[ICoCo]: ICoCo part as a new sub library: libmedicoco.so

[tools/medcoupling.git] / src / ParaMEDMEM / StructuredCoincidentDEC.hxx

diff --git a/src/ParaMEDMEM/StructuredCoincidentDEC.hxx b/src/ParaMEDMEM/StructuredCoincidentDEC.hxx
index 63f0f9120c63489edf468c11a5fbf5693ab383e6..2cf1bf9d43d2b7b1e31a6db6848d3a4ba914dce6 100644 (file)
--- a/src/ParaMEDMEM/StructuredCoincidentDEC.hxx
+++ b/src/ParaMEDMEM/StructuredCoincidentDEC.hxx
@@ -1,4 +1,4 @@
-// Copyright (C) 2007-2020  CEA/DEN, EDF R&D
+// Copyright (C) 2007-2021  CEA/DEN, EDF R&D
 //
 // This library is free software; you can redistribute it and/or
 // modify it under the terms of the GNU Lesser General Public
@@ -29,12 +29,66 @@ namespace MEDCoupling
   class DEC;
   class BlockTopology;
 
+  /*!
+    \anchor StructuredCoincidentDEC-det
+    \class StructuredCoincidentDEC
+
+    This class aims at \ref interpolation "remapping fields" that have identical
+    structured supports (=the same underlying mesh) but different parallel topologies
+    (=different sub-domains in the structured mesh). It can be used to couple
+    together multi-physics codes that operate on the same domain
+    with different partitioning. This can be useful for example if one of
+    the computation is much faster than the other. It can also be used
+    to couple together codes that share an interface that was generated
+    in the same manner (with identical global ids).
+    Also, this \ref para-dec "DEC" can be used for fields that have component topologies,
+    i.e., components that are scattered over several processors.
+
+    The remapping between the two supports is based on identity of global
+    ids, instead of geometrical considerations (as it is the case for
+    \ref InterpKernelDEC-det "InterpKernelDEC").
+    Therefore, beware that this \ref para-dec "DEC" can not be used
+    for coincident meshes if they do *not* have the exact same numbering.
+
+    With this %DEC no projection, and no interpolation of the field data is done, contrary
+    to what happens in \ref InterpKernelDEC-det "InterpKernelDEC". It is just
+    a matter of allocating the values from one side to the other, using directly the cell
+    identifiers.
+
+    As all the other DECs, its usage requires two phases :
+    - a setup phase during which the topologies are exchanged so that
+    the target side knows from which processors it should expect
+    the data.
+    - a send/recv phase during which the field data is actually transferred.
+
+    This example illustrates the sending of a field with
+    the \c StructuredCoincidentDEC :
+    \code
+    ...
+    StructuredCoincidentDEC dec(groupA, groupB);
+    dec.attachLocalField(field);
+    dec.synchronize();
+    if (groupA.containsMyRank())
+    dec.recvData();
+    else if (groupB.containsMyRank())
+    dec.sendData();
+    ...
+    \endcode
+
+    Creating a ParaFIELD to be attached to the %DEC is done in exactly the same way as for
+    the other DECs, if only the partitioning of the support mesh differs.
+    In the case where the
+    fields have also different *component* topologies, creating the ParaFIELD
+    requires some more effort. See the \ref para-over "parallelism" section for more details.
+  */
   class StructuredCoincidentDEC : public DisjointDEC
   {
   public:
     StructuredCoincidentDEC();
     StructuredCoincidentDEC( ProcessorGroup& source, ProcessorGroup& target);
     virtual ~StructuredCoincidentDEC();
+    void release();
+
     void synchronize();
     void recvData();
     void sendData();
@@ -47,6 +101,10 @@ namespace MEDCoupling
 
     BlockTopology* _topo_source;
     BlockTopology* _topo_target;
+
+    bool _owns_topo_source;
+    bool _owns_topo_target;
+
     int* _send_counts;
     int* _recv_counts;
     int* _send_displs;