`multiprocessing.dummy` exports names that were not yet listed in the typeshed stub:
```python
>>> from multiprocessing import dummy as mpdummy
>>> imported_objects = (
... (name, obj) for name, obj in vars(mpdummy).items()
... if name in mpdummy.__all__ and not obj.__module__.startswith("multiprocessing.dummy")
... )
>>> print(*(f"{name}: {obj.__module__}" for name, obj in sorted(imported_objects)), sep="\n")
Barrier: threading
BoundedSemaphore: threading
Condition: threading
Event: threading
JoinableQueue: queue
Lock: _thread
Queue: queue
RLock: threading
Semaphore: threading
current_process: threading
```
Of these, only `JoinableQueue` was listed.
The implementation of `logging.adapters.QueueHandler` and `logging.adapters.QueueListener` works great with `queue.SimpleQueue` too, so update the stub to reflect this.
The new queue.SimpleQueue class (introduced in 3.7) is faster but is not a Queue subclass as it doesn't implement task handling (`handle_task()` / `join()`) or queue bounds (raising `queue.Full` / `full()`). The logging handler / listener implementations do not make use of those features however.
Related Python bug, asking for an explicit documentation mention: https://bugs.python.org/issue37469
Martijn Pieters