DataStream doesn't follow Dispose() pattern regarding the unmanaged references

[aienabled]

Hello!

DataStream has a _gCHandle field which will be never released for abandoned (collected with GC) instance as there is no finalizer defined.

I've noticed a memory leak in MonoGame related to this issue in the way I use SoundEffect class from here (by keeping it abandoned and relying on GC). I understand that DataStream might have been never intended to be used the way it's used there and that if used with using or try-finally patterns controlling auto disposal it should not be a problem, however it's a public API of SharpDX and so there should be never a possibility for memory leaks related to the unmanaged resources. Also, I see no point of having a properly implemented Dispose(disposing) method when it's never called with disposing==false (as there is no finalizer in this and parent classes) - maybe you just forgot/missed that System.IO.Stream doesn't have a finalizer and it's up to derived class to implement it?

The issue could be completely resolved by adding to DataStream.cs:

~DataStream()
{
     Dispose(false);
}

And GC.SuppressFinalize(this); at the end of the Dispose method.

I could create a pull request if needed. (Created!)

Regards!

[KonajuGames]

System.IO.Stream does call GC.SuppressFinalize(), so that is not required.

[aienabled]

@KonajuGames , thanks! https://referencesource.microsoft.com/#mscorlib/system/io/stream.cs I've looked only on Dispose() and not on the Close() method which is called by Dispose(). So the fix is even simpler - just need a finalizer in the DataStream class.

[xoofx]

Yeah, at that time, DataStream was imported from SlimDX... so I believe it was left as it was exposed there... There are also two other reasons why It has not been updated:

• There is a story in SharpDX to not dispose object automatically for you via finalizers, mainly because many COM problems can arise for certain API (releasing on another thread, heard many stories about this, while myself never confronted to it)
• I have never used DataStream in any projects when using SharpDX, so it's a reason why it hasn't received much attention

Though PR welcome and going to be merged! 😉