Returning Memory Stream from a method

Question

Wanted to know if the below scenario will cause any memory leak.

Aspx page contains the below.

private void Generator(input)
{
    using (MemoryStream memoryStream = Helper.Instance.Generate(input))
    {
    }
}

Below method is called from the aspx page which returns memory stream.

MemoryStream Generate(input)
{
    MemoryStream stream = new MemoryStream();
    //doing some stream manipulation here

    return stream;
}

Answer 1

• First point: if an exception is thrown by the code at:

  // doing some stream manipulation here
  

  then the MemoryStream will not be returned by Helper.Instance.Generate, so will not be disposed by the caller.

• Second point: MemoryStream doesn't use any unmanaged resources, so it isn't essential to call Dispose.

So in this case there will be no memory leak.

It would be arguably better to force a Dispose in Helper.Instance.Generate if an exception is thrown thus:

MemoryStream Generate(input)  
{      
    MemoryStream stream = new MemoryStream();      

    try
    {
        //doing some stream manipulation here        

        return stream;  
    }
    catch
    {
        stream.Dispose();
        throw;
    }
}  

This is a general pattern for methods that construct, manipulate and return an IDisposable object.