Re: [Caml-list] effect of -thread with ocamlc/ocamlopt -c

[Trevor Jim <trevor@research.att.com>]

Thanks!

I hope that the manual can incorporate this clarification.

-Trevor

Jacques Garrigue wrote:
> The question is a bit different depending on whether you use system
> threads or vmthreads. Note that if your platform supports system
> threads, they are the ones used with the -thread option, while on
> platforms without them -thread and -vmthread are equivalent.
> 
> For system threads, the standard library is unchanged, and you don't
> need the -thread option for modules that don't use threads. So there
> is no problem.
> 
> For vm threads, some modules from the standard library have different
> implementations (namely, Pervasives, Marshal and Unix). So it is
> essential that you use the -thread option to link with them. Note
> however that the interfaces being identical, again you don't need
> -thread for unrelated modules, so that in practice you shouldn't see
> any difference with system threads. IIRC, at some point in the past
> some modified functions were defined as external in the standard
> library, making interfaces different, so that using -thread everywhere
> was a strict requirement.
> 
> Jacques Garrigue