C comment: explain procArray->pgprocnos[]

bmomjian · bmomjian · commit 434c6cdf0cc9 · 2022-10-11T13:08:17.000-04:00
Reported-by: Aleksander Alekseev Discussion: https://postgr.es/m/CAJ7c6TOs9Dh3KNR2kiQJ3Ow0=TBucL_57DAbm--2p8w5x_8YXQ@mail.gmail.com Author: Aleksander Alekseev Backpatch-through: master
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
@@ -193,7 +193,11 @@ struct PGPROC
 
 	int			pgxactoff;		/* offset into various ProcGlobal->arrays with
 								 * data mirrored from this PGPROC */
-	int			pgprocno;
+
+	int			pgprocno;		/* Number of this PGPROC in
+								 * ProcGlobal->allProcs array. This is set
+								 * once by InitProcGlobal().
+								 * ProcGlobal->allProcs[n].pgprocno == n */
 
 	/* These fields are zero while a backend is still starting up: */
 	BackendId	backendId;		/* This backend's backend ID (if assigned) */
