Is a memory leak created if a MemoryStream in .NET is not closed?


I have the following code:

MemoryStream foo(){
    MemoryStream ms = new MemoryStream();
    // write stuff to ms
    return ms;

void bar(){
    MemoryStream ms2 = foo();
    // do stuff with ms2

Is there any chance that the MemoryStream that I've allocated will somehow fail to be disposed of later?

I've got a peer review insisting that I manually close this, and I can't find the information to tell if he has a valid point or not.

10/24/2008 3:41:49 PM

Accepted Answer

If something is Disposable, you should always Dispose it. You should be using a using statement in your bar() method to make sure ms2 gets Disposed.

It will eventually get cleaned up by the garbage collector, but it is always good practice to call Dispose. If you run FxCop on your code, it would flag it as a warning.

8/29/2019 12:25:21 PM

You won't leak anything - at least in the current implementation.

Calling Dispose won't clean up the memory used by MemoryStream any faster. It will stop your stream from being viable for Read/Write calls after the call, which may or may not be useful to you.

If you're absolutely sure that you never want to move from a MemoryStream to another kind of stream, it's not going to do you any harm to not call Dispose. However, it's generally good practice partly because if you ever do change to use a different Stream, you don't want to get bitten by a hard-to-find bug because you chose the easy way out early on. (On the other hand, there's the YAGNI argument...)

The other reason to do it anyway is that a new implementation may introduce resources which would be freed on Dispose.

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