package textbender.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 "Textbender Software"), to deal in the Textbender Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Textbender Software, and to permit persons to whom the Textbender 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 Textbender Software. THE TEXTBENDER 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 TEXTBENDER SOFTWARE OR THE USE OR OTHER DEALINGS IN THE TEXTBENDER SOFTWARE.

import java.util.*;
import java.util.concurrent.atomic.AtomicBoolean;
//import textbender.g.util.logging.LoggerX;
import textbender.g.lang.*;


/** A thread-safe implementation of a spool, based on a Vector.
  */
public @ThreadSafe class SpoolT extends Vector<Hold> implements Spool
{


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


    /** Adds the hold to the spool, or releases it immediately.
      *
      *     @throws IllegalArgumentException if the hold
      *         is not annotated {@linkplain ThreadSafe thread-safe}
      */
    public boolean add( Hold hold )
    {
        if( !ThreadSafe.U.isThreadSafe( hold, "release")) throw new IllegalArgumentException( "hold is not thread-safe" );

        synchronized( SpoolT.this )
        {
            if( isUnwindingA.get() )
            {
                hold.release();
                return false;
            }
            boolean isAdded = super.add( hold ); assert isAdded;
        }
        return true;
    }



    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( catcher0 ); }



    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



}