Fundamental defect of the concept of shared libraries

Masataka Ohta mohta at necom830.cc.titech.ac.jp
Mon Jun 3 12:15:37 AEST 1991


In article <8144 at auspex.auspex.com>
	guy at auspex.auspex.com (Guy Harris) writes:

>You cited B news as an
>example of a place where inlining is a win; that particular example
>doesn't require unshared libraries to get that win.

Don't distort what I said.

See <246 at titccy.cc.titech.ac.jp>:

:Yes, of course. Bnews is the real example showing significance of call
:overhead.

I cited B news as the real example showing significance of call overhead.

>There are two separate issues here, which you're mixing together:
>
>1) the issue of code that will run regardless of what its virtual
>   address is, and that doesn't have to be modified to run at a
>   different address;
>
>2) the issue of mapping the same physical page into different virtual
>   addresses within different processes.

I am not mixing them. Both issues have nothing to do with the current
discussion now.

>I
>sincerely *hope* nobody was claiming that the fact that you couldn't was
>at *all* a major obstacle to implementing position-independent shareable
>code objects!

What you don't and I didn't understand is position-independent code is
not necessary for shared libraries. Roughly-position-independent code
is enough.

							Masataka Ohta



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