move notifySocket out of signalHandler

In fact, notifySocket has no relationship to signalHandler, we
can move it out of signalHandler to make the code more clear.

Signed-off-by: lifubang <lifubang@acmcoder.com>

signals.go

@@ -16,9 +16,7 @@ const signalBufferSize = 2048
 
 // newSignalHandler returns a signal handler for processing SIGCHLD and SIGWINCH signals
 // while still forwarding all other signals to the process.
-// If notifySocket is present, use it to read systemd notifications from the container and
-// forward them to notifySocketHost.
-func newSignalHandler(enableSubreaper bool, notifySocket *notifySocket) chan *signalHandler {
+func newSignalHandler(enableSubreaper bool) chan *signalHandler {
 	if enableSubreaper {
 		// set us as the subreaper before registering the signal handler for the container
 		if err := system.SetSubreaper(1); err != nil {
@@ -37,8 +35,7 @@ func newSignalHandler(enableSubreaper bool, notifySocket *notifySocket) chan *si
 		// handle all signals for the process.
 		signal.Notify(s)
 		handler <- &signalHandler{
-			signals:      s,
-			notifySocket: notifySocket,
+			signals: s,
 		}
 	}()
 	return handler
@@ -52,8 +49,7 @@ type exit struct {
 }
 
 type signalHandler struct {
-	signals      chan os.Signal
-	notifySocket *notifySocket
+	signals chan os.Signal
 }
 
 // forward handles the main signal event loop forwarding, resizing, or reaping depending
@@ -61,7 +57,7 @@ type signalHandler struct {
 func (h *signalHandler) forward(process *libcontainer.Process, tty *tty, detach bool) (int, error) {
 	// make sure we know the pid of our main process so that we can return
 	// after it dies.
-	if detach && h.notifySocket == nil {
+	if detach {
 		return 0, nil
 	}
 
@@ -70,15 +66,6 @@ func (h *signalHandler) forward(process *libcontainer.Process, tty *tty, detach
 		return -1, err
 	}
 
-	if h.notifySocket != nil {
-		if detach {
-			_ = h.notifySocket.run(pid1)
-			return 0, nil
-		}
-		_ = h.notifySocket.run(os.Getpid())
-		go func() { _ = h.notifySocket.run(0) }()
-	}
-
 	// Perform the initial tty resize. Always ignore errors resizing because
 	// stdout might have disappeared (due to races with when SIGHUP is sent).
 	_ = tty.resize()