Add GitHub actions for testing VOL connectors (#3849)

* Fix issue with HDF5_VOL_ALLOW_EXTERNAL CMake variable

* Add initial API test workflow

* Initialize parallel testing with MPI_THREAD_MULTIPLE when testing API

* Add CMake variable to allow specifying a VOL connector's package name

* Remove call to MPI_Init in serial API tests

While previously necessary, it now interferes with VOL connectors that
may need to be initialized with MPI_THREAD_MULTIPLE

1 files changed, 36 insertions, 3 deletions

diff --git a/testpar/t_shapesame.c b/testpar/t_shapesame.c
index 4f48f93..2a2cfe8 100644
--- a/testpar/t_shapesame.c
+++ b/testpar/t_shapesame.c
@@ -4271,6 +4271,11 @@ int
 main(int argc, char **argv)
 {
     int mpi_size, mpi_rank; /* mpi variables */
+    int mpi_code;
+#ifdef H5_HAVE_TEST_API
+    int required = MPI_THREAD_MULTIPLE;
+    int provided;
+#endif
 
 #ifndef H5_HAVE_WIN32_API
     /* Un-buffer the stdout and stderr */
@@ -4278,9 +4283,37 @@ main(int argc, char **argv)
     HDsetbuf(stdout, NULL);
 #endif
 
-    MPI_Init(&argc, &argv);
-    MPI_Comm_size(MPI_COMM_WORLD, &mpi_size);
-    MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank);
+#ifdef H5_HAVE_TEST_API
+    /* Attempt to initialize with MPI_THREAD_MULTIPLE if possible */
+    if (MPI_SUCCESS != (mpi_code = MPI_Init_thread(&argc, &argv, required, &provided))) {
+        printf("MPI_Init_thread failed with error code %d\n", mpi_code);
+        return -1;
+    }
+#else
+    if (MPI_SUCCESS != (mpi_code = MPI_Init(&argc, &argv))) {
+        printf("MPI_Init failed with error code %d\n", mpi_code);
+        return -1;
+    }
+#endif
+
+    if (MPI_SUCCESS != (mpi_code = MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank))) {
+        printf("MPI_Comm_rank failed with error code %d\n", mpi_code);
+        MPI_Finalize();
+        return -1;
+    }
+
+#ifdef H5_HAVE_TEST_API
+    /* Warn about missing MPI_THREAD_MULTIPLE support */
+    if ((provided < required) && MAINPROCESS)
+        printf("** MPI doesn't support MPI_Init_thread with MPI_THREAD_MULTIPLE **\n");
+#endif
+
+    if (MPI_SUCCESS != (mpi_code = MPI_Comm_size(MPI_COMM_WORLD, &mpi_size))) {
+        if (MAINPROCESS)
+            printf("MPI_Comm_size failed with error code %d\n", mpi_code);
+        MPI_Finalize();
+        return -1;
+    }
 
     mpi_rank_framework_g = mpi_rank;