package votorola.g.hold; // Copyright 2005-2006, Michael Allan.  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Votorola Software"), to deal in the Votorola Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Votorola Software, and to permit persons to whom the Votorola Software is furnished to do so, subject to the following conditions: The preceding copyright notice and this permission notice shall be included in all copies or substantial portions of the Votorola Software. THE VOTOROLA SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE VOTOROLA SOFTWARE OR THE USE OR OTHER DEALINGS IN THE VOTOROLA SOFTWARE.

import java.util.*;
import java.util.concurrent.atomic.AtomicBoolean;
import votorola.g.lang.*;


/** A thread-safe implementation of a spool based on a Vector.
  */
public final @ThreadSafe class SpoolT extends Vector<Hold> implements Spool // better to extend Vector by composition, cf. Spool1
{


   // - C o l l e c t i o n --------------------------------------------------------------


    public boolean addAll( int index, Collection<? extends Hold> c ) { throw new UnsupportedOperationException(); } // no need



   // - L i s t --------------------------------------------------------------------------


    public void add( int index, Hold hold ) { throw new UnsupportedOperationException(); } // no need


    public List<Hold> subList( int fromIndex, int toIndex ) { throw new UnsupportedOperationException(); } // back door to bypass add(Hold)



   // - S p o o l ------------------------------------------------------------------------


    public boolean isUnwinding() { return isUnwindingA.get(); }


        private final AtomicBoolean isUnwindingA = new AtomicBoolean();



    public boolean unwind() { return unwind( CATCHER_0 ); }



    public boolean unwind( Catcher<Hold> catcher )
    {
        if( isUnwindingA.getAndSet( true )) return false;

        for( ;; )
        {
            final Hold hold;
            synchronized( SpoolT.this ) // atomic test/remove, since other threads may be calling remove()
            {
                if( isEmpty() ) break;

                hold = remove( size() - 1 );
            }
            try{ hold.release(); }
            catch( Error r ) { catcher.catchError( hold, r ); }
            catch( Exception x ) { catcher.catchException( hold, x ); }
        }
        return true;
    }



   // - V e c t o r ----------------------------------------------------------------------


    public void addElement( Hold hold ) { throw new UnsupportedOperationException(); } // no need


    public void insertElementAt( Hold hold, int index ) { throw new UnsupportedOperationException(); } // no need



}