Merge "Simplify socket configuration in DNSResponder::startServer()" am: 1de4036525

        return false;

    }

    for (const addrinfo* ai = ai_res ; ai ; ai = ai->ai_next) {

        android::base::unique_fd s(socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol));

        if (s.get() < 0) {

            APLOGI("ignore creating socket %d failed", s.get());

        socket_.reset(socket(ai->ai_family, ai->ai_socktype | SOCK_NONBLOCK, ai->ai_protocol));

        if (socket_.get() < 0) {

            APLOGI("ignore creating socket %d failed", socket_.get());

            continue;

        }

        enableSockopt(s.get(), SOL_SOCKET, SO_REUSEPORT).ignoreError();

        enableSockopt(s.get(), SOL_SOCKET, SO_REUSEADDR).ignoreError();

        enableSockopt(socket_.get(), SOL_SOCKET, SO_REUSEPORT).ignoreError();

        enableSockopt(socket_.get(), SOL_SOCKET, SO_REUSEADDR).ignoreError();

        std::string host_str = addr2str(ai->ai_addr, ai->ai_addrlen);

        if (bind(s.get(), ai->ai_addr, ai->ai_addrlen)) {

        if (bind(socket_.get(), ai->ai_addr, ai->ai_addrlen)) {

            APLOGI("failed to bind UDP %s:%s", host_str.c_str(), listen_service_.c_str());

            continue;

        }

        ALOGI("bound to UDP %s:%s", host_str.c_str(), listen_service_.c_str());

        socket_ = std::move(s);

        break;

    }

    int flags = fcntl(socket_.get(), F_GETFL, 0);

    if (flags < 0) flags = 0;

    if (fcntl(socket_.get(), F_SETFL, flags | O_NONBLOCK) < 0) {

        APLOGI("fcntl(F_SETFL) failed for socket %d", socket_.get());

        return false;

    }

    // Set up eventfd socket.

    event_fd_.reset(eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC));

    if (event_fd_.get() == -1) {