From: Michael Paquier <michael@paquier.xyz>
Date: Mon, 5 Jul 2021 23:10:59 +0000 (+0900)
Subject: Use WaitLatch() instead of pg_usleep() at the end of backups
X-Git-Url: http://git.postgresql.org/gitweb/static/tut_user.html?a=commitdiff_plain;h=2aca19f2989aa938ece7306678f5494a984ece3f;p=users%2Fgsingh%2Fpostgres.git

Use WaitLatch() instead of pg_usleep() at the end of backups

This concerns pg_stop_backup() and BASE_BACKUP, when waiting for the
WAL segments required for a backup to be archived.  This simplifies a
bit the handling of the wait event used in this code path.

Author: Bharath Rupireddy
Reviewed-by: Michael Paquier, Stephen Frost
Discussion: https://postgr.es/m/CALj2ACU4AdPCq6NLfcA-ZGwX7pPCK5FgEj-CAU0xCKzkASSy_A@mail.gmail.com
---

diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 7890e13d7a..c7c928f50b 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -11638,9 +11638,11 @@ do_pg_stop_backup(char *labelfile, bool waitforarchive, TimeLineID *stoptli_p)
 				reported_waiting = true;
 			}
 
-			pgstat_report_wait_start(WAIT_EVENT_BACKUP_WAIT_WAL_ARCHIVE);
-			pg_usleep(1000000L);
-			pgstat_report_wait_end();
+			(void) WaitLatch(MyLatch,
+							 WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH,
+							 1000L,
+							 WAIT_EVENT_BACKUP_WAIT_WAL_ARCHIVE);
+			ResetLatch(MyLatch);
 
 			if (++waits >= seconds_before_warning)
 			{