include/accel/TrackingManagerConstructor.hh

0001 //------------------------------- -*- C++ -*- -------------------------------//
0002 // Copyright Celeritas contributors: see top-level COPYRIGHT file for details
0003 // SPDX-License-Identifier: (Apache-2.0 OR MIT)
0004 //---------------------------------------------------------------------------//
0005 //! \file accel/TrackingManagerConstructor.hh
0006 //---------------------------------------------------------------------------//
0007 #pragma once
0008
0009 #include <functional>
0010 #include <G4ParticleDefinition.hh>
0011 #include <G4VPhysicsConstructor.hh>
0012
0013 #include "corecel/cont/Span.hh"
0014
0015 namespace celeritas
0016 {
0017 class LocalTransporter;
0018 class SharedParams;
0019 class TrackingManagerIntegration;
0020
0021 //---------------------------------------------------------------------------//
0022 /*!
0023  * Construct a Celeritas tracking manager that offloads EM tracks.
0024  *
0025  * This should be composed with your physics list after it is constructed,
0026  * before the simulation begins.  By default this uses the \c
0027  * celeritas::TrackingManagerIntegration helper:
0028  * \code
0029     auto* physics_list = new FTFP_BERT;
0030     physics_list->RegisterPhysics(new TrackingManagerConstructor{
0031         &TrackingManagerIntegration::Instance()});
0032    \endcode
0033  *
0034  * but for manual integration it can be constructed with a function to get a
0035  * reference to the thread-local \c LocalTransporter from the Geant4 thread ID:
0036  * \code
0037     auto* physics_list = new FTFP_BERT;
0038     physics_list->RegisterPhysics(new TrackingManagerConstructor{
0039         shared_params, [](int){ return &local_transporter; });
0040    \endcode
0041  *
0042  * \note If Celeritas is globally disabled, it will not add the track manager.
0043  * If Celeritas is configured to "kill offload" mode (for testing maximum
0044  * theoretical performance) then the tracking manager will be added but will
0045  * not send the tracks to Celeritas: it will simply kill them.
0046  */
0047 class TrackingManagerConstructor final : public G4VPhysicsConstructor
0048 {
0049   public:
0050     //!@{
0051     //! \name Type aliases
0052     using LocalTransporterFromThread = std::function<LocalTransporter*(int)>;
0053     //!@}
0054
0055   public:
0056     // Get a list of supported particles
0057     static Span<G4ParticleDefinition* const> OffloadParticles();
0058
0059     // Construct name and mode
0060     TrackingManagerConstructor(SharedParams const* shared,
0061                                LocalTransporterFromThread get_local);
0062
0063     // Construct from tracking manager integration
0064     explicit TrackingManagerConstructor(TrackingManagerIntegration* tmi);
0065
0066     //! Null-op: particles are constructed elsewhere
0067     void ConstructParticle() override {}
0068
0069     // Build and attach tracking manager
0070     void ConstructProcess() override;
0071
0072     //// ACCESSORS ////
0073
0074     //! Get the shared params associated with this TM
0075     SharedParams const* shared_params() const { return shared_; }
0076
0077     // Get the local transporter associated with the current thread ID
0078     LocalTransporter* get_local_transporter() const;
0079
0080   private:
0081     SharedParams const* shared_{nullptr};
0082     LocalTransporterFromThread get_local_{};
0083 };
0084
0085 //---------------------------------------------------------------------------//
0086 }  // namespace celeritas