Use a ring channel to avoid blocking write of events (#2082)

* Use a ring channel to avoid blocking write of events

* Add eapache/channels dependency

vendor/github.com/eapache/channels/infinite_channel_test.go

@@ -0,0 +1,48 @@
+package channels
+
+import "testing"
+
+func TestInfiniteChannel(t *testing.T) {
+	var ch Channel
+
+	ch = NewInfiniteChannel()
+	testChannel(t, "infinite channel", ch)
+
+	ch = NewInfiniteChannel()
+	testChannelPair(t, "infinite channel", ch, ch)
+
+	ch = NewInfiniteChannel()
+	testChannelConcurrentAccessors(t, "infinite channel", ch)
+}
+
+func BenchmarkInfiniteChannelSerial(b *testing.B) {
+	ch := NewInfiniteChannel()
+	for i := 0; i < b.N; i++ {
+		ch.In() <- nil
+	}
+	for i := 0; i < b.N; i++ {
+		<-ch.Out()
+	}
+}
+
+func BenchmarkInfiniteChannelParallel(b *testing.B) {
+	ch := NewInfiniteChannel()
+	go func() {
+		for i := 0; i < b.N; i++ {
+			<-ch.Out()
+		}
+		ch.Close()
+	}()
+	for i := 0; i < b.N; i++ {
+		ch.In() <- nil
+	}
+	<-ch.Out()
+}
+
+func BenchmarkInfiniteChannelTickTock(b *testing.B) {
+	ch := NewInfiniteChannel()
+	for i := 0; i < b.N; i++ {
+		ch.In() <- nil
+		<-ch.Out()
+	}
+}