2.9 KiB
Prompt
Simplify bounded actor cancellation by passing an explicit absolute deadline from Portal.cancel_actor() through _run_from_ns(), Actor.start_remote_task(), and Channel.send() into MsgpackTransport.send(). Avoid a ContextVar, watcher tasks, shared status, coalescing, and waiter state. After tracing the current Start -> StartAck -> CancelAck transaction, rename the local result to cancel_ack_received, document its exact semantics, and link a focused follow-up for a dedicated Cancel -> CancelAck protocol.
Response summary
Threaded one absolute Trio deadline through the existing private actor-cancel RPC path. The transport retains complete-frame shielding for ordinary sends, while a cancel-control send that overruns its deadline force-closes the potentially corrupted stream before releasing the send lock. The outer actor-cancel scope uses the same deadline for ack waiting and redelivers pending caller cancellation afterward.
Renamed the completion flag to cancel_ack_received and documented that the current private call consumes StartAck, then receives a real CancelAck after Actor.cancel() completes; this does not establish that the OS process exited. Added a source TODO linking issue #506 for the future first-class Cancel -> CancelAck transaction.
Focused transport and actor-cancel verification passed all four tests.
Files changed
tractor/runtime/_portal.py- own the absolute deadline, accurately record ack receipt, and link the dedicated cancellation protocol.tractor/runtime/_runtime.py- forward the optional deadline for the exact privateStartpublication.tractor/ipc/_chan.py- pass the operation-specific deadline to the transport without changing ordinary sends.tractor/ipc/_transport.py- bound the shielded frame publication and close a partial-frame stream before unlocking it.tests/ipc/test_each_tpt.py- cover deadline expiry after a partial frame prefix reaches the stream.tests/test_to_actor.py- prove actor-cancel publication and ack waiting share one absolute timeout budget.
Human edits
The human rejected the initial watcher-task, shared _SendStatus, cancel coalescing, and per-waiter design as unnecessary complexity. They also rejected ContextVar propagation in favor of explicit functional threading, selected a single absolute deadline for publication and ack waiting, and required item 2 to remain separate from the item-3 child reaping work. After reviewing the result, they requested the precise cancel_ack_received name, a detailed protocol-trace comment, a focused follow-up issue, and a linked source TODO. No direct source-line edits were made by the human.