleMax < 0");
}
if (cycleMin > cycleMean) {
throw new DefinitionException(
"@NegativeExponential cycleMin > cycleMean");
}
if (cycleMean > cycleMax) {
throw new DefinitionException(
"@NegativeExponential cycleMean > cycleMax");
}
if (cycleMax == 0 && cycleType == CycleType.CYCLETIME) {
throw new DefinitionException(
"@NegativeExponential CYCLETIME cycleMax cannot be 0");
}
// Adjust time to nanosec.
cycleMin *= Utilities.TO_NANOS;
cycleMean *= Utilities.TO_NANOS;
cycleMax *= Utilities.TO_NANOS;
}
/**
* Randoms/calculates the delay time for a thread based on its
* supplied random number generator and the actual conditions in the
* distribution.
*
* @param random The random number generator used
* @return The delay time
*/
public long getDelay(Random random) {
long delay = 0;
long mean = cycleMean;
long shift = 0;
if (!truncate) {
shift = cycleMin;
mean -= shift;
}
if (cycleMean > 0) {
double x = random.drandom(0.0, 1.0);
if (x == 0) {
x = 1e-20d;
}
delay = shift + (long)(mean * -Math.log(x));
if (delay < cycleMin) {
delay = cycleMin;
} else if (delay > cycleMax) {
delay = cycleMax;
}
}
return delay;
}
/**
* Provides the maximum value to be represented inside a histogram.
*
* @return The max reasonable delay to be presented in the output histogram.
*/
public double getHistogramMax() {
if (cycleMax > 0) {
return cycleMax;
}
// We know it takes very little time to prepare the data to submit.
// This case can only happen for think time. Giving a histogram
// max of 2 seconds for data prep should be enough.
return 2d;
}
/**
* Configure the cycle based on an XML fragment from the configuration
* file. The format of the fragment is:
*
* <pre>
* <cycleType>CYCLETIME</cycleType> -- or THINKTIME
* <cycleMin>min</cycleMin>
* <cycleMean>mean</cycleMean>
* <cycleMax>max</cycleMax>
* <cycleDeviation>deviation</cycleDeviation>
* <truncateAtMin>true</truncateAtMin> -- or false
* </pre>
*/
protected void configureSubclass(Element e) throws ConfigurationException {
NodeList nl = e.getElementsByTagNameNS(
RunInfo.DRIVERURI, "cycleMin");
if (nl.getLength() > 1) {
String msg = "Bad cycleMin definition; must have only one per cycleTime";
getLogger().severe(msg);
ConfigurationException ce = new ConfigurationException(msg);
getLogger().throwing(getClass().getName(), "configure", ce);
throw ce;
}
if (nl.getLength() == 1) {
cycleMin = Long.parseLong(nl.item(0).getFirstChild().getNodeValue()) * Utilities.TO_NANOS;
}
nl = e.getElementsByTagNameNS(
RunInfo.DRIVERURI, "cycleMean");
if (nl.getLength() > 1) {
String msg = "Bad cycleMean definition; must have only one per cycleTime";
getLogger().severe(msg);
ConfigurationException ce = new ConfigurationException(msg);
getLogger().throwing(getClass().getName(), "configure", ce);
throw ce;
}
if (nl.getLength() == 1) {
cycleMean = Long.parseLong(nl.item(0).getFirstChild().getNodeValue()) * Utilities.TO_NANOS;
}
nl = e.getElementsByTagNameNS(
RunInfo.DRIVERURI, "cycleMax");
if (nl.getLength() > 1) {
String msg = "Bad cycleMax definition; must have only one per cycleTime";
getLogger().severe(msg);
ConfigurationException ce = new ConfigurationException(msg);
getLogger().throwing(getClass().getName(), "configure", ce);
throw ce;
}
if (nl.getLength() == 1) {
cycleMax = Long.parseLong(nl.item(0).getFirstChild().getNodeValue()) * Utilities.TO_NANOS;
}
nl = e.getElementsByTagNameNS(
RunInfo.DRIVERURI, "cycleDeviation");
if (nl.getLength() > 1) {
String msg = "Bad cycleDeviation definition; must have only one per cycleTime";
getLogger().severe(msg);
ConfigurationException ce = new ConfigurationException(msg);
getLogger().throwing(getClass().getName(), "configure", ce);
throw ce;
}
if (nl.getLength() == 1) {
truncate = Boolean.parseBoolean(nl.item(0).getFirstChild().getNodeValue());
}
}
}