domain: use dedicated lock for expiredTimeStamp4PC (#45802) (#46211)

close #45400

Author: ti-chi-bot

domain/BUILD.bazel

@@ -113,13 +113,16 @@ go_test(
         "//metrics",
         "//parser/ast",
         "//parser/model",
+        "//parser/mysql",
         "//parser/terror",
         "//server",
         "//session",
+        "//sessionctx/stmtctx",
         "//sessionctx/variable",
         "//store/mockstore",
         "//testkit",
         "//testkit/testsetup",
+        "//types",
         "//util",
         "//util/mock",
         "@com_github_ngaut_pools//:pools",

domain/domain.go

@@ -118,10 +118,15 @@ type Domain struct {
 	indexUsageSyncLease     time.Duration
 	dumpFileGcChecker       *dumpFileGcChecker
 	planReplayerHandle      *planReplayerHandle
-	expiredTimeStamp4PC     types.Time
-	logBackupAdvancer       *daemon.OwnerDaemon
-	historicalStatsWorker   *HistoricalStatsWorker
-	ttlJobManager           *ttlworker.JobManager
+	expiredTimeStamp4PC     struct {
+		// let `expiredTimeStamp4PC` use its own lock to avoid any block across domain.Reload()
+		// and compiler.Compile(), see issue https://github.com/pingcap/tidb/issues/45400
+		sync.RWMutex
+		expiredTimeStamp types.Time
+	}
+	logBackupAdvancer     *daemon.OwnerDaemon
+	historicalStatsWorker *HistoricalStatsWorker
+	ttlJobManager         *ttlworker.JobManager
 
 	serverID             uint64
 	serverIDSession      *concurrency.Session
@@ -394,18 +399,18 @@ func (do *Domain) GetSnapshotMeta(startTS uint64) (*meta.Meta, error) {
 
 // ExpiredTimeStamp4PC gets expiredTimeStamp4PC from domain.
 func (do *Domain) ExpiredTimeStamp4PC() types.Time {
-	do.m.Lock()
-	defer do.m.Unlock()
+	do.expiredTimeStamp4PC.RLock()
+	defer do.expiredTimeStamp4PC.RUnlock()
 
-	return do.expiredTimeStamp4PC
+	return do.expiredTimeStamp4PC.expiredTimeStamp
 }
 
 // SetExpiredTimeStamp4PC sets the expiredTimeStamp4PC from domain.
 func (do *Domain) SetExpiredTimeStamp4PC(time types.Time) {
-	do.m.Lock()
-	defer do.m.Unlock()
+	do.expiredTimeStamp4PC.Lock()
+	defer do.expiredTimeStamp4PC.Unlock()
 
-	do.expiredTimeStamp4PC = time
+	do.expiredTimeStamp4PC.expiredTimeStamp = time
 }
 
 // DDL gets DDL from domain.
@@ -898,7 +903,6 @@ func NewDomain(store kv.Storage, ddlLease time.Duration, statsLease time.Duratio
 		slowQuery:           newTopNSlowQueries(30, time.Hour*24*7, 500),
 		indexUsageSyncLease: idxUsageSyncLease,
 		dumpFileGcChecker:   &dumpFileGcChecker{gcLease: dumpFileGcLease, paths: []string{GetPlanReplayerDirName(), GetOptimizerTraceDirName()}},
-		expiredTimeStamp4PC: types.NewTime(types.ZeroCoreTime, mysql.TypeTimestamp, types.DefaultFsp),
 		mdlCheckTableInfo: &mdlCheckTableInfo{
 			mu:         sync.Mutex{},
 			jobsVerMap: make(map[int64]int64),
@@ -913,6 +917,7 @@ func NewDomain(store kv.Storage, ddlLease time.Duration, statsLease time.Duratio
 	do.serverMemoryLimitHandle = servermemorylimit.NewServerMemoryLimitHandle(do.exit)
 	do.sysProcesses = SysProcesses{mu: &sync.RWMutex{}, procMap: make(map[uint64]sessionctx.Context)}
 	do.initDomainSysVars()
+	do.expiredTimeStamp4PC.expiredTimeStamp = types.NewTime(types.ZeroCoreTime, mysql.TypeTimestamp, types.DefaultFsp)
 	return do
 }
 

domain/domain_test.go

@@ -34,8 +34,11 @@ import (
 	"github.com/pingcap/tidb/metrics"
 	"github.com/pingcap/tidb/parser/ast"
 	"github.com/pingcap/tidb/parser/model"
+	"github.com/pingcap/tidb/parser/mysql"
+	"github.com/pingcap/tidb/sessionctx/stmtctx"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/store/mockstore"
+	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/mock"
 	dto "github.com/prometheus/client_model/go"
 	"github.com/stretchr/testify/require"
@@ -187,6 +190,17 @@ func TestStatWorkRecoverFromPanic(t *testing.T) {
 	scope := dom.GetScope("status")
 	require.Equal(t, variable.DefaultStatusVarScopeFlag, scope)
 
+	// default expiredTimeStamp4PC = "0000-00-00 00:00:00"
+	ts := types.NewTime(types.ZeroCoreTime, mysql.TypeTimestamp, types.DefaultFsp)
+	expiredTimeStamp := dom.ExpiredTimeStamp4PC()
+	require.Equal(t, expiredTimeStamp, ts)
+
+	// set expiredTimeStamp4PC to "2023-08-02 12:15:00"
+	ts, _ = types.ParseTimestamp(&stmtctx.StatementContext{TimeZone: time.UTC}, "2023-08-02 12:15:00")
+	dom.SetExpiredTimeStamp4PC(ts)
+	expiredTimeStamp = dom.ExpiredTimeStamp4PC()
+	require.Equal(t, expiredTimeStamp, ts)
+
 	err = store.Close()
 	require.NoError(t, err)