X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/5467c565b7568483e25701d74f1167e1fb6ef455..aab64d52aa5254ee3f16264bc3cf83896d5e3879:/examples/msg/parallel_task/parallel_task.c

diff --git a/examples/msg/parallel_task/parallel_task.c b/examples/msg/parallel_task/parallel_task.c
index 7dd874865f..13866dd96c 100644
--- a/examples/msg/parallel_task/parallel_task.c
+++ b/examples/msg/parallel_task/parallel_task.c
@@ -1,94 +1,96 @@
-/* 	$Id$	 */
-
-/* Copyright (c) 2002,2003,2004 Arnaud Legrand. All rights reserved.        */
+/* 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 <stdio.h>
-#include "msg/msg.h" /* Yeah! If you want to use msg, you need to include msg/msg.h */
-#include "xbt/sysdep.h" /* calloc, printf */
+#include "simgrid/msg.h"        /* Yeah! If you want to use msg, you need to include simgrid/msg.h */
+#include "xbt/sysdep.h"         /* calloc, printf */
 
 /* Create a log channel to have nice outputs. */
 #include "xbt/log.h"
 #include "xbt/asserts.h"
-XBT_LOG_NEW_DEFAULT_CATEGORY(msg_test,"Messages specific for this msg example");
+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).
+ */
+
+
+/** Function in charge of running the example (that's a simgrid process) */
+static int runner(int argc, char *argv[])
+{
+  int i, j;
 
-int test(int argc, char *argv[]);
-MSG_error_t test_all(const char *platform_file);
+  /* 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);
 
-/** Emitter function  */
-int test(int argc, char *argv[])
-{
-  int slaves_count = 0;
-  m_host_t *slaves = NULL;
-  double task_comp_size = 100000;
-  double task_comm_size = 10000;
-  double *computation_amount = NULL;
-  double *communication_amount = NULL;
-  m_task_t ptask = NULL;
-  int i,j;
-
-  slaves_count = MSG_get_host_number();
-  slaves = MSG_get_host_table();
-
-  computation_amount = xbt_new0(double,slaves_count);
-  communication_amount = xbt_new0(double,slaves_count*slaves_count);
-  
-  for(i=0;i<slaves_count;i++) 
-    computation_amount[i]=task_comp_size;
-
-  for(i=0;i<slaves_count;i++) 
-    for(j=i+1;j<slaves_count;j++) 
-      communication_amount[i*slaves_count+j]=task_comm_size;
-
-  ptask = MSG_parallel_task_create("parallel task",
-				   slaves_count, slaves,
-				   computation_amount,
-				   communication_amount,
-				   NULL);
+  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 (i = 0; i < slaves_count; i++)
+    computation_amounts[i] = 1e9; // 1 Gflop
+
+  for (i = 0; i < slaves_count; i++)
+    for (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 /* no specific data to attach */);
+  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 (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 /* no data */);
   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 /* no data */);
+  MSG_parallel_task_execute(ptask);
+  MSG_task_destroy(ptask);
+  free(remote);
 
-  /* There is no need to free that! */
-/*   free(communication_amount); */
-/*   free(computation_amount); */
-  
-  INFO0("Goodbye now!");
+  XBT_INFO("Goodbye now!");
   free(slaves);
   return 0;
-} 
+}
 
-/** Test function */
-MSG_error_t test_all(const char *platform_file)
+int main(int argc, char *argv[])
 {
-  MSG_error_t res = MSG_OK;
+  MSG_init(&argc, argv);
+  MSG_config("host/model", "ptask_L07");
 
-  MSG_config("workstation_model","ptask_L07");
-  MSG_set_channel_number(1);
-  MSG_create_environment(platform_file);
+  xbt_assert(argc > 1, "Usage: %s <platform file>", argv[0]);
+  MSG_create_environment(argv[1]);
 
-  MSG_process_create("test",test,NULL,MSG_get_host_table()[0]);
-  res = MSG_main();
-  
-  INFO1("Simulation time %g",MSG_get_clock());
-  return res;
-}
+  /* 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);
 
-int main(int argc, char *argv[])
-{
-  MSG_error_t res = MSG_OK;
-
-  MSG_global_init(&argc,argv);
-  if (argc < 2) {
-     printf ("Usage: %s platform_file\n",argv[0]);
-     printf ("example: %s msg_platform.xml\n",argv[0]);
-     exit(1);
-  }
-  res = test_all(argv[1]);
-  MSG_clean();
-
-  if(res==MSG_OK)
-    return 0;
-  else
-    return 1;
+  MSG_process_create("test", runner, NULL, first_host);
+  msg_error_t res = MSG_main();
+  XBT_INFO("Simulation done.");
+
+  return res != MSG_OK;
 }