From de8d6b379278d1bc145241e678714b4020b9ff48 Mon Sep 17 00:00:00 2001
From: guozhao <guozhao@360.cn>
Date: Tue, 17 Jan 2023 16:57:33 +0800
Subject: [PATCH] etcdserver: use time.Ticker instead of time.After

Using time.After will create a new Timer in each cycle, In these cases
, it is better to use time.Ticker.

Signed-off-by: guozhao <guozhao@360.cn>
---
 server/etcdserver/server.go            |  4 +++-
 server/lease/lessor.go                 |  5 ++++-
 server/storage/mvcc/watchable_store.go | 10 +++++++---
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/server/etcdserver/server.go b/server/etcdserver/server.go
index c46b73ad4..eb07dab55 100644
--- a/server/etcdserver/server.go
+++ b/server/etcdserver/server.go
@@ -2206,6 +2206,8 @@ func (s *EtcdServer) monitorKVHash() {
 	if t == 0 {
 		return
 	}
+	checkTicker := time.NewTicker(t)
+	defer checkTicker.Stop()
 
 	lg := s.Logger()
 	lg.Info(
@@ -2217,7 +2219,7 @@ func (s *EtcdServer) monitorKVHash() {
 		select {
 		case <-s.stopping:
 			return
-		case <-time.After(t):
+		case <-checkTicker.C:
 		}
 		if !s.isLeader() {
 			continue
diff --git a/server/lease/lessor.go b/server/lease/lessor.go
index a2e3dab24..860de54f4 100644
--- a/server/lease/lessor.go
+++ b/server/lease/lessor.go
@@ -607,12 +607,15 @@ func (le *lessor) Stop() {
 func (le *lessor) runLoop() {
 	defer close(le.doneC)
 
+	delayTicker := time.NewTicker(500 * time.Millisecond)
+	defer delayTicker.Stop()
+
 	for {
 		le.revokeExpiredLeases()
 		le.checkpointScheduledLeases()
 
 		select {
-		case <-time.After(500 * time.Millisecond):
+		case <-delayTicker.C:
 		case <-le.stopC:
 			return
 		}
diff --git a/server/storage/mvcc/watchable_store.go b/server/storage/mvcc/watchable_store.go
index 8802f439a..adf07f775 100644
--- a/server/storage/mvcc/watchable_store.go
+++ b/server/storage/mvcc/watchable_store.go
@@ -211,6 +211,10 @@ func (s *watchableStore) Restore(b backend.Backend) error {
 func (s *watchableStore) syncWatchersLoop() {
 	defer s.wg.Done()
 
+	waitDuration := 100 * time.Millisecond
+	delayTicker := time.NewTicker(waitDuration)
+	defer delayTicker.Stop()
+
 	for {
 		s.mu.RLock()
 		st := time.Now()
@@ -223,15 +227,15 @@ func (s *watchableStore) syncWatchersLoop() {
 		}
 		syncDuration := time.Since(st)
 
-		waitDuration := 100 * time.Millisecond
+		delayTicker.Reset(waitDuration)
 		// more work pending?
 		if unsyncedWatchers != 0 && lastUnsyncedWatchers > unsyncedWatchers {
 			// be fair to other store operations by yielding time taken
-			waitDuration = syncDuration
+			delayTicker.Reset(syncDuration)
 		}
 
 		select {
-		case <-time.After(waitDuration):
+		case <-delayTicker.C:
 		case <-s.stopc:
 			return
 		}