Remove Thrust from the core and common libraries

This commit removes the Thrust dependency from both the core and common
libraries. As a requirement for this, I had to turn the common device
code into a header-only interface library, which is a good idea
regardless. The advantage of this is that it makes it much easier to
manage the dependencies on Thrust.

Author: stephenswat

CMakeLists.txt

@@ -176,8 +176,6 @@ if( TRACCC_SETUP_THRUST )
       add_subdirectory( extern/cccl )
    endif()
 endif()
-add_library( traccc::Thrust INTERFACE IMPORTED )
-target_link_libraries( traccc::Thrust INTERFACE Thrust::Thrust )
 
 # Set up rocThrust.
 option( TRACCC_SETUP_ROCTHRUST

cmake/traccc-config.cmake.in

@@ -54,12 +54,6 @@ if( TRACCC_BUILD_EXAMPLES )
    endif()
 endif()
 
-# Set up the traccc::Thrust target.
-if ( NOT TARGET traccc::Thrust )
-   add_library( traccc::Thrust INTERFACE IMPORTED )
-   target_link_libraries( traccc::Thrust INTERFACE Thrust::Thrust )
-endif()
-
 # Include the file listing all the imported targets and options.
 include( "${traccc_CMAKE_DIR}/traccc-config-targets.cmake" )
 

core/CMakeLists.txt

@@ -115,7 +115,7 @@ traccc_add_library( traccc_core core TYPE SHARED
   "include/traccc/ambiguity_resolution/greedy_ambiguity_resolution_algorithm.hpp"
   "src/ambiguity_resolution/greedy_ambiguity_resolution_algorithm.cpp" )
 target_link_libraries( traccc_core
-  PUBLIC Eigen3::Eigen vecmem::core detray::core detray::detectors traccc::Thrust
+  PUBLIC Eigen3::Eigen vecmem::core detray::core detray::detectors
          traccc::algebra )
 
 # Prevent Eigen from getting confused when building code for a

device/alpaka/CMakeLists.txt

@@ -50,7 +50,13 @@ if(alpaka_ACC_GPU_CUDA_ENABLE)
 thrust_create_target( traccc::cuda_thrust
   HOST CPP
   DEVICE CUDA )
+  target_link_libraries(traccc::cuda_thrust INTERFACE CUDA::cudart)
   list(APPEND PRIVATE_LIBRARIES traccc::cuda_thrust)
+else()
+thrust_create_target (traccc::alpaka_thrust
+  HOST CPP
+  DEVICE CPP )
+  list(APPEND PRIVATE_LIBRARIES traccc::alpaka_thrust)
 endif()
 
 target_link_libraries(traccc_alpaka PUBLIC ${PUBLIC_LIBRARIES} PRIVATE ${PRIVATE_LIBRARIES})

device/common/CMakeLists.txt

@@ -8,12 +8,11 @@
 include( traccc-compiler-options-cpp )
 
 # Declare the traccc::device_common library.
-traccc_add_library( traccc_device_common device_common TYPE SHARED
+traccc_add_library( traccc_device_common device_common TYPE INTERFACE
    # General function(s).
    "include/traccc/device/fill_prefix_sum.hpp"
    "include/traccc/device/impl/fill_prefix_sum.ipp"
    "include/traccc/device/make_prefix_sum_buffer.hpp"
-   "src/make_prefix_sum_buffer.cpp"
    # General algorithm(s).
    "include/traccc/device/container_h2d_copy_alg.hpp"
    "include/traccc/device/impl/container_h2d_copy_alg.ipp"
@@ -80,4 +79,4 @@ traccc_add_library( traccc_device_common device_common TYPE SHARED
    "include/traccc/fitting/device/impl/fill_sort_keys.ipp"
    )
 target_link_libraries( traccc_device_common
-   PUBLIC traccc::Thrust traccc::core vecmem::core )
+   INTERFACE traccc::core vecmem::core )

device/common/include/traccc/device/make_prefix_sum_buffer.hpp

@@ -49,8 +49,41 @@ using prefix_sum_buffer_t = prefix_sum_buffer;
 /// the view elements, and the total summation of the size vector
 ///
 TRACCC_HOST
-prefix_sum_buffer_t make_prefix_sum_buffer(
+inline prefix_sum_buffer_t make_prefix_sum_buffer(
     const std::vector<prefix_sum_size_t>& sizes, vecmem::copy& copy,
-    const traccc::memory_resource& mr);
+    const traccc::memory_resource& mr) {
 
+    if (sizes.size() == 0) {
+        return prefix_sum_buffer_t{
+            vecmem::data::vector_view<prefix_sum_size_t>{},
+            std::variant<vecmem::vector<prefix_sum_size_t>,
+                         vecmem::data::vector_buffer<prefix_sum_size_t>>{},
+            prefix_sum_size_t{0}};
+    }
+
+    // Create vector with summation of sizes
+    vecmem::vector<prefix_sum_size_t> sizes_sum(sizes.size(),
+                                                mr.host ? mr.host : &(mr.main));
+    std::partial_sum(sizes.begin(), sizes.end(), sizes_sum.begin(),
+                     std::plus<prefix_sum_size_t>());
+    const prefix_sum_size_t totalSize = sizes_sum.back();
+
+    if (mr.host != nullptr) {
+        // Create buffer and view objects
+        vecmem::data::vector_buffer<prefix_sum_size_t> sizes_sum_buff(
+            static_cast<unsigned int>(sizes_sum.size()), mr.main);
+        copy.setup(sizes_sum_buff)->ignore();
+        (copy)(vecmem::get_data(sizes_sum), sizes_sum_buff)->wait();
+        vecmem::data::vector_view<prefix_sum_size_t> sizes_sum_view(
+            sizes_sum_buff);
+
+        return {sizes_sum_view, std::move(sizes_sum_buff), totalSize};
+    } else {
+        // Create view object
+        vecmem::data::vector_view<prefix_sum_size_t> sizes_sum_view =
+            vecmem::get_data(sizes_sum);
+
+        return {sizes_sum_view, std::move(sizes_sum), totalSize};
+    }
+}
 }  // namespace traccc::device

device/common/src/make_prefix_sum_buffer.cpp

@@ -112,8 +112,8 @@ target_link_libraries( traccc_cuda
 thrust_create_target( traccc::cuda_thrust
   HOST CPP
   DEVICE CUDA )
-target_link_libraries( traccc_cuda
-  PRIVATE traccc::cuda_thrust )
+target_link_libraries( traccc::cuda_thrust INTERFACE CUDA::cudart )
+target_link_libraries( traccc_cuda PUBLIC traccc::cuda_thrust )
 
 # For CUDA 11 turn on separable compilation. This is necessary for using
 # Thrust 2.1.0.

device/cuda/CMakeLists.txt

@@ -17,6 +17,10 @@ traccc_add_library( traccc_kokkos kokkos TYPE SHARED
   "src/seeding/spacepoint_binning.cpp"
 )
 
+thrust_create_target (traccc::kokkos_thrust
+  HOST CPP
+  DEVICE CPP )
+
 target_link_libraries( traccc_kokkos 
-  PUBLIC traccc::core vecmem::core Kokkos::kokkos
+  PUBLIC traccc::core vecmem::core Kokkos::kokkos traccc::kokkos_thrust
   PRIVATE traccc::device_common )