Re: [Boost-users] multiprecision thread safety

Subject: Re: [Boost-users] multiprecision thread safety
From: John Maddock (jz.maddock_at_[hidden])
Date: 2016-01-14 14:27:04

On 14/01/2016 17:56, Daniel Brake wrote:
> Hi Boost,
> I have a couple of questions regarding thread safety and 
> Boost.Multiprecision.  I am writing a library, and would like to be 
> able to use mpfr_float (packed into my own complex class) in differing 
> variable precisions on multiple threads simultaneously.
>
>  1. Is this supported?  I looked in documentation, but didn't find
>     comments to that end.
>

The boost wrappers don't add anything new that would be thread unsafe, 
so yes, within whatever limitations mpfr has.

>  1. Must I manually call mpfr_free_cache when terminating threads, as
>     recommended by the mpfr documentation?  see
>     http://www.mpfr.org/mpfr-current/mpfr.html, section 4.7 memory
>     handling.  If so, since Boost.Multiprecision claims to not change
>     the default precision of mpfr_t, do I need to access the
>     particular back end for the thread, and free its cache?
>

Yes.  Boost.Multiprecision can't know when your thread exits, so you 
have to do any thread-specific mpfr cleanup yourself.

HTH, John.