@@ -850,6 +850,7 @@ func parallelJoin(t *testing.T, rc libnetwork.Sandbox, ep libnetwork.Endpoint, t

 	err = ep.Join(sb)

 	runtime.LockOSThread()

+	defer runtime.UnlockOSThread()

 	if err != nil {

 		if _, ok := err.(types.ForbiddenError); !ok {

 			t.Fatalf("thread %d: %v", thrNumber, err)

@@ -867,6 +868,7 @@ func parallelLeave(t *testing.T, rc libnetwork.Sandbox, ep libnetwork.Endpoint,

 	err = ep.Leave(sb)

 	runtime.LockOSThread()

+	defer runtime.UnlockOSThread()

 	if err != nil {

 		if _, ok := err.(types.ForbiddenError); !ok {

 			t.Fatalf("thread %d: %v", thrNumber, err)

@@ -39,19 +39,6 @@ func Init() {

 	}

 }

-// SetNamespace sets the initial namespace handler

-func SetNamespace() error {

-	initOnce.Do(Init)

-	if err := netns.Set(initNs); err != nil {

-		linkInfo, linkErr := getLink()

-		if linkErr != nil {

-			linkInfo = linkErr.Error()

-		}

-		return fmt.Errorf("failed to set to initial namespace, %v, initns fd %d: %v", linkInfo, initNs, err)

-	}

-	return nil

-}

-

 // ParseHandlerInt transforms the namespace handler into an integer

 func ParseHandlerInt() int {

 	return int(getHandler())

@@ -394,13 +394,10 @@ func (n *networkNamespace) InvokeFunc(f func()) error {

 // InitOSContext initializes OS context while configuring network resources

 func InitOSContext() func() {

 	runtime.LockOSThread()

-	if err := ns.SetNamespace(); err != nil {

-		logrus.Error(err)

-	}

 	return runtime.UnlockOSThread

 }

-func nsInvoke(path string, prefunc func(nsFD int) error, postfunc func(callerFD int) error) error {

+func nsInvoke(path string, prefunc, postfunc func(int) error) error {

 	defer InitOSContext()()

 	newNs, err := netns.GetFromPath(path)

@@ -415,10 +412,17 @@ func nsInvoke(path string, prefunc func(nsFD int) error, postfunc func(callerFD

 		return fmt.Errorf("failed in prefunc: %v", err)

 	}

+	// save the current namespace (host namespace)

+	curNs, err := netns.Get()

+	if err != nil {

+		return err

+	}

+	defer curNs.Close()

 	if err = netns.Set(newNs); err != nil {

 		return err

 	}

-	defer ns.SetNamespace()

+	// will restore the previous namespace before unlocking the thread

+	defer netns.Set(curNs)

 	// Invoked after the namespace switch.

 	return postfunc(ns.ParseHandlerInt())

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

 	"net"

 	"os"

 	"path/filepath"

-	"runtime"

 	"strings"

 	"syscall"

 	"testing"

@@ -199,7 +198,6 @@ func TestDisableIPv6DAD(t *testing.T) {

 	if err != nil {

 		t.Fatalf("Failed to create a new sandbox: %v", err)

 	}

-	runtime.LockOSThread()

 	defer s.Destroy()

 	n, ok := s.(*networkNamespace)

@@ -253,7 +251,6 @@ func TestSetInterfaceIP(t *testing.T) {

 	if err != nil {

 		t.Fatalf("Failed to create a new sandbox: %v", err)

 	}

-	runtime.LockOSThread()

 	defer s.Destroy()

 	n, ok := s.(*networkNamespace)

@@ -329,7 +326,6 @@ func TestLiveRestore(t *testing.T) {

 	if err != nil {

 		t.Fatalf("Failed to create a new sandbox: %v", err)

 	}

-	runtime.LockOSThread()

 	defer s.Destroy()

 	n, ok := s.(*networkNamespace)

@@ -2,7 +2,6 @@ package osl

 import (

 	"os"

-	"runtime"

 	"testing"

 	"github.com/docker/docker/pkg/reexec"

@@ -80,7 +79,6 @@ func TestSandboxCreateTwice(t *testing.T) {

 	if err != nil {

 		t.Fatalf("Failed to create a new sandbox: %v", err)

 	}

-	runtime.LockOSThread()

 	// Create another sandbox with the same key to see if we handle it

 	// gracefully.

@@ -88,7 +86,6 @@ func TestSandboxCreateTwice(t *testing.T) {

 	if err != nil {

 		t.Fatalf("Failed to create a new sandbox: %v", err)

 	}

-	runtime.LockOSThread()

 	err = s.Destroy()

 	if err != nil {

@@ -130,7 +127,6 @@ func TestAddRemoveInterface(t *testing.T) {

 	if err != nil {

 		t.Fatalf("Failed to create a new sandbox: %v", err)

 	}

-	runtime.LockOSThread()

 	if s.Key() != key {

 		t.Fatalf("s.Key() returned %s. Expected %s", s.Key(), key)

@@ -33,8 +33,6 @@ func SetupTestOSContext(t *testing.T) func() {

 	// sure to re-initialize initNs context

 	ns.Init()

-	runtime.LockOSThread()

-

 	return func() {

 		if err := syscall.Close(fd); err != nil {

 			t.Logf("Warning: netns closing failed (%v)", err)