C-V2X Get Status Sample App

This Document walks through the cv2x_get_status_app. It demonstrates how to use the C-V2X Radio Manager API to get the C-V2X status.

### 1. Create a RequestCv2xStatusCallback function ###

// Globals
static Cv2xStatus gCv2xStatus;
static promise<ErrorCode> gCallbackPromise;
static map<Cv2xStatusType, string> gCv2xStatusToString = {
    {Cv2xStatusType::INACTIVE, "Inactive"},
    {Cv2xStatusType::ACTIVE, "Active"},
    {Cv2xStatusType::SUSPENDED, "SUSPENDED"},
    {Cv2xStatusType::UNKNOWN, "UNKNOWN"},
};

// Callback function for Cv2xRadioManager->requestCv2xStatus
static void cv2xStatusCallback(Cv2xStatus status, ErrorCode error) {
    if (ErrorCode::SUCCESS == error) {
        gCv2xStatus = status;
    }
    gCallbackPromise.set_value(error);
}

Note: as an alternative, we can use a Lambda function which would eliminate the need for this global scope function.

### 2. Get a handle to the ICv2xRadioManager object ###

int main {
    // Get handle to Cv2xRadioManager
    auto & cv2xFactory = Cv2xFactory::getInstance();
    auto cv2xRadioManager = cv2xFactory.getCv2xRadioManager();

3. Request the C-V2X status

    if (Status::SUCCESS != cv2xRadioManager->requestCv2xStatus(cv2xStatusCallback)) {
        cout << "Error : request for C-V2X status failed." << endl;
        return EXIT_FAILURE;
    }
    if (ErrorCode::SUCCESS != gCallbackPromise.get_future().get()) {
        cout << "Error : failed to retrieve C-V2X status." << endl;
        return EXIT_FAILURE;
    }

    // Print status
    if (Cv2xStatusType::ACTIVE == gCv2xStatus.rxStatus) {
        cout << "C-V2X Status:" << endl
             << "  RX : " << gCv2xStatusToString[gCv2xStatus.rxStatus] << endl
             << "  TX : " << gCv2xStatusToString[gCv2xStatus.txStatus] << endl;
    }

    return EXIT_SUCCESS;

} // main