public void EnqueueJob(IcsCashDesk cashDesk)
    {
        _jobQueue.Enqueue(cashDesk);
        _signal.Release();
    }

    private async Task ProcessJobs()
    {
        while (!_cts.IsCancellationRequested)
        {
            try
            {
                await _signal.WaitAsync(_cts.Token);
                if (_jobQueue.IsEmpty) continue;
                while (_jobQueue.TryDequeue(out var cashDesk))
                {
                    await cashDesk.CompleteWaitAsync();
                }
            }
            catch (OperationCanceledException)
            {
            }
        }
    }

    public void EnqueueJob(IcsCashDesk cashDesk)
    {
        _jobQueue.Enqueue(cashDesk);
        _signal.Release();
    }

    private async Task ProcessJobs()
    {
        while (!_cts.IsCancellationRequested)
        {
            try
            {
                await _signal.WaitAsync(_cts.Token);
                if (_jobQueue.IsEmpty) continue;
                while (_jobQueue.TryDequeue(out var cashDesk))
                {
                    await cashDesk.CompleteWaitAsync();
                }
            }
            catch (OperationCanceledException)
            {
            }
        }
    }

internal class Program
{
    static void Main(string[] args)
    {
        var printService = new PrintService();
        var testService = new TestService(printService);
        
        testService.StartExecuting();
        Thread.Sleep(5000);
        testService.StopExecuting();
        Console.WriteLine("Done");
    }
}

class PrintService
{
    public void PrintSomething()
    {
        Console.WriteLine("Something");
    }
}

class TestService(PrintService printService)
{

    private CancellationTokenSource _cts;
    private Task _task;
    
    public void StartExecuting(CancellationToken cancellationToken = default)
    {
        _cts = new();
        _task = Task.Run(async () =>
        {
            await DoWork(_cts.Token);
        }, cancellationToken);
    }
    
    public void StopExecuting(CancellationToken cancellationToken = default)
    {
        _cts.Cancel();
        _task.Wait(cancellationToken);
    }
    
    public async Task DoWork(CancellationToken cancellationToken)
    {
        while (true)
        {
            try
            {
                Console.WriteLine("Doing work");
                printService.PrintSomething();
                
                await Task.Delay(1000, cancellationToken);
            } catch (OperationCanceledException)
            {
                Console.WriteLine("Operation cancelled");
                break;
            }
        }
    }
}

internal class Program
{
    static void Main(string[] args)
    {
        var printService = new PrintService();
        var testService = new TestService(printService);
        
        testService.StartExecuting();
        Thread.Sleep(5000);
        testService.StopExecuting();
        Console.WriteLine("Done");
    }
}

class PrintService
{
    public void PrintSomething()
    {
        Console.WriteLine("Something");
    }
}

class TestService(PrintService printService)
{

    private CancellationTokenSource _cts;
    private Task _task;
    
    public void StartExecuting(CancellationToken cancellationToken = default)
    {
        _cts = new();
        _task = Task.Run(async () =>
        {
            await DoWork(_cts.Token);
        }, cancellationToken);
    }
    
    public void StopExecuting(CancellationToken cancellationToken = default)
    {
        _cts.Cancel();
        _task.Wait(cancellationToken);
    }
    
    public async Task DoWork(CancellationToken cancellationToken)
    {
        while (true)
        {
            try
            {
                Console.WriteLine("Doing work");
                printService.PrintSomething();
                
                await Task.Delay(1000, cancellationToken);
            } catch (OperationCanceledException)
            {
                Console.WriteLine("Operation cancelled");
                break;
            }
        }
    }
}