Merge pull request #4534 from creack/fix_race_kill

Fix Race when killing the daemon

container.go

@@ -784,17 +784,19 @@ func (container *Container) monitor(callback execdriver.StartCallback) error {
 		utils.Errorf("Error running container: %s", err)
 	}
 
-	container.State.SetStopped(exitCode)
-
-	// FIXME: there is a race condition here which causes this to fail during the unit tests.
-	// If another goroutine was waiting for Wait() to return before removing the container's root
-	// from the filesystem... At this point it may already have done so.
-	// This is because State.setStopped() has already been called, and has caused Wait()
-	// to return.
-	// FIXME: why are we serializing running state to disk in the first place?
-	//log.Printf("%s: Failed to dump configuration to the disk: %s", container.ID, err)
-	if err := container.ToDisk(); err != nil {
-		utils.Errorf("Error dumping container state to disk: %s\n", err)
+	if container.runtime.srv.IsRunning() {
+		container.State.SetStopped(exitCode)
+
+		// FIXME: there is a race condition here which causes this to fail during the unit tests.
+		// If another goroutine was waiting for Wait() to return before removing the container's root
+		// from the filesystem... At this point it may already have done so.
+		// This is because State.setStopped() has already been called, and has caused Wait()
+		// to return.
+		// FIXME: why are we serializing running state to disk in the first place?
+		//log.Printf("%s: Failed to dump configuration to the disk: %s", container.ID, err)
+		if err := container.ToDisk(); err != nil {
+			utils.Errorf("Error dumping container state to disk: %s\n", err)
+		}
 	}
 
 	// Cleanup

server.go

@@ -29,10 +29,6 @@ import (
 	"time"
 )
 
-func (srv *Server) Close() error {
-	return srv.runtime.Close()
-}
-
 // jobInitApi runs the remote api server `srv` as a daemon,
 // Only one api server can run at the same time - this is enforced by a pidfile.
 // The signals SIGINT, SIGQUIT and SIGTERM are intercepted for cleanup.
@@ -2330,6 +2326,7 @@ func NewServer(eng *engine.Engine, config *DaemonConfig) (*Server, error) {
 		pushingPool: make(map[string]chan struct{}),
 		events:      make([]utils.JSONMessage, 0, 64), //only keeps the 64 last events
 		listeners:   make(map[string]chan utils.JSONMessage),
+		running:     true,
 	}
 	runtime.srv = srv
 	return srv, nil
@@ -2379,6 +2376,24 @@ func (srv *Server) GetEvents() []utils.JSONMessage {
 	return srv.events
 }
 
+func (srv *Server) SetRunning(status bool) {
+	srv.Lock()
+	defer srv.Unlock()
+
+	srv.running = status
+}
+
+func (srv *Server) IsRunning() bool {
+	srv.RLock()
+	defer srv.RUnlock()
+	return srv.running
+}
+
+func (srv *Server) Close() error {
+	srv.SetRunning(false)
+	return srv.runtime.Close()
+}
+
 type Server struct {
 	sync.RWMutex
 	runtime     *Runtime
@@ -2387,4 +2402,5 @@ type Server struct {
 	events      []utils.JSONMessage
 	listeners   map[string]chan utils.JSONMessage
 	Eng         *engine.Engine
+	running     bool
 }