Add a trivial example to show how to scale a vector by a constant factor.

examples/Makefile.am

@@ -102,6 +102,12 @@ examplebin_PROGRAMS +=				\
 basic_examples_hello_world_SOURCES =		\
 	basic-examples/hello-world.c
 
+examplebin_PROGRAMS +=				\
+	basic-examples/vector-scal
+
+basic_examples_vector_scal_SOURCES =		\
+	basic-examples/vector-scal.c
+
 ###################
 # PPM downscaling #
 ###################

examples/basic-examples/vector-scal.c

@@ -0,0 +1,81 @@
+/*
+ * StarPU
+ * Copyright (C) INRIA 2008-2009 (see AUTHORS file)
+ *
+ * This program 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.
+ *
+ * This program 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.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <starpu.h>
+
+#define	N	2048
+
+static void scal_func(starpu_data_interface_t *buffers, void *arg)
+{
+	unsigned i;
+	float *factor = arg;
+
+	/* length of the vector */
+	unsigned n = buffers[0].vector.nx;
+
+	/* get a pointer to the local copy of the vector */
+	float *val = (float *)buffers[0].vector.ptr;
+
+	for (i = 0; i < n; i++)
+		val[i] *= *factor;
+}
+
+static starpu_codelet cl = {
+	.where = CORE,
+	.core_func = scal_func,
+	.nbuffers = 1
+};
+
+
+int main(int argc, char **argv)
+{
+	starpu_init(NULL);
+
+	float tab[N];
+
+	unsigned i;
+	for (i = 0; i < N; i++)
+		tab[i] = 1.0f;
+
+	starpu_data_handle tab_handle;
+	starpu_register_vector_data(&tab_handle, 0, (uintptr_t)tab, N, sizeof(float));
+
+	float factor = 3.14;
+
+	struct starpu_task *task = starpu_task_create();
+
+	task->cl = &cl;
+
+	task->buffers[0].handle = tab_handle;
+	task->buffers[0].mode = STARPU_RW;
+
+	task->cl_arg = &factor;
+	task->cl_arg_size = sizeof(float);
+
+	task->synchronous = 1;
+
+	fprintf(stderr, "BEFORE : First element was %f\n", tab[0]);
+
+	starpu_submit_task(task);
+
+	fprintf(stderr, "AFTER First element is %f\n", tab[0]);
+
+	starpu_shutdown();
+
+	return 0;
+}