org.phunt.zookeeper.removewatchexample.ExerciseRemoveWatchTest.java Source code

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Here is the source code for org.phunt.zookeeper.removewatchexample.ExerciseRemoveWatchTest.java

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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.phunt.zookeeper.removewatchexample;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.ZooKeeper;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

/** 
 * Very simple test class which attempts to exercise the removeWatches feature added in 3.5.0
 *
 */
public class ExerciseRemoveWatchTest implements Watcher {
    private static final boolean USE_REMOVE_CALL = true;

    private ZooKeeper zk;
    private String rootZNode;
    private CountDownLatch zkAvail;

    @Before
    public void setUp() throws Exception {
        zkAvail = new CountDownLatch(1);
        zk = new ZooKeeper("localhost:2181", 30, this);
        zkAvail.await(30, TimeUnit.SECONDS);

        rootZNode = zk.create("/", null, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT_SEQUENTIAL);
    }

    @After
    public void tearDown() throws Exception {
        zk.close();
    }

    /**
     * Exercise the functionality of remove watches added in ZooKeeper 3.5.0
     * 
     * Print some basic mem details to make sure we're in the ballpark
     */
    @Test
    public void createAndRemoveLotsOfWatches() throws Exception {
        final int maxIter = 100000;
        final int maxLoops = 10000;
        System.out.println("USE_REMOVE_CALL:" + USE_REMOVE_CALL);
        System.out.println("maxIter:" + maxIter);
        System.out.println("maxLoops:" + maxLoops);
        Runtime rt = Runtime.getRuntime();
        rt.gc();
        rt.gc();
        rt.gc();
        System.out.println("Available free mem is " + rt.freeMemory());
        for (int j = 0; j < maxIter; j++) {
            System.out.println("j:" + j);
            IgnoringWatcher watcher = new IgnoringWatcher();
            for (int i = 0; i < maxLoops; i++) {
                String path = String.format("%s/e-%010d-%010d", rootZNode, j, i);
                zk.exists(path, watcher);
                if (USE_REMOVE_CALL) {
                    zk.removeWatches(path, watcher, WatcherType.Any, true);
                }
            }
            rt.gc();
            rt.gc();
            rt.gc();
            System.out.println("Available free mem is " + rt.freeMemory());
        }
    }

    @Override
    public void process(WatchedEvent event) {
        if (event.getState() == KeeperState.SyncConnected) {
            zkAvail.countDown();
        }
    }

    private static class IgnoringWatcher implements Watcher {
        @Override
        public void process(WatchedEvent event) {
        }
    }
}