Data unchanged when passing data to Python in multiprocessing shared memory

[Chris Angelico]

On Thu, 3 Feb 2022 at 13:32, Avi Gross via Python-list
<python-list at python.org> wrote:
>
> Jen,
>
> I would not be shocked at incompatibilities in the system described making it hard to exchange anything, including text, but am not clear if there is a limitation of four bytes in what can be shared. For me, a character string can use any number of contiguous bytes in memory that some kind of pointer or table lookup provides access to.
>
> Clearly you could squeeze larger number in by not writing decimals but using hexadecimal notation that adds a to f as valid entries, and of course you can make your own customized base 32 or if you use more symbols (such as upper and lower case as different) you could  add a few symbols and stretch it out to base 60 or 64.
>
> Like I said, I may have missed something. If you KNOW that system A will interact with systems B and C and so on, and each machine knows what kind it is, and especially if it knows which kind of machine left it something in shared memory, there has to be a way to coordinate between them. If character strings in ASCII or UTF8 or EBCDIC or some kind of raw are allowed, and used with just a few characters that can spell out numbers, I would think much is possible. If needed, perhaps a fixed size could be set aside and the string use a null terminator if shorter.
>
> Of course if this big-endian issue also scrambles bytes used in strings, forget it.
>
> Or, maybe shared memory is not the easy way to go, even it it might be faster.
>

Structs are fine, and are highly unlikely to be the OP's problem.
Switching to a different system won't help.

Unfortunately I can't offer any serious help about the actual problem,
as I don't know what's going on with the shared memory issue.

ChrisA