スレッド情報出力方法。
忘れないように。
int availableWorkerThreads = 0;
int availableCompletionPortThreads = 0;
int maxWorkerThreads = 0;
int maxCompletionPortThreads = 0;
System.Threading.ThreadPool.GetAvailableThreads(out availableWorkerThreads, out availableCompletionPortThreads);
System.Threading.ThreadPool.GetMaxThreads(out maxWorkerThreads, out maxCompletionPortThreads);