add example for data filtering (as seen in manual)

examples/Makefile.am

@@ -160,6 +160,16 @@ examplebin_PROGRAMS +=				\
 basic_examples_mult_SOURCES =			\
 	basic_examples/mult.c
 
+###########
+# Filters #
+###########
+
+examplebin_PROGRAMS +=				\
+	filters/filters
+
+filters_filters_SOURCES =			\
+	filters/filters.c
+
 ###################
 # PPM downscaling #
 ###################

examples/filters/filters.c

@@ -0,0 +1,92 @@
+/*
+ * 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 <starpu.h>
+
+#define NX    21
+#define PARTS 3
+
+void cpu_func(void *buffers[], void *cl_arg)
+{
+        unsigned i;
+        int *factor = cl_arg;
+
+        /* length of the vector */
+        unsigned n = STARPU_GET_VECTOR_NX(buffers[0]);
+        /* local copy of the vector pointer */
+        int *val = (int *)STARPU_GET_VECTOR_PTR(buffers[0]);
+
+        for (i = 0; i < n; i++)
+                val[i] *= *factor;
+}
+
+int main(int argc, char **argv)
+{
+	unsigned i;
+        int vector[NX];
+        starpu_data_handle handle;
+        int factor=1;
+
+        starpu_codelet cl = {
+                .where = STARPU_CPU,
+                .cpu_func = cpu_func,
+                .nbuffers = 1
+        };
+
+        for(i=0 ; i<NX ; i++) vector[i] = i;
+        fprintf(stderr,"IN  Vector: ");
+        for(i=0 ; i<NX ; i++) fprintf(stderr, "%d ", vector[i]);
+        fprintf(stderr,"\n");
+
+	starpu_init(NULL);
+
+	/* Declare data to StarPU */
+	starpu_vector_data_register(&handle, 0, (uintptr_t)vector, NX, sizeof(vector[0]));
+
+        /* Partition the vector in PARTS sub-vectors */
+	starpu_filter f =
+	{
+		.filter_func = starpu_block_filter_func_vector,
+		.filter_arg = PARTS
+	};
+	starpu_data_partition(handle, &f);
+
+        /* Submit a task on each sub-vector */
+	for (i=0; i<PARTS; i++)
+	{
+                starpu_data_handle sub_handle = starpu_data_get_sub_data(handle, 1, i);
+                struct starpu_task *task = starpu_task_create();
+
+                factor *= 10;
+		task->buffers[0].handle = sub_handle;
+		task->buffers[0].mode = STARPU_R;
+                task->cl = &cl;
+                task->synchronous = 1;
+                task->cl_arg = &factor;
+                task->cl_arg_size = sizeof(factor);
+
+		starpu_task_submit(task);
+	}
+
+        starpu_data_unregister(handle);
+	starpu_shutdown();
+
+        fprintf(stderr,"OUT Vector: ");
+        for(i=0 ; i<NX ; i++) fprintf(stderr, "%d ", vector[i]);
+        fprintf(stderr,"\n");
+
+	return 0;
+}