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Groups > comp.arch.embedded > #27507
| From | Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> |
|---|---|
| Newsgroups | comp.arch.embedded |
| Subject | Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? |
| Date | 2018-01-05 21:40 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <p2pcv1$s3f$1@dont-email.me> (permalink) |
| References | (6 earlier) <p2j5mn$bev$2@dont-email.me> <p2jqj6$9jq$1@dont-email.me> <p2kotf$cu9$1@dont-email.me> <p2lve0$tuv$1@dont-email.me> <%jH3C.197195$nS6.171613@fx23.am4> |
On 01/05/2018 04:12 AM, Tom Gardner wrote: > On 04/01/18 19:31, rickman wrote: >> rickman wrote on 1/4/2018 3:33 AM: >>> Les Cargill wrote on 1/3/2018 6:59 PM: >>>> rickman wrote: >>>>> Les Cargill wrote on 1/3/2018 7:07 AM: >>>>>> rickman wrote: >>>>>>> Ed Prochak wrote on 12/19/2017 11:19 AM: >>>>>>>> On Saturday, December 16, 2017 at 12:56:31 PM UTC-5, >>>>>>>> Les Cargill wrote: >>>>>>>>> Mike Perkins wrote: >>>>>>>>>> On 09/12/2017 16:05, pozz wrote: >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> I use it where I have a number of 'tasks' which >>>>>>>>>> then interact with each other. >>>>>>>>>> >>>>>>>>>> If your system is a pure state machine then there >>>>>>>>>> is no need for an RTOS. >>>>>>>>>> >>>>>>>>> >>>>>>>>> Indeed. Indeed. >>>>>>>> >>>>>>>> If it is just one state machine. Then yes, indeed. ed >>>>>>> >>>>>>> It can always be one state machine. The only issue is >>>>>>> how complex the combined state machine is. >>>>>>> >>>>>> >>>>>> It's always a case of "how long should a man's legs be?" >>>>>> Lincoln is alleged to have said "long enough to touch the >>>>>> ground." >>>>>> >>>>>>> Actually the issue is not how many state machines you >>>>>>> have. It is the timing requirements of the various state >>>>>>> machines. If your timing is lax, sequential operation of >>>>>>> multiple machines is easy. But this often becomes a huge >>>>>>> discussion with everyone talking past each other. >>>>>>> >>>>>> >>>>>> They should use state machines to keep track then :) >>>>>> >>>>>> If your system can be decomposed as roughly events cross >>>>>> state, you have a snowball's chance of "understanding" it. >>>>> >>>>> Sorry, I don't know what this means "roughly events cross >>>>> state". >>>>> >>>>> >>>> >>>> You are in state A. Event 42 occurs. Lookup.... ah, here - if >>>> we get event 42 whilst in state A, we move to state B and send >>>> message m. >>> >>> So what makes that so hard to understand? >> >> To be more explicit, I think every FSM I've ever coded was along >> the lines of a case statement on the state with IF conditions on >> all the interesting inputs. I find this structure to be self >> documenting if the signal names are chosen well. >> >> Why is this structure hard to understand? > > I've seen a commercial case where that type of structure was mutated > by people under pressure to: - have a single state machine for all > different customers - make the minimum change - do it fast - where > the original designers had left - a custom domain specific language, > ugh > > The result was an unholy unmaintainable mess, with if-then-elses > nested up to 10 (ten!) deep. > > Completely insane, of course. > Yup. The whole point of state machine design is to avoid that sort of logic-driven horror. > My preference is for a dispatch table based on event+state, since > that forces you to consider all possibilities. The dispatch table can > be either a 2D array of function pointers, or inherent in an OOP > inheritance hierarchy where the hierarchy is a direct mirror of the > state hierarchy. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
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Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Mike Perkins <spam@spam.com> - 2017-12-10 14:56 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2017-12-16 11:58 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Ed Prochak <edprochak@gmail.com> - 2017-12-19 08:19 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm@gmail.com> - 2017-12-19 11:51 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Ed Prochak <edprochak@gmail.com> - 2018-01-02 14:58 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2018-01-03 06:07 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-03 12:59 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2018-01-03 17:59 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-04 03:33 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-04 14:31 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2018-01-04 11:56 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2018-01-04 21:46 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-04 16:46 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2018-01-04 21:47 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-06 18:55 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 00:54 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-07 13:41 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 23:32 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-10 10:33 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-10 16:29 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? upsidedown@downunder.com - 2018-01-08 08:11 +0200
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-07 23:05 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? upsidedown@downunder.com - 2018-01-08 10:06 +0200
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? David Brown <david.brown@hesbynett.no> - 2018-01-08 10:27 +0100
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-08 09:56 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-08 18:39 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-08 12:20 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-08 22:11 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? David Brown <david.brown@hesbynett.no> - 2018-01-08 22:26 +0100
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-08 22:23 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-08 14:44 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-08 23:06 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-08 10:02 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2018-01-08 17:34 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-06 22:29 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-07 00:46 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2018-01-04 21:44 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-05 09:12 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-01-05 21:40 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2018-01-05 21:29 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-06 09:10 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2018-01-06 16:35 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 01:04 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-06 09:17 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Les Cargill <lcargill99@comcast.com> - 2018-01-06 16:37 -0600
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 01:11 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-06 17:31 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 01:52 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-07 00:39 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 09:55 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-07 10:43 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 19:35 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-06 19:06 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-06 16:58 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-06 22:37 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-07 00:58 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-07 09:32 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Paul Rubin <no.email@nospam.invalid> - 2018-01-07 10:53 -0800
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-10 11:40 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 01:14 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-06 18:57 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 01:17 +0000
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? rickman <gnuarm.deletethisbit@gmail.com> - 2018-01-06 22:40 -0500
Re: When exactly do you choose to use a RTOS (instead of a non-OS approach)? Tom Gardner <spamjunk@blueyonder.co.uk> - 2018-01-07 09:59 +0000
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