From c1bb2ac02db6e5e348ebe3a13bdd4a1b8877b47b Mon Sep 17 00:00:00 2001
From: andy <andy>
Date: Tue, 27 Sep 2011 15:40:28 +0100
Subject: [PATCH] ENH: AMI - only run parallel distributed if AMI is
 distributed

---
 .../AMIInterpolation/AMIInterpolation.C       | 33 ++++++++++++++++++-
 .../AMIInterpolation/AMIInterpolation.H       |  7 ++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.C b/src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.C
index aa638ebd38..535583a9e1 100644
--- a/src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.C
+++ b/src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.C
@@ -119,6 +119,37 @@ void Foam::AMIInterpolation<SourcePatch, TargetPatch>::checkPatches
 }
 
 
+template<class SourcePatch, class TargetPatch>
+bool Foam::AMIInterpolation<SourcePatch, TargetPatch>::distributed
+(
+    const primitivePatch& srcPatch,
+    const primitivePatch& tgtPatch
+)
+{
+    if (Pstream::parRun())
+    {
+        List<label> facesPresentOnProc(Pstream::nProcs(), 0);
+        if ((srcPatch.size() > 0) || (tgtPatch.size() > 0))
+        {
+            facesPresentOnProc[Pstream::myProcNo()] = 1;
+        }
+        else
+        {
+            facesPresentOnProc[Pstream::myProcNo()] = 0;
+        }
+
+        Pstream::gatherList(facesPresentOnProc);
+        Pstream::scatterList(facesPresentOnProc);
+        if (sum(facesPresentOnProc) > 1)
+        {
+            return true;
+        }
+    }
+    
+    return false;
+}
+
+
 template<class SourcePatch, class TargetPatch>
 Foam::label
 Foam::AMIInterpolation<SourcePatch, TargetPatch>::calcOverlappingProcs
@@ -1160,7 +1191,7 @@ void Foam::AMIInterpolation<SourcePatch, TargetPatch>::update
 {
     static label patchI = 0;
 
-    if (Pstream::parRun())
+    if (Pstream::parRun() && distributed(srcPatch, tgtPatch))
     {
         // convert local addressing to global addressing
         globalIndex globalSrcFaces(srcPatch.size());
diff --git a/src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.H b/src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.H
index 8ad3be39ba..b9d73f24ee 100644
--- a/src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.H
+++ b/src/meshTools/AMIInterpolation/AMIInterpolation/AMIInterpolation.H
@@ -167,6 +167,13 @@ class AMIInterpolation
 
         // Parallel functionality
 
+            //- Return true if faces are spread over multiple domains
+            bool distributed
+            (
+                const primitivePatch& srcPatch,
+                const primitivePatch& tgtPatch
+            );
+
             label calcOverlappingProcs
             (
                 const List<treeBoundBoxList>& procBb,