rb_thread_start_0 8728 eval.c             return rb_thread_start_0(fn, arg, rb_thread_alloc(rb_cThread));
rb_thread_start_0 8782 eval.c             return rb_thread_start_0(rb_thread_yield, args, rb_thread_check(thread));
rb_thread_start_0 8792 eval.c             return rb_thread_start_0(rb_thread_yield, args, rb_thread_alloc(klass));