threadsafevalue.hh

#ifndef DUNE_FEM_THREADSAFEVALUES_HH
#define DUNE_FEM_THREADSAFEVALUES_HH
 
#include <vector>
 
#include <dune/fem/misc/mpimanager.hh>
 
namespace Dune {
 
  namespace Fem {
 
 
    template <class T>
    class ThreadSafeValue
    {
#ifdef USE_SMP_PARALLEL
      const typename MPIManager::ThreadPoolType& threadPool_;
      std::vector< T > value_;
#else
      T value_;
#endif
 
      int thread() const {
#ifdef USE_SMP_PARALLEL
        return threadPool_.thread();
#else
        return 0;
#endif
      }
    public:
      typedef T ValueType ;
 
      template< class ...Args >
      ThreadSafeValue( Args&& ...args )
#ifdef USE_SMP_PARALLEL
        : threadPool_( MPIManager::threadPool() ),
          value_( threadPool_.maxThreads(), ValueType( std::forward< Args >( args )... ) )
#else
        : value_( std::forward< Args >( args )... )
#endif
      {}
 
      ThreadSafeValue()
        :
#ifdef USE_SMP_PARALLEL
         threadPool_( MPIManager::threadPool() ),
#endif
          value_(
#ifdef USE_SMP_PARALLEL
            threadPool_.maxThreads()
#endif
             )
      {}
 
      size_t size() const {
#ifdef USE_SMP_PARALLEL
        return threadPool_.maxThreads();
#else
        return 1;
#endif
      }
 
      ValueType& operator * () { return this->operator[]( thread() ); }
      const ValueType& operator * () const { return this->operator[]( thread() ); }
 
      operator const ValueType& () const { return this->operator[]( thread() ); }
      operator ValueType& () { return this->operator[]( thread() ); }
 
      ValueType& operator [] ( const unsigned int thread ) {
        assert( thread < size() );
#ifdef USE_SMP_PARALLEL
        assert( thread < value_.size() );
#endif
        return value_
#ifdef USE_SMP_PARALLEL
          [ thread ]
#endif
          ;
      }
 
      const ValueType& operator [] ( const unsigned int thread ) const {
        assert( thread < size() );
#ifdef USE_SMP_PARALLEL
        assert( thread < value_.size() );
#endif
        return value_
#ifdef USE_SMP_PARALLEL
          [ thread ]
#endif
          ;
      }
    };
 
  } // end namespace Fem
 
} // end namespace Dune
 
 
#endif