Version history

This library adheres to Semantic Versioning 2.0.

2.2.0

• Added the maybe_async() and maybe_async_cm() functions to facilitate forward compatibility with AnyIO 3

• Fixed socket stream bug on asyncio where receiving a half-close from the peer would shut down the entire connection

• Fixed native task names not being set on asyncio on Python 3.8+

• Fixed TLSStream.send_eof() raising ValueError instead of the expected NotImplementedError

• Fixed open_signal_receiver() on asyncio and curio hanging if the cancel scope was cancelled before the function could run

• Fixed Trio test runner causing unwarranted test errors on ``BaseException``s (PR by Matthias Urlichs)

• Fixed formatted output of ExceptionGroup containing too many newlines

2.1.0

• Added the spawn_task() and wrap_async_context_manager() methods to BlockingPortal

• Added the handshake_timeout and error_handler parameters to TLSListener

• Fixed Event objects on the trio backend not inheriting from anyio.abc.Event

• Fixed run_sync_in_worker_thread() raising UnboundLocalError on asyncio when cancelled

• Fixed send() on socket streams not raising any exception on asyncio, and an unwrapped BrokenPipeError on trio and curio when the peer has disconnected

• Fixed MemoryObjectSendStream.send() raising BrokenResourceError when the last receiver is closed right after receiving the item

• Fixed ValueError: Invalid file descriptor: -1 when closing a SocketListener on asyncio

2.0.2

• Fixed one more case of AttributeError: 'async_generator_asend' object has no attribute 'cr_await' on asyncio

2.0.1

• Fixed broken MultiListener.extra() (PR by daa)

• Fixed TLSStream returning an empty bytes object instead of raising EndOfStream when trying to receive from the stream after a closing handshake

• Fixed AttributeError when cancelling a task group’s scope inside an async test fixture on asyncio

• Fixed wait_all_tasks_blocked() raising AttributeError on asyncio if a native task is waiting on an async generator’s asend() method

2.0.0

• General new features:

  • Added support for subprocesses

  • Added support for “blocking portals” which allow running functions in the event loop thread from external threads

  • Added the anyio.aclose_forcefully() function for closing asynchronous resources as quickly as possible

• General changes/fixes:

  • BACKWARDS INCOMPATIBLE Some functions have been renamed or removed (see further below for socket/fileio API changes):

    • finalize() → (removed; use async_generator.aclosing() instead)

    • receive_signals() → open_signal_receiver()

    • run_in_thread() → run_sync_in_worker_thread()

    • current_default_thread_limiter() → current_default_worker_thread_limiter()

    • ResourceBusyError → BusyResourceError

  • BACKWARDS INCOMPATIBLE Exception classes were moved to the top level package

  • Dropped support for Python 3.5

  • Bumped minimum versions of trio and curio to v0.16 and v1.4, respectively

  • Changed the repr() of ExceptionGroup to match trio’s MultiError

• Backend specific changes and fixes:

  • asyncio: Added support for ProactorEventLoop. This allows asyncio applications to use AnyIO on Windows even without using AnyIO as the entry point.

  • asyncio: The asyncio backend now uses asyncio.run() behind the scenes which properly shuts down async generators and cancels any leftover native tasks

  • curio: Worked around the limitation where a task can only be cancelled twice (any cancellations beyond that were ignored)

  • asyncio + curio: a cancellation check now calls sleep(0), allowing the scheduler to switch to a different task

  • asyncio + curio: Host name resolution now uses IDNA 2008 (with UTS 46 compatibility mapping, just like trio)

  • asyncio + curio: Fixed a bug where a task group would abandon its subtasks if its own cancel scope was cancelled while it was waiting for subtasks to finish

  • asyncio + curio: Fixed recursive tracebacks when a single exception from an inner task group is reraised in an outer task group

• Socket/stream changes:

  • BACKWARDS INCOMPATIBLE The stream class structure was completely overhauled. There are now separate abstract base classes for receive and send streams, byte streams and reliable and unreliable object streams. Stream wrappers are much better supported by this new ABC structure and a new “typed extra attribute” system that lets you query the wrapper chain for the attributes you want via .extra(...).

  • BACKWARDS INCOMPATIBLE Socket server functionality has been refactored into a network-agnostic listener system

  • BACKWARDS INCOMPATIBLE TLS functionality has been split off from SocketStream and can now work over any bidirectional bytes-based stream – you can now establish a TLS encrypted communications pathway over UNIX sockets or even memory object streams. The TLSRequired exception has also been removed as it is no longer necessary.

  • BACKWARDS INCOMPATIBLE Buffering functionality (receive_until() and receive_exactly()) was split off from SocketStream into a stream wrapper class (anyio.streams.buffered.BufferedByteReceiveStream)

  • BACKWARDS INCOMPATIBLE IPv6 addresses are now reported as 2-tuples. If original 4-tuple form contains a nonzero scope ID, it is appended to the address with % as the separator.

