Re: [rtl] RT FIFOs and select system call.

[Paolo Mantegazza <mantegazza@aero.polimi.it>]

Laurent.Kersten@alcatel.be wrote:
> 
> Hello,
> 
> I've found a "undocumented feature" in the RTAI fifos  (new fifos (both version 0.9a and 1.5)). We are unable to perform a select system call from a user-space program (actually this is a TCL script that use the filevent TCL feature, but if you look
> through strace you can actually see that this is a call to select with a filedescriptor corresponding to the FIFO). Although the real-time process perform a write on the FIFO, the user-space process doesn't wake-up. We observed that it sleeps on the select
> system call.
> 
> The only work-around we had, is to have a separate user-space process that does a blocking read on the RT-FIFO and then we something is written, reads the RT-FIFO and rewrite the information on named pipe on which the script is now sleeping. This works
> but, it's not very elegant and it wastes CPU power.

Thank for the bug notice. We'll have a look at it ASAP.

Ciao, Paolo.