StackExchange.Redis TimeOut 记录

前言

最近在用.Net Core 做业务模块时，发现经常会出现TimeOut 超时的情况。然后看了官方的解释，说2.0版本之后维护了一个专用的线程池。我就打算阅读源码，看一下这个线程池的实现。

源码

StackExchange.Redis源码 中可以看到，其中维护了一个名为：DedicatedThreadPoolPipeScheduler 的线程池，此线程池引用了一个使用并不多的第三方开源库Pipelines.Sockets.Unofficial。这个库给我的第一感觉就是，用的很少，估计有坑。

我们先来看一下这个 DedicatedThreadPoolpipeScheduler 的实现:

/// 

    /// An implementation of a pipe-scheduler that uses a dedicated pool of threads, deferring to
    /// the thread-pool if that becomes too backlogged
    /// 
    public sealed class DedicatedThreadPoolPipeScheduler : PipeScheduler, IDisposable
    {
        /// 

        /// Reusable shared scheduler instance
        /// 
        public static DedicatedThreadPoolPipeScheduler Default => StaticContext.Instance;

        private static class StaticContext
        {   // locating here rather than as a static field on DedicatedThreadPoolPipeScheduler so that it isn't instantiated too eagerly
            internal static readonly DedicatedThreadPoolPipeScheduler Instance = new DedicatedThreadPoolPipeScheduler(nameof(Default));
        }

        /// 

        /// The name of the pool
        /// 
        public override string ToString() => Name;

        /// 

        /// The number of workers associated with this pool
        /// 
        public int WorkerCount { get; }

        private int UseThreadPoolQueueLength { get; }

        private ThreadPriority Priority { get; }

        private string Name { get; }

        /// 

        /// Create a new dedicated thread-pool
        /// 
        public DedicatedThreadPoolPipeScheduler(string name = null, int workerCount = 5, int useThreadPoolQueueLength = 10,
            ThreadPriority priority = ThreadPriority.Normal)
        {
            if (workerCount < 0) throw new ArgumentNullException(nameof(workerCount));

            WorkerCount = workerCount;
            UseThreadPoolQueueLength = useThreadPoolQueueLength;
            if (string.IsNullOrWhiteSpace(name)) name = GetType().Name;
            Name = name.Trim();
            Priority = priority;
            for (int i = 0; i < workerCount; i++)
            {
                StartWorker(i);
            }
        }

        private long _totalServicedByQueue, _totalServicedByPool;

        /// 

        /// The total number of operations serviced by the queue
        /// 
        public long TotalServicedByQueue => Volatile.Read(ref _totalServicedByQueue);

        /// 

        /// The total number of operations that could not be serviced by the queue, but which were sent to the thread-pool instead
        /// 
        public long TotalServicedByPool => Volatile.Read(ref _totalServicedByPool);

        private readonly struct WorkItem
        {
            public readonly Action