using System;

namespace Example

{

​

    public class DataProcessor

    {

      private object _sampleDataLock = new object();

      private TaskCompletionSource<Data> _sampleData;

      private Thread _processThread;

​

      public DataProcessor()

      {

         _processThread = new(ProcessDataLoop);

         _processThread.Start();

      }

​

      void ProcessDataLoop()

      {

          while (true)

          {

             var processedData = ProcessNextData();

​

             //This code in the lock is what I wonder about

             lock (_sampleDataLock)

             {

                _sampleData?.SetResult(processedData.Clone());

                _sampleData = null;

             }

​

            processedData.Dispose();

          }

      }

​

      public Task<Data> SampleData(TimeSpan timeout)

      {

        // This is the code I'm wondering how to write without a lock

        lock (_sampleDataLock)

        {

          _sampleData ??= new TaskCompletionSource<Data>();

          return _sampleData.Task.WithTimeout(timeout);

        }

      }

    }

​

    public class DataInspector

    {

        private DataProcessor _processor;

​

        public async Task InspectData()

        {

           //wait up to 30s for an item

           var data = await _processor.SampleData(TimeSpan.FromSeconds(30));

           // look at data

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Hello World");

        }

    }

}