CHANGES.md

Changelog

2.2.3 (2025-10-20)

Features

• start_server() now accepts an optional runner argument (default: asyncio.run) to allow using custom coroutine runner implementations such as uvloop.run, for forward compatibility with Python 3.16 and later (#99)

2.2.2 (2025-10-17)

Fixes

• Use thread-local storage to store per-task states and avoid lock contention in free-threaded builds (#96)
• Replace lru_cache() with the aio-libs/async_lru package while preserving backward-compatibility of the API and improving typing support (#97)

2.2.1 (2025-10-15)

Fixes

• Use weak key dict to prevent memroy leak when storing task states by task scopes (#95)

2.2.0 (2025-10-12)

Fixes

• Treat explicitly uncancelled termination as a non-error in cancel_and_wait() (#92)
• Ensure consistency when nesting and mixing aiotools.TaskScope and asyncio.TaskGroup with different shield options and reimplement ShieldScope based on the improved TaskScope (#93)

2.1.0 (2025-10-09)

Features

• Add shield and timeout options to TaskScope, with a shortcut move_on_after() context manager, based on a new ShieldScope, while extending cancel_and_wait() to accept multiple awaitables (#90)
• Support Python 3.14 including TaskScope integration with asyncio's new call-graph inspection, updated signature of allowing arbitrary kwargs in create_task(), and improved support for the new default "forkserver" start method of multiprocessing in afork() and start_server() (#91)

2.0.1 (2025-10-06)

A post-release to fix typo in docs and packaging configurations without any functional changes.

2.0.0 (2025-10-06)

Breaking Changes

• Now it requires Python 3.11 or later to ensure safety and structured concurrency (#53)
• Cancelling and awaiting a timer task returned by create_timer() now raises asyncio.CancelledError to keep consistency with the best practice for writing asyncio tasks. You now should use cancel_and_wait() to safely consume or re-raise it. (#86)
• Migrate the project's dependency manager to uv (#87)

Features

• Add TaskContext and TaskScope to reuse the core concepts and logics for structured concurrency in Supervisor, a structured cancellation helper cancel_and_wait(), and other coroutine aggregation utilities like as_completed_safe(), gather_safe(), and race(). (#58)
• Make the entire package type-annotated (#89)
• Add higher-level coroutine aggregation utilities: as_completed_safe(), gather_safe(), and race() based on a modified version of @DontPanicO's Supervisor implementation (#53)
• Add aiotools.context.resetting() as a sync/async context manager to auto-reset the given context variable (#62)
• Add type checker support - now includes py.typed in the package to indicate to type checkers like mypy that typing is supported. (#63)
• Add Python 3.12 support (#64)
• Add Python 3.13 compatibility (#71)

Fixes

• Replace manual os.fork() with multiprocessing to use platform-specific recommended subprocess mechanisms (e.g., "spawn" in macOS to avoid undefined behavior of native frameworks) (#79)
• Explicitly override loop._clock_resolution with a coarse-grained value to prevent getting stuck when using VirtualClock with a realistic timestamp due to the floating point precision issue (#81)
• Allow importing aiotools in the Windows CI by using Windows-specific type definitions while disabling fork/server tests (#84)
• Ensure the stop signal returned from the server context managers always have a valid value defaulting to SIGTERM (#85)
• Prevent timer tasks from being cancelled by unhandled tick task exceptions (#86)
• Correct the type annotation of the callback argument in create_timer() (#61)

1.6.1 (2023-05-02)

Fixes

• PersistentTaskGroup no longer stores the history of unhandled exceptions and raises them as an exception group to prevent memory leaks (#54)

1.6.0 (2023-03-14)

Features

• Add as_completed_safe() which enhances asyncio.as_completed() using PersistentTaskGroup (#52)

1.5.9 (2022-04-26)

Fixes

• Improve checks for pidfd availability to avoid corner cases that may fail on Linux kernel 5.1 and 5.2 where signal.pidfd_send_signal() is available but os.pidfd_open() is not (#51)

1.5.8 (2022-04-25)

Fixes

• Explicitly attach the event loop to the PidfdChildWatcher when first initialized (#50)

