From 5bbef9ea4b1960686e58298c2c2e192ca99f072f Mon Sep 17 00:00:00 2001
From: Skye Gill <gill.skye95@gmail.com>
Date: Tue, 6 Dec 2022 15:12:20 +0000
Subject: [PATCH] fix: changed eventing configuration mutex to rwmutex and
 added missing lock (#220)

Fixes https://github.com/open-feature/flagd/issues/219
---
 pkg/service/connect_service.go | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/pkg/service/connect_service.go b/pkg/service/connect_service.go
index 7c21418e9..a089c67dc 100644
--- a/pkg/service/connect_service.go
+++ b/pkg/service/connect_service.go
@@ -45,7 +45,7 @@ type ConnectServiceConfiguration struct {
 }
 
 type eventingConfiguration struct {
-	mu   *sync.Mutex
+	mu   *sync.RWMutex
 	subs map[interface{}]chan Notification
 }
 
@@ -53,7 +53,7 @@ func (s *ConnectService) Serve(ctx context.Context, eval eval.IEvaluator) error
 	s.Eval = eval
 	s.eventingConfiguration = &eventingConfiguration{
 		subs: make(map[interface{}]chan Notification),
-		mu:   &sync.Mutex{},
+		mu:   &sync.RWMutex{},
 	}
 	lis, err := s.setupServer()
 	if err != nil {
@@ -144,13 +144,16 @@ func (s *ConnectService) EventStream(
 	req *connect.Request[emptypb.Empty],
 	stream *connect.ServerStream[schemaV1.EventStreamResponse],
 ) error {
-	s.eventingConfiguration.subs[req] = make(chan Notification, 1)
+	requestNotificationChan := make(chan Notification, 1)
+	s.eventingConfiguration.mu.Lock()
+	s.eventingConfiguration.subs[req] = requestNotificationChan
+	s.eventingConfiguration.mu.Unlock()
 	defer func() {
 		s.eventingConfiguration.mu.Lock()
 		delete(s.eventingConfiguration.subs, req)
 		s.eventingConfiguration.mu.Unlock()
 	}()
-	s.eventingConfiguration.subs[req] <- Notification{
+	requestNotificationChan <- Notification{
 		Type: ProviderReady,
 	}
 	for {
@@ -162,7 +165,7 @@ func (s *ConnectService) EventStream(
 			if err != nil {
 				s.Logger.Error(err.Error())
 			}
-		case notification := <-s.eventingConfiguration.subs[req]:
+		case notification := <-requestNotificationChan:
 			d, err := structpb.NewStruct(notification.Data)
 			if err != nil {
 				s.Logger.Error(err.Error())
@@ -181,11 +184,11 @@ func (s *ConnectService) EventStream(
 }
 
 func (s *ConnectService) Notify(n Notification) {
-	s.eventingConfiguration.mu.Lock()
+	s.eventingConfiguration.mu.RLock()
+	defer s.eventingConfiguration.mu.RUnlock()
 	for _, send := range s.eventingConfiguration.subs {
 		send <- n
 	}
-	s.eventingConfiguration.mu.Unlock()
 }
 
 func (s *ConnectService) ResolveBoolean(