BUG: processorCyclic was using incorrect message tag.

Both sides need to use the same tag so it is now calculated as
    nProcs*(max(myProcNo,neighProcNo) + min(myProcNo,neighProcNo)
which is
- commutative
- does not interfere with normal message tag 1

src/OpenFOAM/db/IOstreams/Pstreams/UPstream.C

@@ -219,30 +219,6 @@ Foam::List<int> Foam::UPstream::procIDs_(1, 0);
 // Standard transfer message type
 int Foam::UPstream::msgType_(1);
 
-// New message type 
-int Foam::UPstream::freeTag_(msgType()+1);
-
-// Free'd message types
-Foam::LIFOStack<int> Foam::UPstream::freedTags_;
-
-int Foam::UPstream::allocateTag()
-{
-    if (freedTags_.empty())
-    {
-        return freeTag_++;
-    }
-    else
-    {
-        return freedTags_.pop();
-    }
-}
-
-void Foam::UPstream::freeTag(const int tag)
-{
-    freedTags_.push(tag);
-}
-
-
 // Linear communication schedule
 Foam::List<Foam::UPstream::commsStruct> Foam::UPstream::linearCommunication_(0);
 

src/OpenFOAM/db/IOstreams/Pstreams/UPstream.H

@@ -45,7 +45,6 @@ SourceFiles
 #include "HashTable.H"
 #include "string.H"
 #include "NamedEnum.H"
-#include "LIFOStack.H"
 
 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
@@ -191,12 +190,6 @@ private:
         static List<commsStruct> treeCommunication_;
 
 
-        //- Current free tag
-        static int freeTag_;
-
-        //- Freed tags
-        static LIFOStack<int> freedTags_;
-
     // Private Member Functions
 
         //- Set data for parallel running
@@ -346,11 +339,6 @@ public:
         {
             return msgType_;
         }
-        //- Allocate new tag
-        static int allocateTag();
-
-        //- Release allocated tag
-        static void freeTag(const int tag);
 
 
             //- Get the communications type of the stream

src/OpenFOAM/meshes/polyMesh/polyPatches/constraint/processorCyclic/processorCyclicPolyPatch.C

@@ -55,10 +55,20 @@ Foam::processorCyclicPolyPatch::processorCyclicPolyPatch
 )
 :
     processorPolyPatch(name, size, start, index, bm, myProcNo, neighbProcNo),
-    tag_(UPstream::allocateTag()),
+    tag_
+    (
+        Pstream::nProcs()*max(myProcNo, neighbProcNo)
+      + min(myProcNo, neighbProcNo)
+    ),
     referPatchName_(referPatchName),
     referPatchID_(-1)
-{}
+{
+    if (debug)
+    {
+        Pout<< "processorCyclicPolyPatch " << name << " uses tag " << tag_
+            << endl;
+    }
+}
 
 
 Foam::processorCyclicPolyPatch::processorCyclicPolyPatch
@@ -70,10 +80,20 @@ Foam::processorCyclicPolyPatch::processorCyclicPolyPatch
 )
 :
     processorPolyPatch(name, dict, index, bm),
-    tag_(UPstream::allocateTag()),
+    tag_
+    (
+        Pstream::nProcs()*max(myProcNo(), neighbProcNo())
+      + min(myProcNo(), neighbProcNo())
+    ),
     referPatchName_(dict.lookup("referPatch")),
     referPatchID_(-1)
-{}
+{
+    if (debug)
+    {
+        Pout<< "processorCyclicPolyPatch " << name << " uses tag " << tag_
+            << endl;
+    }
+}
 
 
 Foam::processorCyclicPolyPatch::processorCyclicPolyPatch
@@ -125,9 +145,7 @@ Foam::processorCyclicPolyPatch::processorCyclicPolyPatch
 // * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
 
 Foam::processorCyclicPolyPatch::~processorCyclicPolyPatch()
-{
-    UPstream::freeTag(tag_);
-}
+{}
 
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //