/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
* add the following below this CDDL HEADER, with the fields enclosed
* by brackets "[]" replaced with your own identifying information:
* Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*
*
* Copyright 2006-2009 Sun Microsystems, Inc.
*/
package org.opends.server.backends.task;
import org.opends.messages.Message;
import org.opends.server.api.DirectoryThread;
import org.opends.server.loggers.debug.DebugTracer;
import org.opends.server.types.DebugLogLevel;
import static org.opends.server.loggers.debug.DebugLogger.*;
import static org.opends.server.loggers.ErrorLogger.*;
import static org.opends.messages.BackendMessages.*;
import static org.opends.server.util.StaticUtils.*;
import java.util.Map;
/**
* This class defines a thread that will be used to execute a scheduled task
* within the server and provide appropriate notification that the task is
* complete.
*/
public class TaskThread
extends DirectoryThread
{
/**
* The tracer object for the debug logger.
*/
private static final DebugTracer TRACER = getTracer();
// Indicates whether a request has been made for this thread to exit.
private volatile boolean exitRequested;
// The thread ID for this task thread.
private int threadID;
// The reference to the scheduler with which this thread is associated.
private TaskScheduler taskScheduler;
// The object that will be used for signaling the thread when there is new
// work to perform.
private final Object notifyLock;
/**
* Creates a new task thread with the provided information.
*
* @param taskScheduler The reference to the task scheduler with which this
* thread is associated.
* @param threadID The ID assigned to this task thread.
*/
public TaskThread(TaskScheduler taskScheduler, int threadID)
{
super("Task Thread " + threadID);
this.taskScheduler = taskScheduler;
this.threadID = threadID;
notifyLock = new Object();
exitRequested = false;
setAssociatedTask(null);
}
/**
* Retrieves the task currently being processed by this thread, if it is
* active.
*
* @return The task currently being processed by this thread, or
* <CODE>null</CODE> if it is not processing any task.
*/
public Task getTask()
{
return getAssociatedTask();
}
/**
* Provides a new task for processing by this thread. This does not do any
* check to ensure that no task is already in process.
*
* @param task The task to be processed.
*/
public void setTask(Task task)
{
setAssociatedTask(task);
synchronized (notifyLock)
{
notifyLock.notify();
}
}
/**
* Attempts to interrupt processing on the task in progress.
*
* @param interruptState The state to use for the task if it is
* successfully interrupted.
* @param interruptReason The human-readable reason that the task is to be
* interrupted.
* @param exitThread Indicates whether this thread should exit when
* processing on the active task has completed.
*/
public void interruptTask(TaskState interruptState, Message interruptReason,
boolean exitThread)
{
if (getAssociatedTask() != null)
{
try
{
getAssociatedTask().interruptTask(interruptState, interruptReason);
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
}
}
if (exitThread)
{
exitRequested = true;
}
}
/**
* Operates in a loop, sleeping until there is no work to do, then
* processing the task and returning to the scheduler for more work.
*/
@Override
public void run()
{
while (! exitRequested)
{
if (getAssociatedTask() == null)
{
try
{
synchronized (notifyLock)
{
notifyLock.wait(5000);
}
}
catch (InterruptedException ie)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, ie);
}
}
continue;
}
TaskState taskState = getAssociatedTask().getTaskState();
try
{
if (!TaskState.isDone(taskState))
{
Task task = getAssociatedTask();
Message message = NOTE_TASK_STARTED.get(
task.getDisplayName(), task.getTaskID());
logError(message);
taskState = task.execute();
message = NOTE_TASK_FINISHED.get(
task.getDisplayName(), task.getTaskID());
logError(message);
}
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
Task task = getAssociatedTask();
Message message = ERR_TASK_EXECUTE_FAILED.
get(String.valueOf(task.getTaskEntry().getDN()),
stackTraceToSingleLineString(e));
logError(message);
task.setTaskState(TaskState.STOPPED_BY_ERROR);
}
Task completedTask = getAssociatedTask();
setAssociatedTask(null);
if (! taskScheduler.threadDone(this, completedTask, taskState))
{
exitRequested = true;
break;
}
}
if (getAssociatedTask() != null)
{
Task task = getAssociatedTask();
TaskState taskState = TaskState.STOPPED_BY_SHUTDOWN;
taskScheduler.threadDone(this, task, taskState);
}
}
/**
* Retrieves any relevent debug information with which this tread is
* associated so they can be included in debug messages.
*
* @return debug information about this thread as a string.
*/
@Override
public Map<String, String> getDebugProperties()
{
Map<String, String> properties = super.getDebugProperties();
if (getAssociatedTask() != null)
{
properties.put("task", getAssociatedTask().toString());
}
return properties;
}
}