windows: Fix a few races

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

windows/process.go

@@ -5,6 +5,7 @@ package windows
 import (
 	"context"
 	"io"
+	"sync"
 	"syscall"
 	"time"
 
@@ -19,12 +20,13 @@ import (
 
 // process implements containerd.Process and containerd.State
 type process struct {
+	sync.Mutex
+
 	hcs hcsshim.Process
 
 	id   string
 	pid  uint32
 	io   *pipeSet
-	status runtime.Status
 	task *task
 
 	exitCh   chan struct{}
@@ -93,6 +95,13 @@ func (p *process) ExitCode() (uint32, time.Time, error) {
 }
 
 func (p *process) Start(ctx context.Context) (err error) {
+	p.Lock()
+	defer p.Unlock()
+
+	if p.hcs != nil {
+		return errors.Wrap(errdefs.ErrFailedPrecondition, "process already started")
+	}
+
 	// If we fail, close the io right now
 	defer func() {
 		if err != nil {
@@ -132,6 +141,7 @@ func (p *process) Start(ctx context.Context) (err error) {
 	if p.io.stderr != nil {
 		go ioCopy("stderr", p.io.stderr, stderr)
 	}
+	p.hcs = hp
 
 	// Wait for the process to exit to get the exit status
 	go func() {
@@ -174,8 +184,6 @@ func (p *process) Start(ctx context.Context) (err error) {
 		// Cleanup HCS resources
 		hp.Close()
 	}()
-	p.status = runtime.RunningStatus
-	p.hcs = hp
 	return nil
 }
 

windows/task.go

@@ -111,6 +111,10 @@ func (t *task) Info() runtime.TaskInfo {
 }
 
 func (t *task) Start(ctx context.Context) error {
+	if p := t.getProcess(t.id); p != nil {
+		return errors.Wrap(errdefs.ErrFailedPrecondition, "task already started")
+	}
+
 	conf := newWindowsProcessConfig(t.spec.Process, t.io)
 	p, err := t.newProcess(ctx, t.id, conf, t.io)
 	if err != nil {
@@ -136,13 +140,13 @@ func (t *task) Pause(ctx context.Context) error {
 			t.Lock()
 			t.status = runtime.PausedStatus
 			t.Unlock()
-		}
+
-		if err == nil {
 			t.publisher.Publish(ctx,
 				runtime.TaskPausedEventTopic,
 				&eventsapi.TaskPaused{
 					ContainerID: t.id,
 				})
+			return nil
 		}
 		return errors.Wrap(err, "hcsshim failed to pause task")
 	}
@@ -157,13 +161,13 @@ func (t *task) Resume(ctx context.Context) error {
 			t.Lock()
 			t.status = runtime.RunningStatus
 			t.Unlock()
-		}
+
-		if err == nil {
 			t.publisher.Publish(ctx,
 				runtime.TaskResumedEventTopic,
 				&eventsapi.TaskResumed{
 					ContainerID: t.id,
 				})
+			return nil
 		}
 		return errors.Wrap(err, "hcsshim failed to resume task")
 	}
@@ -313,7 +317,6 @@ func (t *task) newProcess(ctx context.Context, id string, conf *hcsshim.ProcessC
 		id:     id,
 		pid:    pid,
 		io:     pset,
-		status: runtime.CreatedStatus,
 		task:   t,
 		exitCh: make(chan struct{}),
 		conf:   conf,