Re: Call CalculateShmemSize() only once

On Fri, Nov 6, 2026 at 4:46 PM Xuneng Zhou <xunengzhou(at)gmail(dot)com> wrote:
>
> Erroring out can help to stop the misake where it occurs. A build
> without assert could accept the bad call, then fail later somewhere
> else. It might make the problem a bit hard to understand. That said,
> assert seems ok here since we haven't found code can make that bad
> call.
>

Agreed that an ERROR would make an invalid call easier to diagnose in
a build without assertions. I think Assert is sufficient here because
this checks an internal lifecycle invariant, consistent with the other
state-transition assertions. The current callers calculate the size
once per shared-memory initialization cycle, and requests made after
sizing are already rejected by runtime checks.

> A nit - the new state in code is SRS_SIZED, but the commit message
> says SRS_SIZING.

Good catch. Fixed in the attached patch: the code already uses
SRS_SIZED; I’ve corrected the commit message to match.

--
Best Wishes,
Ashutosh Bapat