c# - 当ThreadPool构造新线程而不是重用它们时？

Question

我从Reed Copsey的以下答案中阅读了以下段落:

Will values in my ThreadStatic variables still be there when cycled via ThreadPool?

The thread pool (by design) keeps the threads alive between calls. This means that the ThreadStatic variables will persist between calls to QueueUserWorkItem.

This behavior is also something you should not count on. The ThreadPool will (eventually, at its discretion) release threads back and let them end, and construct new threads as needed.

在什么条件下，线程池最终会构造新线程，而不是重用它们？

Answer 1

AFAIK在“无证”条件下。

首先要考虑的是，至少有4种常用的CLR hosting providers(ASP.Net, IE, shell exes和SQLCLR)，每种都有自己的策略。例如，SQLCLR托管使用SQL Server自己的Thread and Task architecture，并将通过收缩池(所有类型的池，包括线程)来对OS signals of pressure作出 react 。

因此，为什么不仅仅假设线程总是被回收，而您将是正确的(即，不要在池拥有的线程上保持状态)。