Re #19246. Initialize MPI environment by default so tests pass.

Framework/API/inc/MantidAPI/FrameworkManager.h

@@ -7,10 +7,6 @@
 #include <boost/mpi/environment.hpp>
 #endif
 
-#ifdef MPI_EXPERIMENTAL
-#include <boost/mpi/environment.hpp>
-#endif
-
 #include "MantidAPI/DllConfig.h"
 #include "MantidAPI/FileLoaderRegistry.h"
 #include "MantidKernel/SingletonHolder.h"
@@ -133,9 +129,6 @@ private:
   int argc = 0;
   char **argv;
 #endif
-#ifdef MPI_EXPERIMENTAL
-  boost::mpi::environment m_mpi_environment;
-#endif
 };
 
 typedef Mantid::Kernel::SingletonHolder<FrameworkManagerImpl> FrameworkManager;

Framework/API/test/AlgorithmMPITest.h

@@ -529,10 +529,7 @@ public:
   static AlgorithmMPITest *createSuite() { return new AlgorithmMPITest(); }
   static void destroySuite(AlgorithmMPITest *suite) { delete suite; }
 
-  AlgorithmMPITest() {
-    Mantid::API::FrameworkManager::Instance();
-    AnalysisDataService::Instance();
-  }
+  AlgorithmMPITest() { AnalysisDataService::Instance(); }
 
   void testNoParallelism() {
     runNoParallelism(Parallel::Communicator{});

Framework/CMakeLists.txt

@@ -57,6 +57,7 @@ if ( ${CMAKE_SYSTEM_NAME} MATCHES "Linux" )
   endif ( MPI_BUILD )
 endif ()
 
+set ( MPI_EXPERIMENTAL OFF CACHE BOOL "Enable MPI options" )
 if ( MPI_EXPERIMENTAL )
   include ( BoostMPI )
 endif ()

Framework/DataObjects/test/TableWorkspacePropertyTest.h

@@ -66,9 +66,6 @@ public:
   static void destroySuite(TableWorkspacePropertyTest *suite) { delete suite; }
 
   TableWorkspacePropertyTest() {
-    // Calls MPI_Init if applicable, for running algorithms in MPI builds.
-    Mantid::API::FrameworkManager::Instance();
-
     t.reset(new TableWorkspace(10));
     t->addColumn("str", "Name");
     t->addColumn("int", "Nunber");

Framework/DataObjects/test/WorkspaceCreationTest.h

@@ -93,8 +93,6 @@ public:
   static void destroySuite(WorkspaceCreationTest *suite) { delete suite; }
 
   WorkspaceCreationTest() {
-    // Calls MPI_Init, if applicable.
-    Mantid::API::FrameworkManager::Instance();
     // 1 bank, 2x2 pixels, IDs 4,5,6,7
     m_instrument =
         ComponentCreationHelper::createTestInstrumentRectangular(1, 2);

Framework/Parallel/inc/MantidParallel/Communicator.h

@@ -12,10 +12,17 @@
 #include <boost/mpi/communicator.hpp>
 #endif
 
+namespace boost {
+namespace mpi {
+class environment;
+}
+}
+
 namespace Mantid {
 namespace Parallel {
 #ifdef MPI_EXPERIMENTAL
 class ParallelRunner;
+extern boost::mpi::environment environment;
 #endif
 
 /** Wrapper for boost::mpi::communicator. For non-MPI builds an equivalent

Framework/Parallel/src/Communicator.cpp

 #include "MantidParallel/Communicator.h"
 
+#ifdef MPI_EXPERIMENTAL
+#include <boost/mpi/environment.hpp>
+#endif
+
 namespace Mantid {
 namespace Parallel {
 
+#ifdef MPI_EXPERIMENTAL
+boost::mpi::environment environment;
+#endif
+
 #ifdef MPI_EXPERIMENTAL
 Communicator::Communicator(const boost::mpi::communicator &comm)
     : m_communicator(comm) {}

Framework/PythonInterface/mantid/kernel/CMakeLists.txt

@@ -152,12 +152,19 @@ if ( WIN32 ) #.lib -> .dll
   string ( REPLACE "/lib/" "/bin/" NEXUSLIB ${NEXUSLIB} )
   string ( REPLACE ".lib" ".dll" NEXUSLIB ${NEXUSLIB} )
 endif()
+set ( MPISETUP_PY mpisetup )
+if ( MPI_EXPERIMENTAL )
+  set ( IMPORT_MPI_IN_PYTHON True )
+endif()
 
 # Build version
 configure_file ( ${CMAKE_CURRENT_SOURCE_DIR}/${PACKAGESETUP_PY}.py.in ${CMAKE_CURRENT_BINARY_DIR}/${PACKAGESETUP_PY}.py )
+configure_file ( ${CMAKE_CURRENT_SOURCE_DIR}/${MPISETUP_PY}.py.in ${CMAKE_CURRENT_BINARY_DIR}/${MPISETUP_PY}.py )
 # Copy py to build directory, taking care of multi-config (MSVC) builds
 copy_files_to_dir ( ${PACKAGESETUP_PY}.py ${CMAKE_CURRENT_BINARY_DIR} ${OUTPUT_DIR}
                     PYTHON_INSTALL_FILES )
+copy_files_to_dir ( ${MPISETUP_PY}.py ${CMAKE_CURRENT_BINARY_DIR} ${OUTPUT_DIR}
+                    PYTHON_INSTALL_FILES )
 
 # Package version
 if ( WIN32 OR APPLE )
@@ -166,6 +173,7 @@ if ( WIN32 OR APPLE )
   set ( NEXUSLIB ../../${NEXUSLIB_FILE} )
 endif()
 configure_file ( ${CMAKE_CURRENT_SOURCE_DIR}/${PACKAGESETUP_PY}.py.in ${CMAKE_CURRENT_BINARY_DIR}/${PACKAGESETUP_PY}.install.py )
+configure_file ( ${CMAKE_CURRENT_SOURCE_DIR}/${MPISETUP_PY}.py.in ${CMAKE_CURRENT_BINARY_DIR}/${MPISETUP_PY}.install.py )
 
 #############################################################################################
 # Create the target for this directory

Framework/PythonInterface/mantid/kernel/__init__.py

@@ -8,6 +8,9 @@ Defines Python objects that wrap the C++ Kernel namespace.
 from __future__ import (absolute_import, division,
                         print_function)
 
+# Imports boost.mpi if applicable
+from . import mpisetup
+
 ###############################################################################
 # Load the C++ library
 ###############################################################################

Framework/PythonInterface/mantid/kernel/mpisetup.py.in

+# For MPI builds we need to import boost.mpi to initialize the MPI environment.
+# The environment is also instantiated in C++ but that does seem to lead to
+# issues (probably related to how Ubuntu builds their MPI and Python packages).
+if ${IMPORT_MPI_IN_PYTHON}:
+    import boost.mpi