AsyncBackendMixin

Mixin for backends that enables the async API.

Attributes

Attribute	Type	Description
result_consumer	[ResultConsumer](../rpc/resultconsumer.md?sid=celery_backends_rpc_resultconsumer)	The consumer instance responsible for managing result buckets, drainers, and message consumption for asynchronous tasks.
_pending_messages	MessageBuffer	A buffer containing messages that have been received but not yet processed or resolved into result objects.
_pending_results	tuple	A tuple containing two mappings (concrete and weak) used to track active task IDs and their corresponding result objects.
is_async	boolean = True	A read-only flag indicating that the backend supports the asynchronous API.

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Methods

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iter_native()

@classmethod
def iter_native(
    result: [ResultSet](../../result/resultset.md?sid=celery_result_resultset),
    no_ack: boolean = True
) - > generator

Iterates over results as they become available from the native backend, yielding task IDs and their associated data.

Parameters

Name	Type	Description
result	[ResultSet](../../result/resultset.md?sid=celery_result_resultset)	The set of results to iterate over and monitor for completion
no_ack	boolean = True	Whether to disable manual acknowledgment of messages from the underlying transport

Returns

Type	Description
generator	A generator yielding tuples of (task_id, result_data) for each completed task

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add_pending_result()

@classmethod
def add_pending_result(
    result: [AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult),
    weak: boolean = False,
    start_drainer: boolean = True
) - > [AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)

Adds a result to the tracking system and initiates the background drainer to start listening for its completion.

Parameters

Name	Type	Description
result	[AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)	The result object to begin tracking for asynchronous updates
weak	boolean = False	If true, the result is stored using a weak reference to allow for earlier garbage collection
start_drainer	boolean = True	Whether to immediately start the result consumer's background event loop

Returns

Type	Description
[AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)	The result object that was added to the pending tracking system

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add_pending_results()

@classmethod
def add_pending_results(
    results: list,
    weak: boolean = False
) - > list

Registers multiple result objects for tracking and ensures the result consumer drainer is active.

Parameters

Name	Type	Description
results	list	A collection of AsyncResult objects to be tracked asynchronously
weak	boolean = False	If true, all results in the list will be stored as weak references

Returns

Type	Description
list	A list of the AsyncResult objects that were added to the tracking system

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remove_pending_result()

@classmethod
def remove_pending_result(
    result: [AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)
) - > [AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)

Removes a result from the pending tracking system and performs cleanup actions once the result is fulfilled.

Parameters

Name	Type	Description
result	[AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)	The result object to stop tracking

Returns

Type	Description
[AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)	The result object that was removed from tracking

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on_result_fulfilled()

@classmethod
def on_result_fulfilled(
    result: [AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)
) - > null

Handles cleanup for a fulfilled result by canceling any active subscriptions for its task ID in the consumer.

Parameters

Name	Type	Description
result	[AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)	The result object that has been successfully resolved

Returns

Type	Description
null

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wait_for_pending()

@classmethod
def wait_for_pending(
    result: [AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult),
    callback: callable = null,
    propagate: boolean = True
) - > object

Blocks until the specified result is ready, optionally propagating exceptions or executing a callback upon completion.

Parameters

Name	Type	Description
result	[AsyncResult](../../result/asyncresult.md?sid=celery_result_asyncresult)	The result object to wait for
callback	callable = null	An optional function to execute once the result is ready
propagate	boolean = True	Whether to raise the task's exception if the task failed

Returns

Type	Description
object	The resolved value of the result, or raises an exception if propagate is True

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is_async()

@classmethod
def is_async() - > boolean

Indicates whether the backend supports asynchronous operations.

Returns

Type	Description
boolean	Always returns True for this mixin

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