Align with go library layout

signal.go

@@ -0,0 +1,53 @@
+package main
+
+type Signal struct {
+	enabled AtomicBool
+	C       chan struct{}
+}
+
+func NewSignal() (s Signal) {
+	s.C = make(chan struct{}, 1)
+	s.Enable()
+	return
+}
+
+func (s *Signal) Disable() {
+	s.enabled.Set(false)
+	s.Clear()
+}
+
+func (s *Signal) Enable() {
+	s.enabled.Set(true)
+}
+
+/* Unblock exactly one listener
+ */
+func (s *Signal) Send() {
+	if s.enabled.Get() {
+		select {
+		case s.C <- struct{}{}:
+		default:
+		}
+	}
+}
+
+/* Clear the signal if already fired
+ */
+func (s Signal) Clear() {
+	select {
+	case <-s.C:
+	default:
+	}
+}
+
+/* Unblocks all listeners (forever)
+ */
+func (s Signal) Broadcast() {
+	close(s.C)
+}
+
+/* Wait for the signal
+ */
+func (s Signal) Wait() chan struct{} {
+	return s.C
+}