# Problem with Marshal.load in Silverlight

**URL:** <https://www.ruby-forum.com/t/problem-with-marshal-load-in-silverlight/192159>\
**Category:** IronRuby\
**Created:** [July 25, 2010, 11:28am UTC](https://www.ruby-forum.com/t/problem-with-marshal-load-in-silverlight/192159 "2010-07-25T11:28:31Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![valdar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/b5a626/32.png) [@valdar](https://www.ruby-forum.com/u/valdar)\
**Post date:** [July 25, 2010, 11:28am UTC](https://www.ruby-forum.com/t/problem-with-marshal-load-in-silverlight/192159/1 "2010-07-25T11:28:31Z")

</div>

I’ve run into a problem when using Marshal.load in Silverlight - the  
following exception is thrown:

NotSupportedException: Class IronRuby.Builtins.RubyObject does not have  
a  
valid deserializing constructor

I tracked the code down to RubyUtils.CreateObject(RubyClass/_!_/  
theclass,  
IEnumerable\<KeyValuePair\<string, object\>\>/_!_/ attributes). I see that  
CreateObject will always throw in Silverlight when the type is  
assignable  
from ISerializable:

//------------------------------  
public static object/_!_/ CreateObject(RubyClass/_!_/ theclass,  
IEnumerable\<KeyValuePair\<string, object\>\>/_!_/ attributes) {  
Assert.NotNull(theclass, attributes);

```
        Type baseType = theclass.GetUnderlyingSystemType();
        object obj;
        if (typeof(ISerializable).IsAssignableFrom(baseType)) {

```

#if !SILVERLIGHT // serialization  
BindingFlags bindingFlags = BindingFlags.NonPublic |  
BindingFlags.Public | BindingFlags.Instance;  
ConstructorInfo ci =  
baseType.GetConstructor(bindingFlags,  
null, \_serializableTypeSignature, null);  
if (ci == null) {  
#endif  
string message = String.Format(“Class {0} does not have  
a  
valid deserializing constructor”, baseType.FullName);  
throw new NotSupportedException(message);  
#if !SILVERLIGHT // serialization  
}  
SerializationInfo info = new SerializationInfo(baseType,  
new  
FormatterConverter());  
info.AddValue(SerializationInfoClassKey, theclass);  
foreach (var pair in attributes) {  
info.AddValue(pair.Key, pair.Value);  
}  
obj = ci.Invoke(new object[2] { info, new  
StreamingContext(StreamingContextStates.Other, theclass) });  
#endif  
} else {  
obj = CreateObject(theclass);  
foreach (var pair in attributes) {  
theclass.Context.SetInstanceVariable(obj, pair.Key,  
pair.Value);  
}  
}  
return obj;  
}  
//------------------------------

Is this a bug, perhaps? I’d love to step through the code and find for  
myself, but I can’t seem to build IronRuby using the Silverlight3 and  
Silverlight4 build configurations (I get a ton of errors - any help  
getting  
it to build would rock!).

-Charles

---

<div class="post-metadata">

**Author:** ![valdar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/b5a626/32.png) [@valdar](https://www.ruby-forum.com/u/valdar)\
**Post date:** [July 27, 2010, 3:27am UTC](https://www.ruby-forum.com/t/problem-with-marshal-load-in-silverlight/192159/2 "2010-07-27T03:27:53Z")

</div>

Alright, I know I’m not _supposed_ to send in patch’s for the runtime,  
but  
this is a bug in the Silverlight build. Classes implemented in Ruby  
cannot  
be created using RubyUtils.CreateObject, as I mentioned in my previous  
email. As a result, Marshal.load will fail when trying to deserialize  
classes implemented in Ruby, because the \_underlyingSystemType will  
be RubyObject, which implements ISerializable. In the debugger, if I  
force  
the aforementioned CreateObject method to call the  
CreateObject(RubyClass/_!_/ theClass) overload, it works just fine.

We probably need to change this:  
if (typeof(ISerializable).IsAssignableFrom(baseType)) {

to this:  
if (typeof(ISerializable).IsAssignableFrom(baseType) && !(baseType is  
RubyObject)) {

Should I make this change to my fork? Or would one of you core dev’s  
make  
the appropriate change for us (Tomas :p)?

P.S.

Would there be any interest in being able to mspec the Silverlight  
build? I  
would bet that would make catching these little bugs much easier. I  
could  
throw something together if it would help - something like a command  
line  
app called slmspec.

Thanks,

-Charles

On Sun, Jul 25, 2010 at 4:25 AM, Charles S. \<

---

<div class="post-metadata">

**Author:** ![valdar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/b5a626/32.png) [@valdar](https://www.ruby-forum.com/u/valdar)\
**Post date:** [July 27, 2010, 3:47am UTC](https://www.ruby-forum.com/t/problem-with-marshal-load-in-silverlight/192159/3 "2010-07-27T03:47:47Z")

</div>

Filed a bug: [http://ironruby.codeplex.com/workitem/4946](http://ironruby.codeplex.com/workitem/4946)

Jimmy has something almost ready for running tests on Silverlight.

