Merge pull request #1727 from pquentin/release-0.17.0

Author: pquentin

docs/source/history.rst

@@ -5,6 +5,68 @@ Release history
 
 .. towncrier release notes start
 
+Trio 0.17.0 (2020-09-15)
+------------------------
+
+Headline features
+~~~~~~~~~~~~~~~~~
+
+- Trio now supports automatic :ref:`async generator finalization
+  <async-generators>`, so more async generators will work even if you
+  don't wrap them in ``async with async_generator.aclosing():``
+  blocks. Please see the documentation for important caveats; in
+  particular, yielding within a nursery or cancel scope remains
+  unsupported. (`#265 <https://github.com/python-trio/trio/issues/265>`__)
+
+
+Features
+~~~~~~~~
+
+- `trio.open_tcp_stream` has a new ``local_address=`` keyword argument
+  that can be used on machines with multiple IP addresses to control
+  which IP is used for the outgoing connection. (`#275 <https://github.com/python-trio/trio/issues/275>`__)
+- If you pass a raw IP address into ``sendto``, it no longer spends any
+  time trying to resolve the hostname. If you're using UDP, this should
+  substantially reduce your per-packet overhead. (`#1595 <https://github.com/python-trio/trio/issues/1595>`__)
+- `trio.lowlevel.checkpoint` is now much faster. (`#1613 <https://github.com/python-trio/trio/issues/1613>`__)
+- We switched to a new, lower-overhead data structure to track upcoming
+  timeouts, which should make your programs faster. (`#1629 <https://github.com/python-trio/trio/issues/1629>`__)
+
+
+Bugfixes
+~~~~~~~~
+
+- On macOS and BSDs, explicitly close our wakeup socketpair when we're
+  done with it. (`#1621 <https://github.com/python-trio/trio/issues/1621>`__)
+- Trio can now be imported when `sys.excepthook` is a `functools.partial` instance, which might occur in a
+  ``pytest-qt`` test function. (`#1630 <https://github.com/python-trio/trio/issues/1630>`__)
+- The thread cache didn't release its reference to the previous job. (`#1638 <https://github.com/python-trio/trio/issues/1638>`__)
+- On Windows, Trio now works around the buggy behavior of certain
+  Layered Service Providers (system components that can intercept
+  network activity) that are built on top of a commercially available
+  library called Komodia Redirector. This benefits users of products
+  such as Astrill VPN and Qustodio parental controls. Previously, Trio
+  would crash on startup when run on a system where such a product was
+  installed. (`#1659 <https://github.com/python-trio/trio/issues/1659>`__)
+
+
+Deprecations and removals
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- Remove ``wait_socket_*``, ``notify_socket_closing``, ``notify_fd_closing``, ``run_sync_in_worker_thread`` and ``current_default_worker_thread_limiter``. They were deprecated in 0.12.0. (`#1596 <https://github.com/python-trio/trio/issues/1596>`__)
+
+
+Miscellaneous internal changes
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+- When using :ref:`instruments <instrumentation>`, you now only "pay for what you use":
+  if there are no instruments installed that override a particular hook such as
+  :meth:`~trio.abc.Instrument.before_task_step`, then Trio doesn't waste any effort
+  on checking its instruments when the event corresponding to that hook occurs.
+  Previously, installing any instrument would incur all the instrumentation overhead,
+  even for hooks no one was interested in. (`#1340 <https://github.com/python-trio/trio/issues/1340>`__)
+
+
 Trio 0.16.0 (2020-06-10)
 ------------------------