Re: [Boost-users] Thread creation overhead & efficiency

From: James Sutherland (James.Sutherland_at_[hidden])
Date: 2008-02-05 16:07:26

I have tried threadpool.  It is my understanding that the code fragment
below should run in constant time independent of the number of threads
(assuming that the ³Test::operator()² method runs in constant time).
However, I observe an increase in runtime as I increase the pool size from
say 1 to 5.

Any thoughts on this?

James

> int main()
> {
>   const int nt = 5;
>   const int nit = 10000;
> 
>   time_t t1 = clock();
> 
>   boost::threadpool::pool p(1);
>   for( int j=0; j<nit; ++j ){
>     for( int i=0; i<nt; ++i ){
>       p.schedule( Test(i) );
>     }
>     p.wait();
>   }
> 
>   std::cout << "t=" << difftime(clock(), t1) << std::endl;
>   return 0;
> }