Support authentification via basic auth.

lib/connector/semaphore.go

@@ -0,0 +1,19 @@
+package connector
+
+type semaphore chan int
+
+func (s semaphore) Lock() {
+	s <- 1
+}
+
+func (s semaphore) Unlock() {
+	_ = <-s
+}
+
+func newSemaphore(limit uint) semaphore {
+	if limit == 0 {
+		limit = 1
+	}
+
+	return semaphore(make(chan int, limit))
+}