Update Kokkos library in LAMMPS to v4.2

lib/kokkos/core/src/Serial/Kokkos_Serial.cpp

@@ -145,6 +145,12 @@ Serial::Serial()
     : m_space_instance(&Impl::SerialInternal::singleton(),
                        [](Impl::SerialInternal*) {}) {}
 
+Serial::Serial(NewInstance)
+    : m_space_instance(new Impl::SerialInternal, [](Impl::SerialInternal* ptr) {
+        ptr->finalize();
+        delete ptr;
+      }) {}
+
 void Serial::print_configuration(std::ostream& os, bool /*verbose*/) const {
   os << "Host Serial Execution Space:\n";
   os << "  KOKKOS_ENABLE_SERIAL: yes\n";

lib/kokkos/core/src/Serial/Kokkos_Serial.hpp

@@ -72,6 +72,10 @@ class SerialInternal {
 };
 }  // namespace Impl
 
+struct NewInstance {
+  explicit NewInstance() = default;
+};
+
 /// \class Serial
 /// \brief Kokkos device for non-parallel execution
 ///
@@ -108,6 +112,8 @@ class Serial {
 
   Serial();
 
+  Serial(NewInstance);
+
   /// \brief True if and only if this method is being called in a
   ///   thread-parallel function.
   ///
@@ -218,6 +224,38 @@ struct MemorySpaceAccess<Kokkos::Serial::memory_space,
 }  // namespace Impl
 }  // namespace Kokkos
 
+namespace Kokkos::Experimental {
+
+template <class... Args>
+std::vector<Serial> partition_space(const Serial&, Args...) {
+  static_assert(
+      (... && std::is_arithmetic_v<Args>),
+      "Kokkos Error: partitioning arguments must be integers or floats");
+  std::vector<Serial> instances;
+  instances.reserve(sizeof...(Args));
+  std::generate_n(std::back_inserter(instances), sizeof...(Args),
+                  []() { return Serial{NewInstance{}}; });
+  return instances;
+}
+
+template <class T>
+std::vector<Serial> partition_space(const Serial&,
+                                    std::vector<T> const& weights) {
+  static_assert(
+      std::is_arithmetic<T>::value,
+      "Kokkos Error: partitioning arguments must be integers or floats");
+
+  // We only care about the number of instances to create and ignore weights
+  // otherwise.
+  std::vector<Serial> instances;
+  instances.reserve(weights.size());
+  std::generate_n(std::back_inserter(instances), weights.size(),
+                  []() { return Serial{NewInstance{}}; });
+  return instances;
+}
+
+}  // namespace Kokkos::Experimental
+
 #include <Serial/Kokkos_Serial_Parallel_Range.hpp>
 #include <Serial/Kokkos_Serial_Parallel_MDRange.hpp>
 #include <Serial/Kokkos_Serial_Parallel_Team.hpp>