}
+static hb_font_funcs_t *static_ot_funcs = NULL;
+
+#ifdef HB_USE_ATEXIT
+static
+void free_static_ot_funcs (void)
+{
+ hb_font_funcs_destroy (static_ot_funcs);
+}
+#endif
+
static hb_font_funcs_t *
_hb_ot_get_font_funcs (void)
{
- static const hb_font_funcs_t ot_ffuncs = {
- HB_OBJECT_HEADER_STATIC,
+retry:
+ hb_font_funcs_t *funcs = (hb_font_funcs_t *) hb_atomic_ptr_get (&static_ot_funcs);
- true, /* immutable */
-
- {
-#define HB_FONT_FUNC_IMPLEMENT(name) hb_ot_get_##name,
- HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
-#undef HB_FONT_FUNC_IMPLEMENT
+ if (unlikely (!funcs))
+ {
+ funcs = hb_font_funcs_create ();
+
+ hb_font_funcs_set_glyph_func (funcs, hb_ot_get_glyph, NULL, NULL);
+ hb_font_funcs_set_glyph_h_advance_func (funcs, hb_ot_get_glyph_h_advance, NULL, NULL);
+ hb_font_funcs_set_glyph_v_advance_func (funcs, hb_ot_get_glyph_v_advance, NULL, NULL);
+ hb_font_funcs_set_glyph_h_origin_func (funcs, hb_ot_get_glyph_h_origin, NULL, NULL);
+ hb_font_funcs_set_glyph_v_origin_func (funcs, hb_ot_get_glyph_v_origin, NULL, NULL);
+ hb_font_funcs_set_glyph_h_kerning_func (funcs, hb_ot_get_glyph_h_kerning, NULL, NULL);
+ hb_font_funcs_set_glyph_v_kerning_func (funcs, hb_ot_get_glyph_v_kerning, NULL, NULL);
+ hb_font_funcs_set_glyph_extents_func (funcs, hb_ot_get_glyph_extents, NULL, NULL);
+ hb_font_funcs_set_glyph_contour_point_func (funcs, hb_ot_get_glyph_contour_point, NULL, NULL);
+ hb_font_funcs_set_glyph_name_func (funcs, hb_ot_get_glyph_name, NULL, NULL);
+ hb_font_funcs_set_glyph_from_name_func (funcs, hb_ot_get_glyph_from_name, NULL, NULL);
+
+ hb_font_funcs_make_immutable (funcs);
+
+ if (!hb_atomic_ptr_cmpexch (&static_ot_funcs, NULL, funcs)) {
+ hb_font_funcs_destroy (funcs);
+ goto retry;
}
+
+#ifdef HB_USE_ATEXIT
+ atexit (free_static_ot_funcs); /* First person registers atexit() callback. */
+#endif
};
- return const_cast<hb_font_funcs_t *> (&ot_ffuncs);
+ return funcs;
}