Mark, Am 27.04.2013 um 13:06 schrieb Mark Wendt <[email protected]>:
> On Fri, Apr 26, 2013 at 5:15 PM, Michael Haberler <[email protected]>wrote: > >> Mark, >> >>> I was thinking more of hardware resources, such as interrupts. What >>> happens when both instances require the same interrupt at the same time? >> >> Any instance usually will have a HAL driver to talk to the outside world >> exactly like the single instance which we have now, and that driver will >> attach to a hardware device and will be responsible to allocate all >> required resources during startup or bark if isnt possible - there is no >> difference at all from a single instance which loads several drivers >> talking to different devices >> >> this would include an interrupt if there were one - you probably wont find >> any in LinuxCNC >> > > Isn't that presuming that all the hardware devices will be relegated to > that singular instance? No. > That would be okay if there were multiples of each > hardware device, but in cases where there aren't is where my concern lies. In this case what you would do is have the HAL driver in just _one_ instance and cross-link those pins you need into the other instance - problem solved. - Michael > > >> >> >>> Unlike shared memory, interrupts are a bit harder to share, or have >>> concurrent use. Can the separate instances somehow share the IO bus? >> >> no, separation is at the HAL driver level as it always was, no new >> concepts here >> >> an example: >> >> assume you have 2 parports in a PC: >> >> it is exactly the same I/O usage if you do this in a single instance: >> >> loadrt hal_parport cfg="0x278 0x378" >> >> or do this in instance #1 >> loadrt hal_parport cfg="0x278" >> >> and this in instance #2: >> loadrt hal_parport cfg="0x378" >> >> >> Remember: instances are ships in the night _except_ if there are >> cross-linked signals, in which case they can share signal values >> >> you're thinking too complicated ;) >> >> - Michael >> > > I probably am overthinking it, and making it too complicated, but my degree > is computer science, and I've always been intrigued by RTOS systems. Now > that folks are looking into multiple instances of RTOS running on the same > machine, I'm very curious how they get around resources that can't be > shared, or how they schedule them so that a lock on the resource by one > instance affects the other instance which might need that resource at the > same time. > > Mark > ------------------------------------------------------------------------------ > Try New Relic Now & We'll Send You this Cool Shirt > New Relic is the only SaaS-based application performance monitoring service > that delivers powerful full stack analytics. Optimize and monitor your > browser, app, & servers with just a few lines of code. Try New Relic > and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_apr > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only SaaS-based application performance monitoring service that delivers powerful full stack analytics. Optimize and monitor your browser, app, & servers with just a few lines of code. Try New Relic and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_apr _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
