John Kasunich wrote: > Sebastian Kuzminsky wrote: >> If RTAI supported mutexes and thread-blocking, then fast gpio access >> could be easily done even on the EPP boards. >> ... > HAL (and EMC2) uses Rate Monotonic Scheduling > (http://en.wikipedia.org/wiki/Rate_Monotonic_Scheduling) which is the > simplest way to guarantee meeting realtime schedules and avoid > deadlocks. However, you simply _cannot_ share a resource between > threads. Changing the scheduling/priority algorithms is not something > to be done lightly.
Thanks for that John, that settles the issue. I've implemented the "threadsafe" flag; the PCI cards now export read_gpio() and write_gpio() functions for use in any thread the user wants. (This is in TRUNK, not 2.2 yet.) -- Sebastian Kuzminsky Cryogenic travel has improved since then... I woke screaming in a translucent box. “There, there,” said the box. “Everything will be all right. Have some coffee.” -- Ken Macleod, "Who's afraid of Wolf 359" <http://outofthiseos.typepad.com/blog/files/KenMacleodWhosAfraidofWolf359.htm> ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
