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From: alan@shodha.enet.dec.com ( Alan's Home for Wayward Notes File.)
Newsgroups: comp.unix.ultrix
Subject: Re: SunOS vs. Ultrix comparison
Summary: The magick word is trust.
Keywords: SunOS shareable libraries
Message-ID: <2380@shodha.enet.dec.com>
Date: 25 Jan 91 05:44:39 GMT
References: <8012@castle.ed.ac.uk> <1991Jan24.074910.6738@pa.dec.com> <518@decvax.decvax.dec.com.UUCP>
Distribution: comp
Organization: Digital Equipment Corp. - Colorado Springs, CO.
Lines: 45

In article <518@decvax.decvax.dec.com.UUCP>, evans@decvax.DEC.COM (Marc Evans) writes:
> In article <1991Jan24.102601@wsl.dec.com>, klee@wsl.dec.com (Ken Lee) writes:
> |> [ Ken makes the first comment about Q/A and support problems
       and shared libraries. ]
> 
> [ Marc comments about Apollo, VMS and 386 vendors. ]
> 
> My experience with SunOS and third parties is unfortunately limited, so I
> can't really say if vendors are using them, but as you have read above, other
> groups make use of shared libraries. I personally don't buy the argument that
> QA and support issues are good reasons to not use/provide shared libraries.

	IF you trust the vendor not to change the function and interface
	to the parts of shared library, then the Q/A is easy.  As long
	as it still runs then it probably runs correctly.  The problems
	come if the vendor changes the function of something so that it
	isn't quite the same as before.  Or changes the size of data
	structure.  Presumably the vendor will have a method of applying
	version numbers to shared libraries that the dynamic load checks
	to make that things haven't changed (ident mismatch in VMSese).

	Even if the vendor uses these version numbers correctly, if they
	change the version numbers to often (every new release or maybe
	every other release) it requires the 3rd party company to re-link
	at each library change.  And if you have to re-link you have to
	re-test.

	The 3rd party company also has to be careful about taking
	advantage of mis-features in a shared library function.  If
	the vendor decides that feature was a bug and fixes it, the
	application may break.

	Still not an excuse for not having shared libraries, but these
	some of the problems that 3rd party people can run up against.
> 
> - Marc
> -- 
> ===========================================================================
> Marc Evans - WB1GRH - evans@decvax.DEC.COM  | Synergytics     (603)635-8876
>       Unix and X Software Contractor        | 21 Hinds Ln, Pelham, NH 03076
> ===========================================================================


-- 
Alan Rollow				alan@nabeth.cxn.dec.com