Determine managed vs unmanaged resources

Question

There are lots of questions about managed vs unmanaged resources. I understand the basic definition of the two. However, I have a hard time knowing when a resource or obje

Answer 1

It is pretty straight-forward, you can never accidentally allocate an unmanaged resource. A pinvoke call is required to allocate it, you'd know about it. The term "object" is overloaded, but there is no such thing as an unmanaged object, all objects in a .NET program are managed. You may interop with code written in another language that supports creating objects, like C++. But you cannot directly use such an object, a C++/CLI wrapper is required. Which makes it a managed class that implements IDisposable.

If you work with a poorly documented library then do pay attention when you get an IntPtr back. That's a pretty strong indication that an unmanaged allocation is involved, either a pointer to unmanaged memory or an operating system handle. That library should then also give you a way to release it, if it doesn't otherwise manage it automatically. Contact the owner of the library if you are not sure how to properly deal with it.

It was Microsoft's job to provide managed wrapper classes around all common operating system resources. Like FileStream, Socket, etcetera. Those classes almost always implement IDisposable. The only thing you have to do in your code when you store such an class object in your own class is to implement IDisposable yourself, just so you call the Dispose() method on those object. Or use the using statement if you use them as a local variable in a method.