[MonoTouch] Very weird crash

[Pavel Sich]

So thanks to the great guys (Sebastien and Rodrigo) at Xamarin there seems to be a fix for this issue, which looks like linker issue - stripping out the part of the framework that is not used directly but might be introduced during the DataContract use and subsequent exception in it. If proved in the QA process, will inform you about the outcome so you can make a note for that particular type of exceptions inside mono runtime. 

---

Hello Pavel,

You're right there's no public constructor to simply create an
instance. Also tThe `WrappedException` property expose a field that is
shared with the runtime and it will need to be present (not linked
out) in managed code. Something like this:

try {
}
catch (RuntimeWrappedException rwe) {
Console.WriteLine (rwe.WrappedException);
}

should do the trick (i.e. satisfy the runtime/managed contract).

Sebastien

On Wed, Dec 7, 2011 at 1:30 PM, Pavel Sich <pavel.sich at me.com (mailto:pavel.sich at me.com)> wrote:
- Hide quoted message -

> Will do and will update the Monotouch list then.
> 
> Also class RuntimeWrappedException
> 
> has no constructors defined (at least compiler says so). So what I did is
> that I explicitly catch the exception in try catch block (which was catching
> Exception objects) and use that in writing it to console output (so it is
> being used) and marked the method as Preserve.
> 
> Is this correct approach then?
> 
> --
> Pavel Sich
> @sichy
> 
> On Wednesday, December 7, 2011 at 7:22 PM, Sebastien Pouliot wrote:
> 
> Hey,
> 
> Please always c.c. the mailing-list when you reply. Right now no one
> else with a similar issue will be able to google any solution in the
> future.
> 
> Pavel, if you don't mind could you c.c. this back to the list and
> edit/remove your code or anything else that could be sensitive to you.
> 
> Rodrigo, yes the method would work (with any linker setting) to ensure
> the RuntimeWrappedException type is not removed by the linker. If this
> is confirmed (as the fix) I can add this rule to the linker (so it
> won't be needed in the future).
> 
> Note that something is triggering this exception, from time to time,
> and the application needs to handle this (or it will fail with a
> different error). IOW this would fix the present crash, not the
> intermittent problem with the application.
> 
> Sebastien
> 
> On Wed, Dec 7, 2011 at 1:05 PM, Rodrigo Kumpera <kumpera at xamarin.com (mailto:kumpera at xamarin.com)> wrote:
> 
> Hi Pavel,
> 
> I believe the issue is
> that System.Runtime.CompilerServices.RuntimeWrappedException is been linked
> away.
> 
> To resolve that, I believe you can add the following to your main class:
> 
>  [Preserve]
> static void Foo () {
>   new System.Runtime.CompilerServices.RuntimeWrappedException ();
> }
> 
> Sebastien, is that the right idiom for such things?
> 
> Regards,
> Rodrigo
> 



--
Pavel Sich
@sichy


On Wednesday, December 7, 2011 at 7:52 PM, Sebastien Pouliot wrote:

> Hello Pavel,
> 
> You're right there's no public constructor to simply create an
> instance. Also tThe `WrappedException` property expose a field that is
> shared with the runtime and it will need to be present (not linked
> out) in managed code. Something like this:
> 
> try {
> }
> catch (RuntimeWrappedException rwe) {
> Console.WriteLine (rwe.WrappedException);
> }
> 
> should do the trick (i.e. satisfy the runtime/managed contract).
> 
> Sebastien
> 
> On Wed, Dec 7, 2011 at 1:30 PM, Pavel Sich <pavel.sich at me.com (mailto:pavel.sich at me.com)> wrote:
> - Hide quoted message -
> 
> > Will do and will update the Monotouch list then.
> > 
> > Also class RuntimeWrappedException
> > 
> > has no constructors defined (at least compiler says so). So what I did is
> > that I explicitly catch the exception in try catch block (which was catching
> > Exception objects) and use that in writing it to console output (so it is
> > being used) and marked the method as Preserve.
> > 
> > Is this correct approach then?
> > 
> > --
> > Pavel Sich
> > @sichy
> > 
> > On Wednesday, December 7, 2011 at 7:22 PM, Sebastien Pouliot wrote:
> > 
> > Hey,
> > 
> > Please always c.c. the mailing-list when you reply. Right now no one
> > else with a similar issue will be able to google any solution in the
> > future.
> > 
> > Pavel, if you don't mind could you c.c. this back to the list and
> > edit/remove your code or anything else that could be sensitive to you.
> > 
> > Rodrigo, yes the method would work (with any linker setting) to ensure
> > the RuntimeWrappedException type is not removed by the linker. If this
> > is confirmed (as the fix) I can add this rule to the linker (so it
> > won't be needed in the future).
> > 
> > Note that something is triggering this exception, from time to time,
> > and the application needs to handle this (or it will fail with a
> > different error). IOW this would fix the present crash, not the
> > intermittent problem with the application.
> > 
> > Sebastien
> > 
> > On Wed, Dec 7, 2011 at 1:05 PM, Rodrigo Kumpera <kumpera at xamarin.com (mailto:kumpera at xamarin.com)> wrote:
> > 
> > Hi Pavel,
> > 
> > I believe the issue is
> > that System.Runtime.CompilerServices.RuntimeWrappedException is been linked
> > away.
> > 
> > To resolve that, I believe you can add the following to your main class:
> > 
> >  [Preserve]
> > static void Foo () {
> >   new System.Runtime.CompilerServices.RuntimeWrappedException ();
> > }
> > 
> > Sebastien, is that the right idiom for such things?
> > 
> > Regards,
> > Rodrigo
> > 
> 


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