Refactor ParticleState and ParticleParams to SoA (celeritas-project#1012

) * Refactor ParticleState and ParticleParams to SoA * Removed ParticleRecord * rename enum * rename particleparams data member * change underlying type of MatterType, support Quantity for LdgSpan, use LdgSpan as collection storage when possible * Move stable_decal_constant to celeritas::constants --------- Co-authored-by: Seth R. Johnson <johnsonsr@ornl.gov>
sethrj · Nov 20, 2023 · 5de4bb9 · 5de4bb9
1 parent 82e9d34
commit 5de4bb9
Show file tree

Hide file tree

Showing 22 changed files with 246 additions and 151 deletions.
diff --git a/app/demo-interactor/demo-interactor.cc b/app/demo-interactor/demo-interactor.cc
@@ -41,16 +41,16 @@ namespace
 std::shared_ptr<ParticleParams> load_params()
 {
     using namespace celeritas::units;
+    using namespace constants;
     constexpr auto zero = zero_quantity();
-    constexpr auto stable = ParticleRecord::stable_decay_constant();
-
-    return std::make_shared<ParticleParams>(
-        ParticleParams::Input{{"electron",
-                               pdg::electron(),
-                               MevMass{0.5109989461},
-                               ElementaryCharge{-1},
-                               stable},
-                              {"gamma", pdg::gamma(), zero, zero, stable}});
+
+    return std::make_shared<ParticleParams>(ParticleParams::Input{
+        {"electron",
+         pdg::electron(),
+         MevMass{0.5109989461},
+         ElementaryCharge{-1},
+         stable_decay_constant},
+        {"gamma", pdg::gamma(), zero, zero, stable_decay_constant}});
 }
 
 //---------------------------------------------------------------------------//

diff --git a/app/demo-interactor/host-demo-interactor.cc b/app/demo-interactor/host-demo-interactor.cc
@@ -50,16 +50,16 @@ namespace app
 std::shared_ptr<ParticleParams> load_params()
 {
     using namespace celeritas::units;
+    using namespace constants;
     constexpr auto zero = zero_quantity();
-    constexpr auto stable = ParticleRecord::stable_decay_constant();
 
-    return std::make_shared<ParticleParams>(
-        ParticleParams::Input{{"electron",
-                               pdg::electron(),
-                               MevMass{0.5109989461},
-                               ElementaryCharge{-1},
-                               stable},
-                              {"gamma", pdg::gamma(), zero, zero, stable}});
+    return std::make_shared<ParticleParams>(ParticleParams::Input{
+        {"electron",
+         pdg::electron(),
+         MevMass{0.5109989461},
+         ElementaryCharge{-1},
+         stable_decay_constant},
+        {"gamma", pdg::gamma(), zero, zero, stable_decay_constant}});
 }
 
 //---------------------------------------------------------------------------//

diff --git a/src/celeritas/Constants.hh b/src/celeritas/Constants.hh
@@ -39,6 +39,7 @@ namespace constants
  * r_electron           | classic_electr_radius   | Classical electron radius
  * kcd_luminous         | [none]                  | Lumens per Watt
  * lambdabar_electron   | electron_Compton_length | Reduced Compton wavelength
+ * stable_decay_constant| [none]                  | Decay for a stable particle
  *
  * Some experimental physical constants are derived from the other physical
  * constants, but for consistency and clarity they are presented numerically
@@ -81,6 +82,10 @@ CELER_ICRT eh_hartree = 4.3597447222071e-18 / units::meter;
 CELER_ICRT lambdabar_electron = 3.8615926796e-13 * units::meter;
 //!@}
 
+//!@{
+//! \name Other constants
+CELER_ICRT stable_decay_constant = 0;
+//!@}
 #undef CELER_ICRT
 
 //---------------------------------------------------------------------------//

diff --git a/src/celeritas/phys/ParticleData.hh b/src/celeritas/phys/ParticleData.hh
@@ -19,36 +19,21 @@ namespace celeritas
 //---------------------------------------------------------------------------//
 // PARAMS
 //---------------------------------------------------------------------------//
-/*!
- * Fundamental (static) properties of a particle type.
- *
- * These should only be fundamental physical properties. Setting particles is
- * done through the ParticleParams. Physical state of a particle
- * (kinetic energy, ...) is part of a ParticleState.
- *
- * Particle definitions are accessed via the ParticleParams: using PDGs
- * to look up particle IDs, etc.
- */
-struct ParticleRecord
-{
-    units::MevMass mass;  //!< Rest mass [MeV / c^2]
-    units::ElementaryCharge charge;  //!< Charge in units of [e]
-    real_type decay_constant;  //!< Decay constant [1/s]
-    bool is_antiparticle;  //!< Antiparticle (negative PDG number)
 
