@@ -47,9 +47,11 @@ func (d *driver) createContainer(c *execdriver.Command) (*libcontainer.Container

 		return nil, err

 	}

 	cmds := make(map[string]*exec.Cmd)

+	d.Lock()

 	for k, v := range d.activeContainers {

 		cmds[k] = v.cmd

 	}

+	d.Unlock()

 	if err := configuration.ParseConfiguration(container, cmds, c.Config["native"]); err != nil {

 		return nil, err

 	}

@@ -86,7 +88,9 @@ func (d *driver) createNetwork(container *libcontainer.Container, c *execdriver.

 	}

 	if c.Network.ContainerID != "" {

+		d.Lock()

 		active := d.activeContainers[c.Network.ContainerID]

+		d.Unlock()

 		if active == nil || active.cmd.Process == nil {

 			return fmt.Errorf("%s is not a valid running container to join", c.Network.ContainerID)

 		}

@@ -8,6 +8,7 @@ import (

 	"os/exec"

 	"path/filepath"

 	"strings"

+	"sync"

 	"syscall"

 	"github.com/dotcloud/docker/daemon/execdriver"

@@ -62,6 +63,7 @@ type driver struct {

 	root             string

 	initPath         string

 	activeContainers map[string]*activeContainer

+	sync.Mutex

 }

 func NewDriver(root, initPath string) (*driver, error) {

@@ -87,10 +89,12 @@ func (d *driver) Run(c *execdriver.Command, pipes *execdriver.Pipes, startCallba

 	if err != nil {

 		return -1, err

 	}

+	d.Lock()

 	d.activeContainers[c.ID] = &activeContainer{

 		container: container,

 		cmd:       &c.Cmd,

 	}

+	d.Unlock()

 	var (

 		dataPath = filepath.Join(d.root, c.ID)

@@ -186,7 +190,9 @@ func (d *driver) Name() string {

 }

 func (d *driver) GetPidsForContainer(id string) ([]int, error) {

+	d.Lock()

 	active := d.activeContainers[id]

+	d.Unlock()

 	if active == nil {

 		return nil, fmt.Errorf("active container for %s does not exist", id)

@@ -212,7 +218,9 @@ func (d *driver) createContainerRoot(id string) error {

 }

 func (d *driver) removeContainerRoot(id string) error {

+	d.Lock()

 	delete(d.activeContainers, id)

+	d.Unlock()

 	return os.RemoveAll(filepath.Join(d.root, id))

 }