fix: replace heartbeat signal channel with context.WithCancel

Author: kavu

ring.go

@@ -310,11 +310,10 @@ func (c *ringShards) Random() (*ringShard, error) {
 }
 
 // Heartbeat monitors state of each shard in the ring.
-func (c *ringShards) Heartbeat(frequency time.Duration, closeCh chan struct{}) {
+func (c *ringShards) Heartbeat(ctx context.Context, frequency time.Duration) {
 	ticker := time.NewTicker(frequency)
 	defer ticker.Stop()
 
-	ctx := context.Background()
 	for {
 		select {
 		case <-ticker.C:
@@ -332,7 +331,7 @@ func (c *ringShards) Heartbeat(frequency time.Duration, closeCh chan struct{}) {
 			if rebalance {
 				c.rebalance()
 			}
-		case <-closeCh:
+		case <-ctx.Done():
 			return
 		}
 	}
@@ -392,10 +391,10 @@ func (c *ringShards) Close() error {
 //------------------------------------------------------------------------------
 
 type ring struct {
-	opt                 *RingOptions
-	shards              *ringShards
-	cmdsInfoCache       *cmdsInfoCache //nolint:structcheck
-	hearbeatCloseSignal chan struct{}
+	opt               *RingOptions
+	shards            *ringShards
+	cmdsInfoCache     *cmdsInfoCache //nolint:structcheck
+	heartbeatCancelFn context.CancelFunc
 }
 
 // Ring is a Redis client that uses consistent hashing to distribute
@@ -421,20 +420,20 @@ type Ring struct {
 func NewRing(opt *RingOptions) *Ring {
 	opt.init()
 
-	hearbeatCloseSignal := make(chan struct{})
+	hbCtx, hbCancel := context.WithCancel(context.Background())
 
 	ring := Ring{
 		ring: &ring{
-			opt:                 opt,
-			shards:              newRingShards(opt),
-			hearbeatCloseSignal: hearbeatCloseSignal,
+			opt:               opt,
+			shards:            newRingShards(opt),
+			heartbeatCancelFn: hbCancel,
 		},
 	}
 
 	ring.cmdsInfoCache = newCmdsInfoCache(ring.cmdsInfo)
 	ring.cmdable = ring.Process
 
-	go ring.shards.Heartbeat(opt.HeartbeatFrequency, hearbeatCloseSignal)
+	go ring.shards.Heartbeat(hbCtx, opt.HeartbeatFrequency)
 
 	return &ring
 }
@@ -722,6 +721,7 @@ func (c *Ring) Watch(ctx context.Context, fn func(*Tx) error, keys ...string) er
 // It is rare to Close a Ring, as the Ring is meant to be long-lived
 // and shared between many goroutines.
 func (c *Ring) Close() error {
-	close(c.hearbeatCloseSignal)
+	c.heartbeatCancelFn()
+
 	return c.shards.Close()
 }