ServiceLocator.Current.GetInstance causes excessive number of calls to ObjectBuilder2.PolicyList.GetNoDefault

问题

In my MVC4, .NET4.5 web app using Unity IoC container, in the method IoCContainerFactory.GetControllerInstance() we use ServiceLocator.Current.GetInstance to get the controller instance:

public class IoCControllerFactory : DefaultControllerFactory
{
    protected override IController GetControllerInstance(
         System.Web.Routing.RequestContext requestContext, Type controllerType)
    {
        // snip other code
        // this is the problem line:
        return ServiceLocator.Current.GetInstance(controllerType) as IController;
    }
}

But this has been performing too slowly. Using JetBrains DotNetTrace product I've found that ServiceLocator.Current.GetInstance appears to be calling ObjectBuilder2.PolicyList.GetNoDefault more than one million times. How can I figure out why it is making so many calls, and what can I do to fix this problem? Attached screenshot shows the output from dotnetTrace:

And what policy is it trying to get in the method PolicyList.GetNoDefault? I I knew what policy it was trying to find I could perhaps change that policy so that it does need to be checked so many times.

回答1:

This problem was never solved and we ended up dropping Unity in favor of LightInject, which is a significantly faster IoC implementation, as seen here:

IoC Container Benchmark - Performance comparison

We had similar improvements when we implemented LightInject.

回答2:

I ran into a remotely similar issue, but my problem resulted in a StackOverflowException. It was caused by a circular dependency between some of my classes.

来源：https://stackoverflow.com/questions/18807355/servicelocator-current-getinstance-causes-excessive-number-of-calls-to-objectbui