/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Jan 2, 2012
*/
package com.bigdata.cache;
import java.lang.ref.WeakReference;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Random;
import com.bigdata.util.Bytes;
import junit.framework.TestCase2;
/**
* Test suite for {@link ConcurrentWeakValueCacheWithBatchedUpdates}.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class TestConcurrentWeakValueCacheWithBatchingUpdates extends TestCase2 {
/**
*
*/
public TestConcurrentWeakValueCacheWithBatchingUpdates() {
}
/**
* @param name
*/
public TestConcurrentWeakValueCacheWithBatchingUpdates(String name) {
super(name);
}
public void test_memoryLeak() {
final ConcurrentWeakValueCacheWithBatchedUpdates<Long, String> fixture = new ConcurrentWeakValueCacheWithBatchedUpdates<Long, String>(//
16,// backing hard reference LRU queue capacity.
.75f, // loadFactor (.75 is the default)
16 // concurrency level (16 is the default)
);
/*
* Populate the cache. We will hold hard references to all of the values
* in the map inside of this block but only to some of the values in the
* map outside of this block.
*/
final int outerSize = 100;
final int innerSize = 1000000; // 1M
final Map<Long, String> outerMap = new HashMap<Long, String>();
{
final Map<Long, String> innerMap = new HashMap<Long, String>();
/*
* Note: Fill the inner map first. This way the references for the
* inner map will all be batched through the lock.,
*/
// The inner map
for (long i = outerSize; i < (outerSize + innerSize); i++) {
final Long key;
final String val;
innerMap.put(key = Long.valueOf(i), val = "" + i);
fixture.put(key, val);
}
assertEquals(0, outerMap.size());
assertEquals(innerSize, innerMap.size());
assertEquals(innerSize, fixture.size());
// The outer map.
for (long i = 0; i < outerSize; i++) {
final Long key;
final String val;
outerMap.put(key = Long.valueOf(-i), val = "outerMap" + i);
fixture.put(key, val);
}
assertEquals(innerSize, innerMap.size());
assertEquals(outerSize, outerMap.size());
assertEquals(outerSize + innerSize, fixture.size());
if(log.isInfoEnabled()){
log.info("Outer: " + outerMap.size() + " , Inner: " + innerMap.size());
}
System.gc();
if(log.isInfoEnabled()){
log.info("Outer: " + outerMap.size() + " , Inner: " + innerMap.size());
}
assertEquals(outerSize + innerSize, fixture.size());
// innerMap.clear(); // clear all entries to facilite GC?
}
/*
* Now that the inner map from the block above is out of scope we might
* be able to force a GC which will clear references which were only
* retained by that map. To help move things along, we allocate a bunch
* of stuff and put it into yet another hard reference map.
*/
{
final Random r = new Random();
final Map<Long, String> junkMap = new HashMap<Long, String>();
while (junkMap.size() < Bytes.megabyte32 * 1) {
for (int i = 0; i < 100000; i++) {
final long n = r.nextLong();
junkMap.put(new Long(n), "" + n);
}
// System.gc();
final int fixtureSize = fixture.size();
if (log.isInfoEnabled())
log.info("GC: fixtureSize=" + fixtureSize);
if (fixture.size() == outerSize) {
break;
}
}
}
if(log.isInfoEnabled()) {
/*
* Dump the contents of the weak value cache.
*/
final Iterator<Map.Entry<Long, WeakReference<String>>> itr = fixture
.entryIterator();
while (itr.hasNext()) {
final Map.Entry<Long, WeakReference<String>> e = itr.next();
log.info(e.getKey() + "\t" + e.getValue().get());
}
}
/*
* Note: We have to access the outer map after the code which seeks to
* force a GC in order to have the outer map remain strongly referenced.
* Without this, the reference winds up being cleared even though we are
* in the same lexical scope in which the [outerMap] was declared.
*/
assertEquals(outerSize, outerMap.size());
/*
* We should be able to get rid of everything in the inner map.
*/
assertEquals(outerSize, fixture.size());
}
}