X-Recipient: archive-cygwin@delorie.com X-SWARE-Spam-Status: No, hits=-1.8 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW X-Spam-Check-By: sourceware.org MIME-Version: 1.0 In-Reply-To: References: Date: Wed, 7 Mar 2012 15:59:35 -0500 Message-ID: Subject: Re: Anamoly with ioctl() in cygwin 1.7.10 From: Jon Clugston To: cygwin@cygwin.com Content-Type: text/plain; charset=ISO-8859-1 X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id q27Kxshb006772 On Wed, Mar 7, 2012 at 1:51 PM, Lee Collier wrote: > Hello, > > I'm new to cygwin and ran into an anamoly with calling ioctl() that > I've not experienced on Linux. It appears that ioctl() behaves as > expected when it is called from the main thread; however, it does not > when called from a thread created by the main thread. Is this expected > behavior when using cygwin? > > I've added a sample program to demonstrate the anomaly. The call to > listInterfaces() from main() will function properly. The call to > listInterfaces() from handlePackets() will fail at ioctl(sck, > SIOCGIFCONF, &ifc); however, the errno result reported by perror is > "No error". > > Regards, > LC > > #include > #include > #include > #include > #include > #include > > int listInterfaces(void); > void* handlePackets (void* data); > > int main(void) > { >   pthread_t pktHandlerThreadId; >   pthread_mutex_t pktMutex; > >   printf("Result from main thread:\n"); >   listInterfaces(); >   pthread_mutex_lock(&pktMutex); Don't know if it will fix your problem, but you cannot just create a mutex on the stack and call "lock" on it. You must initialize it with "pthread_mutex_init()". Jon -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple