Move MPIInitHelpers into ablastr (#4026)

* move MPIInitHelper into ablastr

* fix bug

* fix bug

1 files changed, 45 insertions, 0 deletions

diff --git a/Source/ablastr/parallelization/MPIInitHelpers.H b/Source/ablastr/parallelization/MPIInitHelpers.H
new file mode 100644
index 000000000..6b9bdfa47
--- /dev/null
+++ b/Source/ablastr/parallelization/MPIInitHelpers.H
@@ -0,0 +1,45 @@
+/* Copyright 2020 Axel Huebl
+ *
+ * This file is part of ABLASTR.
+ *
+ * License: BSD-3-Clause-LBNL
+ */
+#ifndef ABLASTR_MPI_INIT_HELPERS_H_
+#define ABLASTR_MPI_INIT_HELPERS_H_
+
+#include <utility>
+
+namespace ablastr::parallelization
+{
+    /** Return the required MPI threading
+     *
+     * @return the MPI_THREAD_* level required for MPI_Init_thread
+     */
+    int
+    mpi_thread_required ();
+
+    /** Initialize MPI
+     *
+     * @return pair(required, provided) of MPI thread level from MPI_Init_thread
+     */
+    std::pair< int, int >
+    mpi_init (int argc, char* argv[]);
+
+    /** Finalize MPI
+     *
+     * This function is simply a wrapper around MPI_Finalize(). It is a no-op if
+     * ABLASTR is compiled without MPI support.
+     */
+    void
+    mpi_finalize ();
+
+    /** Check if the requested MPI thread level is valid
+     *
+     * Prints warnings and notes otherwise.
+     */
+    void
+    check_mpi_thread_level ();
+
+} // namespace ablastr::parallelization
+
+#endif // ABLASTR_MPI_INIT_HELPERS_H_