From a1adfb8c1beeb30d2891ed4084e16b05115dc486 Mon Sep 17 00:00:00 2001
From: Ewan Chou <coocood@gmail.com>
Date: Tue, 3 Dec 2019 12:25:55 +0800
Subject: [PATCH] store/tikv: fix lockTTL too large if local time is behind
 timestamp. (#13865)

---
 store/tikv/2pc.go      |  6 +++---
 store/tikv/2pc_test.go | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/store/tikv/2pc.go b/store/tikv/2pc.go
index 4d786377b9..dc288d667a 100644
--- a/store/tikv/2pc.go
+++ b/store/tikv/2pc.go
@@ -648,6 +648,8 @@ func (tm *ttlManager) keepAlive(c *twoPhaseCommitter) {
 			}
 
 			newTTL := uptime + ManagedLockTTL
+			logutil.BgLogger().Info("send TxnHeartBeat",
+				zap.Uint64("startTS", c.startTS), zap.Uint64("newTTL", newTTL))
 			startTime := time.Now()
 			_, err = sendTxnHeartBeat(bo, c.store, c.primary(), c.startTS, newTTL)
 			if err != nil {
@@ -675,9 +677,7 @@ func (action actionPessimisticLock) handleSingleBatch(c *twoPhaseCommitter, bo *
 		}
 		mutations[i] = mut
 	}
-
-	t0 := oracle.GetTimeFromTS(c.forUpdateTS)
-	elapsed := uint64(time.Since(t0) / time.Millisecond)
+	elapsed := uint64(time.Since(c.txn.startTime) / time.Millisecond)
 	req := tikvrpc.NewRequest(tikvrpc.CmdPessimisticLock, &pb.PessimisticLockRequest{
 		Mutations:    mutations,
 		PrimaryLock:  c.primary(),
diff --git a/store/tikv/2pc_test.go b/store/tikv/2pc_test.go
index 9760c9e2c5..f5cb8ad103 100644
--- a/store/tikv/2pc_test.go
+++ b/store/tikv/2pc_test.go
@@ -619,6 +619,21 @@ func (s *testCommitterSuite) TestPessimisticTTL(c *C) {
 	c.Assert(false, IsTrue, Commentf("update pessimistic ttl fail"))
 }
 
+// TestElapsedTTL tests that elapsed time is correct even if ts physical time is greater than local time.
+func (s *testCommitterSuite) TestElapsedTTL(c *C) {
+	key := kv.Key("key")
+	txn := s.begin(c)
+	txn.startTS = oracle.ComposeTS(oracle.GetPhysical(time.Now().Add(time.Second*10)), 1)
+	txn.SetOption(kv.Pessimistic, true)
+	time.Sleep(time.Millisecond * 100)
+	forUpdateTS := oracle.ComposeTS(oracle.ExtractPhysical(txn.startTS)+100, 1)
+	err := txn.LockKeys(context.Background(), nil, forUpdateTS, kv.LockAlwaysWait, key)
+	c.Assert(err, IsNil)
+	lockInfo := s.getLockInfo(c, key)
+	c.Assert(lockInfo.LockTtl-ManagedLockTTL, GreaterEqual, uint64(100))
+	c.Assert(lockInfo.LockTtl-ManagedLockTTL, Less, uint64(150))
+}
+
 func (s *testCommitterSuite) getLockInfo(c *C, key []byte) *kvrpcpb.LockInfo {
 	txn := s.begin(c)
 	err := txn.Set(key, key)