brpc namingservice的调用栈

int Channel::Init(const char* ns_url,
                  const char* lb_name,
                  const ChannelOptions* options)

int LoadBalancerWithNaming::Init(const char* ns_url, const char* lb_name,
                                 const NamingServiceFilter* filter,
                                 const GetNamingServiceThreadOptions* options)

int GetNamingServiceThread(
    butil::intrusive_ptr<NamingServiceThread>* nsthread_out,
    const char* url,
    const GetNamingServiceThreadOptions* options)

static const char* ParseNamingServiceUrl(const char* url, char* protocol) 

int NamingServiceThread::Start(NamingService* naming_service,
                               const std::string& protocol,
                               const std::string& service_name,
                               const GetNamingServiceThreadOptions* opt_in) 

void NamingServiceThread::Run()

int PeriodicNamingService::RunNamingService(
    const char* service_name, NamingServiceActions* actions)