Foo.java

package Q15_05_Call_In_Order;

import java.util.concurrent.Semaphore;

public class Foo {
	public int pauseTime = 1000;
	public Semaphore sem1;
	public Semaphore sem2;
	
	public Foo() {	
		try {
			sem1 = new Semaphore(1);
			sem2 = new Semaphore(1);
			
			sem1.acquire();
			sem2.acquire();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
	
	public void first() {
		try {
			System.out.println("Started Executing 1");
			Thread.sleep(pauseTime);
			System.out.println("Finished Executing 1");
			sem1.release();
		} catch (Exception ex) {
			ex.printStackTrace();
		}
	}
	
	public void second() {
		try {
			sem1.acquire();
			sem1.release();
			System.out.println("Started Executing 2");
			Thread.sleep(pauseTime);
			System.out.println("Finished Executing 2");
			sem2.release();
		} catch (Exception ex) {
			ex.printStackTrace();
		}
	}	
	
	public void third() {
		try {
			sem2.acquire();
			sem2.release();
			System.out.println("Started Executing 3");
			Thread.sleep(pauseTime);
			System.out.println("Finished Executing 3");
		} catch (Exception ex) {
			ex.printStackTrace();
		}
	}		
}