Thread ID Cleanup, main branch (2025.01.09.) (acts-project#810)

* Harmonized the different thread_id classes with each other.

Made all of them into "private headers", and added automated tests that they
would fulfill the appropriate concept.

* Synchronized how thread IDs would be used in the device functions.

While also cleaning up the includes of the files a bit.

* Call device functions consistently from CUDA.

* Call device functions consistently from SYCL.

* Implement (some of) Stephen's suggestions.

Author: krasznaa

device/alpaka/include/traccc/alpaka/utils/thread_id.hpp

@@ -1,6 +1,6 @@
 /** TRACCC library, part of the ACTS project (R&D line)
  *
- * (c) 2024 CERN for the benefit of the ACTS project
+ * (c) 2024-2025 CERN for the benefit of the ACTS project
  *
  * Mozilla Public License Version 2.0
  */
@@ -9,10 +9,10 @@
 #include "traccc/alpaka/clusterization/clusterization_algorithm.hpp"
 
 #include "../utils/barrier.hpp"
+#include "../utils/thread_id.hpp"
 #include "../utils/utils.hpp"
 
 // Project include(s)
-#include "traccc/alpaka/utils/thread_id.hpp"
 #include "traccc/clusterization/clustering_config.hpp"
 #include "traccc/clusterization/device/ccl_kernel.hpp"
 
@@ -36,7 +36,7 @@ struct CCLKernel {
         measurement_collection_types::view measurements_view,
         vecmem::data::vector_view<unsigned int> cell_links) const {
 
-        traccc::alpaka::thread_id1 thread_id(acc);
+        details::thread_id1 thread_id(acc);
 
         auto& partition_start =
             ::alpaka::declareSharedVar<std::size_t, __COUNTER__>(acc);

device/alpaka/src/clusterization/clusterization_algorithm.cpp

@@ -0,0 +1,69 @@
+/**
+ * traccc library, part of the ACTS project (R&D line)
+ *
+ * (c) 2024-2025 CERN for the benefit of the ACTS project
+ *
+ * Mozilla Public License Version 2.0
+ */
+
+#pragma once
+
+// Local include(s).
+#include "utils.hpp"
+
+// Project include(s).
+#include "traccc/definitions/qualifiers.hpp"
+#include "traccc/device/concepts/thread_id.hpp"
+
+// Alpaka include(s).
+#include <alpaka/alpaka.hpp>
+
+namespace traccc::alpaka::details {
+
+/// An Alpaka thread identifier type
+template <typename Acc>
+struct thread_id1 {
+    TRACCC_HOST_DEVICE explicit thread_id1(const Acc& acc) : m_acc(acc) {}
+
+    unsigned int inline TRACCC_HOST_DEVICE getLocalThreadId() const {
+        return static_cast<unsigned int>(
+            ::alpaka::getIdx<::alpaka::Block, ::alpaka::Threads>(m_acc)[0u]);
+    }
+
+    unsigned int inline TRACCC_HOST_DEVICE getLocalThreadIdX() const {
+        return getLocalThreadId();
+    }
+
+    unsigned int inline TRACCC_HOST_DEVICE getGlobalThreadId() const {
+        return getLocalThreadId() + getBlockIdX() * getBlockDimX();
+    }
+
+    unsigned int inline TRACCC_HOST_DEVICE getGlobalThreadIdX() const {
+        return getLocalThreadId() + getBlockIdX() * getBlockDimX();
+    }
+
+    unsigned int inline TRACCC_HOST_DEVICE getBlockIdX() const {
+        return static_cast<unsigned int>(
+            ::alpaka::getIdx<::alpaka::Grid, ::alpaka::Blocks>(m_acc)[0u]);
+    }
+
+    unsigned int inline TRACCC_HOST_DEVICE getBlockDimX() const {
+        return static_cast<unsigned int>(
+            ::alpaka::getWorkDiv<::alpaka::Block, ::alpaka::Threads>(
+                m_acc)[0u]);
+    }
+
+    unsigned int inline TRACCC_HOST_DEVICE getGridDimX() const {
+        return static_cast<unsigned int>(
+            ::alpaka::getWorkDiv<::alpaka::Grid, ::alpaka::Blocks>(m_acc)[0u]);
+    }
+
+    private:
+    const Acc& m_acc;
+};
+
+/// Verify that @c traccc::alpaka::details::thread_id1 fulfills the
+/// @c traccc::device::concepts::thread_id1 concept.
+static_assert(traccc::device::concepts::thread_id1<thread_id1<Acc>>);
+
+}  // namespace traccc::alpaka::details

device/alpaka/src/utils/thread_id.hpp

@@ -1,6 +1,6 @@
 /** TRACCC library, part of the ACTS project (R&D line)
  *
- * (c) 2022-2024 CERN for the benefit of the ACTS project
+ * (c) 2022-2025 CERN for the benefit of the ACTS project
  *
  * Mozilla Public License Version 2.0
  */
@@ -254,8 +254,7 @@ TRACCC_DEVICE inline void ccl_kernel(
      */
     if (thread_id.getLocalThreadIdX() == 0) {
         unsigned int start =
-            static_cast<unsigned int>(thread_id.getBlockIdX()) *
-            cfg.target_partition_size();
+            thread_id.getBlockIdX() * cfg.target_partition_size();
         assert(start < num_cells);
         unsigned int end =
             std::min(num_cells, start + cfg.target_partition_size());