  • BACKWARDS INCOMPATIBLE Byte streams (including socket streams) now raise EndOfStream instead of returning an empty bytes object when the stream has been closed from the other end

  • BACKWARDS INCOMPATIBLE The socket API has changes:

    • create_tcp_server() → create_tcp_listener()

    • create_unix_server() → create_unix_listener()

    • create_udp_socket() had some of its parameters changed:

      • interface → local_address

      • port → local_port

      • reuse_address was replaced with reuse_port (and sets SO_REUSEPORT instead of SO_REUSEADDR)

    • connect_tcp() had some of its parameters changed:

      • address → remote_address

      • port → remote_port

      • bind_host → local_address

      • bind_port → (removed)

      • autostart_tls → tls

      • tls_hostname (new parameter, when you want to match the certificate against against something else than remote_address)

    • connect_tcp() now returns a TLSStream if TLS was enabled

    • notify_socket_closing() was removed, as it is no longer used by AnyIO

    • SocketStream has changes to its methods and attributes:

      • address → .extra(SocketAttribute.local_address)

      • alpn_protocol → .extra(TLSAttribute.alpn_protocol)

      • close() → aclose()

      • get_channel_binding → .extra(TLSAttribute.channel_binding_tls_unique)

      • cipher → .extra(TLSAttribute.cipher)

      • getpeercert → .extra(SocketAttribute.peer_certificate) or .extra(SocketAttribute.peer_certificate_binary)

      • getsockopt() → .extra(SocketAttribute.raw_socket).getsockopt(...)

      • peer_address → .extra(SocketAttribute.remote_address)

      • receive_chunks() → (removed; use async for on the stream instead)

      • receive_delimited_chunks() → (removed)

      • receive_exactly() → BufferedReceiveStream.receive_exactly()

      • receive_some() → receive()

      • receive_until() → BufferedReceiveStream.receive_until()

      • send_all() → send()

      • setsockopt() → .extra(SocketAttribute.raw_socket).setsockopt(...)

      • shared_ciphers → .extra(TLSAttribute.shared_ciphers)

      • server_side → .extra(TLSAttribute.server_side)

      • start_tls() → stream = TLSStream.wrap(...)

      • tls_version → .extra(TLSAttribute.tls_version)

    • UDPSocket has changes to its methods and attributes:

      • address → .extra(SocketAttribute.local_address)

      • getsockopt() → .extra(SocketAttribute.raw_socket).getsockopt(...)

      • port → .extra(SocketAttribute.local_port)

      • receive() no longer takes a maximum bytes argument

      • receive_packets() → (removed; use async for on the UDP socket instead)

      • send() → requires a tuple for destination now (address, port), for compatibility with the new UnreliableObjectStream interface. The sendto() method works like the old send() method.

      • setsockopt() → .extra(SocketAttribute.raw_socket).setsockopt(...)

  • BACKWARDS INCOMPATIBLE Renamed the max_size parameter to max_bytes wherever it occurred (this was inconsistently named max_bytes in some subclasses before)

  • Added memory object streams as a replacement for queues

  • Added stream wrappers for encoding/decoding unicode strings

  • Support for the SO_REUSEPORT option (allows binding more than one socket to the same address/port combination, as long as they all have this option set) has been added to TCP listeners and UDP sockets

  • The send_eof() method was added to all (bidirectional) streams

• File I/O changes:

  • BACKWARDS INCOMPATIBLE Asynchronous file I/O functionality now uses a common code base (anyio.AsyncFile) instead of backend-native classes

  • BACKWARDS INCOMPATIBLE The File I/O API has changes to its functions and methods:

    • aopen() → open_file()

    • AsyncFileclose() → AsyncFileaclose()

• Task synchronization changes:

  • BACKWARDS INCOMPATIBLE Queues were replaced by memory object streams

  • BACKWARDS INCOMPATIBLE Added the acquire() and release() methods to the Lock, Condition and Semaphore classes

  • BACKWARDS INCOMPATIBLE Removed the Event.clear() method. You must now replace the event object with a new one rather than clear the old one.

  • Fixed Condition.wait() not working on asyncio and curio (PR by Matt Westcott)

• Testing changes:

  • BACKWARDS INCOMPATIBLE Removed the --anyio-backends command line option for the pytest plugin. Use the -k option to do ad-hoc filtering, and the anyio_backend fixture to control which backends you wish to run the tests by default.

