Re: Improve LWLock tranche name visibility across backends - Mailing list pgsql-hackers

On Fri, Aug 22, 2025 at 3:01 PM Sami Imseih <samimseih@gmail.com> wrote:
>
> >> If there is agreement on setting limits, may I propose
> >> 1024 tranches and NAMEDATALEN. Both seem reasonably sufficient.
>
> > Let's proceed with that approach for now.  We can worry about the exact
> > limits once this is closer to commit.
>
> v11 implements the fixed size shared memory as discussed.

One point I did not make earlier is that the tranche name lengths will
need to be as long as we allow in dsm_registry.c.

```
#define DSMR_NAME_LEN 128

#define DSMR_DSA_TRANCHE_SUFFIX " DSA"
#define DSMR_DSA_TRANCHE_SUFFIX_LEN (sizeof(DSMR_DSA_TRANCHE_SUFFIX) - 1)
#define DSMR_DSA_TRANCHE_NAME_LEN (DSMR_NAME_LEN + DSMR_DSA_TRANCHE_SUFFIX_LEN)
```

We should make the limits external (in lwlock.h) and dsa_registery.c
can enforce
based on those values.

--
Sami