Keep a MemoryMappedFile Alive after Dispose

Question

I need to access a shared memory map file (created and owned by a separate program); To do so I'm using

_map = MemoryMappedFile.OpenExisting(
            "buffer",
            MemoryMappedFileRights.ReadWrite, 
            HandleInheritability.None);

_mapAccessor = _map.CreateViewAccessor(0, 0, MemoryMappedFileAccess.ReadWrite);

When I close the application I call dispose on these:

public void Dispose()
{
    if (_mapAccessor != null)
        _mapAccessor.Dispose();

    if (_map != null)
        _map.Dispose();
}

but it seems like something I'm doing here is killing off the memory map file, because the other program that uses this starts getting protected memory faults.

If I dispose the _map does it actually destroy the memory mapped file, even though its not inherited ownership?

Update

Turns out the other program, not under my control, was doing naughty things after I had signaled it to go-to idle mode (immediately before disposing the memory map).

When using 'MemoryMappedFile.OpenExisting' with 'HandleInheritability.None' the memory map file will not be destroyed after dispose.

Answer 1

No, disposing a MemoryMappedFile opened by calling OpenExisting() will not destroy the underlying MMF.

The process that called the Windows API CreateFileMapping() controls the lifetime of the MMF and OpenExisting() calls OpenFileMapping() instead.