1.5.7 (2022-04-12)

Fixes

• Fix regression of the default imports in macOS by removing the unused code that caused the misleading fix in #47 (#49)

1.5.6 (2022-04-11)

Features

• Add the closing_async() async context manager, in addition to aclosing() (#48)

Fixes

• Allow importing aiotools on Windows platforms, removing incompatible modules from the default __all__ import list (#47)

1.5.5 (2022-03-22)

Features

• Add wait_timeout option to start_server() (#46)

Fixes

• Resolve singal races by minimizing expose of event loop in afork()-ed child processes (#46)

Miscellaneous

• Now the CI runs with Python 3.11a6 or later, with stdlib support of asyncio.TaskGroup (#45)

1.5.4 (2022-03-10)

Features

• Propagate task results and exceptions via separate future instances if they are await-ed by the caller of create_task() in PersistentTaskGroup, in addition to invocation of task group exception handler. Note that await-ing those futures hangs indefinitely in Python 3.6 but we don't fix it since Python 3.6 is EoL as of December 2021. (#44)

1.5.3 (2022-03-07)

Fixes

• Fix feature detection for ExceptionGroup and let MultiError inherit ExceptionGroup instead of BaseExceptionGroup (#42)

1.5.2 (2022-03-06)

Fixes

• Restore the default export of MultiError for backward compatibility (#40)
• Set current_ptaskgroup only when PersistentTaskGroup is used via the async with statement. (#41)

1.5.1 (2022-03-06)

Fixes

• Fix missing naming support of TaskGroup in Python 3.11 (#39)

1.5.0 (2022-03-06)

Features

• Add support for Python 3.9's msg argument to Task.cancel(). (#32)
• Fix "unexpected cancel" bug in TaskGroup. (#35)
• Rewrite PersistentTaskGroup to use Python 3.11's latest additions such as Task.uncancel() and Task.cancelling() while still supporting older Python versions (#36)
• Add PersistentTaskGroup.all() to enumerate all non-terminated persistent task groups (#38)

1.4.0 (2022-01-10)

Features

• ptaskgroup: Implement PersistentTaskGroup (#30)
• server: Expose process_index context variable for worker processes (#31)

1.3.0 (2021-12-19)

Fixes

• Add support for Python 3.10. (#28)

Documentation Changes

• Fix documentation builds on Python 3.10 and Sphinx 4.x, by removing the 3rd-party autodoc-typehints extension and custom stylesheet overrides. (#28)

1.2.2 (2021-06-07)

Fixes

• fork: Handle children's segfault (core-dump with signals) explicitly in PidfdChildProcess (#27)

1.2.1 (2021-01-12)

Fixes

• Avoid side effects of custom clone() function and resorts back to the combinatino of os.fork() and os.pidfd_open() for now (#25)

1.2.0 (2021-01-12)

Breaking Changes

• server: The use_threading argument for start_server() is completely deprecated. (#23)

Features

• Now the primary target is Python 3.9, though we still support from Python 3.6 (#22)
• fork: Add a new module fork to support PID file descriptors in Linux 5.4+ and a POSIX-compatible fallback to asynchornously fork the Python process without signal/PID races. (#22)
• server: Completely rewrote the module using the new fork module with handling of various edge cases such as async failures of sibiling child processes (#23)

1.1.1 (2020-12-16)

Fixes

• Fix a potential memory leak with TaskGroup when it's used for long-lived asyncio tasks. (#21)

1.1.0 (2020-10-18)

Features

• Add a current_taskgroup context-variable to the taskgroup module (only available for Python 3.7 or later)

Fixes

• Fix missing auto-import of taskgroup module exports in the aiotools root package.

1.0.0 (2020-10-18)

Features

• Adopt an implementation of the taskgroup API as aiotools.taskgroup from EdgeDB (#18)
• Add timer.VirtualClock which provides a virtual clock that makes a block of asyncio codes using asyncio.sleep() to complete instantly and deterministically (#19)

Miscellaneous

• Adopt towncrier for changelog management (#15)
• Migrate to GitHub Actions for CI (#19)

0.9.1 (2020-02-25)

• A maintenance release to fix up the defer module exports in the aiotools namespace.

