Class FixedThreadPool<Data, Response>

A thread pool with a fixed number of threads.

Author

Alessandro Pio Ardizio

Since

0.0.1

Type Parameters

  • Data = unknown

    Type of data sent to the worker. This can only be structured-cloneable data.

  • Response = unknown

    Type of execution response. This can only be structured-cloneable data.

Hierarchy (view full)

Constructors

Properties

emitter?: EventEmitterAsyncResource

Pool event emitter integrated with async resource. The async tracking tooling identifier is poolifier:<PoolType>-<WorkerType>-pool.

Events that can currently be listened to:

  • 'ready': Emitted when the number of workers created in the pool has reached the minimum size expected and are ready. If the pool is dynamic with a minimum number of workers is set to zero, this event is emitted when at least one dynamic worker is ready.
  • 'busy': Emitted when the number of workers created in the pool has reached the maximum size expected and are executing concurrently their tasks quota.
  • 'full': Emitted when the pool is dynamic and the number of workers created has reached the maximum size expected.
  • 'empty': Emitted when the pool is dynamic with a minimum number of workers set to zero and the number of workers has reached the minimum size expected.
  • 'destroy': Emitted when the pool is destroyed.
  • 'error': Emitted when an uncaught error occurs.
  • 'taskError': Emitted when an error occurs while executing a task.
  • 'backPressure': Emitted when all worker nodes have back pressure (i.e. their tasks queue is full: queue size >= maximum queue size).
filePath: string

Path to the worker file.

maximumNumberOfWorkers?: number

Maximum number of workers that this pool manages.

minimumNumberOfWorkers: number

Minimum number of workers that this pool manages.

opts: PoolOptions<Worker>

Options for the pool.

promiseResponseMap: Map<`${string}-${string}-${string}-${string}-${string}`, PromiseResponseWrapper<Response>> = ...

The task execution response promise map:

  • key: The message id of each submitted task.
  • value: An object that contains task's worker node key, execution response promise resolve and reject callbacks, async resource.

When we receive a message from the worker, we get a map entry with the promise resolve/reject bound to the message id.

workerChoiceStrategiesContext?: WorkerChoiceStrategiesContext<Worker, Data, Response>

Worker choice strategies context referencing worker choice algorithms implementation.

workerNodes: IWorkerNode<Worker, Data>[] = []

Pool worker nodes.

Accessors

  • get busy(): boolean
  • Whether the pool is busy or not.

    The pool busyness boolean status.

    Returns boolean

  • get full(): boolean
  • Whether the pool is full or not.

    The pool filling boolean status.

    Returns boolean

  • get type(): "fixed" | "dynamic"
  • The pool type.

    If it is 'dynamic', it provides the max property.

    Returns "fixed" | "dynamic"

  • get utilization(): number
  • The approximate pool utilization.

    Returns number

    The pool utilization.

  • get worker(): "thread" | "cluster"
  • The worker type.

    Returns "thread" | "cluster"

Methods

  • Sends a message to worker given its worker node key.

    Parameters

    • workerNodeKey: number

      The worker node key.

    • message: MessageValue<Data, unknown>

      The message.

    • Optional transferList: readonly TransferListItem[]

      The optional array of transferable objects.

    Returns void