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/*
* 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.commons.math3.stat.descriptive;
import org.apache.commons.math3.exception.MathIllegalArgumentException;
import org.apache.commons.math3.exception.NullArgumentException;
import org.apache.commons.math3.util.MathUtils;
/**
* Implementation of
* {@link org.apache.commons.math3.stat.descriptive.DescriptiveStatistics} that
* is safe to use in a multithreaded environment. Multiple threads can safely
* operate on a single instance without causing runtime exceptions due to race
* conditions. In effect, this implementation makes modification and access
* methods atomic operations for a single instance. That is to say, as one
* thread is computing a statistic from the instance, no other thread can modify
* the instance nor compute another statistic.
*
* @since 1.2
*/
public class SynchronizedDescriptiveStatistics extends DescriptiveStatistics {
/** Serialization UID */
private static final long serialVersionUID = 1L;
/**
* Construct an instance with infinite window
*/
public SynchronizedDescriptiveStatistics() {
// no try-catch or advertized IAE because arg is valid
this(INFINITE_WINDOW);
}
/**
* Construct an instance with finite window
* @param window the finite window size.
* @throws MathIllegalArgumentException if window size is less than 1 but
* not equal to {@link #INFINITE_WINDOW}
*/
public SynchronizedDescriptiveStatistics(int window) throws MathIllegalArgumentException {
super(window);
}
/**
* A copy constructor. Creates a deep-copy of the {@code original}.
*
* @param original the {@code SynchronizedDescriptiveStatistics} instance to copy
* @throws NullArgumentException if original is null
*/
public SynchronizedDescriptiveStatistics(SynchronizedDescriptiveStatistics original)
throws NullArgumentException {
copy(original, this);
}
/**
* {@inheritDoc}
*/
@Override
public synchronized void addValue(double v) {
super.addValue(v);
}
/**
* {@inheritDoc}
*/
@Override
public synchronized double apply(UnivariateStatistic stat) {
return super.apply(stat);
}
/**
* {@inheritDoc}
*/
@Override
public synchronized void clear() {
super.clear();
}
/**
* {@inheritDoc}
*/
@Override
public synchronized double getElement(int index) {
return super.getElement(index);
}
/**
* {@inheritDoc}
*/
@Override
public synchronized long getN() {
return super.getN();
}
/**
* {@inheritDoc}
*/
@Override
public synchronized double getStandardDeviation() {
return super.getStandardDeviation();
}
/**
* {@inheritDoc}
*/
@Override
public synchronized double getQuadraticMean() {
return super.getQuadraticMean();
}
/**
* {@inheritDoc}
*/
@Override
public synchronized double[] getValues() {
return super.getValues();
}
/**
* {@inheritDoc}
*/
@Override
public synchronized int getWindowSize() {
return super.getWindowSize();
}
/**
* {@inheritDoc}
*/
@Override
public synchronized void setWindowSize(int windowSize) throws MathIllegalArgumentException {
super.setWindowSize(windowSize);
}
/**
* {@inheritDoc}
*/
@Override
public synchronized String toString() {
return super.toString();
}
/**
* Returns a copy of this SynchronizedDescriptiveStatistics instance with the
* same internal state.
*
* @return a copy of this
*/
@Override
public synchronized SynchronizedDescriptiveStatistics copy() {
SynchronizedDescriptiveStatistics result =
new SynchronizedDescriptiveStatistics();
// No try-catch or advertised exception because arguments are guaranteed non-null
copy(this, result);
return result;
}
/**
* Copies source to dest.
* <p>Neither source nor dest can be null.</p>
* <p>Acquires synchronization lock on source, then dest before copying.</p>
*
* @param source SynchronizedDescriptiveStatistics to copy
* @param dest SynchronizedDescriptiveStatistics to copy to
* @throws NullArgumentException if either source or dest is null
*/
public static void copy(SynchronizedDescriptiveStatistics source,
SynchronizedDescriptiveStatistics dest)
throws NullArgumentException {
MathUtils.checkNotNull(source);
MathUtils.checkNotNull(dest);
synchronized (source) {
synchronized (dest) {
DescriptiveStatistics.copy(source, dest);
}
}
}
}
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