How to wait for result of asynchronous web service call in ASP.NET for best performance

Question

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.

Of course I can generate asynchronous operations for service reference in Visual Studio and call BeginGetFoo instead of GetFoo, but still I must wait somehow for result from web service.

Here comes question. If I use AsyncWaitHandle.WaitOne (as below) will it be any better in whole application performance terms from synchronous call I use today?

IAsyncResult result = fooSoapClient.BeginGetFoo();
result.AsyncWaitHandle.WaitOne();
var foo = fooSoapClient.EndGetFoo(result);

And of course, if waiting can be done better I am open for suggestions.

Answer 1

You want to use an Asynchronous Page. See "Wicked Code: Scalable Apps with Asynchronous Programming in ASP.NET", also Asynchronous Pages in ASP.NET 2.0, which talks about web services and Asynchronous Tasks with RegisterAsyncTask.