Re: [Bug-gnubg] Simple multi-threading...

[Øystein Johansen]

Threading each moverecord sounds like a smart thing to do.

>> Which library do you use? pthreads? glib threads?
>
> Initially I've coded the multi-threaded calls directly using
> the windows API, it should be easy to convert this to pthreads
> (or maybe glib) - there are only 5 or so lines of code using
> multi-threaded functions.

I think I will prefere glib threads. That will make porting
simple. Windows API will limit things to Windows, pthreads
will limit things to POSIX systems. (Though there is a
pthread port to Windows.) Maybe some #ifdef if we can't decide.

>> (I remember I once tried threading in the evaluations
>> functions and made one tread each dice roll in the
>> lookahead. That failed completly.)

> I did consider the evaluation functions (as it would be the ideal
> solution in one sense - i.e. it would multi-thread everything in one
> go), they're not great candidates for multi-threading though.

My problem was joining threads. I believe I used a static counter
to generate a thread ID for each tread, the problem was when I then
should join the threads, some threads did never end/return. I'm not
exactly sure what went wrong, but I belive there was a problem with
the counter for thread ID. There is also the drawback that this
method for threading will not improve 0-ply analysis/evaluations.

> I'll try and check the initial code in tonight - I'll add a
> USE_MULTITHREADED guard to the new code.

I won't be able to look at this tonight. (I have an important
meeting at the local pub.) Maybe later this weekend. I have a lot
of things to install to the new box as wll, before I'm up and
running.

-Øystein