/*************************************************************************
* Copyright 2009-2012 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
* 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 OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO
* IDENTIFIED, OR WITHDRAWAL OF THE CODE CAPABILITY TO THE EXTENT
* NEEDED TO COMPLY WITH ANY SUCH LICENSES OR RIGHTS.
************************************************************************/
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 ){
Thread.currentThread( ).interrupt( );
}
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 ) {
Thread.currentThread( ).interrupt( );
}
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;
}
}