From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11811 invoked by alias); 19 Jun 2006 09:17:51 -0000 Received: (qmail 11803 invoked by uid 22791); 19 Jun 2006 09:17:51 -0000 X-Spam-Check-By: sourceware.org Received: from mxout02-esl-se-cyg.cygrids.net (HELO mxout02-esl-se-cyg.cygrids.net) (85.118.200.137) by sourceware.org (qpsmtpd/0.31) with ESMTP; Mon, 19 Jun 2006 09:17:49 +0000 Received: from era.faiveley.com (smtp.faiveley.fr [194.3.149.193]) by mxout02-esl-se-cyg.cygrids.net (Cygrids SMTP Service) with ESMTP id 794102E5E4D for ; Mon, 19 Jun 2006 11:18:01 +0200 (CEST) Received: by smtp.faiveley.fr(Lotus SMTP MTA v4.6.3 (778.2 1-4-1999)) id C1257192.00330DB5 ; Mon, 19 Jun 2006 11:17:37 +0200 X-Lotus-FromDomain: FAIVELEY From: e.coullien@faiveley.com To: ecos-discuss@ecos.sourceware.org Message-ID: Date: Mon, 19 Jun 2006 09:17:00 -0000 Mime-Version: 1.0 Content-type: text/plain; charset=us-ascii Content-Disposition: inline X-IsSubscribed: yes Mailing-List: contact ecos-discuss-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: ecos-discuss-owner@ecos.sourceware.org Subject: [ECOS] Question on Posix Select function X-SW-Source: 2006-06/txt/msg00166.txt.bz2 We are working on a package to complete the eCos Intrument package for communicating with a PC software through Ethernet. The goal is to record in real time the Instrument informations from the board to the PC and to watch a graph to show tasks and other instrument traces. If someone is interresting on, we can share it... We began to graph a module with a SELECT function but we have some difficulties to understand what we see on the Graph. In a task, before sending, we call the select function. In fact the task which calls the SELECT function is switching on even if the driver is not ready to send. So the graph shows that this task is active very often instead to sleep until the driver is ready to send. Do someone know how to explain this phenomenon and how does the Posix select function really work ? Thank you, Emmanuel Coullien -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss