thread_free      1612 vm.c               obj = Data_Wrap_Struct(klass, rb_thread_mark, thread_free, th);
thread_free      1615 vm.c               obj = Data_Make_Struct(klass, rb_thread_t, rb_thread_mark, thread_free, th);
thread_free      1919 vm.c           	th_self = th->self = Data_Wrap_Struct(rb_cThread, rb_thread_mark, thread_free, th);