inet::tcp::TcpLwipMsgBasedSendQueue Class Reference

Send queue that manages "objects". More...

#include <TcpLwipMsgBasedQueues.h>

Inheritance diagram for inet::tcp::TcpLwipMsgBasedSendQueue:

Classes
struct	Payload

Public Member Functions
	TcpLwipMsgBasedSendQueue ()
	Ctor. More...
virtual	~TcpLwipMsgBasedSendQueue ()
	Virtual dtor. More...
virtual void	setConnection (TcpLwipConnection *connP) override
	set connection queue. More...
virtual void	enqueueAppData (cPacket *msgP) override
	Called on SEND app command, it inserts in the queue the data the user wants to send. More...
virtual unsigned int	getBytesForTcpLayer (void *bufferP, unsigned int bufferLengthP) const override
	Copy data to the buffer for send to LWIP. More...
virtual void	dequeueTcpLayerMsg (unsigned int msgLengthP) override
	Remove msgLengthP bytes from TCP Layer queue. More...
unsigned long	getBytesAvailable () const override
	Utility function: returns how many bytes are available in the queue. More...
virtual TCPSegment *	createSegmentWithBytes (const void *tcpDataP, unsigned int tcpLengthP) override
	Called when the TCP wants to send or retransmit data, it constructs a TCP segment which contains the data from the requested sequence number range. More...
virtual void	discardAckedBytes ()
	Tells the queue that bytes up to (but NOT including) seqNum have been transmitted and ACKed, so they can be removed from the queue. More...
Public Member Functions inherited from inet::tcp::TcpLwipSendQueue
	TcpLwipSendQueue ()
	Ctor. More...
virtual	~TcpLwipSendQueue ()
	Virtual dtor. More...

Protected Types
typedef std::list< Payload >	PayloadQueue

Protected Attributes
PayloadQueue	payloadQueueM
uint32	beginM
uint32	endM
bool	isValidSeqNoM
unsigned long int	unsentTcpLayerBytesM
Protected Attributes inherited from inet::tcp::TcpLwipSendQueue
TcpLwipConnection *	connM

Detailed Description

Send queue that manages "objects".

Member Typedef Documentation

typedef std::list<Payload> inet::tcp::TcpLwipMsgBasedSendQueue::PayloadQueue

protected

Constructor & Destructor Documentation

inet::tcp::TcpLwipMsgBasedSendQueue::TcpLwipMsgBasedSendQueue

(

)

Ctor.

    :
    beginM(0),
    endM(0),
    unsentTcpLayerBytesM(0)
{
}

inet::tcp::TcpLwipMsgBasedSendQueue::~TcpLwipMsgBasedSendQueue ( )

virtual

Virtual dtor.

{
    while (!payloadQueueM.empty()) {
        EV_TRACE << "SendQueue Destructor: Drop msg from " << connM->tcpLwipM.getFullPath()
                 << " Queue: seqno=" << payloadQueueM.front().endSequenceNo
                 << ", length=" << payloadQueueM.front().msg->getByteLength() << endl;
        delete payloadQueueM.front().msg;
        payloadQueueM.pop_front();
    }
}

Member Function Documentation

TCPSegment * inet::tcp::TcpLwipMsgBasedSendQueue::createSegmentWithBytes ( const void *  tcpDataP, unsigned int  tcpLengthP  )

overridevirtual

Called when the TCP wants to send or retransmit data, it constructs a TCP segment which contains the data from the requested sequence number range.

The actually returned segment may contain less then maxNumBytes bytes if the subclass wants to reproduce the original segment boundaries when retransmitting.

called from inside of send_callback() called before called the send() to IP layer

Parameters

tcpDataP	the tcp segment (with tcp header) created by LWIP
tcpLenthP	the length of tcp segment.

Implements inet::tcp::TcpLwipSendQueue.

{
    ASSERT(tcpDataP);

    TCPSegment *tcpseg = serializer::TCPSerializer().deserialize((const unsigned char *)tcpDataP, tcpLengthP, false);

    uint32 fromSeq = tcpseg->getSequenceNo();
    uint32 numBytes = tcpseg->getPayloadLength();
    uint32 toSeq = fromSeq + numBytes;

    if ((!isValidSeqNoM) && (numBytes > 0)) {
        for (auto & elem : payloadQueueM) {
            elem.endSequenceNo += fromSeq;
        }

        beginM += fromSeq;
        endM += fromSeq;
        isValidSeqNoM = true;
    }

    if (numBytes && !seqLE(toSeq, endM))
        throw cRuntimeError("Implementation bug");

    EV_DEBUG << "sendQueue: " << connM->connIdM << ": [" << fromSeq << ":" << toSeq
             << ",l=" << numBytes << "] (unsent bytes:" << unsentTcpLayerBytesM << "\n";

    for (auto & elem : payloadQueueM) {
        EV_DEBUG << "  buffered msg: endseq=" << elem.endSequenceNo
                 << ", length=" << elem.msg->getByteLength() << endl;
    }

    const char *payloadName = nullptr;

    if (numBytes > 0) {
        // add payload messages whose endSequenceNo is between fromSeq and fromSeq+numBytes
        auto i = payloadQueueM.begin();

        while (i != payloadQueueM.end() && seqLE(i->endSequenceNo, fromSeq))
            ++i;

        while (i != payloadQueueM.end() && seqLE(i->endSequenceNo, toSeq)) {
            if (!payloadName)
                payloadName = i->msg->getName();

            cPacket *msg = i->msg->dup();
            tcpseg->addPayloadMessage(msg, i->endSequenceNo);
            ++i;
        }
    }

