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Approximate LSTF with eight FIFO queues. #1

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Approximate LSTF with eight FIFO queues. #1

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a1cb0dd
Implemented LSTF approximation with 8 FIFO queues.
ccheng32 Nov 3, 2019
96abc2b
Dequeueing should start from the highest priority queues.
ccheng32 Nov 3, 2019
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108 changes: 42 additions & 66 deletions ns-allinone-2.35/ns-2.35/queue/lstf.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -30,8 +30,13 @@ LstfQueue::LstfQueue() : queueid_(-1), tchan_(0)
bind("control_packets_", &control_packets_);
bind("control_packets_time_", &control_packets_time_);
bind("bandwidth_", &bandwidth_);
char name[100];
for (int i = 0; i < LSTF_NUM_QUEUES; i++) {
sprintf(name, "queue_bounds_%d", i);
bind(name, &q_bounds_[i+1]);
}

for(int i=0; i<2; i++) {
for(int i=0; i<=LSTF_NUM_QUEUES; i++) {
bin_[i].q_ = new PacketQueue();
bin_[i].index = i;
}
Expand All @@ -53,61 +58,28 @@ void LstfQueue::reset()
double LstfQueue::txtime(Packet* p) {
return (8. * hdr_cmn::access(p)->size() / bandwidth_);
}

void LstfQueue::insertPacketinSortedQueue(Packet* pkt) {

hdr_ip *iph = hdr_ip::access(pkt);
long long int curSlack = iph->prio() + (long long int)(txtime(pkt) * kTime_);

for(Packet *pp= 0, *p= (bin_[1].q_)->head(); p; pp= p, p= p->next_) {
hdr_ip *tempIph = hdr_ip::access(p);
long long int slack = tempIph->prio() - ((Scheduler::instance().clock()*kTime_) - (long long int)(HDR_CMN(p)->ts_*kTime_)) + (long long int)(txtime(p) * kTime_);
if(slack > curSlack) {
if (p == (bin_[1].q_)->head()) {
(bin_[1].q_)->enqueHead(pkt);
}
else {
(bin_[1].q_)->enqueAfterPkt(pkt, pp);
}
return;
}
}

(bin_[1].q_)->enque(pkt);

}




// Add a new packet to the queue. If the entire buffer space is full, drop highest slack packet
void LstfQueue::enque(Packet* pkt)
{
hdr_ip *iph = hdr_ip::access(pkt);
int seqNo = getSeqNo(pkt);
long long int curSlack = iph->prio() + (long long int)(txtime(pkt) * kTime_);

// check for full buffer
// Drop a packet from the lowest priority queue if the buffer is full.
if(curlen_ >= qlim_) {
if((bin_[1].q_)->tail() == 0) {
drop(pkt);
return;
}
Packet* tail_pkt = (bin_[1].q_)->tail();
hdr_ip *tail_pkt_iph = hdr_ip::access(tail_pkt);
int tail_pkt_seqNo = getSeqNo(tail_pkt);
long long int tail_pkt_slack = tail_pkt_iph->prio() - ((Scheduler::instance().clock()*kTime_) -
(long long int)(HDR_CMN(tail_pkt)->ts_*kTime_)) + (long long int)(txtime(tail_pkt) * kTime_);
if(iph->prio() + (long long int)(txtime(pkt) * kTime_) > tail_pkt_slack) {
drop(pkt);
return;
}
if (debug_)
printf("%lf: Lstf: QueueID %d: Dropped packet with id %d and sequence %d\n",
Scheduler::instance().clock(), queueid_, tail_pkt_iph->flowid(), tail_pkt_seqNo);
(bin_[1].q_)->remove(tail_pkt);
curq_ -= HDR_CMN(tail_pkt)->size();
curlen_--;
drop(tail_pkt);
for (int i = LSTF_NUM_QUEUES; i >= 1; i--) {
if (curSlack > q_bounds_[i]) {
drop(pkt);
return;
}
if ((bin_[i].q_)->length() == 0) continue;
Packet* tail_pkt = (bin_[i].q_)->tail();
(bin_[i].q_)->remove(tail_pkt);
curq_ -= HDR_CMN(tail_pkt)->size();
curlen_--;
drop(tail_pkt);
}
}
curlen_++;
curq_ += HDR_CMN(pkt)->size();
Expand All @@ -116,7 +88,9 @@ void LstfQueue::enque(Packet* pkt)
if((HDR_CMN(pkt)->size() >= 1460) || (!control_packets_)|| (Scheduler::instance().clock() >= double(control_packets_time_))) {

