Java and Memory Protections [LWN.net]

Java and Memory Protections

Posted Nov 22, 2006 14:16 UTC (Wed) by smitty_one_each (subscriber, #28989)
In reply to: Java and Memory Protections by NAR
Parent article: Virtual Machines and Memory Protections

Isn't dynamic code generation a natural consequence of a virtual machine coupled with reflection?
If my understanding of what the Apache Tomcat code was correct back in '03, at boot-time, the XML configuration files got parsed and instantiated all of the security classes for the app server via reflection: the XML was a de facto scripting language for the JVM.

(Log in to post comments)

Java and Memory Protections

Posted Nov 22, 2006 14:49 UTC (Wed) by NAR (subscriber, #1313) [Link]

Isn't dynamic code generation a natural consequence of a virtual machine coupled with reflection?

I'm not sure - in my mind, reflection is about getting runtime information about the objects, it has nothing to do with creating anything. Anyway, as far as I understand, the problem with memory protection is not simply the dynamic code generation, but the compilation of the generated code to machine-level instructions. So even though one can write self-modifing code in LISP or perl, it's not a problem until the interpreter executes this code, not the CPU directly.

Bye,NAR