From 7593cbfc4657e206415167818fe2110b2f125302 Mon Sep 17 00:00:00 2001
From: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr>
Date: Thu, 16 May 2013 16:32:03 +0200
Subject: [PATCH] Revert "Remove parmap from surf."

This reverts commit 61a993d9efe970edcbb1cb3d947553b2f188b327.
---
 src/simgrid/sg_config.c | 12 ++++++++
 src/surf/surf.c         | 68 +++++++++++++++++++++++++++++++++++++----
 2 files changed, 74 insertions(+), 6 deletions(-)

diff --git a/src/simgrid/sg_config.c b/src/simgrid/sg_config.c
index b812c87d55..4203815fc1 100644
--- a/src/simgrid/sg_config.c
+++ b/src/simgrid/sg_config.c
@@ -389,6 +389,11 @@ static void _sg_cfg_cb__surf_network_coordinates(const char *name,
       xbt_die("Setting of whether to use coordinate cannot be disabled once set.");
 }
 
+static void _sg_cfg_cb_surf_nthreads(const char *name, int pos)
+{
+  surf_set_nthreads(xbt_cfg_get_int(_sg_cfg_set, name));
+}
+
 static void _sg_cfg_cb__surf_network_crosstraffic(const char *name,
                                                   int pos)
 {
@@ -658,6 +663,13 @@ void sg_config_init(int *argc, char **argv)
     xbt_cfg_setdefault_string(_sg_cfg_set, "contexts/synchro", "busy_wait");
 #endif
 
+    /* number of parallel threads for Surf */
+    xbt_cfg_register(&_sg_cfg_set, "surf/nthreads",
+                     "Number of parallel threads used to update Surf models",
+                     xbt_cfgelm_int, NULL, 1, 1,
+                     _sg_cfg_cb_surf_nthreads, NULL);
+    xbt_cfg_setdefault_int(_sg_cfg_set, "surf/nthreads", surf_get_nthreads());
+
     xbt_cfg_register(&_sg_cfg_set, "network/coordinates",
                      "\"yes\" or \"no\", specifying whether we use a coordinate-based routing (as Vivaldi)",
                      xbt_cfgelm_boolean, 1, 1, _sg_cfg_cb__surf_network_coordinates, NULL);
diff --git a/src/surf/surf.c b/src/surf/surf.c
index 807bfaf8d5..c3c1d93c03 100644
--- a/src/surf/surf.c
+++ b/src/surf/surf.c
@@ -567,9 +567,20 @@ double surf_solve(double max_date)
   }
   surf_min_index = 0;
 
-  /* sequential version */
-  xbt_dynar_foreach(model_list, iter, model) {
-    surf_share_resources(model);
+
+  if (surf_get_nthreads() > 1) {
+    /* parallel version */
+#ifdef CONTEXT_THREADS
+    xbt_parmap_apply(surf_parmap, (void_f_pvoid_t) surf_share_resources, model_list);
+#else
+    xbt_die("Asked to run in parallel, but no thread at hand...");
+#endif
+  }
+  else {
+    /* sequential version */
+    xbt_dynar_foreach(model_list, iter, model) {
+      surf_share_resources(model);
+    }
   }
 
   unsigned i;
@@ -648,9 +659,17 @@ double surf_solve(double max_date)
 
   NOW = NOW + min;
 
-  /* sequential version */
-  xbt_dynar_foreach(model_list, iter, model) {
-    surf_update_actions_state(model);
+  if (surf_get_nthreads() > 1) {
+    /* parallel version */
+#ifdef CONTEXT_THREADS
+    xbt_parmap_apply(surf_parmap, (void_f_pvoid_t) surf_update_actions_state, model_list);
+#endif
+  }
+  else {
+    /* sequential version */
+    xbt_dynar_foreach(model_list, iter, model) {
+      surf_update_actions_state(model);
+    }
   }
 
 #ifdef HAVE_TRACING
@@ -683,3 +702,40 @@ static void surf_update_actions_state(surf_model_t model)
   model->model_private->update_actions_state(NOW, min);
 }
 
+/**
+ * \brief Returns the number of parallel threads used to update the models.
+ * \return the number of threads (1 means no parallelism)
+ */
+int surf_get_nthreads(void) {
+  return surf_nthreads;
+}
+
+/**
+ * \brief Sets the number of parallel threads used to update the models.
+ *
+ * A value of 1 means no parallelism.
+ *
+ * \param nb_threads the number of threads to use
+ */
+void surf_set_nthreads(int nthreads) {
+
+  if (nthreads<=0) {
+     nthreads = xbt_os_get_numcores();
+     XBT_INFO("Auto-setting surf/nthreads to %d",nthreads);
+  }
+
+#ifdef CONTEXT_THREADS
+  xbt_parmap_destroy(surf_parmap);
+  surf_parmap = NULL;
+#endif
+
+  if (nthreads > 1) {
+#ifdef CONTEXT_THREADS
+    surf_parmap = xbt_parmap_new(nthreads, XBT_PARMAP_DEFAULT);
+#else
+    THROWF(arg_error, 0, "Cannot activate parallel threads in Surf: your architecture does not support threads");
+#endif
+  }
+
+  surf_nthreads = nthreads;
+}
-- 
2.20.1