Re: Embedded platforms for beginners?

From	David Brown <david.brown@hesbynett.no>
Newsgroups	comp.arch.embedded
Subject	Re: Embedded platforms for beginners?
Date	2017-09-05 10:16 +0200
Organization	A noiseless patient Spider
Message-ID	<oolmg4$630$1@dont-email.me> (permalink)
References	(10 earlier) <ooi22u$riv$2@dont-email.me> <lG0rB.65702$EZ2.14489@fx22.iad> <v4OdnVKvv-PMBjHEnZ2dnUU7-LOdnZ2d@supernews.com> <2i5rB.35182$OC1.2645@fx06.iad> <87o9qrm3xw.fsf@nightsong.com>

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On 04/09/17 07:24, Paul Rubin wrote:
> Clifford Heath <no.spam@please.net> writes:
>> Generational GC relies on being able to move things between heaps,
>> so object handles cannot be pointers (or rather, must be indirect).
> 
> The handles are usually still pointers.  First you copy the object to
> the other heap, then later you scan it, copy the objects that the first
> objects points to, and update the pointers in the first object to point
> to the new locations.  This is described pretty well in the SICP chapter
> on metacircular evaluators (mitpress.mit.edu/sicp).
> 

That is /one/ way to handle it.  There are many others.

For example, when you have pools of memory that have blocks of the same
size, you might use an array and have indexes into that array as your
handles.

Or you might have something that is basically an address, but
specifically manipulated in order to make it easily distinguishable to a
garbage collector, and to avoid user code accidentally using it as a
pointer.  This could be as simple as adding an offset to put the value
outside the valid range in the device - software bugs would then cause
hard faults that can quickly be identified.

Thread

Embedded platforms for beginners? Elof Huang <elof.huang@runbox.com> - 2017-09-01 14:07 +0800
  Re: Embedded platforms for beginners? Jack <jack4747@gmail.com> - 2017-08-31 23:22 -0700
  Re: Embedded platforms for beginners? rickman <gnuarm@gmail.com> - 2017-09-01 04:10 -0400
  Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-01 21:49 +1000
    Re: Embedded platforms for beginners? Elof Huang <elof.huang@runbox.com> - 2017-09-02 11:57 +0800
      Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-02 18:25 +1000
        Re: Embedded platforms for beginners? Elof Huang <elof.huang@runbox.com> - 2017-09-03 15:37 +0800
          Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-03 17:54 +1000
          Re: Embedded platforms for beginners? rickman <gnuarm@gmail.com> - 2017-09-03 13:49 -0400
    Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-02 11:41 -0400
      Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-03 09:44 +1000
        Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-02 20:39 -0400
          Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-03 11:16 +1000
        Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-02 18:21 -0700
          Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-03 14:26 +1000
            Re: Embedded platforms for beginners? rickman <gnuarm@gmail.com> - 2017-09-03 02:14 -0400
              Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-03 17:52 +1000
                Re: Embedded platforms for beginners? rickman <gnuarm@gmail.com> - 2017-09-03 13:50 -0400
                Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-03 22:20 -0700
                Re: Embedded platforms for beginners? rickman <gnuarm@gmail.com> - 2017-09-05 22:06 -0400
                Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-06 12:21 +1000
                Re: Embedded platforms for beginners? rickman <gnuarm@gmail.com> - 2017-09-05 22:42 -0400
                Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-06 14:26 +1000
                Re: Embedded platforms for beginners? rickman <gnuarm@gmail.com> - 2017-09-06 01:20 -0400
                Re: Embedded platforms for beginners? George Neuner <gneuner2@comcast.net> - 2017-09-03 15:58 -0400
                Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-04 08:00 +1000
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-03 19:13 -0400
                Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-04 09:58 +1000
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-03 20:16 -0400
                Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-04 15:13 +1000
                Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-03 22:24 -0700
                Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-04 15:55 +1000
                Re: Embedded platforms for beginners? David Brown <david.brown@hesbynett.no> - 2017-09-05 14:15 +0200
                Re: Embedded platforms for beginners? George Neuner <gneuner2@comcast.net> - 2017-09-05 12:35 -0400
                Re: Embedded platforms for beginners? Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2017-09-05 10:02 -0700
                Re: Embedded platforms for beginners? Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-09-05 18:13 +0100
                Re: Embedded platforms for beginners? David Brown <david.brown@hesbynett.no> - 2017-09-06 10:24 +0200
                Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-05 17:10 -0700
                Re: Embedded platforms for beginners? David Brown <david.brown@hesbynett.no> - 2017-09-06 09:57 +0200
                Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-05 16:57 -0700
                Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-05 16:54 -0700
                Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-06 12:31 +1000
                Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-05 19:42 -0700
                Re: Embedded platforms for beginners? David Brown <david.brown@hesbynett.no> - 2017-09-05 10:16 +0200
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-05 16:56 -0400
                Re: Embedded platforms for beginners? Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-09-04 10:46 +0100
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-05 17:09 -0400
                Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-05 19:35 -0700
                Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-06 12:40 +1000
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-06 00:42 -0400
                Re: Embedded platforms for beginners? Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-09-06 08:55 +0100
                Re: Embedded platforms for beginners? Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-09-06 08:45 +0100
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-07 20:23 -0400
                Re: Embedded platforms for beginners? Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-09-08 08:42 +0100
                Re: Embedded platforms for beginners? David Brown <david.brown@hesbynett.no> - 2017-09-08 12:07 +0200
                Re: Embedded platforms for beginners? Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-09-08 11:40 +0100
                Re: Embedded platforms for beginners? David Brown <david.brown@hesbynett.no> - 2017-09-08 13:24 +0200
                Re: Embedded platforms for beginners? Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-09-08 13:36 +0100
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-09 13:16 -0400
                Re: Embedded platforms for beginners? Les Cargill <lcargill99@comcast.com> - 2017-09-10 08:53 -0500
                Re: Embedded platforms for beginners? Dimiter_Popoff <dp@tgi-sci.com> - 2017-09-10 20:18 +0300
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-11 21:24 -0400
                Re: Embedded platforms for beginners? Les Cargill <lcargill99@comcast.com> - 2017-09-15 22:22 -0500
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-18 11:26 -0400
                Re: Embedded platforms for beginners? Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-09-18 18:26 +0100
                Re: Embedded platforms for beginners? Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-19 14:27 -0400
                Re: Embedded platforms for beginners? Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-09-18 18:24 +0100
                Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-03 22:30 -0700
                Re: Embedded platforms for beginners? Clifford Heath <no.spam@please.net> - 2017-09-04 15:51 +1000
            Re: Embedded platforms for beginners? Paul Rubin <no.email@nospam.invalid> - 2017-09-03 22:04 -0700
      Re: Embedded platforms for beginners? kristoff <kristoff@skypro.be> - 2017-09-05 17:56 +0200
        Re: Embedded platforms for beginners? Luke A. Guest <laguest@archeia.com> - 2017-09-10 17:10 +0100
  Re: Embedded platforms for beginners? tarjei99@gmail.com - 2017-09-10 05:49 -0700
    Re: Embedded platforms for beginners? Les Cargill <lcargill99@comcast.com> - 2017-09-10 09:03 -0500

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