fire callback method only on selected pair binding

agent.go

@@ -41,10 +41,10 @@ type Agent struct {
 	afterRunFn []func(ctx context.Context)
 	muAfterRun sync.Mutex
 
-	onConnectionStateChangeHdlr       atomic.Value // func(ConnectionState)
-	onSelectedCandidatePairChangeHdlr atomic.Value // func(Candidate, Candidate)
-	onCandidateHdlr                   atomic.Value // func(Candidate)
-	onSuccessfulBindingResponseHdlr   atomic.Value // func(Candidate)
+	onConnectionStateChangeHdlr                 atomic.Value // func(ConnectionState)
+	onSelectedCandidatePairChangeHdlr           atomic.Value // func(Candidate, Candidate)
+	onCandidateHdlr                             atomic.Value // func(Candidate)
+	onSuccessfulSelectedPairBindingResponseHdlr atomic.Value // func(*Candidate)
 
 	// State owned by the taskLoop
 	onConnected     chan struct{}

agent_handlers.go

@@ -23,9 +23,9 @@ func (a *Agent) OnCandidate(f func(Candidate)) error {
 	return nil
 }
 
-// OnSuccessfulBindingResponse sets a handler that is fired when a successful binding response is received
-func (a *Agent) OnSuccessfulBindingResponse(f func(*CandidatePair)) error {
-	a.onSuccessfulBindingResponseHdlr.Store(f)
+// OnSuccessfulSelectedPairBindingResponse sets a handler that is fired when a successful binding response is received for the selected candidate pair
+func (a *Agent) OnSuccessfulSelectedPairBindingResponse(f func(*CandidatePair)) error {
+	a.onSuccessfulSelectedPairBindingResponseHdlr.Store(f)
 	return nil
 }
 
@@ -47,8 +47,8 @@ func (a *Agent) onConnectionStateChange(s ConnectionState) {
 	}
 }
 
-func (a *Agent) onSuccessfulBindingResponse(p *CandidatePair) {
-	if h, ok := a.onSuccessfulBindingResponseHdlr.Load().(func(*CandidatePair)); ok {
+func (a *Agent) onSuccessfulSelectedPairBindingResponse(p *CandidatePair) {
+	if h, ok := a.onSuccessfulSelectedPairBindingResponseHdlr.Load().(func(*CandidatePair)); ok {
 		h(p)
 	}
 }

candidatepair.go

@@ -110,12 +110,13 @@ func (p *CandidatePair) markBindingRequest(transactionID [12]byte) {
 	p.lastBindingTransactionID = transactionID
 }
 
-func (p *CandidatePair) markBindingResponse(transactionID [12]byte) {
+func (p *CandidatePair) markBindingResponse(transactionID [12]byte) bool {
 	if p.lastBindingRequest.IsZero() || transactionID != p.lastBindingTransactionID {
-		return
+		return false
 	}
 
 	p.latency = time.Since(p.lastBindingRequest)
+	return true
 }
 
 func (p *CandidatePair) Latency() time.Duration {

selection.go

@@ -139,14 +139,16 @@ func (s *controllingSelector) HandleSuccessResponse(m *stun.Message, local, remo
 		return
 	}
 
-	p.markBindingResponse(m.TransactionID)
-	s.agent.onSuccessfulBindingResponse(p)
-
 	p.state = CandidatePairStateSucceeded
 	s.log.Tracef("Found valid candidate pair: %s", p)
 	if pendingRequest.isUseCandidate && s.agent.getSelectedPair() == nil {
 		s.agent.setSelectedPair(p)
 	}
+
+	ok = p.markBindingResponse(m.TransactionID)
+	if ok && s.agent.getSelectedPair() == p {
+		s.agent.onSuccessfulSelectedPairBindingResponse(p)
+	}
 }
 
 func (s *controllingSelector) PingCandidate(local, remote Candidate) {
@@ -233,8 +235,10 @@ func (s *controlledSelector) HandleSuccessResponse(m *stun.Message, local, remot
 		return
 	}
 
-	p.markBindingResponse(m.TransactionID)
-	s.agent.onSuccessfulBindingResponse(p)
+	ok = p.markBindingResponse(m.TransactionID)
+	if ok {
+		s.agent.onSuccessfulSelectedPairBindingResponse(p)
+	}
 
 	p.state = CandidatePairStateSucceeded
 	s.log.Tracef("Found valid candidate pair: %s", p)