Has anyone done any multi-threading at the Dos-X level?

I've developed Multi-threading kernel for DOSX two month ago.
I haven't tested it enough to say it is 100% error-free, but it works pretty
well.

I've implemented most basic synchronization (events, mutexes, semaphores and appropriate functions for using them). Thread's state may include (or if it doesn't use it may not include) i387 state and SSE state.

On my P-III 1000 the scheduler consumes about 0,2% time, while switching
threads 1000 times per second.
Current code runs at least on Pentium (I used RDTSC instruction to time
execution), but if i486 supports mentioned instruction (I guess modern AMD
486 do), it should run on it either.

The problem to be fixed is using DOS. For now I see 2 ways of using DOS:
- hook DOS int 21 and embed mutex into it
- use win3.11 technique and swap static areas of DOS.

By now exceptions are handled so, that faulty thread is terminated while others proceed running.

And one more issue: DOSX multithread no way will go under Win, as long as I program i8253 controller and change the return point from interrupt.

By now, I have no support from RTL, but as soon as I get my Digital Mars CD with RTL sources, I'll embed this support into RTL.

Note. I froze project because I changed my work and because no one seemed to need this feature. If it is interesting for somebody I may proceed working and develop this DOSX-MT project to ready-to-use product.

Nic Tiger.

"Karl" <someone@unknown.org> wrote in message news:aa5cne$1pod$1@digitaldaemon.com...
> Has anyone done any multi-threading at the Dos-X level?
>
>
>

That's pretty fantastic!

"Nic Tiger" <nictiger@pt.comcor.ru> wrote in message news:aa5iuv$207h$1@digitaldaemon.com...
> I've developed Multi-threading kernel for DOSX two month ago.
> I haven't tested it enough to say it is 100% error-free, but it works
pretty
> well.
>
> I've implemented most basic synchronization (events, mutexes, semaphores
and
> appropriate functions for using them). Thread's state may include (or if
it
> doesn't use it may not include) i387 state and SSE state.
>
> On my P-III 1000 the scheduler consumes about 0,2% time, while switching
> threads 1000 times per second.
> Current code runs at least on Pentium (I used RDTSC instruction to time
> execution), but if i486 supports mentioned instruction (I guess modern AMD
> 486 do), it should run on it either.
>
> The problem to be fixed is using DOS. For now I see 2 ways of using DOS:
> - hook DOS int 21 and embed mutex into it
> - use win3.11 technique and swap static areas of DOS.
>
> By now exceptions are handled so, that faulty thread is terminated while others proceed running.
>
> And one more issue: DOSX multithread no way will go under Win, as long as
I
> program i8253 controller and change the return point from interrupt.
>
> By now, I have no support from RTL, but as soon as I get my Digital Mars
CD
> with RTL sources, I'll embed this support into RTL.
>
> Note. I froze project because I changed my work and because no one seemed
to
> need this feature. If it is interesting for somebody I may proceed working and develop this DOSX-MT project to ready-to-use product.
>
> Nic Tiger.
>
> "Karl" <someone@unknown.org> wrote in message news:aa5cne$1pod$1@digitaldaemon.com...
> > Has anyone done any multi-threading at the Dos-X level?
> >
> >
> >
>
>

Thanks for the info.

It has always been a difficult decision on whether to use Linux or
Dos-32.  I only need something quite simple - no disk I/O, just
a single multithreading program running on a PC-104 box with
flash disk.

Nic Tiger <nictiger@pt.comcor.ru> wrote in message news:aa5iuv$207h$1@digitaldaemon.com...
> I've developed Multi-threading kernel for DOSX two month ago.
> I haven't tested it enough to say it is 100% error-free, but it works
pretty
> well.
>
> I've implemented most basic synchronization (events, mutexes, semaphores
and
> appropriate functions for using them). Thread's state may include (or if
it
> doesn't use it may not include) i387 state and SSE state.
>
> On my P-III 1000 the scheduler consumes about 0,2% time, while switching
> threads 1000 times per second.
> Current code runs at least on Pentium (I used RDTSC instruction to time
> execution), but if i486 supports mentioned instruction (I guess modern AMD
> 486 do), it should run on it either.
>
> The problem to be fixed is using DOS. For now I see 2 ways of using DOS:
> - hook DOS int 21 and embed mutex into it
> - use win3.11 technique and swap static areas of DOS.
>
> By now exceptions are handled so, that faulty thread is terminated while others proceed running.
>
> And one more issue: DOSX multithread no way will go under Win, as long as
I
> program i8253 controller and change the return point from interrupt.
>
> By now, I have no support from RTL, but as soon as I get my Digital Mars
CD
> with RTL sources, I'll embed this support into RTL.
>
> Note. I froze project because I changed my work and because no one seemed
to
> need this feature. If it is interesting for somebody I may proceed working and develop this DOSX-MT project to ready-to-use product.
>
> Nic Tiger.
>
> "Karl" <someone@unknown.org> wrote in message news:aa5cne$1pod$1@digitaldaemon.com...
> > Has anyone done any multi-threading at the Dos-X level?
> >
> >
> >
>
>

Hi Karl,

I suppose PC-104 means industrial computer (like as Advantec), is it so? What version of DOS is there? I hope MS-DOS 5+.

If you need any assistance or my multithreading lib, just let me no.

Nic Tiger.

"Karl" <someone@unknown.org> wrote in message news:aai47a$250h$1@digitaldaemon.com...
> Thanks for the info.
>
> It has always been a difficult decision on whether to use Linux or
> Dos-32.  I only need something quite simple - no disk I/O, just
> a single multithreading program running on a PC-104 box with
> flash disk.
>

DR-Dos.

I can do multithreading in Dos-16 and it served the purposed quite well. The only reason to go further is networking support. The program size is not that managable. Going to Linux is OK, but configuring for production is messy.

Nic Tiger <nictiger@pt.comcor.ru> wrote in message news:aais3t$30bi$1@digitaldaemon.com...
> Hi Karl,
>
> I suppose PC-104 means industrial computer (like as Advantec), is it so? What version of DOS is there? I hope MS-DOS 5+.
>
> If you need any assistance or my multithreading lib, just let me no.
>
> Nic Tiger.
>
> "Karl" <someone@unknown.org> wrote in message news:aai47a$250h$1@digitaldaemon.com...
> > Thanks for the info.
> >
> > It has always been a difficult decision on whether to use Linux or
> > Dos-32.  I only need something quite simple - no disk I/O, just
> > a single multithreading program running on a PC-104 box with
> > flash disk.
> >
>
>
>