如何在ASP.NET中等待异步Web服务调用的结果以获得最佳性能

In WebForms ASP.NET site (IIS, single app pool), I have call to lengthy web service method referenced in Visual Studio as Service Reference (.NET 4.0). Unfortunately I must wait for information from web service before I can serve page to user. Currently web service is called synchronously so server can’t reuse current thread to process other requests which has performance impact.In WebForms ASP.NET site (IIS, single app pool)