[boost] [Boost.Function] How about parallel functions?

5 Sep 2009

      Hi,

I required to call few functions is separate threads and use the 
results. However, the code for this looks really ugly, you have to create 
threads, then join the threads when ever you require the result of the functions.

So I have created a boost.parallel_function library that does this 
seamlessly just like invoking a normal function and it only joins the 
thread when the value of the function result type is required. Is this 
library of any interest to any one?

Here is the a hello world example:

#include <cstdlib>
#include <limits>
#include <boost/parallel_function.hpp>
using namespace boost;

int F0()
{
   volatile int x = 0;
   for(int i=0; i<std::numeric_limits<int>::max()/1024; i++)
     x ^= std::rand();
   return (int)x;
}

int F2(int y)
{
   volatile int x = 0;
   for(int i=0; i<std::numeric_limits<int>::max()/512; i++)
     x ^= std::rand();
   return (int)x ^ y;
}

int main()
{  
   typedef boost::parallel_function< void (   ) > f0_type;
   typedef boost::parallel_function< void (int) > f1_type;

   f0_type f0( &::F0 );
   f1_type f1( &::F1 );

   f0_type::result_type r0 = f0();
   f1_type::result_type r1 = f1(32);

   // use r0 and r1 as if they are int
   r0 += 34;
   int value = r1 *= r0 + 452;

   std::cout << "Hello world " << value << std::endl;

   return 0;
}

With Best Regards

Mr. Kasra Nassiri
Department of Mathematics & 
Computer Science
Imperial College London