Remove the unnecessary RWLock in client

Signed-off-by: JmPotato <ghzpotato@gmail.com>
tikv · Mar 21, 2023 · 254ac85 · 254ac85
1 parent 695d6b1
commit 254ac85
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Showing 4 changed files with 89 additions and 77 deletions.
diff --git a/client/client.go b/client/client.go
@@ -240,20 +240,15 @@ func WithMaxErrorRetry(count int) ClientOption {
 
 var _ Client = (*client)(nil)
 
-// serviceModeKeeper is for service mode switching
-type serviceModeKeeper struct {
-	svcModeMutex    sync.RWMutex
-	serviceMode     pdpb.ServiceMode
-	tsoClient       atomic.Value
-	tsoSvcDiscovery ServiceDiscovery
-}
-
 type client struct {
 	keyspaceID      uint32
 	svrUrls         []string
 	pdSvcDiscovery  ServiceDiscovery
 	tokenDispatcher *tokenDispatcher
-	serviceModeKeeper
+
+	serviceMode     pdpb.ServiceMode
+	tsoClient       atomic.Value // *tsoClient
+	tsoSvcDiscovery ServiceDiscovery
 
 	// For internal usage.
 	updateTokenConnectionCh chan struct{}
@@ -364,57 +359,56 @@ func (c *client) Close() {
 }
 
 func (c *client) setServiceMode(newMode pdpb.ServiceMode) {
-	c.svcModeMutex.Lock()
-	defer c.svcModeMutex.Unlock()
-
 	if newMode == c.serviceMode {
 		return
 	}
-
-	log.Info("changing service mode", zap.String("old-mode", pdpb.ServiceMode_name[int32(c.serviceMode)]),
-		zap.String("new-mode", pdpb.ServiceMode_name[int32(newMode)]))
-
-	if newMode == pdpb.ServiceMode_UNKNOWN_SVC_MODE {
-		log.Warn("intend to switch to unknown service mode. do nothing")
-		return
-	}
-
-	var newTSOCli *tsoClient
-	tsoSvcDiscovery := c.tsoSvcDiscovery
-	ctx, cancel := context.WithCancel(c.ctx)
-
-	if newMode == pdpb.ServiceMode_PD_SVC_MODE {
-		newTSOCli = newTSOClient(ctx, cancel, c.option, c.keyspaceID,
-			c.pdSvcDiscovery, c.pdSvcDiscovery.(tsoAllocatorEventSource), &pdTSOStreamBuilderFactory{})
-		newTSOCli.Setup()
-	} else {
-		tsoSvcDiscovery = newTSOServiceDiscovery(ctx, cancel, MetaStorageClient(c),
+	log.Info("[pd] changing service mode",
+		zap.String("old-mode", c.serviceMode.String()),
+		zap.String("new-mode", newMode.String()))
+	// Re-create a new TSO client.
+	var (
+		newTSOCli          *tsoClient
+		newTSOSvcDiscovery ServiceDiscovery
+	)
+	switch newMode {
+	case pdpb.ServiceMode_PD_SVC_MODE:
+		newTSOCli = newTSOClient(c.ctx, c.option, c.keyspaceID,
+			c.pdSvcDiscovery, &pdTSOStreamBuilderFactory{})
+	case pdpb.ServiceMode_API_SVC_MODE:
+		newTSOSvcDiscovery = newTSOServiceDiscovery(c.ctx, MetaStorageClient(c),
 			c.GetClusterID(c.ctx), c.keyspaceID, c.svrUrls, c.tlsCfg, c.option)
-		newTSOCli = newTSOClient(ctx, cancel, c.option, c.keyspaceID,
-			tsoSvcDiscovery, tsoSvcDiscovery.(tsoAllocatorEventSource), &tsoTSOStreamBuilderFactory{})
-		if err := tsoSvcDiscovery.Init(); err != nil {
-			cancel()
-			log.Error("failed to initialize tso service discovery. keep the current service mode",
-				zap.Strings("svr-urls", c.svrUrls), zap.String("current-mode", pdpb.ServiceMode_name[int32(c.serviceMode)]), zap.Error(err))
+		newTSOCli = newTSOClient(c.ctx, c.option, c.keyspaceID,
+			newTSOSvcDiscovery, &tsoTSOStreamBuilderFactory{})
+		if err := newTSOSvcDiscovery.Init(); err != nil {
+			log.Error("[pd] failed to initialize tso service discovery. keep the current service mode",
+				zap.Strings("svr-urls", c.svrUrls), zap.String("current-mode", c.serviceMode.String()), zap.Error(err))
 			return
 		}
-		newTSOCli.Setup()
+	case pdpb.ServiceMode_UNKNOWN_SVC_MODE:
+		log.Warn("[pd] intend to switch to unknown service mode, just return")
+		return
 	}
+	newTSOCli.Setup()
+
+	// Replace the old TSO client.
+	oldTSOClient := c.getTSOClient()
+	c.tsoClient.Store(newTSOCli)
+	oldTSOClient.Close()
 
