class CubbyHole {
    private int seq;         // this is the condition variable.
    private boolean available = false;

    public native synchronized int get();
    public native synchronized void put(int value);

    static {
        try {
            System.loadLibrary("threadex");
        } catch (UnsatisfiedLinkError e) {
            System.err.println("can't find your library");
            System.exit(-1);
        }
    }
}