-    //! Value of decay_constant for a stable particle
-    static CELER_CONSTEXPR_FUNCTION real_type stable_decay_constant()
-    {
-        return 0;
-    }
+enum class MatterType : char
+{
+    particle,
+    antiparticle
 };
 
 //---------------------------------------------------------------------------//
 /*!
  * Access particle definitions on the device.
  *
- * This view is created from \c ParticleParams. The size of the \c defs data
- * member is the number of particle types (accessed by \c ParticleId).
+ * Fundamental (static) properties of a particle type. Physical state of a
+ * particle (kinetic energy, ...) is part of a ParticleState. This view is
+ * created from \c ParticleParams. The size of the \c defs data member is the
+ * number of particle types (accessed by \c ParticleId).
  *
  * \sa ParticleParams (owns the pointed-to data)
  * \sa ParticleTrackView (uses the pointed-to data in a kernel)
@@ -59,26 +44,40 @@ struct ParticleParamsData
     //// TYPES ////
 
     template<class T>
-    using Items = celeritas::Collection<T, W, M>;
+    using Items = celeritas::Collection<T, W, M, ParticleId>;
 
     //// DATA ////
 
-    Items<ParticleRecord> particles;
+    Items<units::MevMass> mass;  //!< Rest mass [MeV / c^2]
+    Items<units::ElementaryCharge> charge;  //!< Charge in units of [e]
+    Items<real_type> decay_constant;  //!< Decay constant [1/s]
+    Items<MatterType> matter;  //!< Antiparticle (negative PDG
+                               //!< number)
 
     //// METHODS ////
 
     //! Whether the data is assigned
     explicit CELER_FUNCTION operator bool() const
     {
-        return !particles.empty();
+        return !mass.empty() && !charge.empty() && !decay_constant.empty()
+               && !matter.empty();
+    }
+
+    //! Params size
+    CELER_FUNCTION typename Items<real_type>::size_type size() const
+    {
+        return decay_constant.size();
     }
 
     //! Assign from another set of data
     template<Ownership W2, MemSpace M2>
     ParticleParamsData& operator=(ParticleParamsData<W2, M2> const& other)
     {
         CELER_EXPECT(other);
-        particles = other.particles;
+        mass = other.mass;
+        charge = other.charge;
+        decay_constant = other.decay_constant;
+        matter = other.matter;
         return *this;
     }
 };
@@ -98,11 +97,6 @@ struct ParticleParamsData
  * immutable: collisions and other interactions should return changes to the
  * particle state.
  */
-struct ParticleTrackState
-{
-    ParticleId particle_id;  //!< Type of particle (electron, gamma, ...)
-    real_type energy;  //!< Kinetic energy [MeV]
-};
 
 struct ParticleTrackInitializer
 {
@@ -132,22 +126,31 @@ struct ParticleStateData
 
     //// DATA ////
 
-    Items<ParticleTrackState> state;
+    Items<ParticleId> particle_id;  //!< Type of particle (electron, gamma,
+                                    //!< ...)
+    Items<real_type> particle_energy;  //!< Kinetic energy [MeV]
 
     //// METHODS ////
 
     //! Whether the interface is assigned
-    explicit CELER_FUNCTION operator bool() const { return !state.empty(); }
+    explicit CELER_FUNCTION operator bool() const
+    {
+        return !particle_id.empty() && !particle_energy.empty();
+    }
 
     //! State size
-    CELER_FUNCTION TrackSlotId::size_type size() const { return state.size(); }
+    CELER_FUNCTION TrackSlotId::size_type size() const
+    {
+        return particle_id.size();
+    }
 
