Glib::signal_timeout() and gdk_threads_enter()

[Konishchev Dmitry <konishchev gmail com>]

Hello, everybody.

gtkmm-demo's "Pixbufs" example has the following code:
> m_TimeoutConnection = Glib::signal_timeout().connect(
>     sigc::mem_fun(*this, &Example_Pixbufs::on_timeout), FRAME_DELAY);
> ...
> bool Example_Pixbufs::on_timeout()
> {
>    ...
> }

As I understand, Glib::signal_timeout() is equivalent to the
g_timeout_add(), but in this case we need to surround
Example_Pixbufs::on_timeout() callback by the gdk_threads_enter() and
gdk_threads_leave() as in the following lines:
> bool Example_Pixbufs::on_timeout()
> {
>    gdk_threads_enter();
>    ...
>    gdk_threads_leave();
> }

Is this example wrong, or my understanding of this is wrong?

Thanks for your answer,
Konishchev Dmitry.