/*******************************************************************************
*
* Copyright (c) 2010 Fujitsu Services Ltd.
*
* Author: Nick Battle
*
* This file is part of VDMJ.
*
* VDMJ 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 3 of the License, or
* (at your option) any later version.
*
* VDMJ 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 VDMJ. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
package org.overture.interpreter.scheduler;
import java.io.Serializable;
import java.util.LinkedList;
import java.util.List;
import org.overture.ast.intf.lex.ILexLocation;
import org.overture.interpreter.runtime.Context;
public class ControlQueue implements Serializable
{
private static final long serialVersionUID = 1L;
private ISchedulableThread joined = null;
private boolean stimmed = false;
private List<ISchedulableThread> waiters = new LinkedList<ISchedulableThread>();
public void reset()
{
joined = null;
stimmed = false;
waiters.clear();
}
public void join(Context ctxt, ILexLocation location)
{
ISchedulableThread th = BasicSchedulableThread.getThread(Thread.currentThread());
if (joined != null && joined != th)
{
synchronized (waiters)
{
waiters.add(th);
}
th.waiting(ctxt, location);
}
joined = th;
}
public void block(Context ctxt, ILexLocation location)
{
if (stimmed)
{
stimmed = false;
} else
{
joined.waiting(ctxt, location);
}
}
public void stim()
{
stimmed = true;
if (joined != null)
{
joined.setState(RunState.RUNNABLE);
}
}
public void leave()
{
joined = null;
ISchedulableThread head = null;
synchronized (waiters)
{
if (!waiters.isEmpty())
{
head = waiters.remove(0);
}
}
if (head != null)
{
head.setState(RunState.RUNNABLE);
}
}
}