simple-intserv-sched.cc

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#ifndef lint
static const char rcsid[] =
    "@(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/adc/simple-intserv-sched.cc,v 1.7 2005/08/26 05:05:28 tomh Exp $ (LBL)";
#endif


//Simple scheduler with 2 service priority levels and protects signalling
//ctrl  packets


#include "config.h"
#include "queue.h"

#define CLASSES 2

class SimpleIntServ : public Queue {
public:
    SimpleIntServ() {
        int i;
        char buf[10];
        for (i=0;i<CLASSES;i++) {
            q_[i] = new PacketQueue;
            qlimit_[i] = 0;
            sprintf(buf,"qlimit%d_",i);
            bind(buf,&qlimit_[i]);
        }
    }
    protected :
    void enque(Packet *);
    Packet *deque();
    PacketQueue *q_[CLASSES];
    int qlimit_[CLASSES];
};


static class SimpleIntServClass : public TclClass {
public:
    SimpleIntServClass() : TclClass("Queue/SimpleIntServ") {}
    TclObject* create(int, const char*const*) {
        return (new SimpleIntServ);
    }
} class_simple_intserv;

void SimpleIntServ::enque(Packet* p)
{
    
    hdr_ip* iph=hdr_ip::access(p);
    int cl=(iph->flowid()) ? 1:0;
    
    if (q_[cl]->length() >= (qlimit_[cl]-1)) {
        hdr_cmn* ch=hdr_cmn::access(p);
        packet_t ptype = ch->ptype();
        if ( (ptype != PT_REQUEST) && (ptype != PT_REJECT) && (ptype != PT_ACCEPT) && (ptype != PT_CONFIRM) && (ptype != PT_TEARDOWN) ) {
            drop(p);
        }
        else {
            q_[cl]->enque(p);
        }
    }
    else {
        q_[cl]->enque(p);
    }
}


Packet *SimpleIntServ::deque()
{
    int i;
    for (i=CLASSES-1;i>=0;i--)
        if (q_[i]->length())
            return q_[i]->deque();
    return 0;
}

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