# Get TCU power state updates

This sample application demonstrates how to register for TCU-activity state notifications on the local machine, for performing any tasks before the state transition.

1. Implement ITcuActivityListener and IServiceStatusListener interface

class MyTcuActivityStateListener : public ITcuActivityListener,
                                       public IServiceStatusListener {
    public:
        void onTcuActivityStateUpdate(TcuActivityState state, std::string machineName) override;
        void onServiceStatusChange(ServiceStatus status) override;
    };
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2. Get an instance of PowerFactory, and then obtain a TCU-activity manager instance with clientType as SLAVE and machine name as LOCAL\_MACHINE

auto &powerFactory = PowerFactory::getInstance();
    std::promise<telux::common::ServiceStatus> prom = std::promise<telux::common::ServiceStatus>();
    ClientInstanceConfig config;
    config.clientType = ClientType::SLAVE;
    config.clientName = "client_name_" + std::to_string(getpid());
    config.machineName =  LOCAL_MACHINE;
    auto tcuActivityManager = powerFactory.getTcuActivityManager(config,
                                  [&](telux::common::ServiceStatus status) {
                                     std::cout << " Init Callback called " << std::endl;
                                     prom.set_value(status);
                                  });
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3. Wait for the TCU-activity management services to be initialized and ready

if (tcuActivityStateMgr_ == nullptr) {
       std::cout << " ERROR - Failed to get manager instance" << std::endl;
    }
    std::cout << "  Waiting for TCU Activity Manager to be ready" << std::endl;
    telux::common::ServiceStatus serviceStatus = prom.get_future().get();
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4. Exit the application, if SDK is unable to initialize TCU-activity management service

if (serviceStatus == telux::common::ServiceStatus::SERVICE_AVAILABLE) {
       std::cout << " *** TCU-activity management service is Ready *** " << std::endl;
    } else {
       std::cout << " *** ERROR - Unable to initialize TCU-activity management service" << std::endl;
       return 1;
    }
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5. Instantiate MyTcuActivityStateListener and register for updates on TCU-activity state and its management service status

auto myTcuStateListener = std::make_shared<MyTcuActivityStateListener>();
    tcuActivityManager->registerListener(myTcuStateListener);
    tcuActivityManager->registerServiceStateListener(myTcuStateListener);
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6. When the TCU activity state of the local machine is about to change, the below listener callback is invoked with the new activity state

void MyTcuActivityStateListener::onTcuActivityStateUpdate(TcuActivityState tcuState, std::string machineName) {
         std::cout << std::endl << "********* TCU-activity state update *********" << std::endl;
         // Avoid long blocking calls when handling notifications
         // Perform necessary tasks and prepare for the state transition
    }
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7. After successfully processing the SUSPEND/SHUTDOWN notification, send an acknowledgement to convey the readiness of the application for the state transition

tcuActivityManager->sendActivityStateAck(StateChangeResponse::ACK, tcuState);
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8. Implement onServiceStatusChange callback to know when TCU-activity management service goes down

// When the TCU-activity management service goes down, this API is invoked
    // with status UNAVAILABLE. All TCU-activity state notifications will be
    // stopped until the status becomes AVAILABLE again.
    void MyTcuActivityStateListener::onServiceStatusChange(ServiceStatus status) {
         std::cout << std::endl << "****** TCU-activity management service status update ******" << std::endl;
         // Avoid long blocking calls when handling notifications
    }
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Last Published: Jun 24, 2026

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