From 1038068978546c432868ae827dade038e42750f6 Mon Sep 17 00:00:00 2001
From: tiancaiamao <tiancaiamao@gmail.com>
Date: Sat, 8 Jan 2022 15:06:37 +0800
Subject: [PATCH] table/tables: avoid repeated renew lease operation for cached
 table (#31475)

close pingcap/tidb#31474
---
 table/tables/cache.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/table/tables/cache.go b/table/tables/cache.go
index c4856fe52e98b..73d2f908fcda2 100644
--- a/table/tables/cache.go
+++ b/table/tables/cache.go
@@ -94,7 +94,12 @@ func (c *cachedTable) TryReadFromCache(ts uint64, leaseDuration time.Duration) k
 		nowTime := oracle.GetTimeFromTS(ts)
 		distance := leaseTime.Sub(nowTime)
 		if distance >= 0 && distance <= leaseDuration/2 {
-			c.renewCh <- c.renewLease(ts, RenewReadLease, data, leaseDuration)
+			op := c.renewLease(ts, RenewReadLease, data, leaseDuration)
+			select {
+			case c.renewCh <- op:
+			default:
+				// Skip this time, if the previous renew lease operation hasn't finished.
+			}
 		}
 		return data.MemBuffer
 	}