Reduce false sharing by late array assignment

src/dijsktra_omp.c

@@ -101,6 +101,9 @@ int main(int argc, char *argv[]) {
             // find local minima
             #pragma omp parallel num_threads(thread_count) shared(minimumLocalDist,minimumLocalNode,graph,minDist)
             {
+
+                int minLocalDist = -1;
+                int minLocalNode = -1;
                 int my_rank = omp_get_thread_num();
                 for (int node = binSize * my_rank; node < binSize * (my_rank + 1); node++) {
                     if (!visited[node]) {
@@ -108,15 +111,18 @@ int main(int argc, char *argv[]) {
                             minDist[node] = minDist[activeNode] + graph[activeNode * n_nodes + node];
                         }
 
-                        if (minimumLocalDist[my_rank] == -1) {
-                            minimumLocalDist[my_rank] = minDist[node];
-                            minimumLocalNode[my_rank] = node;
-                        } else if (minimumLocalDist[my_rank] > minDist[node]) {
-                            minimumLocalDist[my_rank] = minDist[node];
-                            minimumLocalNode[my_rank] = node;
+                        if (minLocalDist == -1) {
+                            minLocalDist = minDist[node];
+                            minLocalNode = node;
+                        } else if (minLocalDist > minDist[node]) {
+                            minLocalDist = minDist[node];
+                            minLocalNode = node;
                         }
                     }
                 }
+
+                minimumLocalDist[my_rank] = minLocalDist;
+                minimumLocalNode[my_rank] = minLocalNode;
             }
 
             thrMinimum = 0;