On Thu, 18 Jul 2019 23:07:08 +0100 andy pugh <bodge...@gmail.com> wrote:
> On Thu, 18 Jul 2019 at 22:01, Nicklas Karlsson <nicklas.karlsso...@gmail.com> > wrote: > > > It seems by no suprise writing real time to data to file within real time > > task have a negative impact on likelihood of real time delay. > > > > With RTAI and kernel modules I don't think that is is even possible. > > I tried non blocking fcntl(...) function and O_NONBLOCK flag without > > success. Adding some kind of buffer in for example shared memory between > > written by real time task and let another lower priority task write is a > > solution > > > Take a look at how streamer and hal_streamer do exactly this. Yes. They do it with a FIFO and the FIFO is what I need. Have done FIFO in embedded Micro controller with similar purpose before and used two "counters" to keep track of position within buffer, properly implemented I think it works perfect if it is known one process may interrupt the other but not the opposite as have been the case, if the FIFO get full oldest value is overwritten which in many cases is a good way to handle the situation in case there it not enough time available. Nicklas Karlsson _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
