Gevent

=========================

- Fix Windows wheel builds.
- Fix macOS wheel builds.

===================


Bugfixes
--------

- Make ``gevent.select.select`` accept arbitrary iterables, not just
sequences. That is, you can now pass in a generator of file
descriptors instead of a realized list. Internally, arbitrary
iterables are copied into lists. This better matches what the standard
library does. Thanks to David Salvisberg.
See :issue:`1979`.
- On Python 3.11 and newer, opt out of Cython's fast exception
manipulation, which *may* be causing problems in certain circumstances
when combined with greenlets.

On all versions of Python, adjust some error handling in the default
C-based loop. This fixes several assertion failures on debug versions
of CPython. Hopefully it has a positive impact under real conditions.
See :issue:`1985`.
- Make ``gevent.pywsgi`` comply more closely with the HTTP specification
for chunked transfer encoding. In particular, we are much stricter
about trailers, and trailers that are invalid (too long or featuring
disallowed characters) forcibly close the connection to the client
*after* the results have been sent.

Trailers otherwise continue to be ignored and are not available to the
WSGI application.

Previously, carefully crafted invalid trailers in chunked requests on
keep-alive connections might appear as two requests to
``gevent.pywsgi``. Because this was handled exactly as a normal
keep-alive connection with two requests, the WSGI application should
handle it normally. However, if you were counting on some upstream
server to filter incoming requests based on paths or header fields,
and the upstream server simply passed trailers through without
validating them, then this embedded second request would bypass those
checks. (If the upstream server validated that the trailers meet the
HTTP specification, this could not occur, because characters that are
required in an HTTP request, like a space, are not allowed in
trailers.) CVE-2023-41419 was reserved for this.

Our thanks to the original reporters, Keran Mu
(mkr22mails.tsinghua.edu.cn) and Jianjun Chen
(jianjuntsinghua.edu.cn), from Tsinghua University and Zhongguancun
Laboratory.
See :issue:`1989`.


----

===================


Features
--------

- Add preliminary support for Python 3.12, using greenlet 3.0a1. This
is somewhat tricky to build from source at this time, and there is
one known issue: On Python 3.12b3, dumping tracebacks of greenlets
is not available.
:issue:`1969`.
- Update the bundled c-ares version to 1.19.1.
See :issue:`1947`.


Bugfixes
--------

- Fix an edge case connecting a non-blocking ``SSLSocket`` that could result
in an AttributeError. In a change to match the standard library,
calling ``sock.connect_ex()`` on a subclass of ``socket`` no longer
calls the subclass's ``connect`` method.

Initial fix by Priyankar Jain.
See :issue:`1932`.
- Make gevent's ``FileObjectThread`` (mostly used on Windows) implement
``readinto`` cooperatively. PR by Kirill Smelkov.
See :issue:`1948`.
- Work around an ``AttributeError`` during cyclic garbage collection
when Python finalizers (``__del__`` and the like) attempt to use
gevent APIs. This is not a recommended practice, and it is unclear if
catching this ``AttributeError`` will fix any problems or just shift
them. (If we could determine the root situation that results in this
cycle, we might be able to solve it.)
See :issue:`1961`.


Deprecations and Removals
-------------------------

- Remove support for obsolete Python versions. This is everything prior
to 3.8.

Related changes include:

- Stop using ``pkg_resources`` to find entry points (plugins).
Instead, use ``importlib.metadata``.
- Honor ``sys.unraisablehook`` when a callback function produces an
exception, and handling the exception in the hub *also* produces an
exception. In older versions, these would be simply printed.
- ``setup.py`` no longer includes the ``setup_requires`` keyword.
Installation with a tool that understands ``pyproject.toml`` is
recommended.
- The bundled tblib has been updated to version 2.0.


----

====================


Bugfixes
--------

- Update to greenlet 2.0. This fixes a deallocation issue that required
a change in greenlet's ABI. The design of greenlet 2.0 is intended to
prevent future fixes and enhancements from requiring an ABI change,
making it easier to update gevent and greenlet independently.

.. caution::

greenlet 2.0 requires a modern-ish C++ compiler. This may mean
certain older platforms are no longer supported.
See :issue:`1909`.


----

====================


Features
--------

- Update bundled libuv to 1.44.2.
See :issue:`1913`.


Misc
----

- See :issue:`1898`., See :issue:`1910`., See :issue:`1915`.


----

====================


Features
--------

- Windows: Test and provide binary wheels for PyPy3.7.

Note that there may be issues with subprocesses, signals, and it may
be slow.
See :issue:`1798`.
- Upgrade embedded c-ares to 1.18.1.
See :issue:`1847`.
- Upgrade bundled libuv to 1.42.0 from 1.40.0.
See :issue:`1851`.
- Added preliminary support for Python 3.11 (rc2 and later).

Some platforms may or may not have binary wheels at this time.

.. important:: Support for legacy versions of Python, including 2.7
and 3.6, will be ending soon. The
maintenance burden has become too great and the
maintainer's time is too limited.

Ideally, there will be a release of gevent compatible
with a final release of greenlet 2.0 that still
supports those legacy versions, but that may not be
possible; this may be the final release to support them.

:class:`gevent.threadpool.ThreadPool` can now optionally expire idle
threads. This is used by default in the implicit thread pool used for
DNS requests and other user-submitted tasks; other uses of a
thread-pool need to opt-in to this.
See :issue:`1867`.


Bugfixes
--------

- Truly disable the effects of compiling with ``-ffast-math``.
See :issue:`1864`.


----