v1.0.0

common/signal/semaphore/semaphore.go

@@ -0,0 +1,27 @@
+package semaphore
+
+// Instance is an implementation of semaphore.
+type Instance struct {
+	token chan struct{}
+}
+
+// New create a new Semaphore with n permits.
+func New(n int) *Instance {
+	s := &Instance{
+		token: make(chan struct{}, n),
+	}
+	for i := 0; i < n; i++ {
+		s.token <- struct{}{}
+	}
+	return s
+}
+
+// Wait returns a channel for acquiring a permit.
+func (s *Instance) Wait() <-chan struct{} {
+	return s.token
+}
+
+// Signal releases a permit into the semaphore.
+func (s *Instance) Signal() {
+	s.token <- struct{}{}
+}