made broadcasts threadsafe

broadcast.go

@@ -6,9 +6,12 @@ import (
 
 type Broadcast struct {
 	channels []chan interface{}
+	channelLock sync.Mutex
 }
 
 func (b *Broadcast) Subscribe() chan interface{} {
+	b.channelLock.Lock()
+	defer b.channelLock.Unlock()
 	newChannel := make(chan interface{})
 	b.channels = append(b.channels, newChannel)
 	return newChannel
@@ -21,6 +24,8 @@ func (b *Broadcast) WaitNext() interface{} {
 func (b *Broadcast) Send(value interface{}) {
 	wg := sync.WaitGroup{}
 
+	b.channelLock.Lock()
+
 	for _, channel := range b.channels {
 		wg.Add(1)
 		//Do not use closure as reference will change
@@ -30,6 +35,8 @@ func (b *Broadcast) Send(value interface{}) {
 		}(channel)
 	}
 
+	b.channelLock.Unlock()
+
 	wg.Wait()
 }