platform: Add sleep support for NetworkExtension

common/sleep/manager.go

@@ -0,0 +1,43 @@
+package sleep
+
+import (
+	"sync"
+)
+
+type Manager struct {
+	access sync.Mutex
+	done   chan struct{}
+}
+
+func NewManager() *Manager {
+	closedChan := make(chan struct{})
+	close(closedChan)
+	return &Manager{
+		done: closedChan,
+	}
+}
+
+func (m *Manager) Sleep() {
+	m.access.Lock()
+	defer m.access.Unlock()
+	select {
+	case <-m.done:
+	default:
+		return
+	}
+	m.done = make(chan struct{})
+}
+
+func (m *Manager) Wake() {
+	m.access.Lock()
+	defer m.access.Unlock()
+	select {
+	case <-m.done:
+	default:
+		close(m.done)
+	}
+}
+
+func (m *Manager) Active() <-chan struct{} {
+	return m.done
+}