read_internal_call 2529 io.c           	rb_str_locktmp_ensure(str, read_internal_call, (VALUE)&arg);
read_internal_call 2659 io.c           	rb_str_locktmp_ensure(str, read_internal_call, (VALUE)&arg);
read_internal_call 4730 io.c               rb_ensure(read_internal_call, (VALUE)&arg, rb_str_unlocktmp, str);