sjamesr

class Santa {
  volatile int reindeers = 0;
  
  // Call this in any old thread when a reindeer arrives
  public synchronized void reindeerArrived() {
    reindeers++;
    notify();
  }
  
  // Returns only when 8 or more reindeer have come in

sjamesr

$ time scanimage -d net:localhost:pixma --resolution 600 > /tmp/blah
real    1m47.591s
user    0m0.015s
sys     0m0.159s

Equivalent Java test:
    SaneDevice device = session.getDevice("pixma");
    device.open();
    device.getOption("resolution").setIntegerValue(600);
    Stopwatch stopwatch = Stopwatch.createStarted();