processCrossEdges is now atomic

amgprec/impl/aggregator/processCrossEdge.cpp

@@ -4,20 +4,20 @@ void PROCESS_CROSS_EDGE(vector<MilanLongInt> &Counter,
                         MilanLongInt edge,
                         MilanLongInt *SPtr)
 {
-    // Decrement the counter:
     // Start: PARALLEL_PROCESS_CROSS_EDGE_B
-    if (Counter[edge] > 0)
+    MilanLongInt captureCounter;
-    {
+
-        Counter[edge] -= 1; // Decrement
+#pragma omp atomic capture
-        if (Counter[edge] == 0)
+    captureCounter = --Counter[edge]; // Decrement
-        {
+
+    if (captureCounter == 0)
+#pragma omp atomic
         (*SPtr)--; // Decrement S
+
 #ifdef PRINT_DEBUG_INFO_
     cout << "\n(" << myRank << ")Decrementing S: Ghost vertex " << edge << " has received all its messages";
     fflush(stdout);
 #endif
-        }
 
-    } // End of if Counter[edge] > 0
     // End: PARALLEL_PROCESS_CROSS_EDGE_B
 }

amgprec/impl/aggregator/processMatchedVertices.cpp

@@ -130,8 +130,6 @@ void processMatchedVertices(
                                                     Mate[v - StartIndex] = w;     // v is a local vertex
                                                     GMate[Ghost2LocalMap[w]] = v; // w is a ghost vertex
 
-                                                    // Decrement the counter:
-                                                    PROCESS_CROSS_EDGE(Counter, Ghost2LocalMap[w], SPtr);
                                                 } // End of if CandidateMate[w] = v
                                             }     // End of if a Ghost Vertex
                                             else
@@ -150,7 +148,8 @@ void processMatchedVertices(
                                             }     // End of Else
 
                                         } // End of if(w >=0)
-                                        else option = 4;// End of Else: w == -1
+                                        else
+                                            option = 4; // End of Else: w == -1
                                         // End:   PARALLEL_PROCESS_EXPOSED_VERTEX_B(v)
                                     }
                                 } // End of task
@@ -164,11 +163,11 @@ void processMatchedVertices(
                             {
                                 if (candidateMate[NLVer + Ghost2LocalMap[v]] == u)
                                     candidateMate[NLVer + Ghost2LocalMap[v]] = -1;
-                                if (v != Mate[u - StartIndex]) option = 5; // u is local
+                                if (v != Mate[u - StartIndex])
+                                    option = 5; // u is local
                             }                   // End of critical
                         }                       // End of Else //A Ghost Vertex
 
-
                         switch (option)
                         {
                         case -1:
@@ -184,6 +183,8 @@ void processMatchedVertices(
                             cout << "\n(" << myRank << ")MATCH: (" << v << "," << w << ") ";
                             fflush(stdout);
 #endif
+                            // Decrement the counter:
+                            PROCESS_CROSS_EDGE(Counter, Ghost2LocalMap[w], SPtr);
                         case 2:
                             // Found a dominating edge, it is a ghost
                             ghostOwner = findOwnerOfGhost(w, verDistance, myRank, numProcs);