Programming C#

Destroying Objects

C# provides garbage collection and thus does not need an explicit destructor. If you do control an unmanaged resource, however, you will need to explicitly free that resource when you are done with it. Implicit control over this resource is provided with a Finalize( ) method (called a finalizer), which will be called by the garbage collector when your object is destroyed.

The finalizer should only release resources that your object holds on to, and should not reference other objects. Note that if you have only managed references you do not need to and should not implement the Finalize() method; you want this only for handling unmanaged resources. Because there is some cost to having a finalizer, you ought to implement this only on methods that require it (that is, methods that consume valuable unmanaged resources).

You must never call an object’s Finalize( ) method directly (except that you can call the base class’ Finalize( ) method in your own Finalize( )). The garbage collector will call Finalize( ) for you.

How Finalize Works

The garbage collector maintains a list of objects that have a Finalize( ) method. This list is updated every time a finalizable object is created or destroyed.

When an object on the garbage collector’s finalizable list is first collected, it is placed on a queue with other objects waiting to be finalized. After the Finalize( ) method executes, the garbage collector then collects the object and updates the queue, as well as its list of ...