Files
openfoam/applications/test/parallel-broadcast/Test-parallel-broadcast.C
Mark Olesen 8478595a15 ENH: new broadcast version of Pstreams (#2371)
- The idea of broadcast streams is to replace multiple master to
  subProcs communications with a single MPI_Bcast.

    if (Pstream::master())
    {
        OPBstream toAll(Pstream::masterNo());
        toAll << data;
    }
    else
    {
        IPBstream fromMaster(Pstream::masterNo());
        fromMaster >> data;
    }

    // vs.
    if (Pstream::master())
    {
        for (const int proci : Pstream::subProcs())
        {
            OPstream os(Pstream::commsTypes::scheduled, proci);
            os << data;
        }
    }
    else
    {
        IPstream is(Pstream::commsTypes::scheduled, Pstream::masterNo());
        is >> data;
    }

  Can simply use UPstream::broadcast() directly for contiguous data
  with known lengths.

Based on ideas from T.Aoyagi(RIST), A.Azami(RIST)
2022-03-04 17:49:23 +00:00

148 lines
3.6 KiB
C

/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | www.openfoam.com
\\/ M anipulation |
-------------------------------------------------------------------------------
Copyright (C) 2022 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
This file is part of OpenFOAM.
OpenFOAM is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
Application
Test-parallel-broadcast
Description
Test for various broadcast routines.
\*---------------------------------------------------------------------------*/
#include "List.H"
#include "argList.H"
#include "Time.H"
#include "vector.H"
#include "IPstream.H"
#include "OPstream.H"
#include "IOstreams.H"
using namespace Foam;
// This is what our new scatter will look like inside
template<class Type>
void testBroadcastStream
(
Type& value,
const label comm = UPstream::worldComm
)
{
Info<< nl << "is_contiguous:" << is_contiguous<Type>::value << endl;
Pout<< "pre-broadcast: " << value << endl;
if (is_contiguous<Type>::value)
{
UPstream::broadcast
(
reinterpret_cast<char*>(&value),
sizeof(Type),
comm,
UPstream::masterNo()
);
}
else
{
if (UPstream::master())
{
OPBstream toAll(UPstream::masterNo(), comm);
toAll << value;
}
else
{
IPBstream fromMaster(UPstream::masterNo(), comm);
fromMaster >> value;
}
}
Pout<< "post-broadcast: " << value << endl;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
int main(int argc, char *argv[])
{
argList::noCheckProcessorDirectories();
#include "setRootCase.H"
#include "createTime.H"
{
label value = -1;
if (Pstream::master())
{
value = UPstream::nProcs();
}
testBroadcastStream(value);
}
{
labelList values;
if (Pstream::master())
{
values = identity(UPstream::nProcs());
}
testBroadcastStream(values);
}
{
wordList values;
if (Pstream::master())
{
values.resize(UPstream::nProcs());
forAll(values, i)
{
values[i] = "value_" + Foam::name(i);
}
}
testBroadcastStream(values);
}
{
vector values(vector::uniform(-1));
if (Pstream::master())
{
values = vector(1,2,3);
}
testBroadcastStream(values);
}
{
FixedList<vector, 3> values(vector::uniform(-1));
if (Pstream::master())
{
values = vector(1,2,3);
}
testBroadcastStream(values);
}
Info<< "End\n" << endl;
return 0;
}
// ************************************************************************* //