msakai/ruby-gnome2 — comment on commit aca7d33ac40f877024807edc2fa9dd1d3e6c4672
File: glib2/ext/glib2/rbgutil_callback.c line 170
By msakai:

ruby_thread_has_gvl_p and rb_thread_call_with_gvl are rather experimental API declared only in vm_core.h at the moment.
(But their declaration will be moved to public header file (possibly after 1.9.3 release) if there are no problems found.)
This is the reason why I declared them by myself.