Re: How To Create And Use Memory Map Files

[Patrick Jakubowski <patrick.jakubowski@googlemail.com>]

On Monday, 18 February 2019 11:44:33 UTC+1, Niklas Holsti  wrote:
> On 19-02-18 10:19 , Dmitry A. Kazakov wrote:
> 
> > In more OSes more advanced than Linux one can have shared memory without
> > any files involved. The memory object could even be anonymous if one
> > process passes a handle to the memory to another.
> 
> Linux supports the "Unix System V" inter-process communication 
> mechanisms, including shared memory segments that are not memory-mapped 
> files and can be anonymous in the above sense.
> 
> See e.g. http://man7.org/linux/man-pages/man7/svipc.7.html

In Linux even memory mapped files are not necessary backed by a file. It can be just pages of memory even without file descriptor. These mappings are called ANONYMOUS and can be both private to a process or shared between processes. I did quick look at gnatcoll and that library doesn't support anonymous mappings.I would make quick C function call to mmap() or modify GNATCOLL.Mmap package.