Document a bug with parallel executions.

[loba.git] / deployment.cpp

diff --git a/deployment.cpp b/deployment.cpp
index 8f52806bb15fc591f28b6c5c6215466fb4770627..bbb47e5392a1b55d58d5bb16e1e4a31e9b9df2cd 100644 (file)
--- a/deployment.cpp
+++ b/deployment.cpp
@@ -1,4 +1,5 @@
 #include <algorithm>
+#include <cmath>
 #include <cstdlib>
 #include <functional>
 #include <iomanip>
@@ -56,13 +57,39 @@ void deployment_generator::distribute_load()
         set_load(0, opt::auto_depl::load);
         return;
     }
-    srand48(opt::auto_depl::random_seed);
     std::vector<double> loads(hosts.size());
-    std::generate(loads.begin(), loads.end(), drand48);
+    if (opt::auto_depl::random_seed != 1) {
+        srand48(opt::auto_depl::random_seed);
+        std::generate(loads.begin(), loads.end(), drand48);
+    } else {
+        std::fill(loads.begin(), loads.end(), 1.0);
+    }
     double factor = opt::auto_depl::load /
         std::accumulate(loads.begin(), loads.end(), 0.0);
     std::transform(loads.begin(), loads.end(), loads.begin(),
                    std::bind(std::multiplies<double>(), _1, factor));
+    if (opt::integer_transfer) {
+        double iload;
+        double residue = 0.0;
+        unsigned i;
+        for (i = 0 ; i < hosts.size() - 1; ++i) {
+            if (residue < 0.0)
+                iload = std::floor(loads[i]);
+            else if (residue > 0.0)
+                iload = std::ceil(loads[i]);
+            else // residue == 0.0
+                iload = std::round(loads[i]);
+            residue += (loads[i] - iload);
+            loads[i] = iload;
+        }
+        // abs(round(...)) to avoid rounding errors, or a value of -0
+        // Note: i == hosts.size() - 1
+        iload = std::abs(std::round(loads[i] + residue));
+        loads[i] = iload;
+        // final sanity check
+        xbt_assert(opt::auto_depl::load ==
+                   std::accumulate(loads.begin(), loads.end(), 0.0));
+    }
     for (unsigned i = 0 ; i < hosts.size() ; ++i)
         set_load(i, loads[i]);
 }
@@ -159,7 +186,7 @@ void deployment_torus::generate()
             b = c;
     }
     unsigned width = b;
-    // here width == ceil(sqrt(size))
+    // here width == std::ceil(std::sqrt(size))
 
     unsigned first_on_last_line = (size() - 1) - (size() - 1) % width;
     XBT_DEBUG("torus size = %zu ; width = %u ; height = %zu ; foll = %u",