mpi4py support

CMakeLists.txt

@@ -14,6 +14,7 @@ option( USE_NATIVE_ARCH  "build for native cpu architecture" ON)
 option( USE_GUI     "don't build netgen with GUI" ON )
 option( USE_PYTHON  "build with python interface" ON )
 option( USE_MPI     "enable mpi parallelization" OFF )
+option( USE_MPI4PY  "enable mpi4py interface" ON )
 option( USE_OCC     "(not supported) compile with OpenCascade geometry kernel" OFF)
 option( USE_JPEG    "enable snapshots using library libjpeg" OFF )
 option( USE_MPEG    "enable video recording with FFmpeg, uses libavcodec" OFF )
@@ -297,6 +298,14 @@ if (USE_MPI)
     target_include_directories(netgen_metis INTERFACE ${METIS_INCLUDE_DIR})
     target_link_libraries(netgen_metis INTERFACE ${METIS_LIBRARY} )
     target_compile_definitions(netgen_metis INTERFACE METIS )
+
+    if(USE_MPI4PY AND USE_PYTHON)
+      execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "import mpi4py;print(mpi4py.get_include())" OUTPUT_VARIABLE mpi4py_path OUTPUT_STRIP_TRAILING_WHITESPACE)
+      find_path(MPI4PY_INCLUDE_DIR mpi4py.h HINTS ${mpi4py_path}/mpi4py NO_DEFAULT_PATH REQUIRED)
+      target_include_directories(netgen_metis INTERFACE ${MPI4PY_INCLUDE_DIR})
+      target_compile_definitions(netgen_metis INTERFACE NG_MPI4PY )
+      message(STATUS "Found mpi4py: ${MPI4PY_INCLUDE_DIR}")
+    endif(USE_MPI4PY AND USE_PYTHON)
 endif (USE_MPI)
 install(TARGETS netgen_mpi netgen_metis ${NG_INSTALL_DIR})
 

libsrc/meshing/python_mesh.cpp

@@ -13,6 +13,53 @@
 #include <../interface/writeuser.hpp>
 
 
+#ifdef NG_MPI4PY
+#include <mpi4py.h>
+
+struct mpi4py_comm {
+  mpi4py_comm() = default;
+  mpi4py_comm(MPI_Comm value) : value(value) {}
+  operator MPI_Comm () { return value; }
+
+  MPI_Comm value;
+};
+
+namespace pybind11 { namespace detail {
+  template <> struct type_caster<mpi4py_comm> {
+    public:
+    PYBIND11_TYPE_CASTER(mpi4py_comm, _("mpi4py_comm"));
+
+      // Python -> C++
+      bool load(handle src, bool) {
+        PyObject *py_src = src.ptr();
+        // Check that we have been passed an mpi4py communicator
+        if (PyObject_TypeCheck(py_src, &PyMPIComm_Type)) {
+          // Convert to regular MPI communicator
+          value.value = *PyMPIComm_Get(py_src);
+        } else {
+          return false;
+        }
+
+        return !PyErr_Occurred();
+      }
+
+      // C++ -> Python
+      static handle cast(mpi4py_comm src,
+                         return_value_policy /* policy */,
+                         handle /* parent */)
+      {
+        // Create an mpi4py handle
+        return PyMPIComm_New(src.value);
+      }
+  };
+}} // namespace pybind11::detail
+
+#endif // NG_MPI4PY
+
+
+
+
+
 using namespace netgen;
 
 extern const char *ngscript[];
@@ -50,8 +97,15 @@ void TranslateException (const NgException & ex)
 
 static Transformation<3> global_trafo(Vec<3> (0,0,0));
 
+
+
+
+
 DLL_HEADER void ExportNetgenMeshing(py::module &m) 
 {
+#ifdef NG_MPI4PY
+  import_mpi4py();
+#endif // NG_MPI4PY
   py::register_exception<NgException>(m, "NgException");
   m.attr("_netgen_executable_started") = py::cast(netgen::netgen_executable_started);
   string script;
@@ -71,6 +125,12 @@ DLL_HEADER void ExportNetgenMeshing(py::module &m)
   m.def("_SetThreadPercentage", [](double percent) { SetThreadPercent(percent); });
 
   py::class_<NgMPI_Comm> (m, "MPI_Comm")
+#ifdef NG_MPI4PY
+    .def(py::init([] (mpi4py_comm comm)
+                  {
+                    return NgMPI_Comm(comm);
+                  }))
+#endif // NG_MPI4PY
     .def_property_readonly ("rank", &NgMPI_Comm::Rank)
     .def_property_readonly ("size", &NgMPI_Comm::Size)
     .def("Barrier", &NgMPI_Comm::Barrier)
@@ -100,6 +160,9 @@ DLL_HEADER void ExportNetgenMeshing(py::module &m)
   ;
 
 
+#ifdef NG_MPI4PY
+  py::implicitly_convertible<mpi4py_comm, NgMPI_Comm>();
+#endif // NG_MPI4PY
 
   
   py::class_<NGDummyArgument>(m, "NGDummyArgument")

tests/dockerfile_mpi

@@ -1,5 +1,5 @@
 FROM ubuntu:18.04
 ENV DEBIAN_FRONTEND=noninteractive
 MAINTAINER Matthias Hochsteger <matthias.hochsteger@tuwien.ac.at>
-RUN apt-get update && apt-get -y install python3 libpython3-dev libxmu-dev tk-dev tcl-dev cmake git g++ libglu1-mesa-dev ccache python3-pytest python3-numpy python3-tk clang-tidy python3-distutils clang libopenmpi-dev openmpi-bin gfortran
+RUN apt-get update && apt-get -y install python3 libpython3-dev libxmu-dev tk-dev tcl-dev cmake git g++ libglu1-mesa-dev ccache python3-pytest python3-numpy python3-tk python3-mpi4py clang-tidy python3-distutils clang libopenmpi-dev openmpi-bin gfortran
 ADD . /root/src/netgen