Garbage collector and event handlers

Question

A quick question. Say that I have a class implemented as in below example.

class Subscriber
{
    private Publisher publisher = new Publisher;


    public Subscriber()
    {
       publisher.SomeEvent += new EventHandler(OnEventFired);
    }

    private void OnEventFired(object sender, EventArgs e)
    {
    }

}

And somewhere in the program I have a method that looks like this:

public void DoSomething()
{
    Subscriber subscriber = new Subscriber();
}

Am I right to expect that this would cause a memory leak since subscriber never unsubscribes from publishers event, thus resulting in them both maintaining strong reference to each other?

Answer 1

It wouldn't cause a leak - the GC can handle circular references with no problems.

However, it would mean that the publisher would effectively have a reference to the subscriber, so the subscriber couldn't be garbage collected until either the publisher is eligible for GC, or it unsubscribes from the event.