0.9.0 (2020-02-25)

• defer: A new module that emulates Golang's defer() API with asyncio awareness.

0.8.5 (2019-11-19)

• server: Rewrite internals of the worker main functions to use native async with instead of manually unrolling __aenter__() and __aexit__() dunder methods, to keep the code simple and avoid potential bugs.

0.8.4 (2019-11-18)

• Python 3.8 is now officially supported.
• server: Fix errors when multiprocessing.set_start_method("spawn") is used.
  • NOTE: This is now the default for macOS since Python 3.8.
  • KNOWN ISSUE: #12
• Remove some packaging hacks in __init__.py and let setuptools read the version from a separate aiotools/VERSION text file.

0.8.3 (2019-10-07)

• context: Fix aclosing()'s __aexit__() exception arguments.

0.8.2 (2019-08-28)

• context, server: Catch asyncio.CancelledError along with BaseException to make the cancellation behavior consistent in Python 3.6, 3.7, and 3.8.

0.8.1 (2019-02-24)

• server: Fix yields of the received stop signal in main/worker context managers when using threaded workers.

0.8.0 (2018-11-18)

• server: Updated stop signal handling and now user-defined worker/main context managers have a way to distinguish the stop signal received. See the updated docs for more details.

0.7.3 (2018-10-16)

• This ia a technical release to fix a test case preventing the automated CI release procedure.

0.7.2 (2018-10-16)

• Improve support for Python 3.6/3.7 using a small compatibility module against asyncio.
• func: Add expire_after option to lru_cache() function.

0.7.1 (2018-08-24)

• Minor updates to the documentation

0.7.0 (2018-08-24)

• Add support for Python 3.7
• context: Updated to work like Python 3.7
• context: Deprecated AsyncContextDecorator stuffs in Python 3.7+
• context: Added an alias to contextlib.AsyncExitStack in the standard library.

0.6.0 (2018-04-10)

• Introduce a new module aiotools.iter with aiter() function which corresponds to an async version of the builtin iter().

0.5.4 (2018-02-01)

• server: Remove use of unncessary setpgrp syscall, which is also blocked by Docker's default seccomp profile!

0.5.3 (2018-01-12)

• server: Ooops! (a finally block should have been an else block)

0.5.2 (2018-01-12)

• server: Improve inner beauty (code readability)
• server: Improve reliability and portability of worker-to-main interrupts

0.5.1 (2018-01-11)

• server: Fix a race condition related to handling of worker initialization errors with multiple workers

0.5.0 (2017-11-08)

• func: Add lru_cache() which is a coroutine version of functools.lru_cache()

0.4.5 (2017-10-14)

• server: Fix a race condition related to signal handling in the multiprocessing module during termination
• server: Improve error handling during initialization of workers (automatic shutdown of other workers and the main loop after logging the exception)

0.4.4 (2017-09-12)

• Add a new module aiotools.func with apartial() function which is an async version of functools.partial() in the standard library

0.4.3 (2017-08-06)

• Add aclosing() context manager like closing() in the standard library
• Speed up Travis CI builds for packaging
• Now provide README in rst as well as CHANGES (this file)

0.4.2 (2017-08-01)

• server: Fix spawning subprocesses in child workers
• Add support for uvloop

0.4.0 (2017-08-01)

• Add use_threading argument to
• Add initial documentation (which currently not served on readthedocs.io due to Python version problem)

0.3.2 (2017-07-31)

• Add extra_procs argument to start_server() function
• Add socket and ZeroMQ server examples
• Improve CI configs

0.3.1 (2017-07-26)

• Improve CI scripts
• Adopt editorconfig

0.3.0 (2017-04-26)

• Add start_server() function using multiprocessing with automatic children lifecycle management
• Clarify the semantics of AsyncContextGroup using asyncio.gather() with return_exceptions=True

0.2.0 (2017-04-20)

• Add abstract types for AsyncContextManager
• Rename AsyncGenContextManager to AsyncContextManager
• Add AsyncContextGroup

0.1.1 (2017-04-14)

• Initial release