The ``compile()`` builtin functions now support the ``ast.PyCF_ALLOW_TOP_LEVEL_AWAIT`` flag, which allow to compile sources that contains top-level ``await``, ``async with`` or ``async for``. This is useful to evaluate async-code from with an already async functions; for example in a custom REPL.
Freeing a great many small objects could take time quadratic in the number of arenas, due to using linear search to keep ``obmalloc.c``'s list of usable arenas sorted by order of number of free memory pools. This is accomplished without search now, leaving the worst-case time linear in the number of arenas. For programs where this quite visibly matters (typically with more than 100 thousand small objects alive simultaneously), this can greatly reduce the time needed to release their memory.
Enable plistlib to read and write binary plist files that were created as a KeyedArchive file. Specifically, this allows the plistlib to process 0x80 tokens as UID objects.
The multiprocessing.resource_tracker replaces the multiprocessing.semaphore_tracker module. Other than semaphores, resource_tracker also tracks shared_memory segments.
Introduce :class:`asyncio.Stream` class that merges :class:`asyncio.StreamReader` and :class:`asyncio.StreamWriter` functionality.
:class:`asyncio.Stream` can work in readonly, writeonly and readwrite modes.
Provide :func:`asyncio.connect`, :func:`asyncio.connect_unix`, :func:`asyncio.connect_read_pipe` and :func:`asyncio.connect_write_pipe` factories to open :class:`asyncio.Stream` connections. Provide :class:`asyncio.StreamServer` and :class:`UnixStreamServer` to serve servers with asyncio.Stream API.
Modify :func:`asyncio.create_subprocess_shell` and :func:`asyncio.create_subprocess_exec` to use :class:`asyncio.Stream` instead of deprecated :class:`StreamReader` and :class:`StreamWriter`.
Deprecate :class:`asyncio.StreamReader` and :class:`asyncio.StreamWriter`.
Deprecate usage of private classes, e.g. :class:`asyncio.FlowControlMixing` and :class:`asyncio.StreamReaderProtocol` outside of asyncio package.
:func:`shutil.copystat` now ignores :const:`errno.EINVAL` on :func:`os.setxattr` which may occur when copying files on filesystems without extended attributes support.
Original patch by Giampaolo Rodola, updated by Ying Wang.
Skip httplib and nntplib networking tests when they would otherwise fail due to a modern OS or distro with a default OpenSSL policy of rejecting connections to servers with weak certificates.
