From owner-freebsd-hackers Sun Nov 10 13:33:17 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id NAA05768 for hackers-outgoing; Sun, 10 Nov 1996 13:33:17 -0800 (PST) Received: from trapdoor.dstc.edu.au (root@trapdoor.dstc.edu.au [130.102.176.12]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id NAA05752 for ; Sun, 10 Nov 1996 13:33:14 -0800 (PST) Received: from azure.dstc.edu.au (azure.dstc.edu.au [130.102.176.27]) by trapdoor.dstc.edu.au (8.6.9/8.6.12) with ESMTP id HAA11946; Mon, 11 Nov 1996 07:33:02 +1000 Received: (from leonard@localhost) by azure.dstc.edu.au (8.6.10/8.6.12) id HAA07495; Mon, 11 Nov 1996 07:33:02 +1000 From: David Leonard Message-Id: <199611102133.HAA07495@azure.dstc.edu.au> Subject: Re: semaphores/shared memory To: hackers@freebsd.org, scrappy@ki.net Date: Mon, 11 Nov 1996 07:33:01 +1000 (EST) Reply-To: leonard@dstc.edu.au X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk scrappy@ki.net (Marc G. Fournier) writes: > I have a copy of Unix Network Programming, and am working on > designing a server-client system where there is one server and X clients > that are talking to it, using shared memory. > according to the book, I'm looking at using semaphores for the > IPC, and the general concepts of semaphores presented makes sense...but > it seems to only allow for a 1-1 relationship, vs a 1-many relationship. > can anyone suggestion a reference that goes a bit deeper into > shared memory/semaphores that might give me a better idea of a 1-many > relationship, if possible? > essentially, I want the server to write a line of data to > shared memory, then signal all the clients at once that the data is > there, so that they all pick up the data... you might want to look at multicast ports: the LBL conferencing tools use what they term a 'conferencing bus' to allow all the tools to talk to each other in a 1-many kind of way. AFAIK it is implemented as a multicast group on the loopback interface. d -- David Leonard Developer, DSTC The University of Queensland david.leonard@dstc.edu.au http://www.dstc.edu.au/~leonard/ "What is contemplation but laxative for the mind?" - T.A.Casady (?)