tractor/NEWS.rst

154 lines
5.9 KiB
ReStructuredText

=========
Changelog
=========
.. towncrier release notes start
tractor 0.1.0a2 (2021-09-07)
============================
Features
--------
- Add `tokio-style broadcast channels
<https://docs.rs/tokio/1.11.0/tokio/sync/broadcast/index.html>`_ as
a solution for `#204 <https://github.com/goodboy/tractor/pull/204>`_ and
discussed thoroughly in `trio/#987
<https://github.com/python-trio/trio/issues/987>`_.
This gives us local task broadcast functionality using a new
``BroadcastReceiver`` type which can wrap ``trio.ReceiveChannel`` and
provide fan-out copies of a stream of data to every subscribed consumer.
We use this new machinery to provide a ``ReceiveMsgStream.subscribe()``
async context manager which can be used by actor-local concumers tasks
to easily pull from a shared and dynamic IPC stream. (`#229
<https://github.com/goodboy/tractor/pull/229>`_)
Bugfixes
--------
- Handle broken channel/stream faults where the root's tty lock is left
acquired by some child actor who went MIA and the root ends up hanging
indefinitely. (`#234 <https://github.com/goodboy/tractor/pull/234>`_)
There's two parts here: we no longer shield wait on the lock and,
now always do our best to release the lock on the expected worst
case connection faults.
Deprecations and Removals
-------------------------
- Drop stream "shielding" support which was originally added to sidestep
a cancelled call to ``.receive()``
In the original api design a stream instance was returned directly from
a call to ``Portal.run()`` and thus there was no "exit phase" to handle
cancellations and errors which would trigger implicit closure. Now that
we have said enter/exit semantics with ``Portal.open_stream_from()`` and
``Context.open_stream()`` we can drop this implicit (and arguably
confusing) behavior. (`#230 <https://github.com/goodboy/tractor/pull/230>`_)
- Drop Python 3.7 support in preparation for supporting 3.9+ syntax.
(`#232 <https://github.com/goodboy/tractor/pull/232>`_)
tractor 0.1.0a1 (2021-08-01)
============================
Features
--------
- Updated our uni-directional streaming API (`#206
<https://github.com/goodboy/tractor/pull/206>`_) to require a context
manager style ``async with Portal.open_stream_from(target) as stream:``
which explicitly determines when to stop a stream in the calling (aka
portal opening) actor much like ``async_generator.aclosing()``
enforcement.
- Improved the ``multiprocessing`` backend sub-actor reaping (`#208
<https://github.com/goodboy/tractor/pull/208>`_) during actor nursery
exit, particularly during cancellation scenarios that previously might
result in hard to debug hangs.
- Added initial bi-directional streaming support in `#219
<https://github.com/goodboy/tractor/pull/219>`_ with follow up debugger
improvements via `#220 <https://github.com/goodboy/tractor/pull/220>`_
using the new ``tractor.Context`` cross-actor task syncing system.
The debugger upgrades add an edge triggered last-in-tty-lock semaphore
which allows the root process for a tree to avoid clobbering children
who have queued to acquire the ``pdb`` repl by waiting to cancel
sub-actors until the lock is known to be released **and** has no
pending waiters.
Experiments and WIPs
--------------------
- Initial optional ``msgspec`` serialization support in `#214
<https://github.com/goodboy/tractor/pull/214>`_ which should hopefully
land by next release.
- Improved "infect ``asyncio``" cross-loop task cancellation and error
propagation by vastly simplifying the cross-loop-task streaming approach.
We may end up just going with a use of ``anyio`` in the medium term to
avoid re-doing work done by their cross-event-loop portals. See the
``infect_asyncio`` for details.
Improved Documentation
----------------------
- `Updated our readme <https://github.com/goodboy/tractor/pull/211>`_ to
include more (and better) `examples
<https://github.com/goodboy/tractor#run-a-func-in-a-process>`_ (with
matching multi-terminal process monitoring shell commands) as well as
added many more examples to the `repo set
<https://github.com/goodboy/tractor/tree/master/examples>`_.
- Added a readme `"actors under the hood" section
<https://github.com/goodboy/tractor#under-the-hood>`_ in an effort to
guard against suggestions for changing the API away from ``trio``'s
*tasks-as-functions* style.
- Moved to using the `sphinx book theme
<https://sphinx-book-theme.readthedocs.io/en/latest/index.html>`_
though it needs some heavy tweaking and doesn't seem to show our logo
on rtd :(
Trivial/Internal Changes
------------------------
- Added a new ``TransportClosed`` internal exception/signal (`#215
<https://github.com/goodboy/tractor/pull/215>`_ for catching TCP
channel gentle closes instead of silently falling through the message
handler loop via an async generator ``return``.
Deprecations and Removals
-------------------------
- Dropped support for invoking sync functions (`#205
<https://github.com/goodboy/tractor/pull/205>`_) in other
actors/processes since you can always wrap a sync function from an
async one. Users can instead consider using ``trio-parallel`` which
is a project specifically geared for purely synchronous calls in
sub-processes.
- Deprecated our ``tractor.run()`` entrypoint `#197
<https://github.com/goodboy/tractor/pull/197>`_; the runtime is now
either started implicitly in first actor nursery use or via an
explicit call to ``tractor.open_root_actor()``. Full removal of
``tractor.run()`` will come by beta release.
tractor 0.1.0a0 (2021-02-28)
============================
..
TODO: fill out more of the details of the initial feature set in some TLDR form
Summary
-------
- ``trio`` based process spawner (using ``subprocess``)
- initial multi-process debugging with ``pdb++``
- windows support using both ``trio`` and ``multiprocessing`` spawners
- "portal" api for cross-process, structured concurrent, (streaming) IPC