Re: Shared libraries revisited

>[not overriding a library call from a user's definition]...
>This implies poor dynamicity. I've found that replacing
>system services with your own meta-service, which may, for
>instance, count occurences, or something, is *extrememly* helpful
>in debugging, especially so-called 'ring 3' services.

Now you've confused me. On the one hand you were indicating that
relocating a library to fixed addresses at "share time" was a win.
I understand this, and agree. But now you indicate that you want
to override the symbols called by the library at run time. If
you've already relocated the library, then presumably you've nailed
down, say, fprintf()'s call to malloc() in the offered image.
How do you go back and change your mind when the user's program offers
a new definition for malloc() (but inherits the libc fprintf())?
Do you intend to keep the original, un-relocated library around
as well, and spin off a new one as needed?

Your claims concerning debugging are valid, but I think they could
be covered by linking a static executable. This will give you the
functionality. The extra memory/a.out size is probably irrelevant
for a debugging version.

                                                Andy
Received on Fri Aug 27 17:52:18 1993