Horton

RE: ResourceOwner refactoring

Hayato Kuroda (Fujitsu) <kuroda.hayato@fujitsu.com>

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From: "kuroda.hayato@fujitsu.com" <kuroda.hayato@fujitsu.com>
To: 'Heikki Linnakangas' <hlinnaka@iki.fi>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, "rjuju123@gmail.com" <rjuju123@gmail.com>
Cc: "michael@paquier.xyz" <michael@paquier.xyz>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, "andres@anarazel.de" <andres@anarazel.de>
Date: 2021-01-14T10:15:35Z
Lists: pgsql-hackers 
Hi,

I put some comments.

Throughout, some components don’t have helper functions.
(e.g. catcache has ResOwnerReleaseCatCache, but tupdesc doesn't.)
I think it should be unified.

[catcache.c]
> +/* support for catcache refcount management */
> +static inline void
> +ResourceOwnerEnlargeCatCacheRefs(ResourceOwner owner)
> +{
> +       ResourceOwnerEnlarge(owner);
> +}

This function is not needed.

[syscache.c]
> -static CatCache *SysCache[SysCacheSize];
> + CatCache *SysCache[SysCacheSize];

Is it right? Compilation is done even if this variable is static...

[fd.c, dsm.c]
In these files helper functions are implemented as the define directive.
Could you explain the reason? For the performance?

> Previously, this was OK, because resources AAA and BBB were kept in 
> separate arrays. But after this patch, it's not guaranteed that the 
> ResourceOwnerRememberBBB() will find an empty slot.
>
> I don't think we do that currently, but to be sure, I'm planning to grep 
> ResourceOwnerRemember and look at each call carefullly. And perhaps we 
> can add an assertion for this, although I'm not sure where.

Indeed, but I think this line works well, isn't it?

> 	Assert(owner->narr < RESOWNER_ARRAY_SIZE);

Best regards,
Hayato Kuroda
FUJITSU LIMITED

Commits

  1. Make RelationFlushRelation() work without ResourceOwner during abort

  2. Fix bug in bulk extending temp relation after failure

  3. Add missing PGDLLIMPORT markings

  4. Add test_dsa module.

  5. Clear CurrentResourceOwner earlier in CommitTransaction.

  6. Fix dsa.c with different resource owners.

  7. Fix bug in the new ResourceOwner implementation.

  8. Change pgcrypto to use the new ResourceOwner mechanism.

  9. Use a faster hash function in resource owners.

  10. Make ResourceOwners more easily extensible.

  11. Move a few ResourceOwnerEnlarge() calls for safety and clarity.