cadrumo.core.async_cleanup module

Cancellation-complete awaiting for owned asynchronous cleanup.

Resource owners use await_cancellation_complete() when losing the local task handle would make a second cancellation leak an external process or session. The cleanup runs in one retained task; every caller cancellation is deferred until that task reaches a terminal state.

class AsyncCloseable(*args, **kwargs)

Bases: Protocol

Structural asynchronous resource owner.

async close()

Release the owned resource.

Return type:

None

exception AsyncResourceCleanupError(resources, failures, *, retry_task_name, close_attempts)

Bases: CoreError

Retain asynchronous resource owners whose close attempts failed.

Parameters:

• resources (tuple[AsyncCloseable, ...])

• failures (tuple[BaseException, ...])

• retry_task_name (str)

• close_attempts (int)

Return type:

None

async retry_cleanup()

Retry only the resource owners whose prior close failed.

Return type:

None

merged_with(later)

Combine nested cleanup failures without losing either owner.

Return type:

AsyncResourceCleanupError

Parameters:

later (AsyncResourceCleanupError)

code

async await_cancellation_complete(awaitable, *, task_name, cancellation=None)

Finish awaitable before preserving and re-raising cancellation.

Repeated calls to asyncio.Task.cancel() are absorbed while the retained cleanup task is pending. If cleanup itself fails while a caller cancellation is pending, that failure is retained on the cancellation as cleanup_error and the cancellation remains the primary exception.

Return type:

TypeVar(T)

Parameters:

• awaitable (Awaitable)

• task_name (str)

• cancellation (CancelledError | None)

async close_async_resources(*resources, task_name, cancellation=None, primary_error=<cadrumo.core.async_cleanup._AutoPrimaryException object>, close_attempts=1)

Close every resource without replacing an exception already unwinding.

When called from an async finally block, sys.exception() exposes the body exception across this coroutine boundary. Cleanup still reaches a terminal state, and any owner-retaining cleanup error is attached to that primary exception instead of replacing it.

Return type:

None

Parameters:

• resources (AsyncCloseable | None)

• task_name (str)

• cancellation (CancelledError | None)

• primary_error (BaseException | _AutoPrimaryException | None)

• close_attempts (int)