v1.0.0

common/signal/done/done.go

@@ -0,0 +1,49 @@
+package done
+
+import (
+	"sync"
+)
+
+// Instance is a utility for notifications of something being done.
+type Instance struct {
+	access sync.Mutex
+	c      chan struct{}
+	closed bool
+}
+
+// New returns a new Done.
+func New() *Instance {
+	return &Instance{
+		c: make(chan struct{}),
+	}
+}
+
+// Done returns true if Close() is called.
+func (d *Instance) Done() bool {
+	select {
+	case <-d.Wait():
+		return true
+	default:
+		return false
+	}
+}
+
+// Wait returns a channel for waiting for done.
+func (d *Instance) Wait() <-chan struct{} {
+	return d.c
+}
+
+// Close marks this Done 'done'. This method may be called multiple times. All calls after first call will have no effect on its status.
+func (d *Instance) Close() error {
+	d.access.Lock()
+	defer d.access.Unlock()
+
+	if d.closed {
+		return nil
+	}
+
+	d.closed = true
+	close(d.c)
+
+	return nil
+}