From owner-freebsd-hackers Sat Feb 8 19:21:46 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id TAA22149 for hackers-outgoing; Sat, 8 Feb 1997 19:21:46 -0800 (PST) Received: from pdx1.world.net (pdx1.world.net [192.243.32.18]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id TAA22143 for ; Sat, 8 Feb 1997 19:21:42 -0800 (PST) From: proff@suburbia.net Received: from suburbia.net (suburbia.net [203.4.184.1]) by pdx1.world.net (8.7.5/8.7.3) with SMTP id TAA04041 for ; Sat, 8 Feb 1997 19:23:06 -0800 (PST) Received: (qmail 25672 invoked by uid 110); 9 Feb 1997 03:21:07 -0000 Message-ID: <19970209032107.25671.qmail@suburbia.net> Subject: Re: In what way are shared libs ``shared''? In-Reply-To: <199702090257.VAA06891@dyson.iquest.net> from "John S. Dyson" at "Feb 8, 97 09:57:11 pm" To: toor@dyson.iquest.net (John S. Dyson) Date: Sun, 9 Feb 1997 14:21:07 +1100 (EST) Cc: hackers@freebsd.org X-Mailer: ELM [version 2.4ME+ PL28 (25)] 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 > > My guess would be that this is due to writable statics in library code, so > > the library is shared, but copy-on-write. > > > Note that alot of really broken VM systems immediately copy .data > in order to simplify the COW action. We don't do that, and it > does complicate the code, but of course, shares more completely. > > John > John, is it possible to force this behavior with rfork/mprotect? i.e if I rfork(RFPROC|RFMEM), and then do inet_ntoa(addr) in both parent and child, will the child COW the inet_ntoa static buffer, or will they collide? -- Prof. Julian Assange |If you want to build a ship, don't drum up people |together to collect wood and don't assign them tasks proff@iq.org |and work, but rather teach them to long for the endless proff@gnu.ai.mit.edu |immensity of the sea. -- Antoine de Saint Exupery