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Posted by Lew on 11/14/07 18:38
"Wojtek" <nowhere@a.com> wrote in message
>> So the longer your code runs, the faster it runs.
Steve wrote:
> that is UTTERLY FALSE! there is a thing called an optimal limit. java will
> hit a primary, ultimate, optimzed execution plan at some point. however, it
> evaluates what 'optimal' is EVERY SINGLE TIME that code portion is going to
> be executed.
You are mistaken. JVMs do not use a static optimization plan. It changes how
it runs different code paths depending on the runtime profile. It will
decompile code back to bytecode, for example, if it falls into relative
disuse, and JIT another part that is currently undergoing heavy use.
It can also dynamically examine things like method arguments to determine if
it's safe to lift instance variables into registers or not.
Go back and review how JVMs actually work. Sun has a number of white papers
on java.sun.com that explain the sorts of things they can do. IBM
DeveloperWorks has a series of articles by Brian Goetz that explained these
matters back in about 2003 / 2004.
--
Lew
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