diff --git a/libsrc/core/python_ngcore.hpp b/libsrc/core/python_ngcore.hpp
index 6bedabf9..a089c5e8 100644
--- a/libsrc/core/python_ngcore.hpp
+++ b/libsrc/core/python_ngcore.hpp
@@ -11,6 +11,7 @@
 #include "archive.hpp"
 #include "flags.hpp"
 #include "ngcore_api.hpp"
+#include "profiler.hpp"
 namespace py = pybind11;
 
 namespace ngcore
@@ -297,18 +298,25 @@ namespace ngcore
                       {
                         PyArchive<T_ARCHIVE_OUT> ar;
                         ar & self;
+                        static Timer t("ngspickle 2");
+                        t.Start();
                         auto output = pybind11::make_tuple(ar.WriteOut());
+                        t.Stop();
+                        /*
                         GetLogger("Archive")->trace("Pickling output for object of type {} = {}",
                                                     Demangle(typeid(T).name()),
                                                     std::string(pybind11::str(output)));
+                        */
                         return output;
                       },
                       [](const pybind11::tuple & state)
                       {
                         T* val = nullptr;
+                        /*
                         GetLogger("Archive")->trace("State for unpickling of object of type {} = {}",
                                                     Demangle(typeid(T).name()),
                                                     std::string(pybind11::str(state[0])));
+                        */
                         PyArchive<T_ARCHIVE_IN> ar(state[0]);
                         ar & val;
                         return val;
diff --git a/libsrc/general/parthreads.hpp b/libsrc/general/parthreads.hpp
index 2e242484..d7f42a4a 100644
--- a/libsrc/general/parthreads.hpp
+++ b/libsrc/general/parthreads.hpp
@@ -96,8 +96,8 @@ void ParallelFor( int first, int next, const TFunc & f )
 
 
   
-  typedef void (*TaskManager)(std::function<void(int,int)>);
-  typedef void (*Tracer)(string, bool);  // false .. start, true .. stop
+  typedef void (*NgTaskManager)(std::function<void(int,int)>);
+  typedef void (*NgTracer)(string, bool);  // false .. start, true .. stop
 
   inline void DummyTaskManager (std::function<void(int,int)> func)
   {
@@ -108,7 +108,7 @@ void ParallelFor( int first, int next, const TFunc & f )
   inline void DummyTracer (string, bool) { ; }
   
   template <typename FUNC>
-  inline void ParallelFor (TaskManager tm, size_t n, FUNC func)
+  inline void ParallelFor (NgTaskManager tm, size_t n, FUNC func)
   {
     (*tm) ([n,func] (size_t nr, size_t nums)
            {
@@ -121,7 +121,7 @@ void ParallelFor( int first, int next, const TFunc & f )
   }
   
   template <typename FUNC>
-  inline void ParallelForRange (TaskManager tm, size_t n, FUNC func)
+  inline void ParallelForRange (NgTaskManager tm, size_t n, FUNC func)
   {
     (*tm) ([n,func] (size_t nr, size_t nums)
            {
diff --git a/libsrc/interface/nginterface_v2.cpp b/libsrc/interface/nginterface_v2.cpp
index e06d83eb..e2501ab4 100644
--- a/libsrc/interface/nginterface_v2.cpp
+++ b/libsrc/interface/nginterface_v2.cpp
@@ -1157,7 +1157,7 @@ namespace netgen
   
   void Ngx_Mesh :: Refine (NG_REFINEMENT_TYPE reftype,
                            void (*task_manager)(function<void(int,int)>),
-                           Tracer tracer)
+                           NgTracer tracer)
   {
     NgLock meshlock (mesh->MajorMutex(), 1);
     
diff --git a/libsrc/meshing/bisect.cpp b/libsrc/meshing/bisect.cpp
index 9b5c770f..1f9bbba8 100644
--- a/libsrc/meshing/bisect.cpp
+++ b/libsrc/meshing/bisect.cpp
@@ -1681,7 +1681,7 @@ namespace netgen
 
   int MarkHangingTets (T_MTETS & mtets, 
 		       const INDEX_2_CLOSED_HASHTABLE<PointIndex> & cutedges,
-                       TaskManager tm)                       
+                       NgTaskManager tm)                       
   {
     static int timer = NgProfiler::CreateTimer ("MarkHangingTets");    
     NgProfiler::RegionTimer reg (timer);    
@@ -1759,7 +1759,7 @@ namespace netgen
 
   bool MarkHangingTris (T_MTRIS & mtris, 
                         const INDEX_2_CLOSED_HASHTABLE<PointIndex> & cutedges,
-                        TaskManager tm)
+                        NgTaskManager tm)
   {
     bool hanging = false;
     // for (int i = 1; i <= mtris.Size(); i++)
diff --git a/libsrc/meshing/bisect.hpp b/libsrc/meshing/bisect.hpp
index 6b96bd07..16849227 100644
--- a/libsrc/meshing/bisect.hpp
+++ b/libsrc/meshing/bisect.hpp
@@ -12,8 +12,8 @@ public:
   int usemarkedelements;
   bool refine_hp;
   bool refine_p;
-  TaskManager task_manager = &DummyTaskManager;
-  Tracer tracer = &DummyTracer;
+  NgTaskManager task_manager = &DummyTaskManager;
+  NgTracer tracer = &DummyTracer;
   DLL_HEADER BisectionOptions ();
 };
 
diff --git a/libsrc/meshing/clusters.cpp b/libsrc/meshing/clusters.cpp
index dafe81f8..dae820df 100644
--- a/libsrc/meshing/clusters.cpp
+++ b/libsrc/meshing/clusters.cpp
@@ -16,7 +16,7 @@ namespace netgen
     ;
   }
 
-  void AnisotropicClusters ::  Update(TaskManager tm, Tracer tracer)
+  void AnisotropicClusters ::  Update(NgTaskManager tm, NgTracer tracer)
   {
     static int timer = NgProfiler::CreateTimer ("clusters");
     // static int timer1 = NgProfiler::CreateTimer ("clusters1");
diff --git a/libsrc/meshing/clusters.hpp b/libsrc/meshing/clusters.hpp
index bf9a5a56..21e122fb 100644
--- a/libsrc/meshing/clusters.hpp
+++ b/libsrc/meshing/clusters.hpp
@@ -27,7 +27,7 @@ public:
   AnisotropicClusters (const Mesh & amesh);
   ~AnisotropicClusters();
 
-  void Update(TaskManager tm = &DummyTaskManager, Tracer trace = &DummyTracer);
+  void Update(NgTaskManager tm = &DummyTaskManager, NgTracer trace = &DummyTracer);
 
   int GetVertexRepresentant (int vnr) const
   { return cluster_reps.Get(vnr); }
diff --git a/libsrc/meshing/meshclass.cpp b/libsrc/meshing/meshclass.cpp
index 2eacb717..5229f5d2 100644
--- a/libsrc/meshing/meshclass.cpp
+++ b/libsrc/meshing/meshclass.cpp
@@ -1280,10 +1280,14 @@ namespace netgen
 
   void Mesh :: DoArchive (Archive & archive)
   {
+    static Timer t("Mesh::Archive"); RegionTimer r(t);
+    static Timer tvol("Mesh::Archive vol elements");
     archive & dimension;
     archive & points;
     archive & surfelements;
+    tvol.Start();
     archive & volelements;
+    tvol.Stop();
     archive & segments;
     archive & facedecoding;
     archive & materials & bcnames & cd2names & cd3names;
@@ -6417,8 +6421,8 @@ namespace netgen
     return 1;
   }
 
-  void Mesh :: UpdateTopology (TaskManager tm,
-                               Tracer tracer)
+  void Mesh :: UpdateTopology (NgTaskManager tm,
+                               NgTracer tracer)
   {
     static Timer t("Update Topology"); RegionTimer reg(t);
     topology.Update(tm, tracer);
diff --git a/libsrc/meshing/meshclass.hpp b/libsrc/meshing/meshclass.hpp
index 4ff21ae8..5139cb8c 100644
--- a/libsrc/meshing/meshclass.hpp
+++ b/libsrc/meshing/meshclass.hpp
@@ -777,8 +777,8 @@ namespace netgen
     const MeshTopology & GetTopology () const
     { return topology; }
 
-    DLL_HEADER void UpdateTopology (TaskManager tm = &DummyTaskManager,
-                                    Tracer tracer = &DummyTracer);
+    DLL_HEADER void UpdateTopology (NgTaskManager tm = &DummyTaskManager,
+                                    NgTracer tracer = &DummyTracer);
   
     class CurvedElements & GetCurvedElements () const
     { return *curvedelems; }
diff --git a/libsrc/meshing/python_mesh.cpp b/libsrc/meshing/python_mesh.cpp
index a7edcec5..0d0877b0 100644
--- a/libsrc/meshing/python_mesh.cpp
+++ b/libsrc/meshing/python_mesh.cpp
@@ -11,6 +11,15 @@
 // #include <csg.hpp>
 // #include <geometry2d.hpp>
 #include <../interface/writeuser.hpp>
+#include <../include/nginterface.h>
+
+
+class ClearSolutionClass
+{
+public:
+  ClearSolutionClass() { } 
+  ~ClearSolutionClass() { Ng_ClearSolutionData(); }
+};
 
 
 #ifdef NG_MPI4PY
@@ -1238,6 +1247,10 @@ grow_edges : bool = False
            }, py::arg("quads")=true, py::arg("nx")=10, py::arg("ny")=10, py::arg("flip_triangles")=false, py::arg("bbbpts")=py::list(), py::arg("bbbnames")=py::list())
       ;
     ;
+
+    py::class_<ClearSolutionClass> (m, "ClearSolutionClass")
+      .def(py::init<>())
+      ;
 }
 
 PYBIND11_MODULE(libmesh, m) {
diff --git a/libsrc/meshing/topology.cpp b/libsrc/meshing/topology.cpp
index 6fd54b8b..65dca902 100644
--- a/libsrc/meshing/topology.cpp
+++ b/libsrc/meshing/topology.cpp
@@ -3,7 +3,8 @@
 
 namespace netgen
 {
-
+  using ngcore::ParallelForRange;
+  
   
   template <class T>
   void QuickSortRec (NgFlatArray<T> data,
@@ -332,10 +333,10 @@ namespace netgen
   }
   
   
-  void MeshTopology :: Update (TaskManager tm, Tracer tracer)
+  void MeshTopology :: Update (NgTaskManager tm_unused, NgTracer tracer)
   {
-    static int timer = NgProfiler::CreateTimer ("topology");
-    NgProfiler::RegionTimer reg (timer);
+    static Timer timer("Topology::Update");
+    RegionTimer reg (timer);
 
 #ifdef PARALLEL
     // ParallelMeshTopology & paralleltop = mesh.GetParallelTopology();
@@ -382,10 +383,9 @@ namespace netgen
       }
     */
     ParallelForRange
-      (tm, ne,
-       [&] (size_t begin, size_t end)
+      (ne, [&] (IntRange r) 
        {
-         for (ElementIndex ei = begin; ei < end; ei++)
+         for (ElementIndex ei : r) 
            {
              const Element & el = (*mesh)[ei];
              for (int j = 0; j < el.GetNV(); j++)
@@ -426,10 +426,10 @@ namespace netgen
       }
     */
     ParallelForRange
-      (tm, nse,
-       [&] (size_t begin, size_t end)
+      (nse,
+       [&] (IntRange r)
        {
-         for (SurfaceElementIndex ei = begin; ei < end; ei++)
+         for (SurfaceElementIndex ei : r)
            {
              const Element2d & el = (*mesh)[ei];
              for (int j = 0; j < el.GetNV(); j++)
@@ -553,9 +553,11 @@ namespace netgen
         cnt = 0;
 
