Re: Avoid unecessary MemSet call (src/backend/utils/cache/relcache.c)

Ranier Vilela <ranier.vf@gmail.com>

From: Ranier Vilela <ranier.vf@gmail.com>
To: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Cc: Justin Pryzby <pryzby@telsasoft.com>, David Rowley <dgrowleyml@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2022-07-07T12:45:34Z
Lists: pgsql-hackers
Em qui., 7 de jul. de 2022 às 08:00, Peter Eisentraut <
peter.eisentraut@enterprisedb.com> escreveu:
>diff --git a/src/backend/access/transam/twophase.c
b/src/backend/access/transam/twophase.c
>index 41b31c5c6f..803d169f57 100644
>--- a/src/backend/access/transam/twophase.c
>+++ b/src/backend/access/transam/twophase.c
>@@ -780,8 +780,8 @@ pg_prepared_xact(PG_FUNCTION_ARGS)
>  {
>  GlobalTransaction gxact = &status->array[status->currIdx++];
>  PGPROC   *proc = &ProcGlobal->allProcs[gxact->pgprocno];
>- Datum values[5];
>- bool nulls[5];
>+ Datum values[5] = {0};
>+ bool nulls[5] = {0};

values variable no initialization or MemSet needed.

diff --git a/src/backend/access/transam/xlogfuncs.c
b/src/backend/access/transam/xlogfuncs.c
index 02bd919ff6..61e0f4a29c 100644
--- a/src/backend/access/transam/xlogfuncs.c
+++ b/src/backend/access/transam/xlogfuncs.c
@@ -106,8 +106,8 @@ pg_backup_stop(PG_FUNCTION_ARGS)
 {
 #define PG_STOP_BACKUP_V2_COLS 3
  TupleDesc tupdesc;
- Datum values[PG_STOP_BACKUP_V2_COLS];
- bool nulls[PG_STOP_BACKUP_V2_COLS];
+ Datum values[PG_STOP_BACKUP_V2_COLS] = {0};
+ bool nulls[PG_STOP_BACKUP_V2_COLS] = {0};

Same, values variable no initialization or MemSet needed.

diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 5f1726c095..17ff617fba 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -1188,9 +1188,6 @@ SetDefaultACL(InternalDefaultACL *iacls)
  Acl   *old_acl;
  Acl   *new_acl;
  HeapTuple newtuple;
- Datum values[Natts_pg_default_acl];
- bool nulls[Natts_pg_default_acl];
- bool replaces[Natts_pg_default_acl];
  int noldmembers;
  int nnewmembers;
  Oid   *oldmembers;
@@ -1341,13 +1338,11 @@ SetDefaultACL(InternalDefaultACL *iacls)
  }
  else
  {
+ Datum values[Natts_pg_default_acl] = {0};
+ bool nulls[Natts_pg_default_acl] = {0};

replaces, can be reduced more one level.

line 1365:
else
{
         +bool replaces[Natts_pg_default_acl] = {0};
          defAclOid = ((Form_pg_default_acl) GETSTRUCT(tuple))->oid;

please, wait a minute, I will produce a new version of your patch, with
some changes for your review.

regards,
Ranier Vilela

Commits

  1. Replace many MemSet calls with struct initialization

  2. Change some unnecessary MemSet calls

  3. Avoid unnecessary MemSet call