MMFile usage

[Alex Burton via Digitalmars-d-learn]

Hi,
I want to use MmFile to manage memory mapped files. I want 
multiple processes to be able to read in many files using the 
virtual memory system to page them in and reuse the memory.

If I read the contents of the file, I can cast it to immutable 
and then I get segfaults when accessing the data.

Or I have to .dup the data, causing memory allocation in addition 
to the paging to get the data in the first place.

Is this special memory not managed by the GC ? Do I need to keep 
all the MmFile references around to avoid segfaults ?
Alex