API Reference - Signals

Core signal system components and built-in signals.

Signal System

SoftSignal

class SoftSignal

Base class for implementing the soft signal system.

Methods:

connect(sender: Any, listener: Callable) → None

Connect a listener function to this signal.

Parameters:

  • sender – The sender class/instance to listen for

  • listener – The callback function to execute

disconnect(sender: Any, listener: Callable) → None

Disconnect a listener from this signal.

emit(sender: Any, **kwargs) → List[Tuple[Any, Any]]

Emit the signal to all registered listeners.

Parameters:

  • sender – The sender instance triggering the signal

  • kwargs – Additional data to pass to listeners

Returns:

List of (listener, response) tuples

Built-in Signals

Pipeline Lifecycle

pipeline_pre_init

Signal emitted before pipeline initialization.

Arguments:

  • cls: The pipeline class

  • args: Initialization positional arguments

  • kwargs: Initialization keyword arguments

pipeline_post_init

Signal emitted after pipeline initialization.

Arguments:

  • pipeline: The initialized pipeline instance

pipeline_shutdown

Signal emitted during pipeline shutdown.

Arguments:

  • pipeline: The pipeline instance

  • execution_context: Current execution context

pipeline_stop

Signal emitted when pipeline is stopped.

Arguments:

  • pipeline: The pipeline instance

  • execution_context: Current execution context

Pipeline Execution

pipeline_execution_start

Signal emitted when pipeline execution begins.

Arguments:

  • pipeline: The pipeline instance

pipeline_execution_end

Signal emitted when pipeline execution completes.

Arguments:

  • execution_context: Final execution context

Event Execution

event_execution_init

Signal emitted when event execution is initialized.

Arguments:

  • event: The event being executed

  • execution_context: Current execution context

  • executor: The executor instance

  • call_kwargs: Event call arguments

event_execution_start

Signal emitted when event execution starts.

Arguments:

  • event: The event being executed

  • execution_context: Current execution context

event_execution_end

Signal emitted when event execution ends.

Arguments:

  • event: The completed event

  • execution_context: Current execution context

  • future: The execution future object

event_execution_retry

Signal emitted when event execution is retried.

Arguments:

  • event: The event being retried

  • execution_context: Current execution context

  • task_id: ID of the task being retried

  • backoff: Backoff strategy/duration

  • retry_count: Current retry attempt number

  • max_attempts: Maximum retry attempts allowed

event_execution_retry_done

Signal emitted when event retry is completed.

Arguments:

  • event: The retried event

  • execution_context: Current execution context

  • task_id: ID of the retried task

  • max_attempts: Maximum attempts allowed