// Start create a live P2P node and starts running it.
func (n *Node) Start() error {
n.lock.Lock()
defer n.lock.Unlock()
// Short circuit if the node's already running
if n.server != nil {
return ErrNodeRunning
}
// Otherwise copy and specialize the P2P configuration
running := new(p2p.Server)
*running = *n.serverConfig
services := make(map[reflect.Type]Service)
for _, constructor := range n.serviceFuncs {
// Create a new context for the particular service
ctx := &ServiceContext{
datadir: n.datadir,
services: make(map[reflect.Type]Service),
EventMux: n.eventmux,
}
for kind, s := range services { // copy needed for threaded access
ctx.services[kind] = s
}
// Construct and save the service
service, err := constructor(ctx)
if err != nil {
return err
}
kind := reflect.TypeOf(service)
if _, exists := services[kind]; exists {
return &DuplicateServiceError{Kind: kind}
}
services[kind] = service
}
// Gather the protocols and start the freshly assembled P2P server
for _, service := range services {
running.Protocols = append(running.Protocols, service.Protocols()...)
}
if err := running.Start(); err != nil {
if errno, ok := err.(syscall.Errno); ok && datadirInUseErrnos[uint(errno)] {
return ErrDatadirUsed
}
return err
}
// Start each of the services
started := []reflect.Type{}
for kind, service := range services {
// Start the next service, stopping all previous upon failure
if err := service.Start(running); err != nil {
for _, kind := range started {
services[kind].Stop()
}
running.Stop()
return err
}
// Mark the service started for potential cleanup
started = append(started, kind)
}
// Finish initializing the startup
n.services = services
n.server = running
n.stop = make(chan struct{})
return nil
}
