[fpc-pascal] Threading in FPC DOS

[Marco van de Voort]

> Marco van de Voort wrote:
> > me.
> > I assume you are implementing a basic fixed timeslicer?  What are you
> > going
> > to use it for btw?  This because DV/X (which is free nowadays) afaik gives
> > you preemptive scheduling on Dos.
> 
> Well, multitasking <> multithreading. I'm not sure if DV or Win 3.x
> provide special multithreading support for DOS applications... 

Totally right. Sorry. They might, but that is a different thing from what I
was thinking about.

> In contrary to Marco's suggestion, I can imagine the multithreading
> support could be general and included by default for GO32v2 (similarly to
> Win32).

However, even then, the scheduler would be probably so crude that every non
trivial use would need its own tweaks, one reason the more to make it
pluggable. It's not like win32 where the preemptive scheduler can deal with
a wide range of behaviour. 

> However, it certainly depends on whether a general solution (not
> requiring special support like DV, etc.) is really feasible and practical.

I doubt it. Note that it also probably needs enhancing of the
threadinterface with a giveuptimeslice functionality, something for which
now sleep(0) is abused.