     //! Assign from another set of data
     template<Ownership W2, MemSpace M2>
     ParticleStateData& operator=(ParticleStateData<W2, M2>& other)
     {
         CELER_EXPECT(other);
-        state = other.state;
+        particle_id = other.particle_id;
+        particle_energy = other.particle_energy;
         return *this;
     }
 };
@@ -162,7 +165,8 @@ inline void resize(ParticleStateData<Ownership::value, M>* data,
                    size_type size)
 {
     CELER_EXPECT(size > 0);
-    resize(&data->state, size);
+    resize(&data->particle_id, size);
+    resize(&data->particle_energy, size);
 }
 
 //---------------------------------------------------------------------------//

diff --git a/src/celeritas/phys/ParticleParams.cc b/src/celeritas/phys/ParticleParams.cc
@@ -47,7 +47,7 @@ ParticleParams::from_import(ImportData const& data)
         defs[i].mass = units::MevMass(particle.mass);
         defs[i].charge = units::ElementaryCharge(particle.charge);
         defs[i].decay_constant = (particle.is_stable
-                                      ? ParticleRecord::stable_decay_constant()
+                                      ? constants::stable_decay_constant
                                       : 1. / particle.lifetime);
     }
 
@@ -82,8 +82,14 @@ ParticleParams::ParticleParams(Input const& input)
 
     // Build elements and materials on host.
     HostVal<ParticleParamsData> host_data;
-    auto particles = make_builder(&host_data.particles);
-    particles.reserve(input.size());
+    auto mass = make_builder(&host_data.mass);
+    auto charge = make_builder(&host_data.charge);
+    auto decay_constant = make_builder(&host_data.decay_constant);
+    auto matter = make_builder(&host_data.matter);
+    mass.reserve(input.size());
+    charge.reserve(input.size());
+    decay_constant.reserve(input.size());
+    matter.reserve(input.size());
 
     for (auto const& particle : input)
     {
@@ -105,12 +111,11 @@ ParticleParams::ParticleParams(Input const& input)
         md_.push_back({particle.name, particle.pdg_code});
 
         // Save the definitions on the host
-        ParticleRecord host_def;
-        host_def.mass = particle.mass;
-        host_def.charge = particle.charge;
-        host_def.decay_constant = particle.decay_constant;
-        host_def.is_antiparticle = particle.pdg_code.get() < 0;
-        particles.push_back(std::move(host_def));
+        mass.push_back(particle.mass);
+        charge.push_back(particle.charge);
+        decay_constant.push_back(particle.decay_constant);
+        matter.push_back(particle.pdg_code.get() < 0 ? MatterType::antiparticle
+                                                     : MatterType::particle);
     }
 
     // Move to mirrored data, copying to device
@@ -119,7 +124,7 @@ ParticleParams::ParticleParams(Input const& input)
     CELER_ENSURE(md_.size() == input.size());
     CELER_ENSURE(name_to_id_.size() == input.size());
     CELER_ENSURE(pdg_to_id_.size() == input.size());
-    CELER_ENSURE(this->host_ref().particles.size() == input.size());
+    CELER_ENSURE(this->host_ref().size() == input.size());
 }
 
 //---------------------------------------------------------------------------//
@@ -128,7 +133,7 @@ ParticleParams::ParticleParams(Input const& input)
  */
 ParticleView ParticleParams::get(ParticleId id) const
 {
-    CELER_EXPECT(id < this->host_ref().particles.size());
+    CELER_EXPECT(id < this->host_ref().size());
     return ParticleView(this->host_ref(), id);
 }
 

diff --git a/src/celeritas/phys/ParticleTrackView.hh b/src/celeritas/phys/ParticleTrackView.hh
@@ -134,10 +134,10 @@ ParticleTrackView::ParticleTrackView(ParticleParamsRef const& params,
 CELER_FUNCTION ParticleTrackView&
 ParticleTrackView::operator=(Initializer_t const& other)
 {
-    CELER_EXPECT(other.particle_id < params_.particles.size());
+    CELER_EXPECT(other.particle_id < params_.size());
     CELER_EXPECT(other.energy >= zero_quantity());
-    states_.state[track_slot_].particle_id = other.particle_id;
-    states_.state[track_slot_].energy = other.energy.value();
+    states_.particle_id[track_slot_] = other.particle_id;
+    states_.particle_energy[track_slot_] = other.energy.value();
     return *this;
 }
 
