1. Jim Fawcett CSE775 – Distributed Objects Spring 2012
Managed Environments
Jim Fawcett
CSE775 – Distributed Objects
Spring 2012

2. Managed Environments .Net Common Language Runtime (CLR)
Stack-based virtual machine
Java Virtual Machine
COM Run-time
Support library and API on top of native API

3. Services Service CLR JVM COM RT Instantiation Yes yes Life-time mgmt.
Garbage collect.
Ref. Counting
Error mgmt.
Exceptions
Error codes
Reflection
Object metadata
Type library
Interception
With proxies
COM+ proxies
Isolation
App. Domains, Sandbox
Sandbox
Apartments
Component Strct.
Available
Required
Object Model
Full OO
Sealed, weak
Types
Large type set
Small type set
Remote Comm.
WCF
Sockets, RMI
DCOM
Interoperation
Other .Net Lang, Native, COM
JNI
Native, .Net Lang.

4. Language Facilities Facilities .Net Java COM Collections
Generic, object
Structs, safe arrays, BStrs
Enumerators
Yes
Notifiers
Delegates
Roll your own
Connection Pts
Queries
LINQ
SQL, XML Proc. No
GUI
WPF
Swing
Copy
Dev. Support
Visual Studio, Eclipse
Eclipse, NetBeans
Active Template Library (ATL)
Packaging
Assemblies, Libs
Packages, Jars
component

5. Using AppDomains Effectively
Cross Platform
Java operates in all environments that supply a JVM – Windows, Linux, OSX
.Net languages operate in all environments that supply a CLR
Windows
Linux and OSX via Mono – limited
COM
Windows only
Using AppDomains Effectively

6. Suitable for System Programming
Java
Weak – manage memory & hardware only through JNI
JVM was written in C++
.Net Languages
C++/CLI & C++/CX – fully capable
C++/CLI can call native C++ in same file
C++/CX wraps native COM objects
COM
Fully capable but clumsy due to limited types
Obviously works as much of Windows is COM

7. End of Presentation