Lucene example source code file (LockStressTest.java)

This example Lucene source code file (LockStressTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

file, fslockfactory, id, illegalaccessexception, instantiationexception, io, ioexception, ioexception, lockclass, lockclass, lockfactory, lockfactory, lockverifyserver, string, string

The Lucene LockStressTest.java source code

package org.apache.lucene.store;

/**
 * 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.
 */

import java.io.IOException;
import java.io.File;

/**
 * Simple standalone tool that forever acquires & releases a
 * lock using a specific LockFactory.  Run without any args
 * to see usage.
 *
 * @see VerifyingLockFactory
 * @see LockVerifyServer
 */ 

public class LockStressTest {

  public static void main(String[] args) throws Exception {

    if (args.length != 6) {
      System.out.println("\nUsage: java org.apache.lucene.store.LockStressTest myID verifierHostOrIP verifierPort lockFactoryClassName lockDirName sleepTime\n" +
                         "\n" +
                         "  myID = int from 0 .. 255 (should be unique for test process)\n" +
                         "  verifierHostOrIP = host name or IP address where LockVerifyServer is running\n" +
                         "  verifierPort = port that LockVerifyServer is listening on\n" +
                         "  lockFactoryClassName = primary LockFactory class that we will use\n" +
                         "  lockDirName = path to the lock directory (only set for Simple/NativeFSLockFactory\n" +
                         "  sleepTimeMS = milliseconds to pause betweeen each lock obtain/release\n" +
                         "\n" +
                         "You should run multiple instances of this process, each with its own\n" +
                         "unique ID, and each pointing to the same lock directory, to verify\n" +
                         "that locking is working correctly.\n" +
                         "\n" +
                         "Make sure you are first running LockVerifyServer.\n" + 
                         "\n");
      System.exit(1);
    }

    final int myID = Integer.parseInt(args[0]);

    if (myID < 0 || myID > 255) {
      System.out.println("myID must be a unique int 0..255");
      System.exit(1);
    }

    final String verifierHost = args[1];
    final int verifierPort = Integer.parseInt(args[2]);
    final String lockFactoryClassName = args[3];
    final String lockDirName = args[4];
    final int sleepTimeMS = Integer.parseInt(args[5]);

    LockFactory lockFactory;
    try {
      lockFactory = Class.forName(lockFactoryClassName).asSubclass(LockFactory.class).newInstance();          
    } catch (IllegalAccessException e) {
      throw new IOException("IllegalAccessException when instantiating LockClass " + lockFactoryClassName);
    } catch (InstantiationException e) {
      throw new IOException("InstantiationException when instantiating LockClass " + lockFactoryClassName);
    } catch (ClassCastException e) {
      throw new IOException("unable to cast LockClass " + lockFactoryClassName + " instance to a LockFactory");
    } catch (ClassNotFoundException e) {
      throw new IOException("unable to find LockClass " + lockFactoryClassName);
    }

    File lockDir = new File(lockDirName);

    if (lockFactory instanceof FSLockFactory) {
      ((FSLockFactory) lockFactory).setLockDir(lockDir);
    }

    lockFactory.setLockPrefix("test");
    
    LockFactory verifyLF = new VerifyingLockFactory((byte) myID, lockFactory, verifierHost, verifierPort);

    Lock l = verifyLF.makeLock("test.lock");

    while(true) {

      boolean obtained = false;

      try {
        obtained = l.obtain(10);
      } catch (LockObtainFailedException e) {
        System.out.print("x");
      }

      if (obtained) {
        System.out.print("l");
        l.release();
      }
      Thread.sleep(sleepTimeMS);
    }
  }
}