From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: data received but not detected Date: Tue, 17 Jun 2008 15:31:19 -0700 Message-ID: <48583B37.5070708@candelatech.com> References: <1213740538.5771.192.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Travis Stratman Return-path: Received: from mail.candelatech.com ([66.165.47.212]:42947 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755911AbYFQWbb (ORCPT ); Tue, 17 Jun 2008 18:31:31 -0400 In-Reply-To: <1213740538.5771.192.camel@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: Travis Stratman wrote: > Hello, > > (I sent this earlier today but it doesn't look like it made it, I > apologize if it gets through multiple times) > > I am working on an application that uses a fairly simple UDP protocol to > send data between two embedded devices. I'm noticing an issue with an > initial test that was written where datagrams are received but not seen > by the recvfrom() call until more data arrives after it. As of right now > the test case does not implement any type of lost packet protection or > other flow control, which is what makes the issue so noticeable. UDP packets can be lost anywhere..including in the receive buffer after it has been received by the NIC. You probably just need to write your code smarter to use non-blocking IO and deal with packet loss. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com