线程池中线程的可用性？

Question

如何从线程池中找到60%（或N%）的线程可用性？这背后的逻辑是什么？
父线程使用线程池线程生成多个网址，并等待所有子线程完成。

代码如下所示
父线程

 public void  Save()
 {
  List<Job> Jobs = PickJobs();

  int workerThreads = 0,compThreads = 0;
  ThreadPool.GetMinThreads(workerThreads, compThreads);

  int requiredThreads = 15;
  ThreadPool.SetMaxThreads(requiredThreads, compThreads);

  WaitCallback waitCallBack = default(WaitCallback);
  ManualResetEvent mEvent = default(ManualResetEvent);

 foreach (Job _job in Jobs) 
   {
   waitCallBack = new WaitCallback(CallBackFunc);
   mEvent = new ManualResetEvent(false);
   events.Add(mEvent);
   ThreadPool.QueueUserWorkItem(waitCallBack, new UrlData(_job, mEvent, HttpContext.Current));
   }
     WaitHandle.WaitAll(events.ToArray(), 300000);//05 Minutes
 }

子线程

private void CallBackFunc(object obj)
{
     UrlData msgObj = (UrlData)obj;
   WebRequest lWebRequest = WebRequest.Create(psUrl);
   lWebRequest.Timeout = 60000;
   WebResponse lWebResponse = lWebRequest.GetResponse;

    msgObj.FinishEvent.Set();
}

用于跨线程通信的对象数据

public class UrlData
{
public Job job;
public ManualResetEvent FinishEvent;
public HttpContext HttpContextRef;

public UrlData(Job pJob, ManualResetEvent pEvent, HttpContext pContext)
  {
      job= pJob;
      FinishEvent = pEvent;
      HttpContextRef = pContext;
  }
}

在上述代码中，所需的线程硬编码为：

int requiredThreads = 15;
ThreadPool.SetMaxThreads(requiredThreads, compThreads);

这种硬编码会导致线程池不足吗？如果线程池中没有可用的线程，会发生什么？如何在托管服务器的线程池中查找可用线程的总数？

谢谢。

Answer 1

经过一些研究，我最终得到了一个最大线程数检索函数
返回线程池中当前可用的线程数。如果发生线程不足，则返回零。

/// <returns>int (Number of threads currently available)</returns>
private int GetMaxItemsRetrievalCount()
{
int rtnVal = 1;
try {
    //Get Available idle threads currently in the thead pool.
    ThreadPool.GetAvailableThreads(workerThreads, completionThreads);

    rtnVal = workerThreads > MaxConcurrentThreads ? MaxConcurrentThreads : workerThreads;
    //Math.Min(MaxConcurrentThreads - currentWorkLength, workerThreads - ThreadBuffer);

    rtnVal = rtnVal > 0 ? rtnVal : 0;
} catch (Exception ex) {
    WriteTransactionalJobLog(new JobLogDTO {
        Mode = "Parallel",
        UniqueId = "GetMaxItemsRetrievalCount Exception",
        ThreadId = Thread.CurrentThread.ManagedThreadId.ToString(),
        StartTime = DateTime.Now.ToString(),
        ExceptionOrResult = ex.ToString()
    });
}

return rtnVal;
}