Re: Fwd: Import procedure NEWPROCESS

[Gaius Mulley]

Benjamin Kowarsch <trijezdci@gmail.com> writes:

> On Fri, 4 Oct 2024 at 04:35, Gaius Mulley wrote:
>
>  gm2 moved away from using GNU Portable Threads circa 2018.  It
>  now uses the gnu threading library (found in the gcc sources) not to be
>  confused with GNU Portable Threads.  Around 2018 this was one of the
>  prerequisite changes required to get gm2 into the GCC tree.
>  I think most (if not all) front ends use this library (C++, go,
>  etc) and it implements the user level threads as you describe above
>  (with all the advantages of simplicity and portability)
>
> OK, but does this library provide *actual* user level threads, not
> just an interface that mimics them?
>
> It is always possible to wrap a simpler user interface around any
> concurrency library, but the scalability advantage of user level
> threads cannot be gained this way if the underlying library does not
> use actual user level threading.

Hi Benjamin,

the m2 libraries (iso and pim) both use:

  libgm2/libm2iso/RTco.cc

which uses the libgcc/gthr.h

gthr.h provides a pthread like model.  I think gthr.h also provides a
compatibility layer onto whatever threading availability there is on the
underlying system (or overridden by gcc configure options),

regards,
Gaius