package soot.dava.toolkits.base.DavaMonitor;

/*-
 * #%L
 * Soot - a J*va Optimization Framework
 * %%
 * Copyright (C) 2003 Jerome Miecznikowski
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 2.1 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 Lesser Public License for more details.
 * 
 * You should have received a copy of the GNU General Lesser Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/lgpl-2.1.html>.
 * #L%
 */

import java.util.LinkedList;

class Lock {
  public Thread owner;
  public int level;

  private final LinkedList<Thread> q;

  Lock() {
    level = 0;
    owner = null;
    q = new LinkedList<Thread>();
  }

  public Thread nextThread() {
    return q.getFirst();
  }

  public Thread deQ(Thread t) throws IllegalMonitorStateException {
    if (t != q.getFirst()) {
      throw new IllegalMonitorStateException();
    }

    return q.removeFirst();
  }

  public void enQ(Thread t) {
    q.add(t);
  }
}
