Fix race condition

session/session.go

@@ -1,6 +1,7 @@
 package session
 
 import (
+	"context"
 	"sync"
 	"time"
 
@@ -16,8 +17,7 @@ type session struct {
 
 	logger log.Logger
 
-	sessionActivate sync.Mutex
-	active          bool
+	active bool
 
 	location string
 	peer     string
@@ -33,8 +33,8 @@ type session struct {
 	txBitrate *average.SlidingWindow
 	txBytes   uint64
 
-	tickerStop   chan struct{}
-	sessionClose sync.Once
+	tickerStop context.CancelFunc
+	running    bool
 
 	lock         sync.Mutex
 	topRxBitrate float64
@@ -44,6 +44,9 @@ type session struct {
 }
 
 func (s *session) Init(id, reference string, closeCallback func(*session), inactive, timeout time.Duration, logger log.Logger) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
 	s.id = id
 	s.reference = reference
 	s.createdAt = time.Now()
@@ -71,35 +74,40 @@ func (s *session) Init(id, reference string, closeCallback func(*session), inact
 		s.callback = func(s *session) {}
 	}
 
-	s.tickerStop = make(chan struct{})
-	s.sessionClose = sync.Once{}
+	s.running = true
 
 	pendingTimeout := inactive
 	if timeout < pendingTimeout {
 		pendingTimeout = timeout
 	}
 
-	s.lock.Lock()
-	defer s.lock.Unlock()
-
 	s.stale = time.AfterFunc(pendingTimeout, func() {
 		s.close()
 	})
 }
 
 func (s *session) close() {
-	s.sessionClose.Do(func() {
-		s.lock.Lock()
-		s.stale.Stop()
-		s.lock.Unlock()
+	s.lock.Lock()
+	defer s.lock.Unlock()
 
-		s.closedAt = time.Now()
+	if !s.running {
+		return
+	}
 
-		close(s.tickerStop)
-		s.rxBitrate.Stop()
-		s.txBitrate.Stop()
-		go s.callback(s)
-	})
+	s.running = false
+
+	s.stale.Stop()
+
+	s.closedAt = time.Now()
+
+	if s.tickerStop != nil {
+		s.tickerStop()
+		s.tickerStop = nil
+	}
+
+	s.rxBitrate.Stop()
+	s.txBitrate.Stop()
+	go s.callback(s)
 }
 
 func (s *session) Register(location, peer string) {
@@ -116,15 +124,18 @@ func (s *session) Register(location, peer string) {
 }
 
 func (s *session) Activate() bool {
-	s.sessionActivate.Lock()
-	defer s.sessionActivate.Unlock()
+	s.lock.Lock()
+	defer s.lock.Unlock()
 
 	if s.active {
 		return false
 	}
 
 	s.active = true
-	go s.ticker()
+	ctx, cancel := context.WithCancel(context.Background())
+	s.tickerStop = cancel
+
+	go s.ticker(ctx)
 
 	return true
 }
@@ -237,13 +248,13 @@ func (s *session) SetTopTxBitrate(bitrate float64) {
 	s.topTxBitrate = bitrate
 }
 
-func (s *session) ticker() {
+func (s *session) ticker(ctx context.Context) {
 	ticker := time.NewTicker(time.Second)
 	defer ticker.Stop()
 
 	for {
 		select {
-		case <-s.tickerStop:
+		case <-ctx.Done():
 			return
 		case <-ticker.C:
 			s.lock.Lock()