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  • Re: context as a user?

    From minforth@21:1/5 to Jos Ven on Fri May 5 01:34:05 2023
    Jos Ven schrieb am Freitag, 5. Mai 2023 um 10:17:54 UTC+2:
    It seems context is always defined as a variable.
    Would there be a problem if it was defined as a USER so
    multiple tasks could have their own search context at the same time?

    To hold a task-specific search-order you need a task-specific array/list. Whether you call this array/list or a pointer to it CONTEXT is implementation defined.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jos Ven@21:1/5 to All on Fri May 5 01:17:52 2023
    It seems context is always defined as a variable.
    Would there be a problem if it was defined as a USER so
    multiple tasks could have their own search context at the same time?
    Jos

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jos Ven@21:1/5 to All on Fri May 5 03:05:17 2023
    Op vrijdag 5 mei 2023 om 10:34:07 UTC+2 schreef minforth:
    Jos Ven schrieb am Freitag, 5. Mai 2023 um 10:17:54 UTC+2:
    It seems context is always defined as a variable.
    Would there be a problem if it was defined as a USER so
    multiple tasks could have their own search context at the same time?
    To hold a task-specific search-order you need a task-specific array/list. Whether you call this array/list or a pointer to it CONTEXT is implementation defined.

    CONTEXT is implementation defined.
    That is the problem.
    Under Gforth, Win32forth context is defined as a variable.
    There a variable is a kind of global within Forth then
    all tasks get the same context.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From none) (albert@21:1/5 to josv@planet.nl on Fri May 5 15:28:52 2023
    In article <8e360ba4-7f02-4a0b-ba1b-aa2977b2127cn@googlegroups.com>,
    Jos Ven <josv@planet.nl> wrote:
    It seems context is always defined as a variable.
    Would there be a problem if it was defined as a USER so
    multiple tasks could have their own search context at the same time?
    Jos

    In a decent design (ciforth) the list of context wordlist is
    naturally allocated in the space of USER variables.
    Otherwise it would not make sense to allow processes to compile their
    own separated definitions.

    Groetjes Albertg
    --
    Don't praise the day before the evening. One swallow doesn't make spring.
    You must not say "hey" before you have crossed the bridge. Don't sell the
    hide of the bear until you shot it. Better one bird in the hand than ten in
    the air. First gain is a cat spinning. - the Wise from Antrim -

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Brian Fox@21:1/5 to Jos Ven on Fri May 5 08:39:33 2023
    On Friday, May 5, 2023 at 4:17:54 AM UTC-4, Jos Ven wrote:
    It seems context is always defined as a variable.
    Would there be a problem if it was defined as a USER so
    multiple tasks could have their own search context at the same time?
    Jos

    FigForth defined CONTEXT as a user variable.
    People seemed to forget about multi-tasking and multi-user features
    in Forth as time went on.
    Once you have an O/S underneath I guess it matters less.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From minforth@21:1/5 to Brian Fox on Fri May 5 09:25:46 2023
    Brian Fox schrieb am Freitag, 5. Mai 2023 um 17:39:34 UTC+2:
    On Friday, May 5, 2023 at 4:17:54 AM UTC-4, Jos Ven wrote:
    It seems context is always defined as a variable.
    Would there be a problem if it was defined as a USER so
    multiple tasks could have their own search context at the same time?
    Jos
    FigForth defined CONTEXT as a user variable.
    People seemed to forget about multi-tasking and multi-user features
    in Forth as time went on.
    Once you have an O/S underneath I guess it matters less.

    AFAIK Forth never had a decent interrupt handler or timer. That was
    the main shortcoming, while seemingly savvy people argued enthusiastically about pros and cons of cooperative round-robin scheduling. Water under
    the bridge...

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Schultz@21:1/5 to minforth on Fri May 5 13:29:27 2023
    On 5/5/23 11:25 AM, minforth wrote:

    AFAIK Forth never had a decent interrupt handler or timer. That was
    the main shortcoming, while seemingly savvy people argued enthusiastically about pros and cons of cooperative round-robin scheduling. Water under
    the bridge...

    I found adding interrupt handling to an ARM version of eForth pretty
    easy. It helps that so much context is saved to the stack before the ISR begins.


