On 1 Jun 2001, David Wagner wrote: > >On 1 Jun 2001, David Wagner wrote: > >> Elegant? Not from a software engineering point of view. > >> Almost every module will have a cut-and-pasted copy of the base > >> logic. Software engineering teaches us that code duplication is > >> bad: If you ever want to change that code, making the appropriate > >> change in all necessary places is difficult. > > > >I know I'm going to get into trouble here, but ... doesn't that presume > >that all the changes are going to be the same? > > Two reasons why code duplication is risky: > - If there's a bug in the base logic, you'll want to change > everyone's copy of it, but that's hard. > - If everyone has to cut-and-paste the code, inevitably someone > will cut-and-paste incorrectly, and that's hard to detect. > These are some of the usual arguments for reuse of shared code, > the value of inheritance in object-oriented languages, and so on. > No arguments, there. Just arguing that if one module designer chooses to cut-and-paste, and another module designer divises some OTHER logic to achieve the same or different end, the code isn't being re-used, it's being used in MODULE A, not in MODULE B. So forcing it to be executed before the module has control imposes cost on MODULE B, and saves MODULE A's designer some verification. Should we give one module strategy such advantage over another? J. Melvin Jones |>------------------------------------------------------ || J. MELVIN JONES jmjonesat_private |>------------------------------------------------------ || Microcomputer Systems Consultant || Software Developer || Web Site Design, Hosting, and Administration || Network and Systems Administration |>------------------------------------------------------ || http://www.jmjones.com/ |>------------------------------------------------------ _______________________________________________ linux-security-module mailing list linux-security-moduleat_private http://mail.wirex.com/mailman/listinfo/linux-security-module
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