Class _DummyThread

Lib/threading.py:1431–1458

# when we exit (conform previous semantics).

class _DummyThread(Thread):

    def __init__(self):
        Thread.__init__(self, name=_newname("Dummy-%d"),
                        daemon=_daemon_threads_allowed())
        self._started.set()
        self._set_ident()
        self._os_thread_handle = _make_thread_handle(self._ident)
        if _HAVE_THREAD_NATIVE_ID:
            self._set_native_id()
        with _active_limbo_lock:
            _active[self._ident] = self
        _DeleteDummyThreadOnDel(self)

    def is_alive(self):
        if not self._os_thread_handle.is_done() and self._started.is_set():
            return True
        raise RuntimeError("thread is not alive")

    def join(self, timeout=None):
        raise RuntimeError("cannot join a dummy thread")

    def _after_fork(self, new_ident=None):
        if new_ident is not None:
            self.__class__ = _MainThread
            self._name = 'MainThread'
            self._daemonic = False
        Thread._after_fork(self, new_ident=new_ident)


# Global API functions