Re: [boost] problems with the Random library in Boost v1.47

Subject: Re: [boost] problems with the Random library in Boost v1.47
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2011-07-15 12:04:47

AMDG

On 07/15/2011 08:40 AM, Hongyu Miao wrote:
> Hi, Steven
> 
> Thanks for your reply. I'm using MSVC 2010, too. I met such problems when I
> generated a million random numbers with the mersenne_twister generator and
> OpenMP. I'm not sure whether v1.47 is thread safe, though.

Using a generator concurrently in multiple
threads has never been supported.  Even
if this code worked (or more likely, appeared
to work) in previous versions, it's wrong.

>  Here is the code
> triggered the memory access violation:
> 
> int num_point = 1000;
> int n_para = 1000;
> boost::numeric::ublas::matrix<double> ui(num_point, n_para);
> #pragma omp parallel for shared(ui, num_point, n_para) private(i, j)
> for (i=0; i<num_point; i++)
> {
>     for (j=0; j<n_para; j++)
>     {
>         ui(i,j) = unirand_real(0.0,1.0);
>     }
> }
> 

In Christ,
Steven Watanabe