c# - SemaphoreSlim(1) 如何知道是否有其他线程在等待

Question

为了同步，我创建了一个 SemaphoreSlim(1)。
这意味着如果我在我的类中有这个信号量的单个实例作为锁:

private SemaphoreSlim _initializationSemaphore = new SemaphoreSlim(1);
private bool _isInitialized = false;    

public void Initialize()
{
  await _initializationSemaphore.WaitAsync();
  if (_isInitialized)
  {
     _logger.Warn("SDK is already initialized");
  }
  //Do some logic only once and only ..
  _isInitialized=true;
  _initializationSemaphore.Release();
}

第一个进入函数的线程会继续运行代码，其他线程只有在第一个线程释放信号量后才能进入函数。
我的问题是 - 我怎么知道目前有多少线程卡在了:

await _initializationSemaphore.WaitAsync();

谢谢。

Answer 1

对于一些快速而肮脏的事情，只保留一个保存计数的静态变量怎么样？

private SemaphoreSlim _initializationSemaphore = new SemaphoreSlim(1);
private bool _isInitialized = false;    
private static int _waitingThreads = 0;    

public void Initialize()
{
  try
  {
      Interlocked.Increment(ref _waitingThreads);
      await _initializationSemaphore.WaitAsync();
  }
  finally
  {
      Interlocked.Decrement(ref _waitingThreads);
  }
  if (_isInitialized)
  {
     _logger.Warn("SDK is already initialized");
  }
  //Do some logic only once and only ..
  _isInitialized=true;
  _initializationSemaphore.Release();
}