remove cancel signal

common/signal/cancel.go

@@ -1,51 +0,0 @@
-package signal
-
-import (
-	"sync"
-)
-
-// CancelSignal is a signal passed to goroutine, in order to cancel the goroutine on demand.
-type CancelSignal struct {
-	cancel chan struct{}
-	done   sync.WaitGroup
-}
-
-// NewCloseSignal creates a new CancelSignal.
-func NewCloseSignal() *CancelSignal {
-	return &CancelSignal{
-		cancel: make(chan struct{}),
-	}
-}
-
-func (v *CancelSignal) WaitThread() {
-	v.done.Add(1)
-}
-
-// Cancel signals the goroutine to stop.
-func (v *CancelSignal) Cancel() {
-	close(v.cancel)
-}
-
-func (v *CancelSignal) Cancelled() bool {
-	select {
-	case <-v.cancel:
-		return true
-	default:
-		return false
-	}
-}
-
-// WaitForCancel should be monitored by the goroutine for when to stop.
-func (v *CancelSignal) WaitForCancel() <-chan struct{} {
-	return v.cancel
-}
-
-// FinishThread signals that current goroutine has finished.
-func (v *CancelSignal) FinishThread() {
-	v.done.Done()
-}
-
-// WaitForDone is used by caller to wait for the goroutine finishes.
-func (v *CancelSignal) WaitForDone() {
-	v.done.Wait()
-}