/* This file is part of VoltDB.
* Copyright (C) 2008-2017 VoltDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with VoltDB. If not, see <http://www.gnu.org/licenses/>.
*/
package org.voltdb.iv2;
import java.util.concurrent.LinkedTransferQueue;
import org.voltcore.utils.CoreUtils;
import org.voltdb.StarvationTracker;
/** SiteTaskerScheduler orders SiteTaskers for execution. */
public class SiteTaskerQueue
{
private final LinkedTransferQueue<SiteTasker> m_tasks = new LinkedTransferQueue<SiteTasker>();
private StarvationTracker m_starvationTracker;
public boolean offer(SiteTasker task)
{
return m_tasks.offer(task);
}
// Block on the site tasker queue.
public SiteTasker take() throws InterruptedException
{
SiteTasker task = m_tasks.poll();
if (task == null) {
m_starvationTracker.beginStarvation();
} else {
return task;
}
try {
return CoreUtils.queueSpinTake(m_tasks);
} finally {
m_starvationTracker.endStarvation();
}
}
// Non-blocking poll on the site tasker queue.
public SiteTasker poll()
{
return m_tasks.poll();
}
// Non-blocking peek on the site tasker queue.
public SiteTasker peek()
{
return m_tasks.peek();
}
public boolean isEmpty() {
return m_tasks.isEmpty();
}
public void setStarvationTracker(StarvationTracker tracker) {
m_starvationTracker = tracker;
}
}