<PackageReference Include="System.Reactive" Version="6.0.0" />

System.Reactive.Concurrency.ISchedulerLongRunning

public interface ISchedulerLongRunning
Scheduler with support for starting long-running tasks. This type of scheduler can be used to run loops more efficiently instead of using recursive scheduling.
namespace System.Reactive.Concurrency { public interface ISchedulerLongRunning { IDisposable ScheduleLongRunning<[System.Runtime.CompilerServices.Nullable(2)] TState>(TState state, Action<TState, ICancelable> action); } }