From: Michael Paquier <michael@paquier.xyz>
Date: Fri, 8 Sep 2023 01:00:29 +0000 (+0900)
Subject: Improve BackendXidGetPid() to only access allProcs on matching XID
X-Git-Tag: REL_17_BETA1~1897
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e722846daf4a37797ee39bc8ca3e78a4ef437f51;p=thirdparty%2Fpostgresql.git

Improve BackendXidGetPid() to only access allProcs on matching XID

Compilers are able to optimize that, but it makes the code slightly more
readable this way.

Author: Zhao Junwang
Reviewed-by: Ashutosh Bapat
Discussion: https://postgr.es/m/CAEG8a3+i9gtqF65B+g_puVaCQuf0rZC-EMqMyEjGFJYOqUUWfA@mail.gmail.com
---

diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index bfbf7f903f5..d93475b2bdd 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -3174,11 +3174,11 @@ BackendXidGetPid(TransactionId xid)
 
 	for (index = 0; index < arrayP->numProcs; index++)
 	{
-		int			pgprocno = arrayP->pgprocnos[index];
-		PGPROC	   *proc = &allProcs[pgprocno];
-
 		if (other_xids[index] == xid)
 		{
+			int			pgprocno = arrayP->pgprocnos[index];
+			PGPROC	   *proc = &allProcs[pgprocno];
+
 			result = proc->pid;
 			break;
 		}