Tomas

From: removed\_email\_address@domain.invalid  
[[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Charles  
Strahan  
Sent: Monday, July 26, 2010 6:26 PM  
To: removed\_email\_address@domain.invalid  
Subject: Re: [Ironruby-core] Problem with Marshal.load in Silverlight

Alright, I know I’m not supposed to send in patch’s for the runtime, but  
this is a bug in the Silverlight build. Classes implemented in Ruby  
cannot be created using RubyUtils.CreateObject, as I mentioned in my  
previous email. As a result, Marshal.load will fail when trying to  
deserialize classes implemented in Ruby, because the  
\_underlyingSystemType will be RubyObject, which implements  
ISerializable. In the debugger, if I force the aforementioned  
CreateObject method to call the CreateObject(RubyClass/_!_/ theClass)  
overload, it works just fine.

We probably need to change this:  
if (typeof(ISerializable).IsAssignableFrom(baseType)) {

to this:  
if (typeof(ISerializable).IsAssignableFrom(baseType) && !(baseType is  
RubyObject)) {

Should I make this change to my fork? Or would one of you core dev’s  
make the appropriate change for us (Tomas :p)?

P.S.

Would there be any interest in being able to mspec the Silverlight  
build? I would bet that would make catching these little bugs much  
easier. I could throw something together if it would help - something  
like a command line app called slmspec.

Thanks,

-Charles

On Sun, Jul 25, 2010 at 4:25 AM, Charles S.  
\<removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote:  
I’ve run into a problem when using Marshal.load in Silverlight - the  
following exception is thrown:

NotSupportedException: Class IronRuby.Builtins.RubyObject does not have  
a valid deserializing constructor

I tracked the code down to RubyUtils.CreateObject(RubyClass/_!_/  
theclass, IEnumerable\<KeyValuePair\<string, object\>\>/_!_/ attributes). I  
see that CreateObject will always throw in Silverlight when the type is  
assignable from ISerializable:

//------------------------------  
public static object/_!_/ CreateObject(RubyClass/_!_/ theclass,  
IEnumerable\<KeyValuePair\<string, object\>\>/_!_/ attributes) {  
Assert.NotNull(theclass, attributes);

```
        Type baseType = theclass.GetUnderlyingSystemType();
        object obj;
        if (typeof(ISerializable).IsAssignableFrom(baseType)) {

```

#if !SILVERLIGHT // serialization  
BindingFlags bindingFlags = BindingFlags.NonPublic |  
BindingFlags.Public | BindingFlags.Instance;  
ConstructorInfo ci =  
baseType.GetConstructor(bindingFlags, null, \_serializableTypeSignature,  
null);  
if (ci == null) {  
#endif  
string message = String.Format(“Class {0} does not have  
a valid deserializing constructor”, baseType.FullName);  
throw new NotSupportedException(message);  
#if !SILVERLIGHT // serialization  
}  
SerializationInfo info = new SerializationInfo(baseType,  
new FormatterConverter());  
info.AddValue(SerializationInfoClassKey, theclass);  
foreach (var pair in attributes) {  
info.AddValue(pair.Key, pair.Value);  
}  
obj = ci.Invoke(new object[2] { info, new  
StreamingContext(StreamingContextStates.Other, theclass) });  
#endif  
} else {  
obj = CreateObject(theclass);  
foreach (var pair in attributes) {  
theclass.Context.SetInstanceVariable(obj, pair.Key,  
pair.Value);  
}  
}  
return obj;  
}  
//------------------------------

Is this a bug, perhaps? I’d love to step through the code and find for  
myself, but I can’t seem to build IronRuby using the Silverlight3 and  
Silverlight4 build configurations (I get a ton of errors - any help  
getting it to build would rock!).

-Charles

---

<div class="post-metadata">

**Author:** ![valdar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/b5a626/32.png) [@valdar](https://www.ruby-forum.com/u/valdar)\
**Post date:** [July 27, 2010, 3:59am UTC](https://www.ruby-forum.com/t/problem-with-marshal-load-in-silverlight/192159/4 "2010-07-27T03:59:29Z")

</div>

Excellent - thanks Tomas!

-Charles

On Mon, Jul 26, 2010 at 8:40 PM, Tomas M. \<

---

<div class="post-metadata">

**Author:** ![valdar](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/b5a626/32.png) [@valdar](https://www.ruby-forum.com/u/valdar)\
**Post date:** [July 27, 2010, 3:59am UTC](https://www.ruby-forum.com/t/problem-with-marshal-load-in-silverlight/192159/5 "2010-07-27T03:59:30Z")

</div>

D’oh! I didn’t test that code snippet - sorry.

It should probably be something more along the lines of  
if (typeof(ISerializable).IsAssignableFrom(baseType) &&  
!!typeof(RubyObject).IsAssignableFrom(baseType)) {

or

if (typeof(ISerializable).IsAssignableFrom(baseType) && !(baseType ==  
typeof(RubyObject))) {

-Charles  
On Mon, Jul 26, 2010 at 8:26 PM, Charles S. \<