Merge pull request #6040 from nilsdeppe/add_threading_15

Add ElementLocationsReference tag, and TransformPdalForNodegroup metafunction

src/Parallel/ArrayCollection/CMakeLists.txt

@@ -14,6 +14,7 @@ spectre_target_headers(
   SetTerminateOnElement.hpp
   SpawnInitializeElementsInCollection.hpp
   StartPhaseOnNodegroup.hpp
+  TransformPdalForNodegroup.hpp
 )
 
 spectre_target_sources(

src/Parallel/ArrayCollection/Tags/CMakeLists.txt

@@ -7,5 +7,6 @@ spectre_target_headers(
   HEADERS
   ElementCollection.hpp
   ElementLocations.hpp
+  ElementLocationsReference.hpp
   NumberOfElementsTerminated.hpp
   )

src/Parallel/ArrayCollection/Tags/ElementLocations.hpp

@@ -21,13 +21,4 @@ template <size_t Dim>
 struct ElementLocations : db::SimpleTag {
   using type = std::unordered_map<ElementId<Dim>, size_t>;
 };
-
-/// \brief The node (location) where different elements are.
-///
-/// This should be in the DgElementArrayMember's DataBox and should point to
-/// the one located in the nodegroup's DataBox.
-template <size_t Dim>
-struct ElementLocationsPointer : db::SimpleTag {
-  using type = std::unordered_map<ElementId<Dim>, size_t>*;
-};
 }  // namespace Parallel::Tags

src/Parallel/ArrayCollection/Tags/ElementLocationsReference.hpp

@@ -0,0 +1,59 @@
+// Distributed under the MIT License.
+// See LICENSE.txt for details.
+
+#pragma once
+
+#include <cstddef>
+#include <unordered_map>
+
+#include "DataStructures/DataBox/Tag.hpp"
+#include "Parallel/ArrayCollection/Tags/ElementLocations.hpp"
+#include "Parallel/GlobalCache.hpp"
+#include "Parallel/Invoke.hpp"
+#include "Utilities/Gsl.hpp"
+
+/// \cond
+template <size_t Dim>
+class ElementId;
+namespace Parallel {
+class NodeLock;
+}  // namespace Parallel
+/// \endcond
+
+namespace Parallel::Tags {
+/// \brief The node (location) where different elements are.
+///
+/// This should be in the DgElementArrayMember's DataBox.
+///
+/// Implementation note: This should point to the ElementLocations located in
+/// the nodegroup's DataBox.
+template <size_t Dim, typename Metavariables,
+          typename DgElementCollectionComponent>
+struct ElementLocationsReference : ElementLocations<Dim>, db::ReferenceTag {
+ private:
+  struct GetReference {
+    using return_type = const typename ElementLocations<Dim>::type&;
+
+    template <typename ParallelComponent, typename DbTagList>
+    static return_type apply(
+        db::DataBox<DbTagList>& box,
+        const gsl::not_null<Parallel::NodeLock*> /*node_lock*/) {
+      return db::get_mutable_reference<ElementLocations<Dim>>(
+          make_not_null(&box));
+    }
+  };
+
+ public:
+  using base = ElementLocations<Dim>;
+  using type = typename base::type;
+  using argument_tags =
+      tmpl::list<Parallel::Tags::GlobalCacheImpl<Metavariables>>;
+
+  static const type& get(
+      const Parallel::GlobalCache<Metavariables>* const& cache) {
+    auto& parallel_comp =
+        Parallel::get_parallel_component<DgElementCollectionComponent>(*cache);
+    return Parallel::local_synchronous_action<GetReference>(parallel_comp);
+  }
+};
+}  // namespace Parallel::Tags

src/Parallel/ArrayCollection/TransformPdalForNodegroup.hpp

@@ -0,0 +1,29 @@
+// Distributed under the MIT License.
+// See LICENSE.txt for details.
+
+#pragma once
+
+#include "Parallel/ArrayCollection/StartPhaseOnNodegroup.hpp"
+#include "Parallel/Phase.hpp"
+#include "Parallel/PhaseDependentActionList.hpp"
+#include "Utilities/TMPL.hpp"
+
+namespace Parallel {
+namespace detail {
+template <typename OnePhaseActions>
+struct TransformPdalForNodegroup {
+  using type = tmpl::conditional_t<
+      OnePhaseActions::phase == Parallel::Phase::Initialization, tmpl::list<>,
+      Parallel::PhaseActions<OnePhaseActions::phase,
+                             tmpl::list<Actions::StartPhaseOnNodegroup>>>;
+};
+}  // namespace detail
+
+/// \brief Transforms the `PhaseDepActionList` (phase dependent action
+/// list/PDAL) from one used for a `evolution::DgElementArray` to that for
+/// `Parallel::DgElementCollection`
+template <typename PhaseDepActionList>
+using TransformPhaseDependentActionListForNodegroup =
+    tmpl::flatten<tmpl::transform<PhaseDepActionList,
+                                  detail::TransformPdalForNodegroup<tmpl::_1>>>;
+}  // namespace Parallel

tests/Unit/Parallel/ArrayCollection/Test_Tags.cpp

@@ -8,6 +8,7 @@
 #include "Helpers/DataStructures/DataBox/TestHelpers.hpp"
 #include "Parallel/ArrayCollection/Tags/ElementCollection.hpp"
 #include "Parallel/ArrayCollection/Tags/ElementLocations.hpp"
+#include "Parallel/ArrayCollection/Tags/ElementLocationsReference.hpp"
 #include "Parallel/ArrayCollection/Tags/NumberOfElementsTerminated.hpp"
 
 namespace Parallel {
@@ -16,8 +17,8 @@ SPECTRE_TEST_CASE("Unit.Parallel.ArrayCollection.Tags", "[Unit][Parallel]") {
       Tags::ElementCollection<3, void, void, void>>("ElementCollection");
   TestHelpers::db::test_simple_tag<Tags::ElementLocations<3>>(
       "ElementLocations");
-  TestHelpers::db::test_simple_tag<Tags::ElementLocationsPointer<3>>(
-      "ElementLocationsPointer");
+  TestHelpers::db::test_reference_tag<
+      Tags::ElementLocationsReference<3, void, void>>("ElementLocations");
   TestHelpers::db::test_simple_tag<Tags::NumberOfElementsTerminated>(
       "NumberOfElementsTerminated");
 }