adding example for multiple linear regression

examples/Makefile.am

@@ -193,6 +193,7 @@ STARPU_EXAMPLES +=				\
 if !STARPU_SIMGRID
 STARPU_EXAMPLES +=				\
 	basic_examples/hello_world		\
+	basic_examples/mlr			\
 	basic_examples/vector_scal		\
 	basic_examples/mult			\
 	basic_examples/block			\

examples/basic_examples/mlr.c

@@ -0,0 +1,124 @@
+/* StarPU --- Runtime system for heterogeneous multicore architectures.
+ *
+ * Copyright (C) 2010, 2015  Université de Bordeaux
+ * Copyright (C) 2010, 2011, 2012, 2013  CNRS
+ *
+ * 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 examples demonstrates how to construct and submit a task to StarPU and
+ * more precisely:
+ *  - how to allocate a new task structure (starpu_task_create)
+ *  - how to describe a multi-versionned computational kernel (ie. a codelet) 
+ *  - how to pass an argument to the codelet (task->cl_arg)
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <starpu.h>
+
+#define FPRINTF(ofile, fmt, ...) do { if (!getenv("STARPU_SSILENT")) {fprintf(ofile, fmt, ## __VA_ARGS__); }} while(0)
+
+/* When the task is done, task->callback_func(task->callback_arg) is called. Any
+ * callback function must have the prototype void (*)(void *).
+ * NB: Callback are NOT allowed to perform potentially blocking operations */
+void callback_func(void *callback_arg)
+{       
+}
+
+/* Every implementation of a codelet must have this prototype, the first
+ * argument (buffers) describes the buffers/streams that are managed by the
+ * DSM; the second arguments references read-only data that is passed as an
+ * argument of the codelet (task->cl_arg). Here, "buffers" is unused as there
+ * are no data input/output managed by the DSM (cl.nbuffers = 0) */
+struct params
+{
+	int m;
+	int n;
+	int k;
+};
+
+void cpu_func(void *buffers[], void *cl_arg)
+{
+	struct params *params = (struct params *) cl_arg;
+
+	for(int i=0; i< params->m * params->m * params->n; i++)
+		printf("**i");
+
+	for(int i=0; i< params->n * params->n * params->k; i++)
+		printf("*i");
+}
+
+int main(int argc, char **argv)
+{
+	struct starpu_codelet cl;
+	struct starpu_task *task;
+	struct params params = {1, 2, 3};
+	int ret;
+
+	/* initialize StarPU : passing a NULL argument means that we use
+ 	* default configuration for the scheduling policies and the number of
+	* processors/accelerators */
+	ret = starpu_init(NULL);
+	if (ret == -ENODEV)
+		return 77;
+	STARPU_CHECK_RETURN_VALUE(ret, "starpu_init");
+
+	/* create a new task that is non-blocking by default : the task is not
+	 * submitted to the scheduler until the starpu_task_submit function is
+	 * called */
+	task = starpu_task_create();
+
+	starpu_codelet_init(&cl);
+	/* this codelet may only be executed on a CPU, and its cpu
+ 	 * implementation is function "cpu_func" */
+	cl.cpu_funcs[0] = cpu_func;
+	cl.cpu_funcs_name[0] = "test_codelet";
+	/* the codelet does not manipulate any data that is managed
+	 * by our DSM */
+	cl.nbuffers = 0;
+	cl.name="test";
+
+	/* the task uses codelet "cl" */
+	task->cl = &cl;
+
+	/* It is possible to pass buffers that are not managed by the DSM to the
+ 	 * kernels: the second argument of the "cpu_func" function is a pointer to a
+	 * buffer that contains information for the codelet (cl_arg stands for
+	 * codelet argument). In the case of accelerators, it is possible that
+	 * the codelet is given a pointer to a copy of that buffer: this buffer
+	 * is read-only so that any modification is not passed to other copies
+	 * of the buffer.  For this reason, a buffer passed as a codelet
+	 * argument (cl_arg) is NOT a valid synchronization medium! */
+	task->cl_arg = &params;
+	task->cl_arg_size = sizeof(params);
+
+	/* submit the task to StarPU */
+	ret = starpu_task_submit(task);
+	if (ret == -ENODEV) goto enodev;
+	STARPU_CHECK_RETURN_VALUE(ret, "starpu_task_submit");
+
+	/* terminate StarPU: statistics and other debug outputs are not
+	 * guaranteed to be generated unless this function is called. Once it
+	 * is called, it is not possible to submit tasks anymore, and the user
+	 * is responsible for making sure all tasks have already been executed:
+	 * calling starpu_shutdown() before the termination of all the tasks
+	 * results in an undefined behaviour */
+	starpu_shutdown();
+
+	return 0;
+
+enodev:
+	starpu_shutdown();
+	return 77;
+}