Class _DeleteDummyThreadOnDel

Lib/threading.py:1402–1421

Helper class to remove a dummy thread from threading._active on __del__.

class _DeleteDummyThreadOnDel:
    '''
    Helper class to remove a dummy thread from threading._active on __del__.
    '''

    def __init__(self, dummy_thread):
        self._dummy_thread = dummy_thread
        self._tident = dummy_thread.ident
        # Put the thread on a thread local variable so that when
        # the related thread finishes this instance is collected.
        #
        # Note: no other references to this instance may be created.
        # If any client code creates a reference to this instance,
        # the related _DummyThread will be kept forever!
        _thread_local_info._track_dummy_thread_ref = self

    def __del__(self, _active_limbo_lock=_active_limbo_lock, _active=_active):
        with _active_limbo_lock:
            if _active.get(self._tident) is self._dummy_thread:
                _active.pop(self._tident, None)


# Dummy thread class to represent threads not started here.