API change in SimGrid 3.8: MSG_global_init -> MSG_init.

[loba.git] / loba_bulk.cpp

diff --git a/loba_bulk.cpp b/loba_bulk.cpp
index 9af50cf0f22c3b4ec1d695dcdfdee97c252318d3..de9c0998cb266e421ba9a08f6d169e637385ea05 100644 (file)
--- a/loba_bulk.cpp
+++ b/loba_bulk.cpp
@@ -1,3 +1,4 @@
+#include <cmath>

 #include <xbt/log.h>
 
 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(loba);
 #include <xbt/log.h>
 
 XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(loba);


@@ -6,8 +7,88 @@ XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(loba);
 
 void loba_bulk::load_balance()
 {
 
 void loba_bulk::load_balance()
 {

-    // write code here...
-    xbt_die("Load-balancing algorithm \"bulk\" not implemented!");
+    float myLoad = get_load();
+
+    unsigned NbNwMinLoad = 0;
+    unsigned NbNwLowerLoad = 0;
+    unsigned NbNeighbours = pneigh.size();
+
+    double *S = new double[NbNeighbours];
+    for (unsigned i = 0; i < NbNeighbours; i++)
+        S[i] = 0.0;
+
+    // What is the minimum and maximum load under myLoad?
+    float minLoad = myLoad;
+    for (unsigned i = 0; i < NbNeighbours; i++) {
+        if (pneigh[i]->get_load() < minLoad) {
+            minLoad = pneigh[i]->get_load();
+        }
+        if (pneigh[i]->get_load() < myLoad) {
+            NbNwLowerLoad++;
+        }
+    }
+    for (unsigned i = 0; i < NbNeighbours; i++)
+        if (pneigh[i]->get_load() == minLoad)
+            NbNwMinLoad++;
+
+    float maxLoad = minLoad;
+    for (unsigned i = 0; i < NbNeighbours; i++) {
+        if (pneigh[i]->get_load() > minLoad && pneigh[i]->get_load() < myLoad)
+            if (maxLoad < pneigh[i]->get_load())
+                maxLoad = pneigh[i]->get_load();
+    }
+
+    double alpha = 0.0;
+
+    if (NbNwLowerLoad && NbNwMinLoad < NbNwLowerLoad) {
+        // There is one or many neighbors with minimum load but not
+        // all neighbors have minimum load
+        alpha = (1. / ((double) NbNwMinLoad + 2));
+    }
+    if (NbNwMinLoad == NbNwLowerLoad) {
+        // All neighbors have minimum load
+        alpha = (1. / ((double) NbNwMinLoad + 1));
+    }
+    float myS = 0.;
+    // There exist underloaded neighbors
+    if (NbNwMinLoad && myLoad != 0.0) {
+        for (unsigned i = 0; i < NbNeighbours; i++) {
+            if (pneigh[i]->get_load() == minLoad) {
+                S[i] = std::floor(alpha * (myLoad - minLoad));
+                myS += S[i];
+            } else {
+                if (pneigh[i]->get_load() < myLoad) {
+                    S[i] = std::floor(alpha * (myLoad - pneigh[i]->get_load()));
+                    myS += S[i];
+                }
+            }
+        }
+        // Check assumption 4.2 (b) page 520
+        bool HaveToCorrectS = false;
+        for (unsigned i = 0; i < NbNeighbours; i++) {
+            if (pneigh[i]->get_load() < myLoad) {
+                // Condition 4.6
+                if ((myLoad - myS) < (pneigh[i]->get_load() + S[i])) {
+                    HaveToCorrectS = true;
+                }
+            }
+        }
+        if (HaveToCorrectS) {
+            for (unsigned i = 0; i < NbNeighbours; i++) {
+                while (((myLoad - myS) < pneigh[i]->get_load() + S[i])
+                       && (S[i] > 0)) {
+                    myS -= 1.0;
+                    S[i] -= 1.0;
+                }
+            }
+        }
+    } // End there are underloaded neighbors;
+    for (unsigned i = 0; i < NbNeighbours; i++) {
+        send(pneigh[i], S[i]);
+        XBT_DEBUG("sent to %s", pneigh[i]->get_name());
+    }
+
+    delete[] S;

 }
 
 // Local variables:
 }
 
 // Local variables: