Line data    Source code

       1            0 : // Distributed under the MIT License.
       2              : // See LICENSE.txt for details.
       3              : 
       4              : #pragma once
       5              : 
       6              : #include <pup.h>
       7              : 
       8              : #include "Options/String.hpp"
       9              : #include "Time/History.hpp"
      10              : #include "Time/StepChoosers/StepChooser.hpp"
      11              : #include "Time/TimeStepRequest.hpp"
      12              : #include "Utilities/Serialization/CharmPupable.hpp"
      13              : #include "Utilities/TMPL.hpp"
      14              : #include "Utilities/TypeTraits/IsA.hpp"
      15              : 
      16              : /// \cond
      17              : namespace Tags {
      18              : template <typename Tag>
      19              : struct HistoryEvolvedVariables;
      20              : }  // namespace Tags
      21              : /// \endcond
      22              : 
      23              : namespace StepChoosers {
      24              : namespace PreventRapidIncrease_detail {
      25              : template <typename T>
      26              : bool limit_from_history(const TimeSteppers::ConstUntypedHistory<T>& history,
      27              :                         double last_step);
      28              : }  // namespace PreventRapidIncrease_detail
      29              : /// Limits the time step to prevent multistep integrator instabilities.
      30              : ///
      31              : /// Avoids instabilities due to rapid increases in the step size by
      32              : /// preventing the step size from increasing if any step in the
      33              : /// time-stepper history increased.  If there have been recent step
      34              : /// size increases, the new size bound is the size of the most recent
      35              : /// step, otherwise no restriction is imposed.
      36              : /// @{
      37              : template <typename System,
      38              :           typename = tmpl::conditional_t<
      39              :               tt::is_a_v<tmpl::list, typename System::variables_tag>,
      40              :               typename System::variables_tag,
      41              :               tmpl::list<typename System::variables_tag>>>
      42            1 : class PreventRapidIncrease;
      43              : 
      44              : template <typename System, typename... VariablesTags>
      45            0 : class PreventRapidIncrease<System, tmpl::list<VariablesTags...>>
      46              :     : public StepChooser<StepChooserUse::Slab>,
      47              :       public StepChooser<StepChooserUse::LtsStep> {
      48              :  public:
      49              :   /// \cond
      50              :   PreventRapidIncrease() = default;
      51              :   explicit PreventRapidIncrease(CkMigrateMessage* /*unused*/) {}
      52              :   using PUP::able::register_constructor;
      53              :   WRAPPED_PUPable_decl_template(PreventRapidIncrease);  // NOLINT
      54              :   /// \endcond
      55              : 
      56            0 :   static constexpr Options::String help{
      57              :       "Limits the time step to prevent multistep integrator instabilities."};
      58            0 :   using options = tmpl::list<>;
      59              : 
      60            0 :   using argument_tags =
      61              :       tmpl::list<::Tags::HistoryEvolvedVariables<VariablesTags>...>;
      62              : 
      63            0 :   TimeStepRequest operator()(
      64              :       const ::TimeSteppers::History<typename VariablesTags::type>&... histories,
      65              :       const double last_step) const {
      66              :     if ((... or PreventRapidIncrease_detail::limit_from_history(
      67              :                     histories.untyped(), last_step))) {
      68              :       return {.size = last_step};
      69              :     } else {
      70              :       return {};
      71              :     }
      72              :   }
      73              : 
      74            1 :   bool uses_local_data() const override { return false; }
      75            1 :   bool can_be_delayed() const override { return true; }
      76            1 :   bool must_set_step_size() const override { return true; }
      77              : 
      78            0 :   void pup(PUP::er& p) override {
      79              :     StepChooser<StepChooserUse::Slab>::pup(p);
      80              :     StepChooser<StepChooserUse::LtsStep>::pup(p);
      81              :   }
      82              : };
      83              : /// @}
      84              : 
      85              : /// \cond
      86              : template <typename System, typename... VariablesTags>
      87              : PUP::able::PUP_ID PreventRapidIncrease<
      88              :     System, tmpl::list<VariablesTags...>>::my_PUP_ID =  // NOLINT
      89              :     0;
      90              : /// \endcond
      91              : }  // namespace StepChoosers