/**
* Copyright (c) 2012, University of Konstanz, Distributed Systems Group
* All rights reserved.
*
* Redistribution and use 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.
* * Neither the name of the University of Konstanz nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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 <COPYRIGHT HOLDER> 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.
*/
//Cleversafe open-source code header - Version 1.1 - December 1, 2006
//
//Cleversafe Dispersed Storage(TM) is software for secure, private and
//reliable storage of the world's data using information dispersal.
//
//Copyright (C) 2005-2007 Cleversafe, 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; either version 2
//of the License, or (at your option) any later version.
//
//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, write to the Free Software
//Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
//USA.
//
//Contact Information:
// Cleversafe, 10 W. 35th Street, 16th Floor #84,
// Chicago IL 60616
// email: licensing@cleversafe.org
//
//END-OF-HEADER
//-----------------------
//@author: John Quigley <jquigley@cleversafe.com>
//@date: January 1, 2008
//---------------------
package org.jscsi.scsi.lu;
import java.nio.ByteBuffer;
import java.util.NoSuchElementException;
import org.apache.log4j.Logger;
import org.jscsi.core.scsi.Status;
import org.jscsi.scsi.protocol.Command;
import org.jscsi.scsi.protocol.sense.exceptions.IllegalRequestException;
import org.jscsi.scsi.tasks.Task;
import org.jscsi.scsi.tasks.TaskFactory;
import org.jscsi.scsi.tasks.management.TaskManager;
import org.jscsi.scsi.tasks.management.TaskServiceResponse;
import org.jscsi.scsi.tasks.management.TaskSet;
import org.jscsi.scsi.transport.Nexus;
import org.jscsi.scsi.transport.TargetTransportPort;
//TODO: Describe class or interface
public abstract class AbstractLogicalUnit implements LogicalUnit
{
private static Logger _logger = Logger.getLogger(AbstractLogicalUnit.class);
private TaskSet taskSet;
private TaskManager taskManager;
private TaskFactory taskFactory;
private Thread manager;
/////////////////////////////////////////////////////////////////////////////
// constructors
protected AbstractLogicalUnit()
{
}
protected AbstractLogicalUnit(TaskSet taskSet, TaskManager taskManager, TaskFactory taskFactory)
{
this.taskSet = taskSet;
this.taskManager = taskManager;
this.taskFactory = taskFactory;
}
/////////////////////////////////////////////////////////////////////////////
// operations
public void enqueue(TargetTransportPort port, Command command)
{
if (_logger.isDebugEnabled())
{
_logger.debug("enqueuing command: " + command + ", associated with TargetTransportPort: "
+ port);
}
try
{
Task task = this.getTaskFactory().getInstance(port, command);
assert task != null : "improper task factory implementation returned null task";
if (_logger.isDebugEnabled())
{
_logger.debug("successfully constructed task: " + task);
}
this.taskSet.offer(task); // non-blocking, task set sends any errors to transport port
}
catch (IllegalRequestException e)
{
port.writeResponse(command.getNexus(), command.getCommandReferenceNumber(),
Status.CHECK_CONDITION, ByteBuffer.wrap(e.encode()));
}
}
public void start()
{
this.manager = new Thread(this.taskManager, "TaskManager");
this.manager.start();
}
public void stop()
{
_logger.debug("Signalling LU task manager to stop");
this.manager.interrupt();
try
{
_logger.debug("Waiting for LU task manager to terminate");
this.manager.join();
_logger.debug("LU task manger finished");
}
catch (InterruptedException e)
{
_logger.warn("Interrupted while waiting for LU task manager to finish");
}
}
public TaskServiceResponse abortTask(Nexus nexus)
{
try
{
this.taskSet.remove(nexus);
return TaskServiceResponse.FUNCTION_COMPLETE;
}
catch (NoSuchElementException e)
{
return TaskServiceResponse.FUNCTION_COMPLETE;
}
catch (InterruptedException e)
{
return TaskServiceResponse.SERVICE_DELIVERY_OR_TARGET_FAILURE;
}
}
// TODO: nomenclature of this is strange, this is aborting a task, abortTask() above
// is simply attempting to remove a task from the scheduler
public TaskServiceResponse abortTaskSet(Nexus nexus)
{
try
{
this.taskSet.abort(nexus);
return TaskServiceResponse.FUNCTION_COMPLETE;
}
catch (InterruptedException e)
{
return TaskServiceResponse.SERVICE_DELIVERY_OR_TARGET_FAILURE;
}
catch (IllegalArgumentException e)
{
throw e;
}
}
public TaskServiceResponse clearTaskSet(Nexus nexus)
{
try
{
this.taskSet.clear(nexus);
return TaskServiceResponse.FUNCTION_COMPLETE;
}
catch (InterruptedException e)
{
return TaskServiceResponse.SERVICE_DELIVERY_OR_TARGET_FAILURE;
}
catch (IllegalArgumentException e)
{
throw e;
}
}
public void nexusLost()
{
this.taskSet.clear();
}
public TaskServiceResponse reset()
{
this.taskSet.clear();
return TaskServiceResponse.FUNCTION_COMPLETE;
}
/////////////////////////////////////////////////////////////////////////////
// getters/setters
public TaskSet getTaskSet()
{
return taskSet;
}
protected void setTaskSet(TaskSet taskSet)
{
this.taskSet = taskSet;
}
public TaskManager getTaskManager()
{
return taskManager;
}
protected void setTaskManager(TaskManager taskManager)
{
this.taskManager = taskManager;
}
public TaskFactory getTaskFactory()
{
return taskFactory;
}
protected void setTaskFactory(TaskFactory taskFactory)
{
this.taskFactory = taskFactory;
}
@Override
public String toString()
{
return "<LogicalUnit task: " + this.taskFactory + ">";
}
}