x86 jitter

Raab, Andreas Andreas.Raab at disney.com
Sun Apr 8 20:22:21 UTC 2001


> Rather than look at the source, I'm curious as to how the 
> jitter works:
> 
> * does it generate native machine code (like x86 machine code)?

Well, yes. That's the entire point isn't it ;-)

> * If so, where does it do this? (into malloc'd memory)?

Yes.

> * If  the generation is into malloc'd memory, how do you get 
> the OS to allow you to execute instructions in malloc'd memory
> (seems like you'd have to fiddle with the x86 segment flags to
> get this to work)?

You don't. By default malloc()ed memory is executable on both, Linux and
Win32 (probably because self-modifying code is sooo much fun).

Cheers,
  - Andreas





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