Sharing a variable between multiple different threads

Question

I want to share a variable between multiple threads like this:

boolean flag = true;
T1 main = new T1();
T2 help = new T2();
main.start();
help.start();
         


        

Answer 1

In addition to the other suggestions - you can also wrap the flag in a control class and make a final instance of it in your parent class:

public class Test {
  class Control {
    public volatile boolean flag = false;
  }
  final Control control = new Control();

  class T1 implements Runnable {
    @Override
    public void run() {
      while ( !control.flag ) {

      }
    }
  }

  class T2 implements Runnable {
    @Override
    public void run() {
      while ( !control.flag ) {

      }
    }
  }

  private void test() {
    T1 main = new T1();
    T2 help = new T2();

    new Thread(main).start();
    new Thread(help).start();
  }

  public static void main(String[] args) throws InterruptedException {
    try {
      Test test = new Test();
      test.test();
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}