         ParallelForRange
-          (tm, mesh->GetNV(), // Points().Size(),
-           [&] (size_t begin, size_t end)
+          (mesh->GetNV(), // Points().Size(),
+           [&] (IntRange r)
            {
+             auto begin = r.First();
+             auto end = r.Next();
              INDEX_CLOSED_HASHTABLE<int> v2eht(2*max_edge_on_vertex+10); 
              for (PointIndex v = begin+PointIndex::BASE;
                   v < end+PointIndex::BASE; v++)
@@ -607,9 +609,11 @@ namespace netgen
 	// for (PointIndex v = PointIndex::BASE; v < nv+PointIndex::BASE; v++)
 
         ParallelForRange
-          (tm, mesh->GetNV(), // Points().Size(),
-           [&] (size_t begin, size_t end)
+          (mesh->GetNV(), // Points().Size(),
+           [&] (IntRange r)
            {
+             auto begin = r.First();
+             auto end = r.Next();
              INDEX_CLOSED_HASHTABLE<int> v2eht(2*max_edge_on_vertex+10);
              NgArray<int> vertex2;
              for (PointIndex v = begin+PointIndex::BASE;
@@ -731,9 +735,11 @@ namespace netgen
         // for (auto v : mesh.Points().Range())
         // NgProfiler::StartTimer (timer2b1);
         ParallelForRange
-          (tm, mesh->GetNV(), // Points().Size(),
-            [&] (size_t begin, size_t end)
+          (mesh->GetNV(), // Points().Size(),
+           [&] (IntRange r)
             {
+              auto begin = r.First();
+              auto end = r.Next();
               INDEX_3_CLOSED_HASHTABLE<int> vert2face(2*max_face_on_vertex+10); 
               for (PointIndex v = begin+PointIndex::BASE;
                    v < end+PointIndex::BASE; v++)
@@ -779,9 +785,11 @@ namespace netgen
         // for (auto v : mesh.Points().Range())
 
         ParallelForRange
-          (tm, mesh->GetNV(), // Points().Size(),
-            [&] (size_t begin, size_t end)
+          (mesh->GetNV(), // Points().Size(),
+           [&] (IntRange r)
             {
+              auto begin = r.First();
+              auto end = r.Next();
               INDEX_3_CLOSED_HASHTABLE<int> vert2face(2*max_face_on_vertex+10); 
               for (PointIndex v = begin+PointIndex::BASE;
                    v < end+PointIndex::BASE; v++)
@@ -1164,11 +1172,11 @@ namespace netgen
 	  }
         */
         ParallelForRange
-          (tm, ne,
-            [&] (size_t begin, size_t end)
+          (ne,
+           [&] (IntRange r)
             {
               NgArray<int> hfaces;              
-              for (ElementIndex ei = begin; ei < end; ei++)
+              for (ElementIndex ei : r)
                 {
                   GetElementFaces (ei+1, hfaces);
                   for (auto f : hfaces)
diff --git a/libsrc/meshing/topology.hpp b/libsrc/meshing/topology.hpp
index 8335f101..00f599f6 100644
--- a/libsrc/meshing/topology.hpp
+++ b/libsrc/meshing/topology.hpp
@@ -81,7 +81,7 @@ public:
   bool HasFaces () const
   { return buildfaces; }
 
-  void Update(TaskManager tm = &DummyTaskManager, Tracer tracer = &DummyTracer);
+  void Update(NgTaskManager tm = &DummyTaskManager, NgTracer tracer = &DummyTracer);
   bool NeedsUpdate() const;
 
 
diff --git a/python/__init__.py b/python/__init__.py
index e7c23d66..17dbdbe1 100644
--- a/python/__init__.py
+++ b/python/__init__.py
@@ -22,3 +22,5 @@ def Redraw(*args, **kwargs):
                 cnt += 1
     except:
         pass
+
+
diff --git a/python/meshing.py b/python/meshing.py
index 788f248a..9b912b66 100644
--- a/python/meshing.py
+++ b/python/meshing.py
@@ -59,3 +59,6 @@ class _MeshsizeObject:
                                   optsteps3d=5)
 
 meshsize = _MeshsizeObject()
+
+
+clearsol = ClearSolutionClass()