A #GClosure.
A #GValue to store the return value. May be %NULL if the callback of closure doesn't return a value.
The length of the @param_values array.
An array of #GValues holding the arguments on which to invoke the callback of closure.
The invocation hint given as the last argument to g_closure_invoke().
Additional data specified when registering the marshaller, see g_closure_set_marshal() and g_closure_set_meta_marshal()
2.30
A generic marshaller function implemented via libffi.
Normally this function is not passed explicitly to g_signal_new(), but used automatically by GLib when specifying a %NULL marshaller.