fiber_alloc      1249 cont.c             return fiber_init(fiber_alloc(rb_cFiber), rb_proc_new(func, obj));
fiber_alloc      1301 cont.c             fib = fiber_t_alloc(fiber_alloc(rb_cFiber));
fiber_alloc      1682 cont.c             rb_define_alloc_func(rb_cFiber, fiber_alloc);