// Example 109 from page 83

//

class Printer extends Thread {

final static Object mutex = new Object();

@Override

public void run() {

for (;;) {

synchronized (mutex) {

System.out.print("-");

Util.pause(100,300);

System.out.print("/");

}

Util.pause(200);

} } }

class Example109 {

public static void main(String[] args)

{ new Printer().start(); new Printer().start(); }

}

// Pseudo-random numbers and sleeping threads

class Util {

public static void pause(int length)

{ try { Thread.sleep(length); } catch (InterruptedException x) {} }

public static void pause(int a, int b) { pause(random(a, b)); }

public static int random(int a, int b)

{ return (int)(a + (b-a+1) * Math.random()); }

}