--- /dev/null
+/* Copyright (c) 2007-2015. The SimGrid Team.
+ * All rights reserved. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the license (GNU LGPL) which comes with this package. */
+
+#include "simgrid/msg.h"
+#include "simgrid/plugins/energy.h"
+
+XBT_LOG_NEW_DEFAULT_CATEGORY(msg_test, "Messages specific for this msg example");
+
+/** @addtogroup MSG_examples
+ *
+ * - <b>parallel_task/parallel_task.c</b>: Demonstrates the use of @ref MSG_parallel_task_create, to create special
+ * tasks that run on several hosts at the same time. The resulting simulations are very close to what can be
+ * achieved in @ref SD_API, but still allows to use the other features of MSG (it'd be cool to be able to mix
+ * interfaces, but it's not possible ATM).
+ */
+
+static int runner(int argc, char *argv[])
+{
+ /* Retrieve the list of all hosts as an array of hosts */
+ xbt_dynar_t slaves_dynar = MSG_hosts_as_dynar();
+ int slaves_count = xbt_dynar_length(slaves_dynar);
+ msg_host_t *slaves = xbt_dynar_to_array(slaves_dynar);
+
+ XBT_INFO("First, build a classical parallel task, with 1 Gflop to execute on each node, "
+ "and 10MB to exchange between each pair");
+ double *computation_amounts = xbt_new0(double, slaves_count);
+ double *communication_amounts = xbt_new0(double, slaves_count * slaves_count);
+
+ for (int i = 0; i < slaves_count; i++)
+ computation_amounts[i] = 1e9; // 1 Gflop
+
+ for (int i = 0; i < slaves_count; i++)
+ for (int j = i + 1; j < slaves_count; j++)
+ communication_amounts[i * slaves_count + j] = 1e7; // 10 MB
+
+ msg_task_t ptask =
+ MSG_parallel_task_create("parallel task", slaves_count, slaves, computation_amounts, communication_amounts, NULL);
+ MSG_parallel_task_execute(ptask);
+ MSG_task_destroy(ptask);
+ /* The arrays communication_amounts and computation_amounts are not to be freed manually */
+
+ XBT_INFO("Then, build a parallel task involving only computations and no communication (1 Gflop per node)");
+ computation_amounts = xbt_new0(double, slaves_count);
+ for (int i = 0; i < slaves_count; i++)
+ computation_amounts[i] = 1e9; // 1 Gflop
+ ptask =
+ MSG_parallel_task_create("parallel exec", slaves_count, slaves, computation_amounts, NULL/* no comm */, NULL);
+ MSG_parallel_task_execute(ptask);
+ MSG_task_destroy(ptask);
+
+ XBT_INFO("Finally, trick the ptask to do a 'remote execution', on host %s", MSG_host_get_name(slaves[1]));
+ computation_amounts = xbt_new0(double, 1);
+ computation_amounts[0] = 1e9; // 1 Gflop
+ msg_host_t *remote = xbt_new(msg_host_t,1);
+ remote[0] = slaves[1];
+ ptask = MSG_parallel_task_create("remote exec", 1, remote, computation_amounts, NULL/* no comm */, NULL);
+ MSG_parallel_task_execute(ptask);
+ MSG_task_destroy(ptask);
+ free(remote);
+
+ XBT_INFO("Goodbye now!");
+ free(slaves);
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ MSG_init(&argc, argv);
+ MSG_config("host/model", "ptask_L07");
+
+ xbt_assert(argc <= 3, "1Usage: %s <platform file> [--energy]", argv[0]);
+ xbt_assert(argc >= 2, "2Usage: %s <platform file> [--energy]", argv[0]);
+
+ if(argc == 3 && argv[2][2] == 'e')
+ sg_energy_plugin_init();
+
+ MSG_create_environment(argv[1]);
+
+ /* Pick a process, no matter which, from the platform file */
+ xbt_dynar_t all_hosts = MSG_hosts_as_dynar();
+ msg_host_t first_host = xbt_dynar_getfirst_as(all_hosts,msg_host_t);
+ xbt_dynar_free(&all_hosts);
+
+ MSG_process_create("test", runner, NULL, first_host);
+ msg_error_t res = MSG_main();
+ XBT_INFO("Simulation done.");
+
+ return res != MSG_OK;
+}
