Method Admit
Admit(TState, AsyncQueuedItem<TInput>, IReadOnlyList<AsyncTrackedItem<TInput>>)
Gives the items to start now for a new admitted value. The pipeline tracks
that value with the Queued status. See
AsyncMapBase.AsyncQueuedItem<TInput>. The engine always
calls this in a SodaFlow transaction. See
SodaFlow.Async.AsyncMapExecutionManager<TInput, TResult, TStrategyInput> for
the cause that makes a change to state here safe with
no explicit lock. Return an
AsyncMapBase.AsyncToStart<TInput> with
incoming to start it immediately. Without that, the
item keeps the Queued status. To start a Queued item after this, keep
incoming in state, and not only its
Value. That keeps its identity and its cancellation during the wait, and it
is the value that OnCompleted(TState, AsyncQueuedItem<TInput>, AsyncCompletion, IReadOnlyList<AsyncTrackedItem<TInput>>) gives back.
tracked gives the same items, thus a strategy that
reads only the queue of the pipeline can keep no queue of its own.
protected abstract IReadOnlyList<AsyncMapBase.AsyncToStart<TInput>> Admit(TState state, AsyncMapBase.AsyncQueuedItem<TInput> incoming, IReadOnlyList<AsyncMapBase.AsyncTrackedItem<TInput>> tracked)Parameters
stateTStateThe scheduling state of this MapAsync call.
incomingAsyncMapBase.AsyncQueuedItem<TInput>The value that the pipeline admits now.
trackedIReadOnlyList<AsyncMapBase.AsyncTrackedItem<TInput>>Each item that the pipeline tracks, Queued or Running, in the sequence of their admissions. It does not hold
incoming, which the pipeline adds after this call. It holds each other item that the pipeline tracks at this moment, with the status that item has now. An earlier edit of this same transaction is in it. For example, an item that ended in this transaction is gone, and an item that OnCompleted(TState, AsyncQueuedItem<TInput>, AsyncCompletion, IReadOnlyList<AsyncTrackedItem<TInput>>) started in this transaction is Running. This list does not change while this method runs.
Returns
- IReadOnlyList<AsyncMapBase.AsyncToStart<TInput>>