[Mono-list] Advice on optimisation in xml deserialisation

[Alan McGovern]

(and also sending to the list...)

On Jan 10, 2008 12:41 AM, Alan McGovern <alan.mcgovern at gmail.com> wrote:
> Hi,
>
> I was wondering about that alright. It did seem a bit weird that it
> would work, i would've expected the delegate parameter to be at least
> as restrictive as the method i was calling. Bang goes that idea then.
>
> Alan.
>
>
> On Jan 10, 2008 12:36 AM, Robert Jordan <robertj at gmx.net> wrote:
> > Robert Jordan wrote:
> > > Alan McGovern wrote:
> > >> There was a thread a week or two ago called 'Speed difference Windows
> > >> - Linux' which noted there was a big difference in performance between
> > >> .NET and mono. I did a brief bit of profiling and came up with this
> > >> patch which improves performance ~30% for the testcase which was
> > >> attached in the email. This reduces runtime memory usage by about 10MB
> > >> (80MB -> 70MB) and decreases processing time by 30% (3.4s -> 2.6s).
> > >>
> > >> Anyone have any ideas on how to tidy this up to make it neater? Also,
> > >> would this optimisation be too specific, or can it be generalised
> > >> somewhere higher up in the stack.
> > >
> > > I don't think the patch is correct. It is assuming that every
> > > "Add" method of a collection/list is compatible with
> > > AddDelegate(object).
> > >
> > > If the test cases are still working, it could be that
> > > CreateDelegate is buggy: MSDN states:
> > >
> > > "A parameter of a delegate is compatible with the corresponding
> > > parameter of a method if the type of the delegate parameter is more
> > > restrictive than the type of the method parameter, because this
> > > guarantees that an argument passed to the delegate can be passed safely
> > > to the method."
> >
> > It's indeed a bug in Mono's CreateDelegate. The following test case
> > must fail but it doesn't:
> >
> > using System;
> >
> > delegate void Method(object o);
> >
> > class T
> > {
> >         static void Main ()
> >         {
> >                 T t = new T ();
> >                 Method m = (Method) Delegate.CreateDelegate (typeof(Method), t,
> > t.GetType ().GetMethod ("Test"));
> >                 m (new Uri ("http://mono-project.com"));
> >         }
> >
> >         public void Test (Uri uri)
> >         {
> >                 Console.WriteLine (uri);
> >
> >         }
> > }
> >
> > Robert
> >
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> >
>