fix: bug in server es sessions management.

relay/listener.go

@@ -17,6 +17,10 @@ var sessions = make(map[string]*eventsource.EventSource)
 var backsessions = make(map[*eventsource.EventSource]string)
 var slock = sync.Mutex{}
 
+var watchers = make(map[string][]*eventsource.EventSource)
+var backwatchers = make(map[*eventsource.EventSource][]string)
+var wlock = sync.Mutex{}
+
 func listenUpdates(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("content-type", "application/json")
 	var es eventsource.EventSource
@@ -36,9 +40,9 @@ func listenUpdates(w http.ResponseWriter, r *http.Request) {
 			// proceed, but save the es object at the end
 			defer func() {
 				slock.Lock()
-				defer slock.Unlock()
 				sessions[session] = &es
 				backsessions[&es] = session
+				slock.Unlock()
 			}()
 		}
 	}
@@ -117,15 +121,11 @@ func listenUpdates(w http.ResponseWriter, r *http.Request) {
 	watchPubKeys(keys, &es)
 }
 
-var watchers = make(map[string][]*eventsource.EventSource)
-var index = make(map[*eventsource.EventSource][]string)
-var wlock = sync.Mutex{}
-
 func watchPubKeys(keys []string, es *eventsource.EventSource) {
 	wlock.Lock()
 	defer wlock.Unlock()
 
-	index[es] = keys
+	backwatchers[es] = keys
 
 	for _, key := range keys {
 		if arr, ok := watchers[key]; ok {
@@ -140,7 +140,7 @@ func removeFromWatchers(es *eventsource.EventSource) {
 	wlock.Lock()
 	defer wlock.Unlock()
 
-	for _, key := range index[es] {
+	for _, key := range backwatchers[es] {
 		if arr, ok := watchers[key]; ok {
 			newarr := make([]*eventsource.EventSource, len(arr)-1)
 			i := 0
@@ -151,16 +151,18 @@ func removeFromWatchers(es *eventsource.EventSource) {
 				newarr[i] = oldes
 				i++
 			}
+			watchers[key] = newarr
 		}
 	}
-	delete(index, es)
+	delete(backwatchers, es)
 }
 
 func notifyPubKeyEvent(key string, evt *Event) {
 	wlock.Lock()
-	defer wlock.Unlock()
+	arr, ok := watchers[key]
+	wlock.Unlock()
 
-	if arr, ok := watchers[key]; ok {
+	if ok {
 		for _, es := range arr {
 			jevent, _ := json.Marshal(evt)
 			(*es).SendEventMessage(string(jevent), "happening", "")
@@ -170,16 +172,15 @@ func notifyPubKeyEvent(key string, evt *Event) {
 
 func grabNamedSession(name string) *eventsource.EventSource {
 	slock.Lock()
-	defer slock.Unlock()
 	es, _ := sessions[name]
+	slock.Unlock()
 	return es
 }
 
 func removeFromSessions(es *eventsource.EventSource) {
 	slock.Lock()
-	defer slock.Unlock()
-
 	session := backsessions[es]
 	delete(backsessions, es)
 	delete(sessions, session)
+	slock.Unlock()
 }