Re: s/shm_mq_iovec/struct iovec/

On 15/04/2024 04:20, Thomas Munro wrote:
> Hi,
>
> I was grepping for iovec users and noticed that the shm_mq stuff
> defines its own iovec struct. Is there any reason not to use the
> standard one, now that we can? Will add to next commitfest.

I think it's better to keep them separate. They serve a similar purpose,
but they belong to completely separate APIs; I think "incidental
deduplication" is the right term for that. shm_mq_iovec is only used by
our shm queue implementation, while struct iovec is part of the POSIX
API. We wouldn't want to leak IOV_MAX into how shm_mq_iovec is used, for
example. Or as a thought experiment, if our shm_mq implementation needed
an extra flag in the struct or something, we would be free to just add
it. But if it we reused struct iovec, then we couldn't, or we'd need to
create a new struct again.

--
Heikki Linnakangas
Neon (https://neon.tech)