@@ -153,7 +153,7 @@ void ParticleTrackView::energy(Energy quantity)
 {
     CELER_EXPECT(this->particle_id());
     CELER_EXPECT(quantity >= zero_quantity());
-    states_.state[track_slot_].energy = quantity.value();
+    states_.particle_energy[track_slot_] = quantity.value();
 }
 
 //---------------------------------------------------------------------------//
@@ -165,7 +165,7 @@ CELER_FUNCTION void ParticleTrackView::subtract_energy(Energy eloss)
     CELER_EXPECT(eloss >= zero_quantity());
     CELER_EXPECT(eloss <= this->energy());
     // TODO: save a read/write by only saving if eloss is positive?
-    states_.state[track_slot_].energy -= eloss.value();
+    states_.particle_energy[track_slot_] -= eloss.value();
 }
 
 //---------------------------------------------------------------------------//
@@ -176,7 +176,7 @@ CELER_FUNCTION void ParticleTrackView::subtract_energy(Energy eloss)
  */
 CELER_FUNCTION ParticleId ParticleTrackView::particle_id() const
 {
-    return states_.state[track_slot_].particle_id;
+    return states_.particle_id[track_slot_];
 }
 
 //---------------------------------------------------------------------------//
@@ -185,7 +185,7 @@ CELER_FUNCTION ParticleId ParticleTrackView::particle_id() const
  */
 CELER_FUNCTION auto ParticleTrackView::energy() const -> Energy
 {
-    return Energy{states_.state[track_slot_].energy};
+    return Energy{states_.particle_energy[track_slot_]};
 }
 
 //---------------------------------------------------------------------------//
@@ -205,7 +205,7 @@ CELER_FUNCTION bool ParticleTrackView::is_stopped() const
  */
 CELER_FUNCTION ParticleView ParticleTrackView::particle_view() const
 {
-    return ParticleView(params_, states_.state[track_slot_].particle_id);
+    return ParticleView(params_, states_.particle_id[track_slot_]);
 }
 
 //---------------------------------------------------------------------------//
@@ -250,7 +250,7 @@ CELER_FUNCTION bool ParticleTrackView::is_antiparticle() const
  */
 CELER_FUNCTION bool ParticleTrackView::is_stable() const
 {
-    return this->decay_constant() == ParticleRecord::stable_decay_constant();
+    return this->decay_constant() == constants::stable_decay_constant;
 }
 
 //---------------------------------------------------------------------------//

diff --git a/src/celeritas/phys/ParticleView.hh b/src/celeritas/phys/ParticleView.hh
@@ -60,7 +60,7 @@ CELER_FUNCTION
 ParticleView::ParticleView(ParticleParamsRef const& params, ParticleId id)
     : params_(params), particle_(id)
 {
-    CELER_EXPECT(particle_ < params_.particles.size());
+    CELER_EXPECT(particle_ < params_.size());
 }
 
 //---------------------------------------------------------------------------//
@@ -78,7 +78,7 @@ CELER_FUNCTION ParticleId ParticleView::particle_id() const
  */
 CELER_FUNCTION units::MevMass ParticleView::mass() const
 {
-    return params_.particles[particle_].mass;
+    return params_.mass[particle_];
 }
 
 //---------------------------------------------------------------------------//
@@ -87,7 +87,7 @@ CELER_FUNCTION units::MevMass ParticleView::mass() const
  */
 CELER_FUNCTION units::ElementaryCharge ParticleView::charge() const
 {
-    return params_.particles[particle_].charge;
+    return params_.charge[particle_];
 }
 
 //---------------------------------------------------------------------------//
@@ -96,7 +96,7 @@ CELER_FUNCTION units::ElementaryCharge ParticleView::charge() const
  */
 CELER_FUNCTION real_type ParticleView::decay_constant() const
 {
-    return params_.particles[particle_].decay_constant;
+    return params_.decay_constant[particle_];
 }
 
 //---------------------------------------------------------------------------//
@@ -105,7 +105,7 @@ CELER_FUNCTION real_type ParticleView::decay_constant() const
  */
 CELER_FUNCTION bool ParticleView::is_antiparticle() const
 {
-    return params_.particles[particle_].is_antiparticle;
+    return params_.matter[particle_] == MatterType::antiparticle;
 }
 
 //---------------------------------------------------------------------------//