examples: add example to show how to partition matrices

examples/Makefile.am

@@ -165,11 +165,15 @@ basic_examples_mult_SOURCES =			\
 ###########
 
 examplebin_PROGRAMS +=				\
-	filters/filters
+	filters/filters				\
+	filters/fmatrix
 
 filters_filters_SOURCES =			\
 	filters/filters.c
 
+filters_fmatrix_SOURCES =				\
+	filters/fmatrix.c
+
 ###################
 # PPM downscaling #
 ###################

examples/filters/fmatrix.c

@@ -0,0 +1,109 @@
+/*
+ * 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    5
+#define NY    4
+#define PARTS 2
+
+void cpu_func(void *buffers[], void *cl_arg)
+{
+        unsigned i, j;
+        int *factor = cl_arg;
+
+        /* length of the matrix */
+        unsigned nx = STARPU_GET_MATRIX_NX(buffers[0]);
+        unsigned ny = STARPU_GET_MATRIX_NY(buffers[0]);
+        unsigned ld = STARPU_GET_MATRIX_LD(buffers[0]);
+        /* local copy of the matrix pointer */
+        int *val = (int *)STARPU_GET_MATRIX_PTR(buffers[0]);
+
+        for(j=0; j<ny ; j++) {
+                for(i=0; i<nx ; i++)
+                        val[(j*ld)+i] = *factor;
+        }
+}
+
+int main(int argc, char **argv)
+{
+	unsigned i, j, n=1;
+        int matrix[NX*NY];
+        starpu_data_handle handle;
+        int factor=1;
+
+        starpu_codelet cl = {
+                .where = STARPU_CPU,
+                .cpu_func = cpu_func,
+                .nbuffers = 1
+        };
+
+        fprintf(stderr,"IN  Matrix: \n");
+        for(j=0 ; j<NY ; j++) {
+                for(i=0 ; i<NX ; i++) {
+                        matrix[(j*NX)+i] = n++;
+                        fprintf(stderr, "%2d ", matrix[(j*NX)+i]);
+                }
+                fprintf(stderr,"\n");
+        }
+        fprintf(stderr,"\n");
+
+	starpu_init(NULL);
+
+	/* Declare data to StarPU */
+	starpu_matrix_data_register(&handle, 0, (uintptr_t)matrix, NX, NX, NY, sizeof(matrix[0]));
+
+        /* Partition the matrix in PARTS sub-matrices */
+	struct starpu_data_filter f =
+	{
+		.filter_func = starpu_block_filter_func,
+		.nchildren = PARTS,
+		.get_nchildren = NULL,
+		.get_child_ops = NULL
+	};
+	starpu_data_partition(handle, &f);
+
+        /* Submit a task on each sub-vector */
+	for (i=0; i<PARTS; i++)
+	{
+                struct starpu_task *task = starpu_task_create();
+
+                factor = i;//10;
+		task->buffers[0].handle = starpu_data_get_sub_data(handle, 1, i);
+		task->buffers[0].mode = STARPU_RW;
+                task->cl = &cl;
+                task->synchronous = 1;
+                task->cl_arg = &factor;
+                task->cl_arg_size = sizeof(factor);
+
+		starpu_task_submit(task);
+	}
+
+	starpu_data_unpartition(handle, 0);
+        starpu_data_unregister(handle);
+	starpu_shutdown();
+
+        fprintf(stderr,"OUT Matrix: \n");
+        for(j=0 ; j<NY ; j++) {
+                for(i=0 ; i<NX ; i++) {
+                        fprintf(stderr, "%2d ", matrix[(j*NX)+i]);
+                }
+                fprintf(stderr,"\n");
+        }
+        fprintf(stderr,"\n");
+
+	return 0;
+}