[Feature Request] Workflow cancellation should cancel handler executions #575
Description
Currently, workflow cancellation does not result in cancellation of in-progress signal/update handler executions.
For example, consider the case of update and see the sample below: the client waiting on the update gets an exception, but the exception is workflow execution already completed. This ticket calls for that exception to inform the client that the update was canceled due to cancellation of the workflow.
Doing this for signal handlers would be backwards-incompatible and hence will need to use an SDK workflow logic flag.
@workflow.defn
class UpdateCancellationWorkflow:
def __init__(self) -> None:
self.non_terminating_operation_has_started = False
@workflow.run
async def run(self) -> str:
await workflow.wait_condition(lambda: False)
return "unreachable"
@workflow.update
async def wait_until_non_terminating_operation_has_started(self) -> None:
await workflow.wait_condition(
lambda: self.non_terminating_operation_has_started
)
@workflow.update
async def non_terminating_operation(self) -> str:
self.non_terminating_operation_has_started = True
await workflow.wait_condition(lambda: False)
return "unreachable"
async def test_update_cancellation(client: Client):
async with new_worker(client, UpdateCancellationWorkflow) as worker:
wf_handle = await client.start_workflow(
UpdateCancellationWorkflow.run,
id=str(uuid.uuid4()),
task_queue=worker.task_queue,
)
# Asynchronously run an update that will never complete
non_terminating_update_task = asyncio.create_task(
wf_handle.execute_update(
UpdateCancellationWorkflow.non_terminating_operation
)
)
print("wait until handler started...")
# Wait until we know the update handler has started executing
await wf_handle.execute_update(
UpdateCancellationWorkflow.wait_until_non_terminating_operation_has_started
)
print("cancel the workflow")
await wf_handle.cancel()
print("await non_terminating_update_task...")
await non_terminating_update_task