## Why is this an issue?

The problem with invoking `Thread.start()` in a constructor is that you’ll have a confusing mess on your hands if the class is ever extended because the superclass' constructor will start the thread before the child class has truly been initialized.

This rule raises an issue any time `start` is invoked in the constructor of a non-`final` class.

### Noncompliant code example

    public class MyClass {

      Thread thread = null;

      public MyClass(Runnable runnable) {
        thread = new Thread(runnable);
        thread.start(); // Noncompliant
      }
    }

## Resources

- CERT, TSM02-J. - Do not use background threads during class initialization