package threadbook.ch05;

public class PiInterrupt extends Object implements Runnable {

private double latestPiEstimate;

public void run() {

try {

System.out.println("for comparison, Math.PI=" +

Math.PI);

calcPi(0.000000001);

System.out.println("within accuracy, latest pi=" +

latestPiEstimate);

} catch ( InterruptedException x ) {

System.out.println("INTERRUPTED!! latest pi=" +

latestPiEstimate);

}

}

private void calcPi(double accuracy)

throws InterruptedException {

latestPiEstimate = 0.0;

long iteration = 0;

int sign = -1;

while ( Math.abs(latestPiEstimate - Math.PI) >

accuracy ) {

if ( Thread.interrupted() ) {

throw new InterruptedException();

}

iteration++;

sign = -sign;

latestPiEstimate +=

sign * 4.0 / ( ( 2 * iteration ) - 1 );

}

}

public static void main(String[] args) {

PiInterrupt pi = new PiInterrupt();

Thread t = new Thread(pi);

t.start();

try {

Thread.sleep(10000);

t.interrupt();

} catch ( InterruptedException x ) {

// ignore

}

}

}