device/common/include/traccc/clusterization/device/impl/ccl_kernel.ipp

@@ -7,11 +7,13 @@
 
 #pragma once
 
+// Local include(s).
+#include "traccc/device/concepts/barrier.hpp"
+#include "traccc/device/concepts/thread_id.hpp"
+
 // Project include(s).
 #include "traccc/definitions/primitives.hpp"
 #include "traccc/definitions/qualifiers.hpp"
-#include "traccc/device/concepts/barrier.hpp"
-#include "traccc/device/concepts/thread_id.hpp"
 #include "traccc/edm/measurement.hpp"
 #include "traccc/edm/track_parameters.hpp"
 #include "traccc/finding/candidate_link.hpp"
@@ -140,8 +142,8 @@ struct find_tracks_shared_payload {
 template <typename detector_t, concepts::thread_id1 thread_id_t,
           concepts::barrier barrier_t>
 TRACCC_DEVICE inline void find_tracks(
-    thread_id_t& thread_id, barrier_t& barrier, const finding_config& cfg,
-    const find_tracks_payload<detector_t>& payload,
+    const thread_id_t& thread_id, const barrier_t& barrier,
+    const finding_config& cfg, const find_tracks_payload<detector_t>& payload,
     const find_tracks_shared_payload& shared_payload);
 
 }  // namespace traccc::device

device/common/include/traccc/finding/device/find_tracks.hpp

@@ -19,8 +19,8 @@ namespace traccc::device {
 template <typename detector_t, concepts::thread_id1 thread_id_t,
           concepts::barrier barrier_t>
 TRACCC_DEVICE inline void find_tracks(
-    thread_id_t& thread_id, barrier_t& barrier, const finding_config& cfg,
-    const find_tracks_payload<detector_t>& payload,
+    const thread_id_t& thread_id, const barrier_t& barrier,
+    const finding_config& cfg, const find_tracks_payload<detector_t>& payload,
     const find_tracks_shared_payload& shared_payload) {
 
     /*

device/common/include/traccc/finding/device/impl/find_tracks.ipp

@@ -11,7 +11,8 @@
 #include "traccc/utils/particle.hpp"
 
 // Detray include(s).
-#include "detray/utils/tuple.hpp"
+#include "detray/propagator/constrained_step.hpp"
+#include "detray/utils/tuple_helpers.hpp"
 
 namespace traccc::device {
 

device/common/include/traccc/finding/device/impl/propagate_to_next_surface.ipp

@@ -14,6 +14,7 @@
 #include "traccc/definitions/qualifiers.hpp"
 #include "traccc/edm/track_parameters.hpp"
 #include "traccc/finding/candidate_link.hpp"
+#include "traccc/finding/finding_config.hpp"
 
 // VecMem include(s).
 #include <vecmem/containers/data/vector_view.hpp>

device/common/include/traccc/finding/device/propagate_to_next_surface.hpp

@@ -1,18 +1,18 @@
 /** TRACCC library, part of the ACTS project (R&D line)
  *
- * (c) 2024 CERN for the benefit of the ACTS project
+ * (c) 2024-2025 CERN for the benefit of the ACTS project
  *
  * Mozilla Public License Version 2.0
  */
 
 #pragma once
 
-// Project include(s).
+// Local include(s).
+#include "traccc/device/global_index.hpp"
 #include "traccc/edm/device/sort_key.hpp"
-#include "traccc/edm/track_candidate.hpp"
 
-// System include(s).
-#include <cstddef>
+// Project include(s).
+#include "traccc/edm/track_candidate.hpp"
 
 namespace traccc::device {
 
@@ -24,7 +24,7 @@ namespace traccc::device {
 /// @param[out] ids_view     The param ids
 ///
 TRACCC_HOST_DEVICE inline void fill_sort_keys(
-    std::size_t globalIndex,
+    global_index_t globalIndex,
     const track_candidate_container_types::const_view& track_candidates_view,
     vecmem::data::vector_view<device::sort_key> keys_view,
     vecmem::data::vector_view<unsigned int> ids_view);

device/common/include/traccc/fitting/device/fill_sort_keys.hpp

@@ -1,20 +1,20 @@
 /** TRACCC library, part of the ACTS project (R&D line)
  *
- * (c) 2022 CERN for the benefit of the ACTS project
+ * (c) 2022-2025 CERN for the benefit of the ACTS project
  *
  * Mozilla Public License Version 2.0
  */
 
 #pragma once
 
+// Local include(s).
+#include "traccc/device/global_index.hpp"
+
 // Project include(s).
 #include "traccc/definitions/qualifiers.hpp"
 #include "traccc/edm/track_candidate.hpp"
 #include "traccc/edm/track_state.hpp"
 
-// System include(s).
-#include <cstddef>
-
 namespace traccc::device {
 
 /// Function used for fitting a track for a given track candidates
@@ -26,7 +26,7 @@ namespace traccc::device {
 ///
 template <typename fitter_t>
 TRACCC_HOST_DEVICE inline void fit(
-    std::size_t globalIndex,
+    global_index_t globalIndex,
     typename fitter_t::detector_type::view_type det_data,
     const typename fitter_t::bfield_type field_data,
     const typename fitter_t::config_type cfg,