Fix shim deadlock when joining an existing pid namespace (#290)

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

supervisor/delete.go

@@ -14,6 +14,7 @@ type DeleteTask struct {
 	Status  int
 	PID     string
 	NoEvent bool
+	Process runtime.Process
 }
 
 func (s *Supervisor) delete(t *DeleteTask) error {
@@ -22,6 +23,9 @@ func (s *Supervisor) delete(t *DeleteTask) error {
 		if err := s.deleteContainer(i.container); err != nil {
 			logrus.WithField("error", err).Error("containerd: deleting container")
 		}
+		if t.Process != nil {
+			t.Process.Wait()
+		}
 		if !t.NoEvent {
 			s.notifySubscribers(Event{
 				Type:      StateExit,

supervisor/exit.go

@@ -46,9 +46,10 @@ func (s *Supervisor) exit(t *ExitTask) error {
 	}
 	container := proc.Container()
 	ne := &DeleteTask{
-		ID:     container.ID(),
-		Status: status,
-		PID:    proc.ID(),
+		ID:      container.ID(),
+		Status:  status,
+		PID:     proc.ID(),
+		Process: proc,
 	}
 	s.delete(ne)
 
@@ -72,6 +73,7 @@ func (s *Supervisor) execExit(t *ExecExitTask) error {
 	if err := container.RemoveProcess(t.PID); err != nil {
 		logrus.WithField("error", err).Error("containerd: find container for pid")
 	}
+	t.Process.Wait()
 	s.notifySubscribers(Event{
 		Timestamp: time.Now(),
 		ID:        t.ID,

supervisor/supervisor.go

@@ -282,7 +282,6 @@ func (s *Supervisor) SendTask(evt Task) {
 
 func (s *Supervisor) exitHandler() {
 	for p := range s.monitor.Exits() {
-		p.Wait()
 		e := &ExitTask{
 			Process: p,
 		}

supervisor/worker.go

@@ -51,6 +51,7 @@ func (w *worker) Start() {
 			evt := &DeleteTask{
 				ID:      t.Container.ID(),
 				NoEvent: true,
+				Process: process,
 			}
 			w.s.SendTask(evt)
 			continue
@@ -66,6 +67,7 @@ func (w *worker) Start() {
 			evt := &DeleteTask{
 				ID:      t.Container.ID(),
 				NoEvent: true,
+				Process: process,
 			}
 			w.s.SendTask(evt)
 			continue
@@ -76,6 +78,7 @@ func (w *worker) Start() {
 			evt := &DeleteTask{
 				ID:      t.Container.ID(),
 				NoEvent: true,
+				Process: process,
 			}
 			w.s.SendTask(evt)
 			continue