blob: c9e5d178eac5b8a995d304a260a7b91cc34cb2af [file] [log] [blame]
// Copyright 2019 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package vm
import (
vmtools "chromiumos/vm_tools/vm_rpc"
// StartupListenerServer is struct to manage an instance of a StartupListener
// gRPC server. It is designed to listen for a single VmReady call from a VM at
// the provided CID.
type StartupListenerServer struct {
port uint32
rec chan struct{}
lis net.Listener
server *grpc.Server
// NewStartupListenerServer accepts a vsock port to listen on as a parameter,
// and returns a new StatupListenerServer struct. At this point the server has
// not been started.
func NewStartupListenerServer(vsockPort uint32) (*StartupListenerServer, error) {
s := StartupListenerServer{
server: grpc.NewServer(),
rec: make(chan struct{}),
port: vsockPort,
vmtools.RegisterStartupListenerServer(s.server, &s)
return &s, nil
// Start creates the vsock port listener and starts the gRPC server in a goroutine.
func (s *StartupListenerServer) Start() error {
var err error
if s.lis, err = vsock.Listen(s.port); err != nil {
return errors.Wrapf(err, "unable to start listening on vsock port %d", s.port)
go s.server.Serve(s.lis)
return nil
// Stop will stop the gRPC server.
func (s *StartupListenerServer) Stop() {
// WaitReady will block until the VmReady call is received. If the message is
// not received before the context timeout, an error is returned.
func (s *StartupListenerServer) WaitReady(ctx context.Context) error {
select {
case <-s.rec:
return nil
case <-ctx.Done():
return errors.Wrap(ctx.Err(), "context timeout waiting for server to be ready")
// VmReady is the implementation of the StartupListenerServer gRPC stub. It
// sends a signal through an empty channel when a message is received.
// Note: golint flags this function because Vm is not fully capitalized, however
// this is due to the proto definition.
func (s *StartupListenerServer) VmReady(ctx context.Context, msg *vmtools.EmptyMessage) (*vmtools.EmptyMessage, error) {
return &vmtools.EmptyMessage{}, nil