source: src/main/java/bargainingchips/protocol/AsynchronousOffersProtocol.java@ 318

package bargainingchips.protocol;

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;

import bargainingchips.actions.Accept;
import bargainingchips.actions.Agreement;
import bargainingchips.actions.Disagreement;
import bargainingchips.actions.Offer;
import bargainingchips.actions.OfferBy;


public class AsynchronousOffersProtocol extends BilateralProtocol 
{
        public AsynchronousOffersProtocol(BlockingQueue<Offer> fromA,
                        BlockingQueue<Offer> toA, BlockingQueue<Offer> fromB,
                        BlockingQueue<Offer> toB) {
                super(fromA, toA, fromB, toB);
                // TODO Auto-generated constructor stub
        }

        /**
         * An offer is valid iff:
         * 1) An offer or walk-away is sent by anyone at any time: $o_{t+1} \in \Omega \cup \{End\}$; or
     * 2) A bid is accepted by the other: $o_{t+1} = Accept$ and $o_{t}\in\Omega$ and $g_t \neq g_{t+1}$; or
     * 3) An accept is acknowledged, concluding the thread: $o_{t+1} = Accept$ and $o_{t} = Accept$ and $o_{t-1} \in \Omega$ and $g_{t-1} = g_{t+1} \neq g_{t}$.
         */     
        @Override
        protected Offer validateAndReplace(OfferBy curOffer) 
        {
                // 1)
                if (curOffer.isBid())
                        return curOffer;
                
                if (curOffer.isBreakoff())
                        return new Disagreement();      // we are done
                
                // 2)
                if (log.size() < 2)             // o_t should exist
                        return null;
                
                String curSender = curOffer.getSender();
                OfferBy prevOffer = getLastOffer();
                String prevSender = prevOffer.getSender();
                if (curOffer.isAccept() && prevOffer.isBid() && !curSender.equals(prevSender))
                        return curOffer;
                
                // 3)
                if (log.size() < 3)             // o_{t-1} should exist
                        return null;
                
                OfferBy prevprev = log.get(log.size() - 2);
                String prevprevSender = prevprev.getSender();
                
                if (curOffer.isAccept() && prevOffer.isAccept() 
                                && prevprev.isBid() && prevprevSender.equals(curSender) 
                                && !curSender.equals(prevSender))
                        return new Agreement(prevprev.getBundle());             // we are done
                
                return null;
        }
        
        public static void main(String[] args) throws InterruptedException 
        {
                BlockingQueue<Offer> fromA  = new LinkedBlockingQueue<Offer>();
                BlockingQueue<Offer> toA        = new LinkedBlockingQueue<Offer>();
                BlockingQueue<Offer> fromB  = new LinkedBlockingQueue<Offer>();
                BlockingQueue<Offer> toB        = new LinkedBlockingQueue<Offer>();
                
                AsynchronousOffersProtocol aop = new AsynchronousOffersProtocol(fromA, toA, fromB, toB);
                
                Thread aopThread = new Thread(aop);
                aopThread.start();
                
                fromA.put(Offer.getSampleOffer(3));
                Thread.sleep(1000);
                fromA.put(Offer.getSampleOffer(6));
                Thread.sleep(1000);
                fromB.put(Offer.getSampleOffer(7));
                Thread.sleep(1000);
                fromA.put(new Accept(Offer.getSampleOffer(6)));
                
                Thread.sleep(1000);
                System.out.println("Sent to B:" + toB);
        }

}