.

.github/workflows/linux.yaml

@@ -15,7 +15,7 @@ jobs:
       - run: echo "🐧 This job is now running on a ${{ runner.os }} server hosted by GitHub!"
       - run: echo "🔎 The name of your branch is ${{ github.ref }} and your repository is ${{ github.repository }}."
       - name: Install MPI
-        run: sudo apt-get update && sudo apt-get install -y libopenmpi-dev openmpi-bin
+        run: sudo apt-get update && sudo apt-get install -y libopenmpi-dev openmpi-bin cmake
       - name: Check out repository code
         uses: actions/checkout@v4
       - run: echo "💡 The ${{ github.repository }} repository has been cloned to the runner."
@@ -47,7 +47,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Install MPI
-        run: sudo apt-get update && sudo apt-get install -y mpich
+        run: sudo apt-get update && sudo apt-get install -y mpich cmake
       - name: Check out repository code
         uses: actions/checkout@v4
       - name: Build Kokkos

unit_tests/CMakeLists.txt

@@ -20,6 +20,13 @@ FetchContent_Declare(
 )
 FetchContent_MakeAvailable(mpitest)
 
+add_executable(test-mpi test_mpi.cpp)
+add_test(NAME test-mpi-1
+        COMMAND mpirun -np 1 ./test-mpi
+)
+add_test(NAME test-mpi-2
+        COMMAND mpirun -np 2 ./test-mpi
+)
 
 add_executable(test-main test_main.cpp
   test_initfinalize.cpp
@@ -29,6 +36,7 @@ add_executable(test-main test_main.cpp
 target_link_libraries(test-main KokkosComm gtest gtest_mpi)
 
 add_test(NAME test-main
-         COMMAND mpirun -np 2 ./test-main)
+         COMMAND mpirun -np 2 ./test-main
+)
 
 

unit_tests/test_mpi.cpp

@@ -0,0 +1,13 @@
+#include <mpi.h>
+
+int main(int argc, char *argv[]) {
+  // Initialize MPI before any call to gtest_mpi
+  MPI_Init(&argc, &argv);
+  int rank;
+  MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+  if (0 == rank) {
+    std::cout << "Hello from rank " << rank << "\n";
+  }
+  MPI_Finalize();
+  return 0;
+}