Microsoft.AspNet.SignalR.HighFrequencyTimer.Run C# (CSharp) Method

        private void Run(object state)
        {
            long lastMs = 0;
            var sw = Stopwatch.StartNew();
            long lastFpsCheck = 0;
            var actualFps = 0;

            // Move to running state
            Interlocked.Exchange(ref _state, 2);
            _started();

            while (Interlocked.Read(ref _state) == 2)
            {
                var frameMs = (int)Math.Round(1000.0 / FPS);
                long delta = (lastMs + frameMs) - sw.ElapsedMilliseconds;
                
                // Actual FPS check, update every second
                if ((lastFpsCheck + 1000 - sw.ElapsedMilliseconds) <= 0)
                {
                    _actualFpsUpdate(actualFps);
                    lastFpsCheck = sw.ElapsedMilliseconds;
                    actualFps = 0;
                }

                if (delta <= 0)
                {
                    // Time to call the callback!
                    actualFps++;
                    _callback(Interlocked.Increment(ref _frameId));
                    lastMs = sw.ElapsedMilliseconds;
                }
                else
                {
                    Thread.Yield();
                }
            }

            // Move to stopped state
            Interlocked.Exchange(ref _state, 0);
            Interlocked.Exchange(ref _frameId, 0);
            sw.Stop();
            _stopped();
        }
    }