Can someone please explain why on earth is this guy synchronizing on Thread.sleep ? AFAIK, if you have, say, 4 threads, then one is sleeping while the other 3 are blocked, *waiting* to sleep (!!!) (detail: finished is not volatile). Your sincerely, Ed.

WTF.java

public class WTF extends Thread {

    private boolean finished = false;
    ...

    public void run() {
        ....

        while (!finished) {

            ... [do work]

            Thread.yield();

            if (!finished) {
                synchronized (this) {     // WHY ?????
                    try {
                        Thread.sleep(SLEEP_TIME);
                    }
                    catch (InterruptedException e) {
                        LOG.error(e);
                    }
                }
            }
        }

    }

}