#include <PassiveQueueBase.h>

Inheritance diagram for PassiveQueueBase:

Public Member Functions
virtual void	requestPacket ()
Protected Member Functions
virtual void	initialize ()
virtual void	handleMessage (cMessage *msg)
virtual void	finish ()
virtual bool	enqueue (cMessage *msg)=0
virtual cMessage *	dequeue ()=0
virtual void	sendOut (cMessage *msg)=0
Protected Attributes
int	packetRequested
int	numQueueReceived
int	numQueueDropped

Detailed Description

Abstract base class for passive queues. Implements IPassiveQueue. Enqueue/dequeue have to be implemented in virtual functions in subclasses; the actual queue or piority queue data structure also goes into subclasses.

Definition at line 32 of file PassiveQueueBase.h.

Member Function Documentation

virtual cMessage* PassiveQueueBase::dequeue ( ) [protected, pure virtual]

Returns a packet from the queue, or NULL if the queue is empty.

Implemented in DropTailQoSQueue, DropTailQueue, and REDQueue.

Referenced by requestPacket().

virtual bool PassiveQueueBase::enqueue ( cMessage * msg ) [protected, pure virtual]

Inserts packet into the queue or the priority queue, or drops it (or another packet). Returns true if a packet was dropped.

Implemented in DropTailQoSQueue, DropTailQueue, and REDQueue.

Referenced by handleMessage().

void PassiveQueueBase::finish ( ) [protected, virtual]

Reimplemented in REDQueue.

Definition at line 74 of file PassiveQueueBase.cc.

{
    recordScalar("packets received by queue", numQueueReceived);
    recordScalar("packets dropped by queue", numQueueDropped);
}

void PassiveQueueBase::handleMessage ( cMessage * msg ) [protected, virtual]

Definition at line 36 of file PassiveQueueBase.cc.

{
    numQueueReceived++;
    if (packetRequested>0)
    {
        packetRequested--;
        sendOut(msg);
    }
    else
    {
        bool dropped = enqueue(msg);
        if (dropped)
            numQueueDropped++;
    }

    if (ev.isGUI())
    {
        char buf[40];
        sprintf(buf, "q rcvd: %d\nq dropped: %d", numQueueReceived, numQueueDropped);
        getDisplayString().setTagArg("t",0,buf);
    }
}

void PassiveQueueBase::initialize ( ) [protected, virtual]

Reimplemented in DropTailQoSQueue, DropTailQueue, and REDQueue.

Definition at line 23 of file PassiveQueueBase.cc.

{
    // state
    packetRequested = 0;
    WATCH(packetRequested);

    // statistics
    numQueueReceived = 0;
    numQueueDropped = 0;
    WATCH(numQueueReceived);
    WATCH(numQueueDropped);
}

void PassiveQueueBase::requestPacket ( ) [virtual]

The queue should send a packet whenever this method is invoked. If the queue is currently empty, it should send a packet when when one becomes available.

Implements IPassiveQueue.

Definition at line 59 of file PassiveQueueBase.cc.

{
    Enter_Method("requestPacket()");

    cMessage *msg = dequeue();
    if (msg==NULL)
    {
        packetRequested++;
    }
    else
    {
        sendOut(msg);
    }
}

virtual void PassiveQueueBase::sendOut ( cMessage * msg ) [protected, pure virtual]

Should be redefined to send out the packet; e.g. send(msg,"out").

Implemented in DropTailQoSQueue, DropTailQueue, and REDQueue.

Referenced by handleMessage(), and requestPacket().