Event loop scheduling improvement

Motivation

Think the following situation:

1. The browser event loop has a pending event that fires an event listener that schedules high-priority work to JSKit's executor.
2. But the current JSKit's executor loop does not yield its control to JS event loop until all enqueued works are done

• Even if some of them are low-priority

It resulted in the higher priority works planned to be enqueued to JSKit's executor are blocked by lower priority works that are already enqueued even though browser engine knows about the pending event.

Outcome

• Performance gain

Potential solution

Although yielding control to JS engine for every Swift job is not a realistic approach due to high overheads, but it's still considerable to yield control when certain time is spent for the current JSKit's executor loop.

Sources/JavaScriptEventLoop/JobQueue.swift の executor ループ、特にリンクされたセクションから始め、キューに入れられた Swift ジョブが実行されてから制御がブラウザのイベントループに戻るまでの流れを追跡します。一定量の executor 時間が経過したら実行を譲るスケジューリングアプローチを定義して評価し、より高い優先度の保留中の処理が低い優先度のジョブによってブロックされなくなったことを完了の指標として示し、パフォーマンスへの影響を測定します。