From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753786AbaA3Xtp (ORCPT ); Thu, 30 Jan 2014 18:49:45 -0500 Received: from mail-oa0-f45.google.com ([209.85.219.45]:61117 "EHLO mail-oa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753294AbaA3Xtn convert rfc822-to-8bit (ORCPT ); Thu, 30 Jan 2014 18:49:43 -0500 From: "Network Nut" To: "'Clemens Ladisch'" Cc: References: <00d901cf1a19$0ea62db0$2bf28910$@gmail.com> <52E554EC.3090900@ladisch.de> <012d01cf1ae3$6543e340$2fcba9c0$@gmail.com> <52E6219A.3020405@ladisch.de> <00d001cf1b99$026407d0$072c1770$@gmail.com> <52E77282.4030303@ladisch.de> <009701cf1c6c$fbfaff50$f3f0fdf0$@gmail.com> <95b6e508-1358-4f01-9687-344e25bd4b2b@email.android.com> In-Reply-To: <95b6e508-1358-4f01-9687-344e25bd4b2b@email.android.com> Subject: RE: WaitForMultipleObjects/etc. In Kernel Date: Thu, 30 Jan 2014 17:49:39 -0600 Message-ID: <00f201cf1e15$f134ce70$d39e6b50$@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8BIT X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQNT3acP/4y+UoGLob+8VizidhBl0AFz54/xAX6FO6UBfOQBmQGmz+ZcAX4/+oICHvy7eQGGlUFQlzqd5SA= Content-Language: en-us Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Clemens Ladisch [mailto:clemens@ladisch.de] > Sent: Wednesday, January 29, 2014 2:31 AM > To: Network Nut > Cc: linux-kernel@vger.kernel.org > Subject: RE: WaitForMultipleObjects/etc. In Kernel > > Network Nut wrote: > >I was looking at POSIX because it allows naming of the primitives. > > Linux uses two orthogonal mechanisms for synchronization primitives and for > naming/sharing. > > >I need to epoll_wait on inter-process {mutex, event, semaphore}. > > Use eventfd. > > >I need to reference inter-process {mutex, event, semaphore}, each > >identified by string, if feasible. > > Send the fd through a Unix domain socket. Hi Again, I was thinking that, rather than as for specifics, I should present my general problem, and ask how long-time Linux experts would solve it. I have a master process M, that executes continually, from the birth to death of user-session. I have many (distinct) processes that will be launched, and these processes, P1, P2, ...Pn, expect to see that M is executing. These processes: 1. expect to have access to a shared-memory section that already exists because M created it 2. expect to use a semaphore that already exists because M created it 3. expect to use a mutex that exists because M created it P1, P2, ...Pn all know the path of image on disk of M. They are also permitted to maintain a fixed string that can be used to "get at" the mutex and semaphore. How would P1, P2, ...Pn get at the semaphore that M created? Please note that M cannot have any prior knowledge at all of P1, P2, ...Pn. P1...etc. must initiate communication with M. [I don't want to misuse/abuse linux-kernel with my personal questions, so if there is a more appropriate group, please let me know.] Regards, -Net