TrackingRecHitSoA/interface/TrackingRecHitsDevice.h

0001 #ifndef DataFormats_TrackingRecHitSoA_interface_TrackingRecHitSoADevice_h
0002 #define DataFormats_TrackingRecHitSoA_interface_TrackingRecHitSoADevice_h
0003
0004 #include <cstdint>
0005
0006 #include <alpaka/alpaka.hpp>
0007
0008 #include "DataFormats/Common/interface/Uninitialized.h"
0009 #include "DataFormats/Portable/interface/PortableDeviceCollection.h"
0010 #include "DataFormats/TrackingRecHitSoA/interface/TrackingRecHitsHost.h"
0011 #include "DataFormats/TrackingRecHitSoA/interface/TrackingRecHitsSoA.h"
0012 #include "DataFormats/SiPixelClusterSoA/interface/SiPixelClustersDevice.h"
0013
0014 // TODO: The class is created via inheritance of the PortableCollection.
0015 // This is generally discouraged, and should be done via composition.
0016 // See: https://github.com/cms-sw/cmssw/pull/40465#discussion_r1067364306
0017
0018 namespace reco {
0019
0020   template <typename TDev>
0021   using HitPortableCollectionDevice = PortableDeviceMultiCollection<TDev, reco::TrackingRecHitSoA, reco::HitModuleSoA>;
0022
0023   template <typename TDev>
0024   class TrackingRecHitDevice : public HitPortableCollectionDevice<TDev> {
0025   public:
0026     TrackingRecHitDevice() = default;
0027
0028     TrackingRecHitDevice(edm::Uninitialized) : HitPortableCollectionDevice<TDev>{edm::kUninitialized} {}
0029
0030     // Constructor which specifies only the SoA size, to be used when copying the results from host to device
0031     template <typename TQueue>
0032     explicit TrackingRecHitDevice(TQueue queue, uint32_t nHits, uint32_t nModules)
0033         : HitPortableCollectionDevice<TDev>({{int(nHits), int(nModules + 1)}}, queue) {}
0034
0035     // N.B. why this + 1? Because the HitModulesLayout is holding the
0036     // moduleStart vector that is a cumulative sum of all the hits
0037     // in each module. The extra element of the array (the last one)
0038     // is used to hold the total number of hits. We are "hiding" this
0039     // in the constructor so that one can build the TrackingRecHit class
0040     // in a more natural way, just using the number of needed modules.
0041
0042     // Constructor from clusters
0043     template <typename TQueue>
0044     explicit TrackingRecHitDevice(TQueue queue, SiPixelClustersDevice<TDev> const &clusters)
0045         : HitPortableCollectionDevice<TDev>({{int(clusters.nClusters()), clusters.view().metadata().size()}}, queue),
0046           offsetBPIX2_{clusters.offsetBPIX2()} {
0047       auto hitsView = this->template view<TrackingRecHitSoA>();
0048       auto modsView = this->template view<HitModuleSoA>();
0049
0050       auto nModules = clusters.view().metadata().size();
0051
0052       auto clusters_m = cms::alpakatools::make_device_view(queue, clusters.view().clusModuleStart(), nModules);
0053       auto hits_m = cms::alpakatools::make_device_view(queue, modsView.moduleStart(), nModules);
0054
0055       alpaka::memcpy(queue, hits_m, clusters_m);
0056
0057       auto off_h = cms::alpakatools::make_host_view(offsetBPIX2_);
0058       auto off_d = cms::alpakatools::make_device_view(queue, hitsView.offsetBPIX2());
0059       alpaka::memcpy(queue, off_d, off_h);
0060     }
0061
0062     uint32_t nHits() const { return this->template view<TrackingRecHitSoA>().metadata().size(); }
0063     uint32_t nModules() const { return this->template view<HitModuleSoA>().metadata().size() - 1; }
0064
0065     int32_t offsetBPIX2() const { return offsetBPIX2_; }
0066
0067     // asynchronously update the information cached within the class itself from the information on the device
0068     template <typename TQueue>
0069     void updateFromDevice(TQueue queue) {
0070       auto off_h = cms::alpakatools::make_host_view(offsetBPIX2_);
0071       auto off_d = cms::alpakatools::make_device_view(queue, this->template view<TrackingRecHitSoA>().offsetBPIX2());
0072       alpaka::memcpy(queue, off_h, off_d);
0073     }
0074
0075   private:
0076     // offsetBPIX2 is used on host functions so is useful to have it also stored in the class and not only in the layout
0077     int32_t offsetBPIX2_ = 0;
0078   };
0079 }  // namespace reco
0080
0081 #endif  // DataFormats_RecHits_interface_TrackingRecHitSoADevice_h