include/Geant4/G4TaskSingletonDelegator.hh

0001 //
0002 // ********************************************************************
0003 // * License and Disclaimer                                           *
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0024 // ********************************************************************
0025 //
0026 //  ---------------------------------------------------------------
0027 //  GEANT4 template class header
0028 //  Class Description:
0029 //      This class delegates which singletons a task references
0030 //  ---------------------------------------------------------------
0031 //  Author: Jonathan Madsen
0032 //  ---------------------------------------------------------------
0033
0034 #include "G4AutoLock.hh"
0035 #include "G4Threading.hh"
0036
0037 #include <functional>
0038 #include <map>
0039 #include <memory>
0040 #include <set>
0041 #include <thread>
0042 #include <tuple>
0043 #include <type_traits>
0044 #include <vector>
0045
0046 namespace G4Traits
0047 {
0048   template <typename T>
0049   struct TaskSingletonKey
0050   {
0051     using type         = G4int;
0052     using compare_type = std::less<type>;
0053   };
0054 }  // namespace G4Traits
0055
0056 //----------------------------------------------------------------------------//
0057
0058 /// \class G4TaskSingletonEvaluator
0059 /// \brief This structure must be specialized and use overloads to the
0060 /// constructor
0061 ///
0062 template <typename T>
0063 struct G4TaskSingletonEvaluator;
0064
0065 //----------------------------------------------------------------------------//
0066
0067 template <typename T>
0068 class G4TaskSingletonDelegator;
0069
0070 //----------------------------------------------------------------------------//
0071
0072 template <typename T>
0073 class G4TaskSingletonData
0074 {
0075   using key_type     = typename G4Traits::TaskSingletonKey<T>::type;
0076   using compare_type = typename G4Traits::TaskSingletonKey<T>::compare_type;
0077
0078   friend struct G4TaskSingletonEvaluator<T>;
0079   friend class G4TaskSingletonDelegator<T>;
0080   using this_type = G4TaskSingletonData<T>;
0081
0082  private:
0083   static std::unique_ptr<this_type>& GetInstance()
0084   {
0085     static auto _instance = std::unique_ptr<this_type>(new this_type);
0086     return _instance;
0087   }
0088
0089  private:
0090   std::map<key_type, T*, compare_type> m_data;
0091 };
0092
0093 //----------------------------------------------------------------------------//
0094
0095 template <typename T>
0096 struct G4TaskSingletonEvaluator
0097 {
0098   using key_type  = typename G4Traits::TaskSingletonKey<T>::type;
0099   using data_type = G4TaskSingletonData<T>;
0100
0101   template <typename... Args>
0102   G4TaskSingletonEvaluator(key_type&, Args&&...)
0103   {
0104     throw std::runtime_error("Not specialized!");
0105   }
0106 };
0107
0108 //----------------------------------------------------------------------------//
0109
0110 template <typename T>
0111 class G4TaskSingletonDelegator
0112 {
0113  public:
0114   using pointer        = T*;
0115   using evaluator_type = G4TaskSingletonEvaluator<T>;
0116   using data_type      = G4TaskSingletonData<T>;
0117   using key_type       = typename G4Traits::TaskSingletonKey<T>;
0118
0119   template <typename... Args>
0120   static void Configure(Args&&... args)
0121   {
0122     auto& _data = data_type::GetInstance();
0123     evaluator_type _eval(std::forward<Args>(args)...);
0124     auto _ptr = _data->m_data.at(_eval.index);
0125     _eval.modifier(_ptr);
0126     T::SetInstance(_data->m_data.at(_key));
0127   }
0128 };
0129
0130 //----------------------------------------------------------------------------//