improve locks

.gitignore

@@ -0,0 +1 @@
+swarm

cluster/node.go

@@ -113,6 +113,9 @@ func (n *Node) updateContainers() error {
 		return err
 	}
 
+	n.Lock()
+	defer n.Unlock()
+
 	merged := make(map[string]*Container)
 	for _, c := range containers {
 		if current, exists := n.containers[c.Id]; exists {
@@ -136,9 +139,7 @@ func (n *Node) updateContainers() error {
 		}
 	}
 
-	n.Lock()
 	n.containers = merged
-	n.Unlock()
 
 	log.Debugf("[%s] Updated state", n.ID)
 	return nil

scheduler/scheduler.go

@@ -43,13 +43,13 @@ func (s *Scheduler) selectNodeForContainer(config *dockerclient.ContainerConfig)
 
 // Schedule a brand new container into the cluster.
 func (s *Scheduler) CreateContainer(config *dockerclient.ContainerConfig, name string) (*cluster.Container, error) {
-	s.Lock()
-	defer s.Unlock()
-
 	if config.Memory == 0 || config.CpuShares == 0 {
 		return nil, fmt.Errorf("Creating containers in clustering mode requires resource constraints (-c and -m) to be set")
 	}
 
+	s.Lock()
+	defer s.Unlock()
+
 	node, err := s.selectNodeForContainer(config)
 	if err != nil {
 		return nil, err