From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pradyumna Sampath Subject: Re: Looking for a real time IPC to be used with select Date: Sat, 17 Apr 2010 16:42:59 +0200 Message-ID: References: <3215024.1271427173625.JavaMail.ngmail@webmail08.arcor-online.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-rt-users@vger.kernel.org To: "M. Koehrer" Return-path: Received: from mail-ew0-f220.google.com ([209.85.219.220]:64134 "EHLO mail-ew0-f220.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751997Ab0DQOnE (ORCPT ); Sat, 17 Apr 2010 10:43:04 -0400 Received: by ewy20 with SMTP id 20so1100922ewy.1 for ; Sat, 17 Apr 2010 07:43:01 -0700 (PDT) In-Reply-To: <3215024.1271427173625.JavaMail.ngmail@webmail08.arcor-online.net> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Fri, Apr 16, 2010 at 4:12 PM, M. Koehrer wrote: > Now I have the need that another real time thread B should also be able > to trigger the "select()" in the thread_func_A() above. > This means, I should add a suitable inter-process-communication > between thread A and B that can be used with select() as well. > Having this, the thread A can be triggered by the socket or > by the IPC from thread B by adding two file desciptors to the readfds > of select(). > > My question is now: What kind of IPC is preferred here? > The only IPC I see is a local socket communication, however > this looks like a huge overhead for triggering... POSIX message queues in the kernel work fine for me. I had one problem with the accuracy of the timeouts in mq_timedreceieve and mq_timedsend which has been now fixed and is available as part of the latest -rt patch. regards /prady -- http://www.prady.in