CODEWITHSUNDEEP
javamultithreading
user3806245
user3806245

Reputation:

How can I limit the thread behavior to the method that calls them?

Consider this sample class:

public class Multithreading extends Thread {
    static int i = 0;

    public static void main(String args[]) throws InterruptedException {

        call1();
        call2();
    }

    private static void call2() {

        Multithreading call2obj1 = new Multithreading() {
            public void run() {

            }
        };
        call2obj1.start();

    }

    private static void call1() {

        Multithreading call1obj1 = new Multithreading() {
            public void run() {
                System.out.println("call1obj1");
                sleep(5000);
            }
        };
        Multithreading call1obj2 = new Multithreading() {
            public void run() {
                System.out.println("call1obj2");
                sleep(5000);
            }
        };
        call1obj1.start();
        call1obj2.start();

    }
}

What I want is for call2() to wait until call1() is fully complete. i.e., call1obj2 need not wait until call1obj1 is done executing, but call2obj1 should wait until both call1obj1 and call1obj2 are done.

Basically the thread behavior of call1obj1 and call1obj2 must be limited to call1();

Is that possible?

Upvotes: 0

Views: 50

Answers (1)

dimplex
dimplex

Reputation: 494

Here is a solution using CountDownLatch:

public class Multithreading extends Thread {
static int i = 0;

private static CountDownLatch LATCH;

public static void main(String args[]) throws InterruptedException {

    // Initialize the latch with the number of threads to finish
    LATCH = new CountDownLatch(2);

    call1();

    // Main thread will wait until all thread finished
    LATCH.await();

    call2();
}

private static void call2() {

    Multithreading call2obj1 = new Multithreading() {
        public void run() {
            System.out.println("call2obj1");
        }
    };
    call2obj1.start();

}

private static void call1() {

    Multithreading call1obj1 = new Multithreading() {
        public void run() {
            System.out.println("call1obj1");
            try {
                Thread.sleep(5000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            } finally {
                LATCH.countDown();
            }
        }
    };
    Multithreading call1obj2 = new Multithreading() {
        public void run() {
            System.out.println("call1obj2");
            try {
                Thread.sleep(5000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            } finally {
                LATCH.countDown();
            }
        }
    };
    call1obj1.start();
    call1obj2.start();

}

}

Upvotes: 1

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