}
};
struct receiver : public pqxx::notification_receiver
{
    bool status = false;
    receiver(pqxx::connection_base & c, const std::string & channel)
        : pqxx::notification_receiver(c, channel) { }
    void operator() (const string & payload, int pid) override
    {
        status = true;
    };
    bool get() {
        bool b = status;
        status = false;
        return b;

    struct receiver : public pqxx::notification_receiver
    {
        bool status = false;
        receiver(pqxx::connection_base & c, const std::string & channel)
            : pqxx::notification_receiver(c, channel) { }
        void operator() (const string & payload, int pid) override
        {
            status = true;
        };
        bool get() {
            bool b = status;
            status = false;
            return b;
        }
    };

    receiver dumpStatus(*conn, "dump_status");

        if (dumpStatus.get())
            State::dumpStatus();

    while (true) {
        try {
            auto conn(dbPool.get());
            receiver dumpStatus(*conn, "dump_status");
            while (true) {
                conn->await_notification();
                if (dumpStatus.get())
                    State::dumpStatus();
            }
        } catch (std::exception & e) {
            printMsg(lvlError, format("main thread: %1%") % e.what());
            sleep(10); // probably a DB problem, so don't retry right away
        }
    }

    // Never reached.