-	// cleanup the old tso client
-	if oldTSOCli := c.getTSOClient(); oldTSOCli != nil {
-		oldTSOCli.Close()
+	oldTSOSvcDiscovery := c.tsoSvcDiscovery
+	// Set the new TSO service discovery if needed.
+	if newTSOSvcDiscovery != nil {
+		c.tsoSvcDiscovery = newTSOSvcDiscovery
 	}
-	if c.serviceMode == pdpb.ServiceMode_API_SVC_MODE {
+	// Close the old TSO service discovery safely after the old client is closed.
+	if oldTSOSvcDiscovery != nil {
 		c.tsoSvcDiscovery.Close()
 	}
 
-	c.tsoSvcDiscovery = tsoSvcDiscovery
-	c.tsoClient.Store(newTSOCli)
-
-	log.Info("service mode changed", zap.String("old-mode", pdpb.ServiceMode_name[int32(c.serviceMode)]),
-		zap.String("new-mode", pdpb.ServiceMode_name[int32(newMode)]))
 	c.serviceMode = newMode
+	log.Info("[pd] service mode changed",
+		zap.String("old-mode", c.serviceMode.String()),
+		zap.String("new-mode", newMode.String()))
 }
 
 func (c *client) getTSOClient() *tsoClient {

diff --git a/client/pd_service_discovery.go b/client/pd_service_discovery.go
@@ -138,9 +138,13 @@ type pdServiceDiscovery struct {
 	option *option
 }
 
-// newPDServiceDiscovery returns a new baseClient.
-func newPDServiceDiscovery(ctx context.Context, cancel context.CancelFunc, wg *sync.WaitGroup,
-	serviceModeUpdateCb func(pdpb.ServiceMode), urls []string, tlsCfg *tlsutil.TLSConfig, option *option) *pdServiceDiscovery {
+// newPDServiceDiscovery returns a new PD service discovery-based client.
+func newPDServiceDiscovery(
+	ctx context.Context, cancel context.CancelFunc,
+	wg *sync.WaitGroup,
+	serviceModeUpdateCb func(pdpb.ServiceMode),
+	urls []string, tlsCfg *tlsutil.TLSConfig, option *option,
+) *pdServiceDiscovery {
 	pdsd := &pdServiceDiscovery{
 		checkMembershipCh:   make(chan struct{}, 1),
 		ctx:                 ctx,
@@ -155,26 +159,27 @@ func newPDServiceDiscovery(ctx context.Context, cancel context.CancelFunc, wg *s
 }
 
 func (c *pdServiceDiscovery) Init() error {
-	if !c.isInitialized {
-		if err := c.initRetry(c.initClusterID); err != nil {
-			c.cancel()
-			return err
-		}
-		if err := c.initRetry(c.updateMember); err != nil {
-			c.cancel()
-			return err
-		}
-		log.Info("[pd] init cluster id", zap.Uint64("cluster-id", c.clusterID))
+	if c.isInitialized {
+		return nil
+	}
 
-		c.updateServiceMode()
+	if err := c.initRetry(c.initClusterID); err != nil {
+		c.cancel()
+		return err
+	}
+	if err := c.initRetry(c.updateMember); err != nil {
+		c.cancel()
+		return err
+	}
+	log.Info("[pd] init cluster id", zap.Uint64("cluster-id", c.clusterID))
 
-		c.wg.Add(2)
-		go c.updateMemberLoop()
-		go c.updateServiceModeLoop()
+	c.updateServiceMode()
 
-		c.isInitialized = true
-	}
+	c.wg.Add(2)
+	go c.updateMemberLoop()
+	go c.updateServiceModeLoop()
 