    // give segment a name
    char msgname[80];
    sprintf(msgname, "%.10s%s%s%s(l=%lu,%dmsg)",
            (payloadName ? payloadName : "tcpseg"),
            tcpseg->getSynBit() ? " SYN" : "",
            tcpseg->getFinBit() ? " FIN" : "",
            (tcpseg->getAckBit() && 0 == numBytes) ? " ACK" : "",
            (unsigned long)numBytes,
            tcpseg->getPayloadArraySize());
    tcpseg->setName(msgname);

    discardAckedBytes();

    return tcpseg;
}

void inet::tcp::TcpLwipMsgBasedSendQueue::dequeueTcpLayerMsg ( unsigned int  msgLengthP )

overridevirtual

Remove msgLengthP bytes from TCP Layer queue.

called with return value of socket->send_data() if larger than 0

Implements inet::tcp::TcpLwipSendQueue.

{
    ASSERT(msgLengthP <= unsentTcpLayerBytesM);

    unsentTcpLayerBytesM -= msgLengthP;
}

void inet::tcp::TcpLwipMsgBasedSendQueue::discardAckedBytes ( )

virtual

Tells the queue that bytes up to (but NOT including) seqNum have been transmitted and ACKed, so they can be removed from the queue.

Referenced by createSegmentWithBytes().

{
    if (isValidSeqNoM) {
        uint32 seqNum = connM->pcbM->lastack;

        if (seqLE(beginM, seqNum) && seqLE(seqNum, endM)) {
            beginM = seqNum;

            // remove payload messages whose endSequenceNo is below seqNum
            while (!payloadQueueM.empty() && seqLE(payloadQueueM.front().endSequenceNo, seqNum)) {
                delete payloadQueueM.front().msg;
                payloadQueueM.pop_front();
            }
        }
    }
}

void inet::tcp::TcpLwipMsgBasedSendQueue::enqueueAppData ( cPacket *  msgP )

overridevirtual

Called on SEND app command, it inserts in the queue the data the user wants to send.

Implementations of this abstract class will decide what this means: copying actual bytes, just increasing the "last byte queued" variable, or storing cMessage object(s). The msg object should not be referenced after this point (sendQueue may delete it.)

Implements inet::tcp::TcpLwipSendQueue.

{
    ASSERT(msgP);

    uint32 bytes = msgP->getByteLength();
    endM += bytes;
    unsentTcpLayerBytesM += bytes;

    Payload payload;
    payload.endSequenceNo = endM;
    payload.msg = msgP;
    payloadQueueM.push_back(payload);
}

unsigned long inet::tcp::TcpLwipMsgBasedSendQueue::getBytesAvailable ( ) const

overridevirtual

Utility function: returns how many bytes are available in the queue.

Implements inet::tcp::TcpLwipSendQueue.

{
    return unsentTcpLayerBytesM;
}

unsigned int inet::tcp::TcpLwipMsgBasedSendQueue::getBytesForTcpLayer ( void *  bufferP, unsigned int  bufferLengthP  ) const

overridevirtual

Copy data to the buffer for send to LWIP.

returns lengh of copied data. create msg for socket->send_data()

called before called socket->send_data()

Implements inet::tcp::TcpLwipSendQueue.

{
    ASSERT(bufferP);

    return (unsentTcpLayerBytesM > bufferLengthP) ? bufferLengthP : unsentTcpLayerBytesM;
}

void inet::tcp::TcpLwipMsgBasedSendQueue::setConnection ( TcpLwipConnection *  connP )

overridevirtual

set connection queue.

Reimplemented from inet::tcp::TcpLwipSendQueue.

{
    TcpLwipSendQueue::setConnection(connP);
    endM = beginM = 0;
    isValidSeqNoM = false;
    unsentTcpLayerBytesM = 0;
}

Member Data Documentation

uint32 inet::tcp::TcpLwipMsgBasedSendQueue::beginM

protected

Referenced by createSegmentWithBytes(), discardAckedBytes(), and setConnection().

uint32 inet::tcp::TcpLwipMsgBasedSendQueue::endM

protected

Referenced by createSegmentWithBytes(), discardAckedBytes(), enqueueAppData(), and setConnection().

bool inet::tcp::TcpLwipMsgBasedSendQueue::isValidSeqNoM

protected

Referenced by createSegmentWithBytes(), discardAckedBytes(), and setConnection().

PayloadQueue inet::tcp::TcpLwipMsgBasedSendQueue::payloadQueueM

protected

Referenced by createSegmentWithBytes(), discardAckedBytes(), enqueueAppData(), and ~TcpLwipMsgBasedSendQueue().

unsigned long int inet::tcp::TcpLwipMsgBasedSendQueue::unsentTcpLayerBytesM

protected

Referenced by createSegmentWithBytes(), dequeueTcpLayerMsg(), enqueueAppData(), getBytesAvailable(), getBytesForTcpLayer(), and setConnection().

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The documentation for this class was generated from the following files:

• TcpLwipMsgBasedQueues.h
• TcpLwipMsgBasedQueues.cc