This is part of JavaUnitTestChallengeSolved. -- DonWells
----
Now lets try four threads together:

 public class F''''''ourThreadsTogether extends Test {
    public BoundedBuffer buffer;
    public P''''''utThread firstPutThread;
    public P''''''utThread secondPutThread;
    public T''''''akeThread firstTakeThread;
    public T''''''akeThread secondTakeThread;
    
    public void setUp(){
        buffer = new BoundedBuffer();
        firstPutThread = new P''''''utThread(buffer);
        secondPutThread = new P''''''utThread(buffer);
        firstTakeThread = new T''''''akeThread(buffer);
        secondTakeThread = new T''''''akeThread(buffer);}
    
    public void runTest (){
        T''''''akeThread.resetOutput();
        firstTakeThread.start();
        secondTakeThread.start();
        firstPutThread.start();
        secondPutThread.start();
        waitForTakeToFinish();
        should(T''''''akeThread.doesOuputHaveTwoOf("a"), "should get two a");
        should(T''''''akeThread.doesOuputHaveTwoOf("b"), "should get two b");
        should(T''''''akeThread.doesOuputHaveTwoOf("c"), "should get two c");
        should(T''''''akeThread.doesOuputHaveTwoOf("d"), "should get two d");
        should(T''''''akeThread.doesOuputHaveTwoOf("e"), "should get two e");}
        
    public void waitForTakeToFinish(){
        try {
            firstTakeThread.join(1000);
            secondTakeThread.join(1000);}
        catch (InterruptedException exception) {};}
 }

http://members.aol.com/jdwells123/fourtogetherpass.gif

I was expecting problems of some sort with this one, but it runs just fine.