001package 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.
002
003import java.util.*;
004import java.util.concurrent.atomic.AtomicBoolean;
005import votorola.g.lang.*;
006
007
008/** A thread-safe implementation of a spool based on a Vector.
009  */
010public final @ThreadSafe class SpoolT extends Vector<Hold> implements Spool // better to extend Vector by composition, cf. Spool1
011{
012
013
014   // - C o l l e c t i o n --------------------------------------------------------------
015
016
017    public boolean addAll( int index, Collection<? extends Hold> c ) { throw new UnsupportedOperationException(); } // no need
018
019
020
021   // - L i s t --------------------------------------------------------------------------
022
023
024    public void add( int index, Hold hold ) { throw new UnsupportedOperationException(); } // no need
025
026
027    public List<Hold> subList( int fromIndex, int toIndex ) { throw new UnsupportedOperationException(); } // back door to bypass add(Hold)
028
029
030
031   // - S p o o l ------------------------------------------------------------------------
032
033
034    public boolean isUnwinding() { return isUnwindingA.get(); }
035
036
037        private final AtomicBoolean isUnwindingA = new AtomicBoolean();
038
039
040
041    public boolean unwind() { return unwind( CATCHER_0 ); }
042
043
044
045    public boolean unwind( Catcher<Hold> catcher )
046    {
047        if( isUnwindingA.getAndSet( true )) return false;
048
049        for( ;; )
050        {
051            final Hold hold;
052            synchronized( SpoolT.this ) // atomic test/remove, since other threads may be calling remove()
053            {
054                if( isEmpty() ) break;
055
056                hold = remove( size() - 1 );
057            }
058            try{ hold.release(); }
059            catch( Error r ) { catcher.catchError( hold, r ); }
060            catch( Exception x ) { catcher.catchException( hold, x ); }
061        }
062        return true;
063    }
064
065
066
067   // - V e c t o r ----------------------------------------------------------------------
068
069
070    public void addElement( Hold hold ) { throw new UnsupportedOperationException(); } // no need
071
072
073    public void insertElementAt( Hold hold, int index ) { throw new UnsupportedOperationException(); } // no need
074
075
076
077}