Class PriorityRequestDispatcher

Schedules PLC access requests by eAccessPriority class.

Ordering: High before UserInterface before Normal before Low; FIFO within a class. Custom schedules as Normal.

Concurrency: N worker loops are the sole concurrency mechanism (no semaphore); in-flight work never exceeds N. One worker is dedicated to UserInterface/High (structural reservation) so user-facing work never queues behind background work; with N = 1 the single worker serves all classes and the reservation is void.

Starvation: a waiting Low item is promoted one class per AgingIntervalMs, capped at Normal — aged work never enters the reserved user-interface lane.

Inheritance

object

PriorityRequestDispatcher

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: AXSharp.Connector

Assembly: AXSharp.Connector.dll

Syntax

public sealed class PriorityRequestDispatcher

Constructors

PriorityRequestDispatcher(int)

Creates the dispatcher with the given number of worker slots.

Declaration

public PriorityRequestDispatcher(int workerCount)

Parameters

Type	Name	Description
int	workerCount	Number of concurrent slots; clamped to 1..4 — the PLC WebAPI destabilizes above 4 concurrent requests.

Properties

AgingIntervalMs

Milliseconds of waiting after which a queued item is promoted one priority class (capped at Normal).

Declaration

public int AgingIntervalMs { get; set; }

Property Value

Type	Description
int

InFlightCount

Gets the number of items currently executing.

Declaration

public int InFlightCount { get; }

Property Value

Type	Description
int

IsPaused

Gets whether dispatching is paused.

Declaration

public bool IsPaused { get; }

Property Value

Type	Description
bool

OnUiLatencyBreach

Invoked when a UserInterface batch exceeds UserInterfaceLatencyBudgetMs.

Declaration

public Action<UiLatencyBreach> OnUiLatencyBreach { get; set; }

Property Value

Type	Description
Action<UiLatencyBreach>

PausedEnqueueTtlMs

Milliseconds a queued item may spend in the paused state before it faults with a re-authentication error.

Declaration

public int PausedEnqueueTtlMs { get; set; }

Property Value

Type	Description
int

QueuedCount

Gets the number of queued (not yet dispatched) items.

Declaration

public int QueuedCount { get; }

Property Value

Type	Description
int

UserInterfaceLatencyBudgetMs

Latency budget in milliseconds applied to whole UserInterface batches.

Declaration

public int UserInterfaceLatencyBudgetMs { get; set; }

Property Value

Type	Description
int

WorkerCount

Gets the effective worker (concurrency slot) count, clamped to 1..4.

Declaration

public int WorkerCount { get; }

Property Value

Type	Description
int

Methods

EnqueueAsync(Func<Task>, eAccessPriority)

Enqueues a single work item; the returned task completes when the item has executed (or faults with the item's exception, or with TimeoutException if it expired while paused).

Declaration

public Task EnqueueAsync(Func<Task> work, eAccessPriority priority)

Parameters

Type	Name	Description
Func<Task>	work
eAccessPriority	priority

Returns

Type	Description
Task

EnqueueBatchAsync(IReadOnlyList<Func<Task>>, eAccessPriority, int)

Dispatches a batch of chunks. With interChunkDelayMs of 0 all chunks are enqueued at once and run concurrently; with a positive delay chunks run serially with the delay elapsing between them (the delay never occupies a worker slot). Measures the whole batch and raises OnUiLatencyBreach for UserInterface batches exceeding the budget. The result's ChunkTasks are settled; this method does not throw on chunk failures — inspect the tasks.

Declaration

public Task<BatchDispatchResult> EnqueueBatchAsync(IReadOnlyList<Func<Task>> chunks, eAccessPriority priority, int interChunkDelayMs)

Parameters

Type	Name	Description
IReadOnlyList<Func<Task>>	chunks
eAccessPriority	priority
int	interChunkDelayMs

Returns

Type	Description
Task<BatchDispatchResult>

PauseAsync()

Stops dequeueing and completes when all in-flight items have finished. Queued items are retained but fault with TimeoutException once they spend longer than PausedEnqueueTtlMs paused.

Declaration

public Task PauseAsync()

Returns

Type	Description
Task

Resume()

Resumes dispatching; the backlog drains in priority order.

Declaration

public void Resume()