  • The pytest plugin was refactored to run the test and all its related async fixtures inside the same event loop, making async fixtures much more useful

  • Fixed Hypothesis support in the pytest plugin (it was not actually running the Hypothesis tests at all)

1.4.0

• Added async name resolution functions (anyio.getaddrinfo() and anyio.getnameinfo())

• Added the family and reuse_address parameters to anyio.create_udp_socket() (Enables multicast support; test contributed by Matthias Urlichs)

• Fixed fail.after(0) not raising a timeout error on asyncio and curio

• Fixed move_on_after() and fail_after() getting stuck on curio in some circumstances

• Fixed socket operations not allowing timeouts to cancel the task

• Fixed API documentation on Stream.receive_until() which claimed that the delimiter will be included in the returned data when it really isn’t

• Harmonized the default task names across all backends

• wait_all_tasks_blocked() no longer considers tasks waiting on sleep(0) to be blocked on asyncio and curio

• Fixed the type of the address parameter in UDPSocket.send() to include IPAddress objects (which were already supported by the backing implementation)

• Fixed UDPSocket.send() to resolve host names using anyio.getaddrinfo() before calling socket.sendto() to avoid blocking on synchronous name resolution

• Switched to using anyio.getaddrinfo() for name lookups

1.3.1

• Fixed warnings caused by trio 0.15

• Worked around a compatibility issue between uvloop and Python 3.9 (missing shutdown_default_executor() method)

1.3.0

• Fixed compatibility with Curio 1.0

• Made it possible to assert fine grained control over which AnyIO backends and backend options are being used with each test

• Added the address and peer_address properties to the SocketStream interface

1.2.3

• Repackaged release (v1.2.2 contained extra files from an experimental branch which broke imports)

1.2.2

• Fixed CancelledError leaking from a cancel scope on asyncio if the task previously received a cancellation exception

• Fixed AttributeError when cancelling a generator-based task (asyncio)

• Fixed wait_all_tasks_blocked() not working with generator-based tasks (asyncio)

• Fixed an unnecessary delay in connect_tcp() if an earlier attempt succeeds

• Fixed AssertionError in connect_tcp() if multiple connection attempts succeed simultaneously

1.2.1

• Fixed cancellation errors leaking from a task group when they are contained in an exception group

• Fixed trio v0.13 compatibility on Windows

• Fixed inconsistent queue capacity across backends when capacity was defined as 0 (trio = 0, others = infinite)

• Fixed socket creation failure crashing connect_tcp()

1.2.0

• Added the possibility to parametrize regular pytest test functions against the selected list of backends

• Added the set_total_tokens() method to CapacityLimiter

• Added the anyio.current_default_thread_limiter() function

• Added the cancellable parameter to anyio.run_in_thread()

• Implemented the Happy Eyeballs (RFC 6555) algorithm for anyio.connect_tcp()

• Fixed KeyError on asyncio and curio where entering and exiting a cancel scope happens in different tasks

• Fixed deprecation warnings on Python 3.8 about the loop argument of asyncio.Event()

• Forced the use WindowsSelectorEventLoopPolicy in asyncio.run when on Windows and asyncio to keep network functionality working

• Worker threads are now spawned with daemon=True on all backends, not just trio

• Dropped support for trio v0.11

1.1.0

• Added the lock parameter to anyio.create_condition() (PR by Matthias Urlichs)

• Added async iteration for queues (PR by Matthias Urlichs)

• Added capacity limiters

• Added the possibility of using capacity limiters for limiting the maximum number of threads

• Fixed compatibility with trio v0.12

• Fixed IPv6 support in create_tcp_server(), connect_tcp() and create_udp_socket()

• Fixed mishandling of task cancellation while the task is running a worker thread on asyncio and curio

1.0.0

• Fixed pathlib2 compatibility with anyio.aopen()

• Fixed timeouts not propagating from nested scopes on asyncio and curio (PR by Matthias Urlichs)

• Fixed incorrect call order in socket close notifications on asyncio (mostly affecting Windows)

• Prefixed backend module names with an underscore to better indicate privateness

1.0.0rc2

• Fixed some corner cases of cancellation where behavior on asyncio and curio did not match with that of trio. Thanks to Joshua Oreman for help with this.

• Fixed current_effective_deadline() not taking shielded cancellation scopes into account on asyncio and curio

• Fixed task cancellation not happening right away on asyncio and curio when a cancel scope is entered when the deadline has already passed

• Fixed exception group containing only cancellation exceptions not being swallowed by a timed out cancel scope on asyncio and curio

• Added the current_time() function

• Replaced CancelledError with get_cancelled_exc_class()

• Added support for Hypothesis

• Added support for PEP 561

• Use uvloop for the asyncio backend by default when available (but only on CPython)

1.0.0rc1

• Fixed setsockopt() passing options to the underlying method in the wrong manner

• Fixed cancellation propagation from nested task groups

• Fixed get_running_tasks() returning tasks from other event loops

• Added the parent_id attribute to anyio.TaskInfo

• Added the get_current_task() function

• Added guards to protect against concurrent read/write from/to sockets by multiple tasks

• Added the notify_socket_close() function

1.0.0b2

• Added introspection of running tasks via anyio.get_running_tasks()

• Added the getsockopt() and setsockopt() methods to the SocketStream API

• Fixed mishandling of large buffers by BaseSocket.sendall()

• Fixed compatibility with (and upgraded minimum required version to) trio v0.11

1.0.0b1

• Initial release