openfoam/applications/test/parallel-barrier1/Test-parallel-barrier1.cxx
Mark Olesen c448ea2a11 ENH: add simple handling for point-to-point barriers
- provides an additional means of process synchronization
2025-02-25 09:44:44 +01:00

126 lines
3.7 KiB
C++

/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | www.openfoam.com
\\/ M anipulation |
-------------------------------------------------------------------------------
Copyright (C) 2025 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-barrier1
Description
Simple test of local barriers communication
\*---------------------------------------------------------------------------*/
#include "argList.H"
#include "clockTime.H"
#include "IPstream.H"
#include "OPstream.H"
using namespace Foam;
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
int main(int argc, char *argv[])
{
argList::noCheckProcessorDirectories();
argList::addVerboseOption();
argList::addOption("delay", "sec", "Seconds to sleep (default 2)");
#include "setRootCase.H"
if (!UPstream::parRun())
{
Info<< "###############" << nl
<< "Not running in parallel. Stopping now" << nl
<< "###############" << endl;
return 1;
}
const auto delay = args.getOrDefault<label>("delay", 2);
Info<< nl
<< "Testing local barrier, sleep=" << delay << endl;
const auto myProci = UPstream::myProcNo(UPstream::worldComm);
const auto numProc = UPstream::nProcs(UPstream::worldComm);
constexpr int uniqTag = 1516;
clockTime timing;
if (UPstream::master(UPstream::worldComm))
{
// Wait for the last rank
UPstream::wait_done(numProc-1, UPstream::worldComm);
// Wait for any other rank
if (numProc > 2)
{
int from = UPstream::wait_done(-1, UPstream::worldComm, uniqTag);
Pout<< "done signal from: " << from << endl;
}
}
else if (myProci == numProc-1)
{
Foam::sleep(delay);
UPstream::send_done(UPstream::masterNo(), UPstream::worldComm);
}
// Cascade sequencing (and delays)
if (numProc > 7)
{
if (myProci == 2)
{
Foam::sleep(2*delay);
UPstream::send_done(4, UPstream::worldComm);
}
else if (myProci == 4)
{
UPstream::wait_done(2, UPstream::worldComm);
Foam::sleep(2*delay);
UPstream::send_done(5, UPstream::worldComm);
}
else if (myProci == 5)
{
UPstream::wait_done(4, UPstream::worldComm);
}
}
// Some arbitrary signaling rank
if ((numProc > 2) && (myProci == numProc/2))
{
Pout<< "send done signal " << myProci << " -> 0" << endl;
UPstream::send_done(UPstream::masterNo(), UPstream::worldComm, uniqTag);
}
Pout<< "done: " << timing.elapsedTime() << " s" << endl;
Info<< "\nEnd\n" << endl;
return 0;
}
// ************************************************************************* //