mpi: add program which only waits, useful to check thread binding

mpi/tests/Makefile.am

@@ -140,7 +140,8 @@ starpu_mpi_TESTS +=				\
 	user_defined_datatype			\
 	early_stuff				\
 	sendrecv_bench				\
-	burst
+	burst					\
+	nothing
 
 if !STARPU_USE_MPI_MPI
 starpu_mpi_TESTS +=				\
@@ -241,7 +242,8 @@ noinst_PROGRAMS =				\
 	driver					\
 	sendrecv_bench				\
 	sendrecv_parallel_tasks_bench		\
-	burst
+	burst					\
+	nothing
 
 if !NO_BLAS_LIB
 noinst_PROGRAMS +=				\
@@ -251,7 +253,8 @@ endif
 XFAIL_TESTS=					\
 	policy_register_toomany			\
 	policy_unregister			\
-	starpu_redefine
+	starpu_redefine				\
+	nothing
 
 ring_SOURCES = ring.c
 ring_sync_SOURCES = ring_sync.c

mpi/tests/nothing.c

@@ -0,0 +1,69 @@
+/* StarPU --- Runtime system for heterogeneous multicore architectures.
+ *
+ * Copyright (C) 2020  Université de Bordeaux, CNRS (LaBRI UMR 5800), Inria
+ *
+ * StarPU is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at
+ * your option) any later version.
+ *
+ * StarPU is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * See the GNU Lesser General Public License in COPYING.LGPL for more details.
+ */
+
+/*
+ * This program does nothing. It waits until it is interrupted by the user.
+ * Useful to check binding while StarPU is running.
+ */
+
+#include <starpu_mpi.h>
+#include "helper.h"
+
+
+int main(int argc, char **argv)
+{
+	int ret, rank, worldsize;
+	int mpi_init;
+
+	MPI_INIT_THREAD(&argc, &argv, MPI_THREAD_SERIALIZED, &mpi_init);
+	ret = starpu_mpi_init_conf(&argc, &argv, mpi_init, MPI_COMM_WORLD, NULL);
+	STARPU_CHECK_RETURN_VALUE(ret, "starpu_mpi_init_conf");
+
+	starpu_pause(); // our program will only wait, no need to stress cores by polling workers
+
+	starpu_mpi_comm_rank(MPI_COMM_WORLD, &rank);
+	starpu_mpi_comm_size(MPI_COMM_WORLD, &worldsize);
+
+	starpu_mpi_barrier(MPI_COMM_WORLD);
+
+	char hostname[65];
+	gethostname(hostname, sizeof(hostname));
+
+	printf("[rank %d on %s] ready to wait !\n", rank, hostname);
+
+	if (rank == 0)
+	{
+		printf("You can now check if thread binding is correct, for instance.\n");
+	}
+
+	fflush(stdout);
+
+	while(1)
+	{
+		sleep(1);
+	}
+
+	// TODO: maybe better handle the user interruption ?
+
+
+	starpu_resume();
+
+	starpu_mpi_shutdown();
+	if (!mpi_init)
+		MPI_Finalize();
+
+	return 0;
+}