Re: PARI and POSIX threads

[Bill Allombert <allomber@math.u-bordeaux.fr>]

On Mon, Aug 15, 2005 at 11:24:58PM +0200, Philippe Elbaz-Vincent wrote:
> Hi,
> 
> Is there a way to use PARI (i.e., in lib mode) inside a program
> which uses posix threads (under Linux/2.6 with glibc 2.2.5 on x86_64) ?
> (and of course knowing that there will be calls to PARI functions inside 
> threads).
> As I understand the troubles come from the garbage collector as the 
> variables of 
> the PARI stack are globals and as soon that 2 threads run concurently the 
> PARI stack would be likely messed up [in fact I tested it and indeed it is 
> the case].
> 
> Is there a solution to this problem ?
> [is it technically doable to run several instances of PARI inside the same 
> program ?]

I am not sure the answer is known.

What you can try is to mark avma, bot and top 'thread-local' using the
'__thread' keyword (assuming this is supported) and use
allocatemoremem() or switch_stack() to allocate a separate stack in each
threads.  To copy objects between threads, clone them.

We would be very interested to know if that can be made to work.

Cheers,
Bill.