Remove usage of listenbuffer package

It actually adds nothing to queuing requests.

Signed-off-by: Alexander Morozov <lk4d4@docker.com>

api/server/server.go

@@ -39,7 +39,6 @@ type Config struct {
 // Server contains instance details for the server
 type Server struct {
 	cfg     *Config
-	start   chan struct{}
 	servers []*HTTPServer
 	routers []router.Router
 }
@@ -54,8 +53,7 @@ type Addr struct {
 // It allocates resources which will be needed for ServeAPI(ports, unix-sockets).
 func New(cfg *Config) (*Server, error) {
 	s := &Server{
-		cfg:   cfg,
-		start: make(chan struct{}),
+		cfg: cfg,
 	}
 	for _, addr := range cfg.Addrs {
 		srv, err := s.newServer(addr.Proto, addr.Addr)
@@ -132,7 +130,7 @@ func (s *Server) initTCPSocket(addr string) (l net.Listener, err error) {
 	if s.cfg.TLSConfig == nil || s.cfg.TLSConfig.ClientAuth != tls.RequireAndVerifyClientCert {
 		logrus.Warn("/!\\ DON'T BIND ON ANY IP ADDRESS WITHOUT setting -tlsverify IF YOU DON'T KNOW WHAT YOU'RE DOING /!\\")
 	}
-	if l, err = sockets.NewTCPSocket(addr, s.cfg.TLSConfig, s.start); err != nil {
+	if l, err = sockets.NewTCPSocket(addr, s.cfg.TLSConfig); err != nil {
 		return nil, err
 	}
 	if err := allocateDaemonPort(addr); err != nil {
@@ -202,15 +200,3 @@ func (s *Server) CreateMux() *mux.Router {
 
 	return m
 }
-
-// AcceptConnections allows clients to connect to the API server.
-// Referenced Daemon is notified about this server, and waits for the
-// daemon acknowledgement before the incoming connections are accepted.
-func (s *Server) AcceptConnections() {
-	// close the lock so the listeners start accepting connections
-	select {
-	case <-s.start:
-	default:
-		close(s.start)
-	}
-}

api/server/server_unix.go

@@ -36,7 +36,7 @@ func (s *Server) newServer(proto, addr string) ([]*HTTPServer, error) {
 		}
 		ls = append(ls, l)
 	case "unix":
-		l, err := sockets.NewUnixSocket(addr, s.cfg.SocketGroup, s.start)
+		l, err := sockets.NewUnixSocket(addr, s.cfg.SocketGroup)
 		if err != nil {
 			return nil, err
 		}

docker/daemon.go

@@ -268,10 +268,8 @@ func (cli *DaemonCli) CmdDaemon(args ...string) error {
 		}
 	})
 
-	// after the daemon is done setting up we can tell the api to start
-	// accepting connections with specified daemon
+	// after the daemon is done setting up we can notify systemd api
 	notifySystem()
-	api.AcceptConnections()
 
 	// Daemon is fully initialized and handling API traffic
 	// Wait for serve API to complete

pkg/sockets/tcp_socket.go

@@ -7,17 +7,13 @@ import (
 	"net"
 	"net/http"
 	"time"
-
-	"github.com/docker/docker/pkg/listenbuffer"
 )
 
 // NewTCPSocket creates a TCP socket listener with the specified address and
 // and the specified tls configuration. If TLSConfig is set, will encapsulate the
 // TCP listener inside a TLS one.
-// The channel passed is used to activate the listenbuffer when the caller is ready
-// to accept connections.
-func NewTCPSocket(addr string, tlsConfig *tls.Config, activate <-chan struct{}) (net.Listener, error) {
-	l, err := listenbuffer.NewListenBuffer("tcp", addr, activate)
+func NewTCPSocket(addr string, tlsConfig *tls.Config) (net.Listener, error) {
+	l, err := net.Listen("tcp", addr)
 	if err != nil {
 		return nil, err
 	}

pkg/sockets/unix_socket.go

@@ -10,20 +10,17 @@ import (
 	"syscall"
 
 	"github.com/Sirupsen/logrus"
-	"github.com/docker/docker/pkg/listenbuffer"
 	"github.com/opencontainers/runc/libcontainer/user"
 )
 
 // NewUnixSocket creates a unix socket with the specified path and group.
-// The channel passed is used to activate the listenbuffer when the caller is ready
-// to accept connections.
-func NewUnixSocket(path, group string, activate <-chan struct{}) (net.Listener, error) {
+func NewUnixSocket(path, group string) (net.Listener, error) {
 	if err := syscall.Unlink(path); err != nil && !os.IsNotExist(err) {
 		return nil, err
 	}
 	mask := syscall.Umask(0777)
 	defer syscall.Umask(mask)
-	l, err := listenbuffer.NewListenBuffer("unix", path, activate)
+	l, err := net.Listen("unix", path)
 	if err != nil {
 		return nil, err
 	}