content: /*
   * This file is part of Adblock Plus <https://adblockplus.org/>,
   * Copyright (C) 2006-present eyeo GmbH
   *
   * Adblock Plus is free software: you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 3 as
   * published by the Free Software Foundation.
   *
   * Adblock Plus 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 Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.adblockplus.libadblockplus;
  
  import java.lang.ref.ReferenceQueue;
  import java.lang.ref.WeakReference;
  import java.util.HashSet;
  
  public final class Disposer extends WeakReference<Disposable>
  {
    static final ReferenceQueue<Disposable> referenceQueue = new ReferenceQueue<>();
    private static final HashSet<Disposer> disposerSet = new HashSet<>();
    private final Disposable disposable;
    private volatile boolean disposed = false;
  
    static
    {
      final Thread thread = new Thread(new Cleaner());
      thread.setName(Cleaner.class.getCanonicalName());
      thread.setDaemon(true);
      thread.start();
    }
  
    public Disposer(final Disposable referent, final Disposable disposable)
    {
      super(referent, referenceQueue);
      this.disposable = disposable;
  
      synchronized (disposerSet)
      {
        disposerSet.add(this);
      }
    }
  
    public synchronized void dispose()
    {
      if (!this.disposed)
      {
        try
        {
          this.disposable.dispose();
        }
        catch (final Throwable t)
        {
          // catch to set state to 'disposed' on all circumstances
        }
  
        this.disposed = true;
        synchronized (disposerSet)
        {
          disposerSet.remove(this);
        }
      }
    }
  
    private static final class Cleaner implements Runnable
    {
      public Cleaner()
      {
        //
      }
  
      @Override
      public void run()
      {
        for (;;)
        {
          try
          {
            ((Disposer) Disposer.referenceQueue.remove()).dispose();
          }
          catch (final Throwable t)
          {
            // ignored
          }
        }
      }
    }
  }
  