ShmemCarrier.cpp

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/*
 * Copyright (C) 2006-2020 Istituto Italiano di Tecnologia (IIT)
 * Copyright (C) 2006-2010 RobotCub Consortium
 * All rights reserved.
 *
 * This software may be modified and distributed under the terms of the
 * BSD-3-Clause license. See the accompanying LICENSE file for details.
 */
 
#include "ShmemCarrier.h"
#include "ShmemHybridStream.h"
#include "ShmemLogComponent.h"
 
#include <yarp/os/ConnectionState.h>
#include <yarp/os/Log.h>
 
#include <string>
#include <cstdlib>
 
 
ShmemCarrier::ShmemCarrier() = default;
 
ShmemCarrier::~ShmemCarrier() = default;
 
yarp::os::Carrier* ShmemCarrier::create() const
{
    return new ShmemCarrier();
}
 
std::string ShmemCarrier::getName() const
{
    return "shmem";
}
 
int ShmemCarrier::getSpecifierCode() const
{
    // specifier codes are a very old yarp feature,
    // not necessary any more really, should be replaced.
    return 14;
}
 
bool ShmemCarrier::requireAck() const
{
    return true;
}
 
bool ShmemCarrier::isConnectionless() const
{
    return false;
}
 
bool ShmemCarrier::checkHeader(const yarp::os::Bytes& header)
{
    return getSpecifier(header) % 16 == getSpecifierCode();
}
 
void ShmemCarrier::getHeader(yarp::os::Bytes& header) const
{
    createStandardHeader(getSpecifierCode(), header);
}
 
void ShmemCarrier::setParameters(const yarp::os::Bytes& header)
{
    YARP_UNUSED(header);
}
 
bool ShmemCarrier::becomeShmemVersionHybridStream(yarp::os::ConnectionState& proto, bool sender)
{
    auto* stream = new ShmemHybridStream();
    yCAssert(SHMEMCARRIER, stream != nullptr);
    yarp::os::Contact base;
 
    bool ok = true;
 
    if (!sender) {
        ACE_INET_Addr anywhere((u_short)0, (ACE_UINT32)INADDR_ANY);
        base = yarp::os::Contact(anywhere.get_host_addr(), anywhere.get_port_number());
        bool ok = stream->open(base, sender) == 0;
        if (ok) {
            int myPort = stream->getLocalAddress().getPort();
            writeYarpInt(myPort, proto);
            stream->accept();
            proto.takeStreams(nullptr);
            proto.takeStreams(stream);
        }
    } else {
        int altPort = readYarpInt(proto);
        std::string myName = proto.getStreams().getLocalAddress().getHost();
        proto.takeStreams(nullptr);
        base = yarp::os::Contact(myName, altPort);
        ok = stream->open(base, sender) == 0;
        if (ok) {
            proto.takeStreams(stream);
        }
    }
 
    if (!ok) {
        delete stream;
        stream = nullptr;
        return false;
    }
 
    return true;
}
 
bool ShmemCarrier::becomeShmem(yarp::os::ConnectionState& proto, bool sender)
{
    return becomeShmemVersionHybridStream(proto, sender);
}
 
bool ShmemCarrier::respondToHeader(yarp::os::ConnectionState& proto)
{
    // i am the receiver
    return becomeShmem(proto, false);
}
 
bool ShmemCarrier::expectReplyToHeader(yarp::os::ConnectionState& proto)
{
    // i am the sender
    return becomeShmem(proto, true);
}