UIPstreamRead.C

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/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | www.openfoam.com
     \\/     M anipulation  |
-------------------------------------------------------------------------------
    Copyright (C) 2011-2017 OpenFOAM Foundation
    Copyright (C) 2019-2021 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/>.
 
\*---------------------------------------------------------------------------*/
 
#include "UIPstream.H"
#include "PstreamGlobals.H"
#include "profilingPstream.H"
#include "IOstreams.H"
 
#include <mpi.h>
 
// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //
 
void Foam::UIPstream::bufferIPCrecv()
{
    // Called by constructor
    if (debug)
    {
        Pout<< "UIPstream IPC read buffer :"
            << " from:" << fromProcNo_
            << " tag:" << tag_ << " comm:" << comm_
            << " wanted size:" << recvBuf_.capacity()
            << Foam::endl;
    }
 
    // No buffer size allocated/specified - probe size of incoming message
    if (!recvBuf_.capacity())
    {
        profilingPstream::beginTiming();
 
        MPI_Status status;
 
        MPI_Probe
        (
            fromProcNo_,
            tag_,
            PstreamGlobals::MPICommunicators_[comm_],
            &status
        );
        MPI_Get_count(&status, MPI_BYTE, &messageSize_);
 
        // Assume these are from gathers ...
        profilingPstream::addGatherTime();
 
        recvBuf_.resize(messageSize_);
 
        if (debug)
        {
            Pout<< "UIPstream::UIPstream : probed size:"
                << messageSize_ << Foam::endl;
        }
    }
 
    messageSize_ = UIPstream::read
    (
        commsType(),
        fromProcNo_,
        recvBuf_.data(),
        recvBuf_.capacity(),
        tag_,
        comm_
    );
 
    // Set addressed size. Leave actual allocated memory intact.
    recvBuf_.resize(messageSize_);
 
    if (!messageSize_)
    {
        setEof();
    }
}
 
 
// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
Foam::label Foam::UIPstream::read
(
    const commsTypes commsType,
    const int fromProcNo,
    char* buf,
    const std::streamsize bufSize,
    const int tag,
    const label communicator
)
{
    if (debug)
    {
        Pout<< "UIPstream::read : starting read from:" << fromProcNo
            << " tag:" << tag << " comm:" << communicator
            << " wanted size:" << label(bufSize)
            << " commsType:" << UPstream::commsTypeNames[commsType]
            << Foam::endl;
    }
    if (UPstream::warnComm != -1 && communicator != UPstream::warnComm)
    {
        Pout<< "UIPstream::read : starting read from:" << fromProcNo
            << " tag:" << tag << " comm:" << communicator
            << " wanted size:" << label(bufSize)
            << " commsType:" << UPstream::commsTypeNames[commsType]
            << " warnComm:" << UPstream::warnComm
            << Foam::endl;
        error::printStack(Pout);
    }
 
    profilingPstream::beginTiming();
 
    if
    (
        commsType == commsTypes::blocking
     || commsType == commsTypes::scheduled
    )
    {
        MPI_Status status;
 
        if
        (
            MPI_Recv
            (
                buf,
                bufSize,
                MPI_BYTE,
                fromProcNo,
                tag,
                PstreamGlobals::MPICommunicators_[communicator],
                &status
            )
        )
        {
            FatalErrorInFunction
                << "MPI_Recv cannot receive incoming message"
                << Foam::abort(FatalError);
            return 0;
        }
 
        profilingPstream::addGatherTime();
 
        // Check size of message read
 
        int messageSize;
        MPI_Get_count(&status, MPI_BYTE, &messageSize);
 
        if (debug)
        {
            Pout<< "UIPstream::read : finished read from:" << fromProcNo
                << " tag:" << tag << " read size:" << label(bufSize)
                << " commsType:" << UPstream::commsTypeNames[commsType]
                << Foam::endl;
        }
 
        if (messageSize > bufSize)
        {
            FatalErrorInFunction
                << "buffer (" << label(bufSize)
                << ") not large enough for incoming message ("
                << messageSize << ')'
                << Foam::abort(FatalError);
        }
 
        return messageSize;
    }
    else if (commsType == commsTypes::nonBlocking)
    {
        MPI_Request request;
 
        if
        (
            MPI_Irecv
            (
                buf,
                bufSize,
                MPI_BYTE,
                fromProcNo,
                tag,
                PstreamGlobals::MPICommunicators_[communicator],
                &request
            )
        )
        {
            FatalErrorInFunction
                << "MPI_Irecv cannot start non-blocking receive"
                << Foam::abort(FatalError);
 
            return 0;
        }
 
        profilingPstream::addWaitTime();
 
        if (debug)
        {
            Pout<< "UIPstream::read : started read from:" << fromProcNo
                << " tag:" << tag << " read size:" << label(bufSize)
                << " commsType:" << UPstream::commsTypeNames[commsType]
                << " request:" << PstreamGlobals::outstandingRequests_.size()
                << Foam::endl;
        }
 
        PstreamGlobals::outstandingRequests_.append(request);
 
        // Assume the message is completely received.
        return bufSize;
    }
 
    FatalErrorInFunction
        << "Unsupported communications type " << int(commsType)
        << Foam::abort(FatalError);
 
    return 0;
}
 
 
// ************************************************************************* //