Move task workers to new type

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

supervisor.go

@@ -4,8 +4,6 @@ import (
 	"os"
 	"path/filepath"
 	goruntime "runtime"
-	"sync"
-	"time"
 
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/containerd/runtime"
@@ -13,7 +11,7 @@ import (
 )
 
 // NewSupervisor returns an initialized Process supervisor.
-func NewSupervisor(stateDir string, concurrency int) (*Supervisor, error) {
+func NewSupervisor(stateDir string, tasks chan *StartTask) (*Supervisor, error) {
 	if err := os.MkdirAll(stateDir, 0755); err != nil {
 		return nil, err
 	}
@@ -31,8 +29,8 @@ func NewSupervisor(stateDir string, concurrency int) (*Supervisor, error) {
 		containers: make(map[string]runtime.Container),
 		processes:  make(map[int]runtime.Container),
 		runtime:    r,
-		tasks:      make(chan *startTask, concurrency*100),
 		journal:    j,
+		tasks:      tasks,
 	}
 	// register default event handlers
 	s.handlers = map[EventType]Handler{
@@ -46,10 +44,6 @@ func NewSupervisor(stateDir string, concurrency int) (*Supervisor, error) {
 		UpdateContainerEventType: &UpdateEvent{s},
 	}
 	// start the container workers for concurrent container starts
-	for i := 0; i < concurrency; i++ {
-		s.workerGroup.Add(1)
-		go s.startContainerWorker(s.tasks)
-	}
 	return s, nil
 }
 
@@ -62,8 +56,7 @@ type Supervisor struct {
 	runtime     runtime.Runtime
 	journal     *journal
 	events      chan *Event
-	tasks       chan *startTask
-	workerGroup sync.WaitGroup
+	tasks       chan *StartTask
 	subscribers map[subscriber]bool
 }
 
@@ -104,6 +97,7 @@ func (s *Supervisor) Start(events chan *Event) error {
 		// so that nothing else is scheduled over the top of it.
 		goruntime.LockOSThread()
 		for e := range events {
+			EventsCounter.Inc(1)
 			s.journal.write(e)
 			h, ok := s.handlers[e.Type]
 			if !ok {
@@ -142,27 +136,5 @@ func (s *Supervisor) getContainerForPid(pid int) (runtime.Container, error) {
 }
 
 func (s *Supervisor) SendEvent(evt *Event) {
-	EventsCounter.Inc(1)
 	s.events <- evt
 }
-
-type startTask struct {
-	container runtime.Container
-	err       chan error
-}
-
-func (s *Supervisor) startContainerWorker(tasks chan *startTask) {
-	defer s.workerGroup.Done()
-	for t := range tasks {
-		started := time.Now()
-		if err := t.container.Start(); err != nil {
-			e := NewEvent(StartContainerEventType)
-			e.ID = t.container.ID()
-			s.SendEvent(e)
-			t.err <- err
-			continue
-		}
-		ContainerStartTimer.UpdateSince(started)
-		t.err <- nil
-	}
-}