asyncio

Single-threaded concurrency with coroutines. The event loop schedules coroutines, awaits I/O via selectors, and provides primitives for synchronisation and subprocess management.

Source-of-record: Lib/asyncio/, asyncio docs.

Entry points

Function	Effect
run(coro, *, debug=None, loop_factory=None)	Run a coroutine to completion.
Runner(*, debug=None, loop_factory=None)	Reusable runner context.
get_event_loop() / new_event_loop() / set_event_loop()	Loop management (deprecated direct use).
get_running_loop()	Current loop or raise.

Coroutines and tasks

Name	Purpose
create_task(coro, *, name=None, context=None)	Schedule a coroutine.
gather(*aws, return_exceptions=False)	Concurrent wait.
wait(aws, *, timeout=None, return_when=ALL_COMPLETED)	Set wait.
wait_for(aw, timeout)	Timeout wrapper.
as_completed(aws, *, timeout=None)	Iterator of futures.
shield(aw)	Protect from cancellation.
sleep(delay, result=None)	Async sleep.
to_thread(func, *args, **kwargs)	Off-load to thread.
TaskGroup() (3.11+)	Structured concurrency.
timeout(delay) / timeout_at(when) (3.11+)	Context-manager timeouts.

Streams

open_connection, start_server, open_unix_connection, start_unix_server. StreamReader and StreamWriter.

Subprocesses

create_subprocess_exec(...), create_subprocess_shell(...), returning Process with stdin, stdout, stderr, wait(), communicate(input=None), kill, terminate.

Synchronisation

Lock, Event, Condition, Semaphore, BoundedSemaphore, Barrier (3.11+), Queue, LifoQueue, PriorityQueue. APIs mirror the threading ones but are coroutines.

Exceptions

CancelledError, InvalidStateError, TimeoutError, IncompleteReadError, LimitOverrunError, BrokenBarrierError.

Gopy status

Area	State
Event loop and run	Complete.
Tasks, gather, wait, as_completed, TaskGroup	Complete.
Streams, subprocesses	Complete.
Sync primitives	Complete.
timeout / timeout_at (3.11+)	Complete.

Reference

• CPython 3.14: asyncio.
• Lib/asyncio/.
• module/asyncio/. gopy port.
• PEPs 492, 525, 530, 654.