Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!henry From: henry@utzoo.UUCP (Henry Spencer) Newsgroups: net.unix-wizards Subject: Re: SHMOP (SYSV) - really shmat(2) Message-ID: <6102@utzoo.UUCP> Date: Wed, 30-Oct-85 20:15:23 EST Article-I.D.: utzoo.6102 Posted: Wed Oct 30 20:15:23 1985 Date-Received: Wed, 30-Oct-85 20:15:23 EST References: <2335@brl-tgr.ARPA>, <569@riccb.UUCP> Organization: U of Toronto Zoology Lines: 26 > The interprocess communication primitives included in System V (message > queues, semaphores, and shared memory) are all very messed up. They were > clearly not thought out too well in either their design or implementation. It's no particular secret that the SysV IPC swill was devised by taking the union of several different sets of IPC mechanisms devised by different groups within the Bell System. This is why there's virtually no software in the distributed Unixes that employs them: they were invented for Bell internal applications work, too specialized to be distributed widely. Since each group invented its own mechanism, software using them was very specific to individual groups and didn't transport well enough to gain general acceptance. Remember that System V started out as the attempt to pull all of the Bell-internal Unix variants together. Naturally, each of those groups leaned heavily on the System V people to include *their* favorite IPC scheme, unchanged, so they wouldn't have to fix all their software. Given that the System V group was short on both the technical creativity to do it right and the political clout to make the result stick, it was inevitable that they would implement the union of the schemes rather than the intersection. > With any luck, they'll go away soon and be replaced by something that works. Don't get your hopes too high, given that they got into the SysV Interface Definition (despite attempts to keep them out). -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry