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Re: how JVM works

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On Wed, 13 Apr 2011 17:31:41 -0400, Joshua Cranmer
<Pidgeot18@verizon.invalid> wrote, quoted or indirectly quoted someone
who said :

>
>Looking at the PE format, it appears that it isn't PIC, although it also 
>appears that being non PIC messes up the page-sharing characteristics.

PE = Portable Executable (actually Windows proprietary).
PIC = position independent code.  Code that can be shifted around in
RAM and it still works without patching.

I long time ago I read about chip, perhaps it was the 432 Ada chip,
that had a scheme to force calls to go only to official entry points
in library code.  As I recall the overhead was so heavy, the feature
was never used.

In the olden days the problem was handled by having the equivalent of
a DLL live in its own segment. It did not need to insert somewhere
into the flat virtual address space.
-- 
Roedy Green Canadian Mind Products
http://mindprod.com
Doing what the user expects with respect to navigation is absurdly important for user satisfaction.
~ anonymous Google Android developer

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how JVM works Roedy Green <see_website@mindprod.com.invalid> - 2011-04-13 12:36 -0700
  Re: how JVM works Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-04-13 17:31 -0400
    Re: how JVM works Roedy Green <see_website@mindprod.com.invalid> - 2011-04-13 14:36 -0700
      Re: how JVM works Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-04-13 19:26 -0400
    Re: how JVM works Roedy Green <see_website@mindprod.com.invalid> - 2011-04-13 14:42 -0700

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