使用notify()和notifyAll()在代码中不起作用

class Reader extends Thread{
    Calculator c;
    //here we didn't write no-arg constructor.  Note this.
    // one - arg constructor.
    public Reader(Calculator calc){
        c = calc;
    }
    public void run(){
        synchronized(c){
        // 2. Acquiring the object lock and executes this code of block.
            try{
                System.out.println("Waiting for calculation...");
                c.wait();
                // 3.  Release the object lock and moves to the second synchronize block below
                // 6. Later the object get the lock here and moves on.
            }catch(InterruptedException e){
            }
            System.out.println("Total is: "+c.total);
        }
    }
    public static void main(String[] args){
        //Instantiating new with no-arg.  One more doubt,How this work without no-arg constructor above.  Please explain.
        Calculator calculator = new Calculator();
        //Instantiating new with one-arg
        new Reader(calculator).start();
        new Reader(calculator).start();
        new Reader(calculator).start();
        // 1. Once you start here it will goto first synchronized code block above
        calculator.start();
    }
}

class Calculator extends Thread{
    int total;

    public void run(){
        synchronized(this){
        // 4. This block acquires that object lock and executes the code block below.

            for(int i=0;i<100;i++){
                total +=i;
            }
            // 5.  As per documentation,If we give notify() it will release the object lock to only one thread object of its choice.
            //     If we use notifyAll(); it will release the object lock to all the three thread object.
            notify();
            // My doubt here is without using the notify or notifyAll it is working fine.
            // As per docs if we use notify() only one object should get the lock.  That is also not working here.
        }
    }
}