UIPread.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/>.
 
Description
    Read from UIPstream
 
\*---------------------------------------------------------------------------*/
 
#include "UIPstream.H"
#include "PstreamGlobals.H"
#include "profilingPstream.H"
#include "IOstreams.H"
 
#include <mpi.h>
 
// * * * * * * * * * * * * * * * * Constructor * * * * * * * * * * * * * * * //
 
Foam::UIPstream::UIPstream
(
    const commsTypes commsType,
    const int fromProcNo,
    DynamicList<char>& receiveBuf,
    label& receiveBufPosition,
    const int tag,
    const label comm,
    const bool clearAtEnd,
    IOstreamOption::streamFormat fmt
)
:
    UPstream(commsType),
    Istream(fmt, IOstreamOption::currentVersion),
    fromProcNo_(fromProcNo),
    recvBuf_(receiveBuf),
    recvBufPos_(receiveBufPosition),
    tag_(tag),
    comm_(comm),
    clearAtEnd_(clearAtEnd),
    messageSize_(0)
{
    setOpened();
    setGood();
 
    if (commsType == commsTypes::nonBlocking)
    {
        // Message is already received into buffer
    }
    else
    {
        if (debug)
        {
            Pout<< "UIPstream::UIPstream :"
                << " read 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();
        }
    }
}
 
 
Foam::UIPstream::UIPstream(const int fromProcNo, PstreamBuffers& buffers)
:
    UPstream(buffers.commsType_),
    Istream(buffers.format_, IOstreamOption::currentVersion),
    fromProcNo_(fromProcNo),
    recvBuf_(buffers.recvBuf_[fromProcNo]),
    recvBufPos_(buffers.recvBufPos_[fromProcNo]),
    tag_(buffers.tag_),
    comm_(buffers.comm_),
    clearAtEnd_(true),
    messageSize_(0)
{
    if
    (
        commsType() != UPstream::commsTypes::scheduled
     && !buffers.finishedSendsCalled_
    )
    {
        FatalErrorInFunction
            << "PstreamBuffers::finishedSends() never called." << endl
            << "Please call PstreamBuffers::finishedSends() after doing"
            << " all your sends (using UOPstream) and before doing any"
            << " receives (using UIPstream)" << Foam::exit(FatalError);
    }
 
    setOpened();
    setGood();
 
    if (commsType() == commsTypes::nonBlocking)
    {
        // Message is already received into buffer
        messageSize_ = recvBuf_.size();
 
        if (debug)
        {
            Pout<< "UIPstream::UIPstream PstreamBuffers :"
                << " fromProcNo:" << fromProcNo
                << " tag:" << tag_ << " comm:" << comm_
                << " receive buffer size:" << messageSize_
                << Foam::endl;
        }
    }
    else
    {
        if (debug)
        {
            Pout<< "UIPstream::UIPstream PstreamBuffers :"
                << " read 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 PstreamBuffers : 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_Recv 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;
}
 
 
// ************************************************************************* //