quitOnce & keepSession

database/kv/etcd/v3/client.go

@@ -57,7 +57,8 @@ func NewConfigClient(opts ...Option) *Client {
 
 // Client represents etcd client Configuration
 type Client struct {
-	lock sync.RWMutex
+	lock     sync.RWMutex
+	quitOnce sync.Once
 
 	// these properties are only set once when they are started.
 	name      string
@@ -102,9 +103,9 @@ func NewClient(name string, endpoints []string, timeout time.Duration, heartbeat
 		exit: make(chan struct{}),
 	}
 
-	if err := c.maintenanceStatus(); err != nil {
+	if err := c.keepSession(); err != nil {
 		cancel()
-		return nil, perrors.WithMessage(err, "client maintenance status")
+		return nil, perrors.WithMessage(err, "client keep session")
 	}
 	return c, nil
 }
@@ -124,11 +125,15 @@ func (c *Client) clean() {
 func (c *Client) stop() bool {
 	select {
 	case <-c.exit:
-		return true
+		return false
 	default:
-		close(c.exit)
+		ret := false
+		c.quitOnce.Do(func() {
+			ret = true
+			close(c.exit)
+		})
+		return ret
 	}
-	return false
 }
 
 // Close close client
@@ -138,9 +143,11 @@ func (c *Client) Close() {
 	}
 
 	// stop the client
-	c.stop()
+	if ret := c.stop(); !ret {
+		return
+	}
 
-	// wait client maintenance status stop
+	// wait client keep session stop
 	c.Wait.Wait()
 
 	c.lock.Lock()
@@ -151,22 +158,22 @@ func (c *Client) Close() {
 	log.Printf("etcd client{name:%s, endpoints:%s} exit now.", c.name, c.endpoints)
 }
 
-func (c *Client) maintenanceStatus() error {
+func (c *Client) keepSession() error {
 	s, err := concurrency.NewSession(c.rawClient, concurrency.WithTTL(c.heartbeat))
 	if err != nil {
 		return perrors.WithMessage(err, "new session with server")
 	}
 
-	// must add wg before go maintenance status goroutine
+	// must add wg before go keep session goroutine
 	c.Wait.Add(1)
-	go c.maintenanceStatusLoop(s)
+	go c.keepSessionLoop(s)
 	return nil
 }
 
-func (c *Client) maintenanceStatusLoop(s *concurrency.Session) {
+func (c *Client) keepSessionLoop(s *concurrency.Session) {
 	defer func() {
 		c.Wait.Done()
-		log.Printf("etcd client {endpoints:%v, name:%s} maintenance goroutine game over.", c.endpoints, c.name)
+		log.Printf("etcd client {endpoints:%v, name:%s} keep goroutine game over.", c.endpoints, c.name)
 	}()
 
 	for {