1 files changed, 172 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math/stat/descriptive/SynchronizedDescriptiveStatistics.java b/src/main/java/org/apache/commons/math/stat/descriptive/SynchronizedDescriptiveStatistics.java
new file mode 100644
index 0000000..f1a932d
--- /dev/null
+++ b/src/main/java/org/apache/commons/math/stat/descriptive/SynchronizedDescriptiveStatistics.java
@@ -0,0 +1,172 @@
+/*
+ * 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.math.stat.descriptive;
+
+/**
+ * Implementation of
+ * {@link org.apache.commons.math.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
+ * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $
+ */
+public class SynchronizedDescriptiveStatistics extends DescriptiveStatistics {
+
+    /** Serialization UID */
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * Construct an instance with infinite window
+     */
+    public SynchronizedDescriptiveStatistics() {
+        this(INFINITE_WINDOW);
+    }
+
+    /**
+     * Construct an instance with finite window
+     * @param window the finite window size.
+     */
+    public SynchronizedDescriptiveStatistics(int window) {
+        super(window);
+    }
+
+    /**
+     * A copy constructor. Creates a deep-copy of the {@code original}.
+     *
+     * @param original the {@code SynchronizedDescriptiveStatistics} instance to copy
+     */
+    public SynchronizedDescriptiveStatistics(SynchronizedDescriptiveStatistics original) {
+        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[] getValues() {
+        return super.getValues();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public synchronized int getWindowSize() {
+        return super.getWindowSize();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public synchronized void setWindowSize(int windowSize) {
+        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();
+        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 NullPointerException if either source or dest is null
+     */
+    public static void copy(SynchronizedDescriptiveStatistics source,
+            SynchronizedDescriptiveStatistics dest) {
+        synchronized (source) {
+            synchronized (dest) {
+                DescriptiveStatistics.copy(source, dest);
+            }
+        }
+    }
+}