*: improve the user experience for using Ctrl+C to make tidb exit (#58537)

close pingcap/tidb#58418

cmd/tidb-server/main.go

@@ -325,9 +325,9 @@ func main() {
 	exited := make(chan struct{})
 	signal.SetupSignalHandler(func() {
 		svr.Close()
+		resourcemanager.InstanceResourceManager.Stop()
 		cleanup(svr, storage, dom)
 		cpuprofile.StopCPUProfiler()
-		resourcemanager.InstanceResourceManager.Stop()
 		executor.Stop()
 		close(exited)
 	})

pkg/domain/domain.go

@@ -1004,7 +1004,7 @@ func (do *Domain) CheckAutoAnalyzeWindows() {
 	}
 }
 
-func (do *Domain) refreshMDLCheckTableInfo() {
+func (do *Domain) refreshMDLCheckTableInfo(ctx context.Context) {
 	se, err := do.sysSessionPool.Get()
 
 	if err != nil {
@@ -1013,7 +1013,7 @@ func (do *Domain) refreshMDLCheckTableInfo() {
 	}
 	// Make sure the session is new.
 	sctx := se.(sessionctx.Context)
-	ctx := kv.WithInternalSourceType(context.Background(), kv.InternalTxnMeta)
+	ctx = kv.WithInternalSourceType(ctx, kv.InternalTxnMeta)
 	if _, err := sctx.GetSQLExecutor().ExecuteInternal(ctx, "rollback"); err != nil {
 		se.Close()
 		return
@@ -1182,7 +1182,7 @@ func (do *Domain) loadSchemaInLoop(ctx context.Context) {
 		case <-do.exit:
 			return
 		}
-		do.refreshMDLCheckTableInfo()
+		do.refreshMDLCheckTableInfo(ctx)
 		select {
 		case do.mdlCheckCh <- struct{}{}:
 		default:

pkg/util/signal/signal_posix.go

@@ -32,7 +32,7 @@ func SetupSignalHandler(shutdownFunc func()) {
 
 	signal.Notify(usrDefSignalChan, syscall.SIGUSR1)
 	go func() {
-		buf := make([]byte, 1<<16)
+		buf := make([]byte, 1<<17)
 		for {
 			sig := <-usrDefSignalChan
 			if sig == syscall.SIGUSR1 {

pkg/util/wait_group_wrapper.go

@@ -29,17 +29,20 @@ import (
 // if the `exited` signal is true by print them on log.
 type WaitGroupEnhancedWrapper struct {
 	sync.WaitGroup
-	source          string
-	registerProcess sync.Map
+	source string
+	mu     struct {
+		sync.Mutex
+		registerProcess map[string]struct{}
+	}
 }
 
 // NewWaitGroupEnhancedWrapper returns WaitGroupEnhancedWrapper, the empty source indicates the unit test, then
 // the `checkUnExitedProcess` won't be executed.
 func NewWaitGroupEnhancedWrapper(source string, exit chan struct{}, exitedCheck bool) *WaitGroupEnhancedWrapper {
 	wgew := &WaitGroupEnhancedWrapper{
-		source:          source,
-		registerProcess: sync.Map{},
+		source: source,
 	}
+	wgew.mu.registerProcess = make(map[string]struct{})
 	if exitedCheck {
 		wgew.Add(1)
 		go wgew.checkUnExitedProcess(exit)
@@ -56,7 +59,7 @@ func (w *WaitGroupEnhancedWrapper) checkUnExitedProcess(exit chan struct{}) {
 	<-exit
 	logutil.BgLogger().Info("waitGroupWrapper start exit-checking", zap.String("source", w.source))
 	if w.check() {
-		ticker := time.NewTimer(2 * time.Second)
+		ticker := time.NewTicker(2 * time.Second)
 		defer ticker.Stop()
 		for {
 			<-ticker.C
@@ -70,10 +73,11 @@ func (w *WaitGroupEnhancedWrapper) checkUnExitedProcess(exit chan struct{}) {
 
 func (w *WaitGroupEnhancedWrapper) check() bool {
 	unexitedProcess := make([]string, 0)
-	w.registerProcess.Range(func(key, _ any) bool {
-		unexitedProcess = append(unexitedProcess, key.(string))
-		return true
-	})
+	w.mu.Lock()
+	for key := range w.mu.registerProcess {
+		unexitedProcess = append(unexitedProcess, key)
+	}
+	w.mu.Unlock()
 	if len(unexitedProcess) > 0 {
 		logutil.BgLogger().Warn("background process unexited while received exited signal",
 			zap.Strings("process", unexitedProcess),
@@ -123,20 +127,26 @@ func (w *WaitGroupEnhancedWrapper) RunWithRecover(exec func(), recoverFn func(r
 }
 
 func (w *WaitGroupEnhancedWrapper) onStart(label string) {
-	_, ok := w.registerProcess.Load(label)
+	w.mu.Lock()
+	_, ok := w.mu.registerProcess[label]
+	w.mu.Unlock()
 	if ok {
 		logutil.BgLogger().Panic("WaitGroupEnhancedWrapper received duplicated source process",
 			zap.String("source", w.source),
 			zap.String("process", label))
 	}
-	w.registerProcess.Store(label, struct{}{})
+	w.mu.Lock()
+	w.mu.registerProcess[label] = struct{}{}
+	w.mu.Unlock()
 	logutil.BgLogger().Info("background process started",
 		zap.String("source", w.source),
 		zap.String("process", label))
 }
 
 func (w *WaitGroupEnhancedWrapper) onExit(label string) {
-	w.registerProcess.Delete(label)
+	w.mu.Lock()
+	delete(w.mu.registerProcess, label)
+	w.mu.Unlock()
 	logutil.BgLogger().Info("background process exited",
 		zap.String("source", w.source),
 		zap.String("process", label))