[XML-SIG] WSDL library ?
Fri, 15 Feb 2002 18:13:34 -0500
I said Corba's model is simple, not single. :)
I thought Corba required every object to have a type, and that com/corba
gateways defined a ComObject type.
It's good to know RMI and DCOM can be made to fit inside the Corba model.
> AFAIK, in DCE IDL, you have have a void* field in an struct, and then
> you use attributes of the field (like unique, size, etc) to indicate
> whether this pointer may be shared, and whether the pointer is to
> a single object or an array of objects, in which case you need somehow
> specify the size of the array. It seems easy to get wrong.
DCE IDL cannot marshall void*, only typed pointers. Arrays are not
supported as a primitive concept, you have to use an attribute to
indicate which parameter holds the length. That is because DCE IDL is
"close to the wire"; a VisualBasic or Python IDL compiler could omit the
length_is(foo) declaration, and have the runtime get it automatically
from the language's facilities. (Just like Corba does.)
The other attributes, about pointer sharing -- pointer_defalt(unique),
etc., are optimization hints the compiler can use when generating stubs.
(Remember the short-lived C keyword "noalias"? :)
Zolera Systems, http://www.zolera.com
Information Integrity, XML Security