/*******************************************************************************
*Copyright (c) 2009 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, only version 3 of the License.
*
*
* This file 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., 130 Castilian
* Dr., Goleta, CA 93101 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 LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 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 LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE 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, SANTA
* BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY, WHICH IN
* THE REGENTS’ DISCRETION MAY INCLUDE, WITHOUT LIMITATION, REPLACEMENT
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*******************************************************************************/
/*
*
* Author: chris grzegorczyk <grze@eucalyptus.com>
*/
package edu.ucsb.eucalyptus.util;
import edu.ucsb.eucalyptus.msgs.EucalyptusErrorMessageType;
import edu.ucsb.eucalyptus.msgs.BaseMessage;
import org.apache.log4j.Logger;
import java.util.concurrent.ConcurrentHashMap;
public class ReplyCoordinator {
private static Logger LOG = Logger.getLogger( ReplyCoordinator.class );
private static int MAP_CAPACITY = 64;
private static int MAP_NUM_CONCURRENT = MAP_CAPACITY / 2;
private static float MAP_BIN_AVG_THRESHOLD = 1.0f;
private static long MAP_GET_WAIT_MS = 10;
private static long MAP_SUBMIT_SLEEP_MS = MAP_GET_WAIT_MS;
private long MAP_TIMEOUT_MS = 15000;
private ConcurrentHashMap<String, BaseMessage> replyMap;
private ConcurrentHashMap<String,String> waitList;
public ReplyCoordinator()
{
this.MAP_TIMEOUT_MS = 15000;
this.replyMap = new ConcurrentHashMap<String, BaseMessage>( MAP_CAPACITY, MAP_BIN_AVG_THRESHOLD, MAP_NUM_CONCURRENT );
this.waitList = new ConcurrentHashMap<String, String>( MAP_CAPACITY, MAP_BIN_AVG_THRESHOLD, MAP_NUM_CONCURRENT );
}
public ReplyCoordinator( long user_timeout )
{
this();
this.MAP_TIMEOUT_MS = user_timeout;
}
public void putMessage( BaseMessage msg )
{
long startTime = System.currentTimeMillis();
String msgCorId = msg.getCorrelationId();
//:: what if the requesting thread hasnt entered the wait list yet? :://
//:: - try to wait for the requesting thread to join the list :://
//:: -> if joins, place the reply :://
//:: -> fail gracefully after a predefined timeout :://
while( !this.waitList.containsKey( msgCorId ) && (System.currentTimeMillis()-startTime) < MAP_TIMEOUT_MS )
try
{
Thread.sleep( MAP_SUBMIT_SLEEP_MS );
}
catch ( InterruptedException e ){}
if( this.waitList.containsKey( msgCorId ) )
{
String corId = this.waitList.get(msgCorId);
synchronized(corId)
{
this.replyMap.put( corId, msg );
corId.notifyAll();
}
}
else
{
LOG.error( "TIMEOUT: A message was returned by the system but the requesting client cannot be found, most likely timed out. ");
LOG.error( "TIMEOUT: Waited for msec=" + ( System.currentTimeMillis() - startTime ) );
LOG.error( "TIMEOUT: Message:" + msg );
}
}
public BaseMessage getMessage( String corId )
{
long startTime = System.currentTimeMillis();
this.waitList.put( corId, corId );
BaseMessage reply = null;
synchronized ( corId )
{
while ( !this.replyMap.containsKey( corId ) && (System.currentTimeMillis() - startTime ) < MAP_TIMEOUT_MS )
try
{
corId.wait( MAP_GET_WAIT_MS );
}
catch ( InterruptedException e ) {}
this.waitList.remove( corId );
if( this.replyMap.containsKey( corId ) )
reply = this.replyMap.remove( corId );
else
{
LOG.error( "TIMEOUT: Requesting client has waited for msec=" + (System.currentTimeMillis()-startTime) );
LOG.error( "TIMEOUT: Returning a message to indicate that the system hasn't finished processing yet" );
LOG.error( "TIMEOUT: correlationId:" + corId );
return new EucalyptusErrorMessageType("Looks like you are going to timeout, but we aren't done processing your request yet. Might be a slow network -- or a bug :(", "Raise the timeout value used by your client software.");
}
}
return reply;
}
}