Hi Dennis, I have just detected the very same effect. At least with RTAI-3.3cv it is not working. In rtnet's rt_udp_recvmsg() the timeout will be set to -1 if the flag MSG_DONTWAIT is used.
The call to rtdm_sem_timeddown() with this timeout value fails as the resulting RTAI function _sem_wait_timed rejects a negative timeout => it returns -EWOULDBLOCK immediately without checking the semaphores value. RTDM in RTAI seems not to handle a polling semaphore check correctly. That means the only possible way (without changing rtdm) is to it the way you have done it: Using a extreme small timeout value (=1). By looking at the code I saw same strange things: In rtnet, the time type nanosecs_t is a uint64, however in RTAI's rtdm the timetype is a signed int64. That could lead to confusion... To fix the MSG_DONTWAIT issue I have detected, the code can be modified to set the timeout to 1 (instead of -1) whenever MSG_DONTWAIT is specified. Regards Mathias ----- Original Nachricht ---- Von: Dennis Windisch <[EMAIL PROTECTED]> An: rtnet-users@lists.sourceforge.net Datum: 24.08.2006 12:46 Betreff: [RTnet-users] Non-blocking sockets - possible bug? > I've encountered the following problem setting RTnet sockets into non > blocking mode: > > > long long timeout = -1; > > int res = ioctl_rt(socket,RTNET_RTIOC_TIMEOUT,&timeout); > When setting the socket like above (non-blocking mode) nothing works, > meaning there is no data is received via this socket. > > > long long timeout = 1; > > int res = ioctl_rt(socket,RTNET_RTIOC_TIMEOUT,&timeout); > But when I set the socket like above (note that timeout is no positive), the > socket is set to blocking mode (yet only for a very small time) and all > works fine, data gets received. > > I'm using RTAI 3.3, latest stable version form rtai.org (no CVS version) > and RTnet 0.9.4 from rtnet.org (no SVN version). > > Could it be I found a bug in setting sockets non-blocking? > -- > > > Echte DSL-Flatrate dauerhaft für 0,- Euro*. Nur noch kurze Zeit! > "Feel free" mit GMX DSL: http://www.gmx.net/de/go/dsl > > ------------------------------------------------------------------------- > Using Tomcat but need to do more? Need to support web services, security? > Get stuff done quickly with pre-integrated technology to make your job > easier > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 > _______________________________________________ > RTnet-users mailing list > RTnet-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/rtnet-users > -- Mathias Koehrer [EMAIL PROTECTED] Viel oder wenig? Schnell oder langsam? Unbegrenzt surfen + telefonieren ohne Zeit- und Volumenbegrenzung? DAS TOP ANGEBOT JETZT bei Arcor: günstig und schnell mit DSL - das All-Inclusive-Paket für clevere Doppel-Sparer, nur 44,85 inkl. DSL- und ISDN-Grundgebühr! http://www.arcor.de/rd/emf-dsl-2 ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ RTnet-users mailing list RTnet-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rtnet-users