+	c.isInitialized = true
 	return nil
 }
 
@@ -198,13 +203,15 @@ func (c *pdServiceDiscovery) updateMemberLoop() {
 
 	ctx, cancel := context.WithCancel(c.ctx)
 	defer cancel()
+	ticker := time.NewTicker(memberUpdateInterval)
+	defer ticker.Stop()
 
 	for {
 		select {
-		case <-c.checkMembershipCh:
-		case <-time.After(memberUpdateInterval):
 		case <-ctx.Done():
 			return
+		case <-ticker.C:
+		case <-c.checkMembershipCh:
 		}
 		failpoint.Inject("skipUpdateMember", func() {
 			failpoint.Continue()
@@ -220,25 +227,26 @@ func (c *pdServiceDiscovery) updateServiceModeLoop() {
 
 	ctx, cancel := context.WithCancel(c.ctx)
 	defer cancel()
+	ticker := time.NewTicker(serviceModeUpdateInterval)
+	defer ticker.Stop()
 
 	for {
 		select {
-		case <-time.After(serviceModeUpdateInterval):
 		case <-ctx.Done():
 			return
+		case <-ticker.C:
 		}
-
 		c.updateServiceMode()
 	}
 }
 
-// Close releases all resources
+// Close releases all resources.
 func (c *pdServiceDiscovery) Close() {
 	c.closeOnce.Do(func() {
-		log.Info("close pd service discovery")
+		log.Info("[pd] close pd service discovery client")
 		c.clientConns.Range(func(key, cc interface{}) bool {
 			if err := cc.(*grpc.ClientConn).Close(); err != nil {
-				log.Error("[pd] failed to close gRPC clientConn", errs.ZapError(errs.ErrCloseGRPCConn, err))
+				log.Error("[pd] failed to close grpc clientConn", errs.ZapError(errs.ErrCloseGRPCConn, err))
 			}
 			c.clientConns.Delete(key)
 			return true

diff --git a/client/tso_client.go b/client/tso_client.go
@@ -91,8 +91,11 @@ type tsoClient struct {
 }
 
 // newTSOClient returns a new TSO client.
-func newTSOClient(ctx context.Context, cancel context.CancelFunc, option *option, keyspaceID uint32,
-	svcDiscovery ServiceDiscovery, eventSrc tsoAllocatorEventSource, factory tsoStreamBuilderFactory) *tsoClient {
+func newTSOClient(
+	ctx context.Context, option *option, keyspaceID uint32,
+	svcDiscovery ServiceDiscovery, factory tsoStreamBuilderFactory,
+) *tsoClient {
+	ctx, cancel := context.WithCancel(ctx)
 	c := &tsoClient{
 		ctx:                       ctx,
 		cancel:                    cancel,
@@ -105,6 +108,7 @@ func newTSOClient(ctx context.Context, cancel context.CancelFunc, option *option
 		updateTSOConnectionCtxsCh: make(chan struct{}, 1),
 	}
 
+	eventSrc := svcDiscovery.(tsoAllocatorEventSource)
 	eventSrc.SetTSOLocalServAddrsUpdatedCallback(c.updateTSOLocalServAddrs)
 	eventSrc.SetTSOGlobalServAddrUpdatedCallback(c.updateTSOGlobalServAddr)
 	c.svcDiscovery.AddServiceAddrsSwitchedCallback(c.scheduleUpdateTSOConnectionCtxs)
@@ -124,6 +128,9 @@ func (c *tsoClient) Setup() {
 
 // Close closes the TSO client
 func (c *tsoClient) Close() {
+	if c == nil {
+		return
+	}
 	log.Info("closing tso client")
 
 	c.cancel()

diff --git a/client/tso_service_discovery.go b/client/tso_service_discovery.go
@@ -79,8 +79,11 @@ type tsoServiceDiscovery struct {
 }
 
 // newTSOServiceDiscovery returns a new client-side service discovery for the independent TSO service.
-func newTSOServiceDiscovery(ctx context.Context, cancel context.CancelFunc, metacli MetaStorageClient,
-	clusterID uint64, keyspaceID uint32, urls []string, tlsCfg *tlsutil.TLSConfig, option *option) ServiceDiscovery {
+func newTSOServiceDiscovery(
+	ctx context.Context, metacli MetaStorageClient,
+	clusterID uint64, keyspaceID uint32, urls []string, tlsCfg *tlsutil.TLSConfig, option *option,
+) ServiceDiscovery {
+	ctx, cancel := context.WithCancel(ctx)
 	c := &tsoServiceDiscovery{
 		ctx:               ctx,
 		cancel:            cancel,