openfoam+stella: 5-MOAD scan; openfoam-0002 CWE-407, stella CLEAN

openfoam-0002: CFCFaceToCellStencil::calcCellStencil allGlobalFaces dedup uses findIndex() O(G) linear scan inside nested forAll(cells)*forAll(faces) loop. Developer left comment "Note:should use hashset?" — confirmed defect. Fix: labelHashSet seen replaces findIndex, 77x op-count speedup at C=2000/F=12. stella: all 5 MOADs CLEAN. BreakpointMap uses unordered_map O(1); TrapArray uses std::array<uInt8,0x10000> O(1); single-threaded, no credentials, no thread-local identity, no thundering herd.
2026-03-31 21:55:06 -04:00 · 2026-03-31 21:55:06 -04:00 · edf083b2c4
commit edf083b2c4
parent 38b5c504cf
5 changed files with 593 additions and 0 deletions
--- a/defects/openfoam-0002/patch/openfoam-0002-cfcfacetocelstencil-hashset.patch
+++ b/defects/openfoam-0002/patch/openfoam-0002-cfcfacetocelstencil-hashset.patch
@ -0,0 +1,104 @@
+# UNDF:
+--- a/src/finiteVolume/fvMesh/extendedStencil/faceToCell/globalIndexStencils/CFCFaceToCellStencil.C
+++ b/src/finiteVolume/fvMesh/extendedStencil/faceToCell/globalIndexStencils/CFCFaceToCellStencil.C
+@@ -28,6 +28,7 @@ License
+
+ #include "CFCFaceToCellStencil.H"
+ #include "syncTools.H"
+#include "HashSet.H"
+
+ // * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
+
+@@ -128,37 +129,42 @@ void Foam::CFCFaceToCellStencil::calcCellStencil
+     // Determine faces of cellCells in global numbering
+     // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+-    DynamicList<label> allGlobalFaces(100);
+    DynamicList<label> allGlobalFaces(100);
+    labelHashSet seen(100);
+
+     globalCellFaces.setSize(mesh().nCells());
+     forAll(globalCellFaces, celli)
+     {
+         const cell& cFaces = mesh().cells()[celli];
+
+         allGlobalFaces.clear();
+        seen.clear();
+
+         // My faces first
+         forAll(cFaces, i)
+         {
+             label facei = cFaces[i];
+
+             if
+             (
+                 mesh().isInternalFace(facei)
+              || validBFace[facei-mesh().nInternalFaces()]
+             )
+             {
+-                allGlobalFaces.append(globalNumbering().toGlobal(facei));
+                label globalI = globalNumbering().toGlobal(facei);
+                if (seen.insert(globalI))
+                {
+                    allGlobalFaces.append(globalI);
+                }
+             }
+         }
+
+         // faces of neighbouring cells second
+         forAll(cFaces, i)
+         {
+             label facei = cFaces[i];
+
+             if (mesh().isInternalFace(facei))
+             {
+                 label nbrCelli = own[facei];
+                 if (nbrCelli == celli)
+                 {
+                     nbrCelli = nei[facei];
+                 }
+                 const cell& nbrFaces = mesh().cells()[nbrCelli];
+
+                 forAll(nbrFaces, j)
+                 {
+                     label nbrFacei = nbrFaces[j];
+
+                     if
+                     (
+                         mesh().isInternalFace(nbrFacei)
+                      || validBFace[nbrFacei-mesh().nInternalFaces()]
+                     )
+                     {
+                         label nbrGlobalI = globalNumbering().toGlobal(nbrFacei);
+
+-                        // Check if already there. Note:should use hashset?
+-                        if (findIndex(allGlobalFaces, nbrGlobalI) == -1)
+                        if (seen.insert(nbrGlobalI))
+                         {
+                             allGlobalFaces.append(nbrGlobalI);
+                         }
+                     }
+                 }
+             }
+             else
+             {
+                 const labelList& nbrGlobalFaces =
+                     neiGlobal[facei-mesh().nInternalFaces()];
+
+                 forAll(nbrGlobalFaces, j)
+                 {
+                     label nbrGlobalI = nbrGlobalFaces[j];
+
+-                    // Check if already there. Note:should use hashset?
+-                    if (findIndex(allGlobalFaces, nbrGlobalI) == -1)
+                    if (seen.insert(nbrGlobalI))
+                     {
+                         allGlobalFaces.append(nbrGlobalI);
+                     }
+                 }
+             }
+         }
+
+         globalCellFaces[celli] = allGlobalFaces;
+     }
+ }