— Scott McNealy, Sun Microsystems Chairman, President and ceo

beta.setName(“Beta thread”);
alpha.start();
beta.start();
}
public void 
run()
 {
for (int i = 0; i < 25; i++) {
String threadName = Thread.currentThread().getName();
System.out.println(threadName + “ is running”);
}
}
}
Make one Runnable instance.
Make two threads, with the same Runnable (the 
same job--we’ll talk more about the “two threads 
and one Runnable” in a few pages).
Name the threads.
Start the threads.
Each thread will run through this loop, 
printing its name each time.
What will happen?
Will the threads take turns? Will you see the thread names 
alternating? How often will they switch? With each iteration? 
After five iterations? 
You already know the answer: we don’t know! It’s up to the 
scheduler. And on your OS, with your particular JVM, on 
your CPU, you might get very different results.
Running under OS X 10.2 (Jaguar), with five or fewer 
iterations, the Alpha thread runs to completion, then 
the Beta thread runs to completion. Very consistent. Not 
guaranteed, but very consistent.
But when you up the loop to 25 or more iterations, things 
start to wobble. The Alpha thread might not get to complete 
all 25 iterations before the scheduler sends it back to 
runnable to let the Beta thread have a chance.
File Edit Window Help Centauri 
Alpha thread is running
Alpha thread is running
Alpha thread is running
Beta thread is running
Alpha thread is running
Beta thread is running
Beta thread is running
Beta thread is running
Beta thread is running
Beta thread is running
Beta thread is running
Beta thread is running