    --
    http://davesrocketworks.com
    David Schultz

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From none) (albert@21:1/5 to david.schultz@earthlink.net on Sat May 6 13:01:56 2023
    In article <r1-dnQcSYJea1sj5nZ2dnZfqnPdg4p2d@earthlink.com>,
    David Schultz <david.schultz@earthlink.net> wrote:
    On 5/5/23 11:25 AM, minforth wrote:

    AFAIK Forth never had a decent interrupt handler or timer. That was
    the main shortcoming, while seemingly savvy people argued enthusiastically >> about pros and cons of cooperative round-robin scheduling. Water under
    the bridge...

    I found adding interrupt handling to an ARM version of eForth pretty
    easy. It helps that so much context is saved to the stack before the ISR >begins.

    Many Forths have support for interrupts, but there is not really
    a common ground. Forth's for single board computers (MSP430,
    Arduino, 8051) have supported it because it enhances the usability
    of those boards.
    See e.g.
    https://home.hccnet.nl/anij/nof/noforth.html
    and link through to Egel project.
    It contains several examples using interrupts, and you are right,
    it is not a big deal using interrupts on those stand alone Forths.
    A different situation occurs on Linux/MS-Windows because the
    OS jealously guards those interrupts.

    --
    http://davesrocketworks.com
    David Schultz

    --
    Don't praise the day before the evening. One swallow doesn't make spring.
    You must not say "hey" before you have crossed the bridge. Don't sell the
    hide of the bear until you shot it. Better one bird in the hand than ten in
    the air. First gain is a cat spinning. - the Wise from Antrim -

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Anton Ertl@21:1/5 to Jos Ven on Sat May 6 10:11:46 2023
    Jos Ven <josv@planet.nl> writes:
    It seems context is always defined as a variable.

    In Gforth it's a deferred word that is filled with a colon definition
    that produces an address of a search-order entry.

    Would there be a problem if it was defined as a USER so
    multiple tasks could have their own search context at the same time?

    No problem in principle; of course it depends on the individual system
    what you need to do to support searching in multiple tasks.

    - anton
    --
    M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html
    comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
    New standard: https://forth-standard.org/
    EuroForth 2022: https://euro.theforth.net

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Anton Ertl@21:1/5 to Jos Ven on Sat May 6 10:26:20 2023
    Jos Ven <josv@planet.nl> writes:
    Under Gforth, Win32forth context is defined as a variable.

    Not in the Gforth versions I have looked at (0.7 and the current
    development version).

    There a variable is a kind of global within Forth then
    all tasks get the same context.

    In Gforth we have discussed whether we want to support compilation
    (and, more generally, text interpretation) in multiple tasks, and
    decided against it.

    - anton
    --
    M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html
    comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
    New standard: https://forth-standard.org/
    EuroForth 2022: https://euro.theforth.net

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jos Ven@21:1/5 to All on Sat May 6 07:00:25 2023
    Op zaterdag 6 mei 2023 om 12:30:06 UTC+2 schreef Anton Ertl:
    Jos Ven <jo...> writes:
    Under Gforth, Win32forth context is defined as a variable.
    Not in the Gforth versions I have looked at (0.7 and the current
    development version).
    There a variable is a kind of global within Forth then
    all tasks get the same context.
    In Gforth we have discussed whether we want to support compilation
    (and, more generally, text interpretation) in multiple tasks, and
    decided against it.
    - anton
    --
    M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
    New standard: https://forth-standard.org/
    EuroForth 2022: https://euro.theforth.net

    Hi,
    My problem was as follows:
    2 tasks are using the same word.
    In a first attempt the context was saved at the start of the word and restored at the exit.
    That did not work.
    Now the context of the whole program is changed before the 2 tasks are running. That solved my problem.
    Jos

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jos Ven@21:1/5 to All on Sat May 6 06:45:01 2023
    Op zaterdag 6 mei 2023 om 12:30:06 UTC+2 schreef Anton Ertl:
    Jos Ven <jo..> writes:
    Under Gforth, Win32forth context is defined as a variable.
    Not in the Gforth versions I have looked at (0.7 and the current
    development version).
    There a variable is a kind of global within Forth then
    all tasks get the same context.
    In Gforth we have discussed whether we want to support compilation
    (and, more generally, text interpretation) in multiple tasks, and
    decided against it.
    - anton
    --
    M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
    New standard: https://forth-standard.org/
    EuroForth 2022: https://euro.theforth.net

    Hi,

    Under Gforth, Win32forth context is defined as a variable.

    Sorry, you are right.
    I should have looked better when I got into problems.
    Thanks for the correction.

    Jos

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)