/*************************************************************************
* Copyright 2009-2015 Eucalyptus Systems, Inc.
*
* 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 3 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, see http://www.gnu.org/licenses/.
*
* Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
* CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need
* additional information or have any questions.
*
* This file may incorporate work covered under the following copyright
* and permission notice:
*
* Software License Agreement (BSD License)
*
* Copyright (c) 2008, Regents of the University of California
* All rights reserved.
*
* Redistribution and use of this software in source and binary forms,
* with or without modification, are permitted provided that the
* following conditions are met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* POSSIBILITY OF SUCH DAMAGE. USERS OF THIS SOFTWARE ACKNOWLEDGE
* THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE LICENSED MATERIAL,
* COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS SOFTWARE,
* AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING
* IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA,
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* WHICH IN THE REGENTS' DISCRETION MAY INCLUDE, WITHOUT LIMITATION,
* REPLACEMENT OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO
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* NEEDED TO COMPLY WITH ANY SUCH LICENSES OR RIGHTS.
************************************************************************/
package com.eucalyptus.blockstorage.threadpool;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.log4j.Logger;
import com.eucalyptus.blockstorage.Storage;
import com.eucalyptus.blockstorage.exceptions.ThreadPoolNotInitializedException;
import com.eucalyptus.storage.common.CheckerTask;
import com.eucalyptus.system.Threads;
public class CheckerThreadPool {
private static Logger LOG = Logger.getLogger(CheckerThreadPool.class);
private static ScheduledExecutorService executor;
private static ConcurrentHashMap<String, CheckerTask> checkers;
private static Map<String, ScheduledFuture<?>> futures;
private static final ReentrantLock RLOCK = new ReentrantLock();
private CheckerThreadPool() {}
public static void initialize() { // synchronizing at the class level
RLOCK.lock();
try {
shutdown();
LOG.info("Initializing SC thread pool catering to blockstorage checker service");
executor = Executors.newSingleThreadScheduledExecutor(Threads.lookup(Storage.class, CheckerThreadPool.class));
checkers = new ConcurrentHashMap<String, CheckerTask>();
futures = new HashMap<String, ScheduledFuture<?>>();
} finally {
RLOCK.unlock();
}
}
public static void add(CheckerTask checker) throws ThreadPoolNotInitializedException {
if (executor != null && !executor.isShutdown()) {
if (checkers.putIfAbsent(checker.getName(), checker) == null) {
LOG.info("Adding task " + checker.getName() + " to blockstorage checker service");
ScheduledFuture<?> future = null;
if (checker.getIsFixedDelay()) {
future = executor.scheduleWithFixedDelay(checker, checker.getRunInterval(), checker.getRunInterval(), checker.getRunIntervalUnit());
} else {
future = executor.scheduleAtFixedRate(checker, checker.getRunInterval(), checker.getRunInterval(), checker.getRunIntervalUnit());
}
futures.put(checker.getName(), future);
} else {
LOG.info("Checker " + checker.getName() + " has already been added to Storage Checker Service");
}
} else {
LOG.warn("SC thread pool catering to blockstorage checker service is either not initalized or shut down");
throw new ThreadPoolNotInitializedException("SC thread pool catering to blockstorage checker service is either not initalized or shut down");
}
}
public static void shutdown() {
RLOCK.lock();
try {
if (checkers != null) {
checkers.clear();
checkers = null;
}
if (futures != null) {
for (ScheduledFuture<?> future : futures.values()) {
future.cancel(true);
}
futures.clear();
futures = null;
}
if (executor != null) {
LOG.info("Shutting down SC thread pool catering to blockstorage checker service");
executor.shutdownNow();
executor = null;
}
} finally {
RLOCK.unlock();
}
}
}