added clear synchronization function

src/pe/synchronization/ClearSynchronization.h

+//======================================================================================================================
+//
+//  This file is part of waLBerla. waLBerla is free software: you can
+//  redistribute it and/or modify it under the terms of the GNU General Public
+//  License as published by the Free Software Foundation, either version 3 of
+//  the License, or (at your option) any later version.
+//
+//  waLBerla is distributed in the hope that it will be useful, but WITHOUT
+//  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+//  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+//  for more details.
+//
+//  You should have received a copy of the GNU General Public License along
+//  with waLBerla (see COPYING.txt). If not, see <http://www.gnu.org/licenses/>.
+//
+//! \file ClearSynchronization.h
+//! \author Sebastian Eibl <sebastian.eibl@fau.de>
+//
+//======================================================================================================================
+
+#pragma once
+
+//*************************************************************************************************
+// Includes
+//*************************************************************************************************
+
+#include "pe/rigidbody/BodyStorage.h"
+
+#include "domain_decomposition/BlockStorage.h"
+
+namespace walberla {
+namespace pe {
+
+//*************************************************************************************************
+/*!\brief Removes all synchronization information.
+ *
+ * \param blocks BlockStorage of the simulation.
+ * \param BlockDataID BlockDataID of the pe storage.
+ */
+inline
+void clearSynchronization( BlockStorage& blocks, BlockDataID storageID )
+{
+   for (auto it = blocks.begin(); it != blocks.end(); ++it)
+   {
+      IBlock & currentBlock      = *it;
+      Storage * storage          = currentBlock.getData< Storage >( storageID );
+      BodyStorage& localStorage  = (*storage)[0];
+      BodyStorage& shadowStorage = (*storage)[1];
+
+      for( auto bodyIt = localStorage.begin(); bodyIt != localStorage.end(); ++bodyIt )
+      {
+         bodyIt->MPITrait.clearShadowOwners();
+         bodyIt->MPITrait.clearBlockStates();
+      }
+
+      shadowStorage.clear();
+   }
+}
+//*************************************************************************************************
+
+}  // namespace pe
+}  // namespace walberla