Create semaphore object

semaphore.go

@@ -0,0 +1,17 @@
+package main
+
+type semaphore struct {
+	channel chan bool
+}
+
+func newSemaphore(n int) semaphore {
+	return semaphore{make(chan bool, n)}
+}
+
+func (s semaphore) Request() {
+	s.channel <- true
+}
+
+func (s semaphore) Release() {
+	<-s.channel
+}

semaphore_test.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewSemaphore(t *testing.T) {
+	newSemaphore(1)
+}
+
+func TestSemaphoreRequest(t *testing.T) {
+	s := newSemaphore(1)
+
+	s.Request()
+
+	assert.Equal(t, 1, len(s.channel))
+}
+
+func TestSemaphoreRelease(t *testing.T) {
+	s := newSemaphore(1)
+
+	s.Request()
+	s.Release()
+
+	assert.Equal(t, 0, len(s.channel))
+}