HDR_CMN(pkt)->ts_ = Scheduler::instance().clock();
insertPacketinSortedQueue(pkt);
for (int i = 1; i <= LSTF_NUM_QUEUES; i++) {
if (curSlack < q_bounds_[i]) (bin_[i].q_)->enque(pkt);
}

if(debug_)
printf("%lf: Lstf: QueueID %d: Enqueuing packet from flow with id %d, seqno = %d, size = %d and slack = %lld \n", Scheduler::instance().clock(), queueid_, iph->flowid(), seqNo, HDR_CMN(pkt)->size(), iph->prio());
Expand Down Expand Up @@ -149,26 +123,28 @@ Packet* LstfQueue::deque()
printf("%lf: Lstf: QueueID %d: Dequing packet from flow with id %d, slack %lld, seqno = %d, size = %d from control queue\n", Scheduler::instance().clock(), queueid_, iph->flowid(), iph->prio(), seqNo, HDR_CMN(pkt)->size());
return pkt;
}
while((bin_[1].q_)->length() > 0) {
//if control queue empty, work on data queue
Packet *pkt;
pkt = (bin_[1].q_)->deque();
int seqNo = getSeqNo(pkt);
hdr_ip *iph = hdr_ip::access(pkt);
curlen_--;
curq_ -= HDR_CMN(pkt)->size();

for (int i = 1; i <= LSTF_NUM_QUEUES; i--) {
if ((bin_[i].q_)->length() > 0) {
//if control queue empty, work on data queue
Packet *pkt;
pkt = (bin_[i].q_)->deque();
int seqNo = getSeqNo(pkt);
hdr_ip *iph = hdr_ip::access(pkt);
curlen_--;
curq_ -= HDR_CMN(pkt)->size();


long long int wait_time = (Scheduler::instance().clock() * kTime_) - (long long int)(HDR_CMN(pkt)->ts_*kTime_);
long long int new_slack = iph->prio() - wait_time;

iph->prio() = new_slack;
long long int wait_time = (Scheduler::instance().clock() * kTime_) - (long long int)(HDR_CMN(pkt)->ts_*kTime_);
long long int new_slack = iph->prio() - wait_time;
iph->prio() = new_slack;

if(debug_)
printf("%lf: Lstf: QueueID %d: Dequing packet from flow with id %d, slack %lld, seqno = %d, size = %d \n", Scheduler::instance().clock(), queueid_, iph->flowid(), iph->prio(), seqNo, HDR_CMN(pkt)->size());
if(debug_)
printf("%lf: Lstf: QueueID %d: Dequing packet from flow with id %d, slack %lld, seqno = %d, size = %d \n", Scheduler::instance().clock(), queueid_, iph->flowid(), iph->prio(), seqNo, HDR_CMN(pkt)->size());

return pkt;
}
return pkt;
}
}
}
return 0;
}
Expand Down
6 changes: 3 additions & 3 deletions ns-allinone-2.35/ns-2.35/queue/lstf.h
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@
#include "fstream"

#define DEBUG 1

#define LSTF_NUM_QUEUES 8

struct bindesc {
PacketQueue *q_; // underlying FIFO queue
Expand All @@ -28,13 +28,13 @@ class LstfQueue : public Queue {
LstfQueue();

protected:
void insertPacketinSortedQueue(Packet* pkt);
void enque(Packet* pkt);
int dropPacket(int pr);
double txtime(Packet* p);
Packet* deque();

bindesc bin_[2];
bindesc bin_[1 + LSTF_NUM_QUEUES];
long int q_bounds_[1 + LSTF_NUM_QUEUES];

int curlen_; // the total occupancy of all bins in packets
int debug_;
Expand Down