package sync
type Mutex struct{}
func (m *Mutex) Lock()
func (m *Mutex) Unlock()
type WaitGroup struct{}
func (wg *WaitGroup) Add(delta int)
func (wg *WaitGroup) Done()
func (wg *WaitGroup) Wait()
package sync
type Mutex struct{}
func (m *Mutex) Lock()
func (m *Mutex) Unlock()
type WaitGroup struct{}
func (wg *WaitGroup) Add(delta int)
func (wg *WaitGroup) Done()
func (wg *WaitGroup) Wait()