服务ASP.NET Web-API HTTP请求涉及多少个线程？

Question

我想log Thread-ID是为了跟踪请求并使日志文件可读。

所以，我最初的尝试是logging in Global.asax，就像这样：

protected void Application_BeginRequest()
{
    log4net.ILog writer = log4net.LogManager.GetLogger(this.GetType());
    writer.InfoFormat("Gotta service a request. Id = {0}", System.Threading.Thread.CurrentThread.ManagedThreadId);
}

protected void Application_EndRequest()
{
    log4net.ILog writer = log4net.LogManager.GetLogger(this.GetType());
    writer.InfoFormat("Completed servicing a request. Id = {0}", System.Threading.Thread.CurrentThread.ManagedThreadId);
}

但是当我看到日志文件时，这很奇怪。

2014-06-16 20:27:06,018 -  Gotta service a request. Id = 286 --> From Application_BeginRequest()
2014-06-16 20:27:06,042 - Servicing Request Thread-Id = 286 --> this message comes from controller
2014-06-16 20:27:06,043 - Thread-Id = 286 --> this message comes from controller
2014-06-16 20:27:06,237 - Completed servicing a request. Id = 287 --> From Application_EndRequest()

在Application_Start中，Thread-Id为286，但当它返回Application_EndRequest时，Thread-Id changed to 287。

是不是一个服务于整个HTTP request的线程？

任何想法为什么？

Answer 1

请求是单线程处理的，但这并不意味着它在整个请求中都是相同的线程。

请求可以“跳转”线程，您仍然可以保证按顺序执行，但不能保证在整个运行的同一个线程上运行。