ScmSysFdset      1306 src/system.c   static ScmSysFdset *fdset_copy(ScmSysFdset *fdset)
ScmSysFdset      1366 src/system.c   static ScmObj select_int(ScmSysFdset *rfds, ScmSysFdset *wfds,
ScmSysFdset      1367 src/system.c                            ScmSysFdset *efds, ScmObj timeout)