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exp_.max_p_inv alternating values (bug?)
Hi,
I'm still using ns2.1b5. I'm experimenting with RED and changing linterm_,
but I found that the results were not as I expected. I did a preliminary
debug by printing the value of linterm_ (i.e exp_.max_p_inv) from red.cc
during run-time, and noticed it alternates between its default value of 10
and its assigned value. I'm not sure how this could happen. Any suggestions?
Attached is the trace result and the red.cc with the modification of
printf's in different places.
Thanks in advance.
AA.
----------------
#trace (alternating between the default and the assigned value of 4)
#the first number indicates the function from which printf is called
1 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
7 edp_.max_p_inv is 10.000000
7 edp_.max_p_inv is 10.000000
7 edp_.max_p_inv is 10.000000
1 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
7 edp_.max_p_inv is 10.000000
7 edp_.max_p_inv is 10.000000
7 edp_.max_p_inv is 10.000000
7 edp_.max_p_inv is 4.000000
7 edp_.max_p_inv is 4.000000
7 edp_.max_p_inv is 10.000000
1 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
7 edp_.max_p_inv is 4.000000
1 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 10.000000
2 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
3 edp_.max_p_inv is 10.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
3 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
5 edp_.max_p_inv is 4.000000
2 edp_.max_p_inv is 4.000000
-------------------------------------------
/*modified red.cc*/
/* -*- Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
* Copyright (c) 1990-1997 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Computer Systems
* Engineering Group at Lawrence Berkeley Laboratory.
* 4. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*
* Here is one set of parameters from one of Sally's simulations
* (this is from tcpsim, the older simulator):
*
* ed [ q_weight=0.002 thresh=5 linterm=30 maxthresh=15
* mean_pktsize=500 dropmech=random-drop queue-size=60
* plot-file=none bytes=false doubleq=false dqthresh=50
* wait=true ]
*
* 1/"linterm" is the max probability of dropping a packet.
* There are different options that make the code
* more messy that it would otherwise be. For example,
* "doubleq" and "dqthresh" are for a queue that gives priority to
* small (control) packets,
* "bytes" indicates whether the queue should be measured in bytes
* or in packets,
* "dropmech" indicates whether the drop function should be random-drop
* or drop-tail when/if the queue overflows, and
* the commented-out Holt-Winters method for computing the average queue
* size can be ignored.
* "wait" indicates whether the gateway should wait between dropping
* packets.
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /usr/src/mash/repository/vint/ns-2/red.cc,v 1.34
1999/01/07
19:01:57 sfloyd Exp $ (LBL)";
#endif
#include <math.h>
#include <string.h>
#include <sys/types.h>
#include "template.h"
#include "random.h"
#include "flags.h"
#include "delay.h"
#include "red.h"
static class REDClass : public TclClass {
public:
REDClass() : TclClass("Queue/RED") {}
TclObject* create(int, const char*const*) {
return (new REDQueue);
}
} class_red;
REDQueue::REDQueue() : link_(NULL), bcount_(0), de_drop_(NULL),
tchan_(0), idle_(1)
{
bind_bool("bytes_", &edp_.bytes); // boolean: use bytes?
bind_bool("queue-in-bytes_", &qib_); // boolean: q in bytes?
bind("thresh_", &edp_.th_min); // minthresh
bind("maxthresh_", &edp_.th_max); // maxthresh
bind("mean_pktsize_", &edp_.mean_pktsize); // avg pkt size
bind("q_weight_", &edp_.q_w); // for EWMA
bind_bool("wait_", &edp_.wait);
bind("linterm_", &edp_.max_p_inv);
bind_bool("setbit_", &edp_.setbit); // mark instead of drop
bind_bool("drop-tail_", &drop_tail_); // drop last pkt
bind_bool("drop-front_", &drop_front_); // drop first pkt
bind_bool("drop-rand_", &drop_rand_); // drop pkt at random
bind("ave_", &edv_.v_ave); // average queue sie
bind("prob1_", &edv_.v_prob1); // dropping probability
bind("curq_", &curq_); // current queue size
q_ = new PacketQueue(); // underlying queue
pq_ = q_;
reset();
#ifdef notdef
print_edp();
print_edv();
#endif
}
void REDQueue::reset()
{
/*
* If queue is measured in bytes, scale min/max thresh
* by the size of an average packet (which is specified by user).
*/
printf("1 edp_.max_p_inv is %f\n", edp_.max_p_inv); /* Hussein*/
if (qib_) {
edp_.th_min *= edp_.mean_pktsize;
edp_.th_max *= edp_.mean_pktsize;
}
/*
* Compute the "packet time constant" if we know the
* link bandwidth. The ptc is the max number of (avg sized)
* pkts per second which can be placed on the link.
* The link bw is given in bits/sec, so scale mean psize
* accordingly.
*/
if (link_)
edp_.ptc = link_->bandwidth() /
(8. * edp_.mean_pktsize);
edv_.v_ave = 0.0;
edv_.v_slope = 0.0;
edv_.count = 0;
edv_.count_bytes = 0;
edv_.old = 0;
edv_.v_a = 1 / (edp_.th_max - edp_.th_min);
edv_.v_b = - edp_.th_min / (edp_.th_max - edp_.th_min);
idle_ = 1;
if (&Scheduler::instance() != NULL)
idletime_ = Scheduler::instance().clock();
else
idletime_ = 0.0; /* sched not instantiated yet */
Queue::reset();
bcount_ = 0;
}
/*
* Compute the average queue size.
* The code contains two alternate methods for this, the plain EWMA
* and the Holt-Winters method.
* nqueued can be bytes or packets
*/
void REDQueue::run_estimator(int nqueued, int m)
{
printf("2 edp_.max_p_inv is %f\n", edp_.max_p_inv); /* Hussein*/
float f, f_sl, f_old;
f = edv_.v_ave;
f_sl = edv_.v_slope;
#define RED_EWMA
#ifdef RED_EWMA
while (--m >= 1) {
f_old = f;
f *= 1.0 - edp_.q_w;
}
f_old = f;
f *= 1.0 - edp_.q_w;
f += edp_.q_w * nqueued;
#endif
#ifdef RED_HOLT_WINTERS
while (--m >= 1) {
f_old = f;
f += f_sl;
f *= 1.0 - edp_.q_w;
f_sl *= 1.0 - 0.5 * edp_.q_w;
f_sl += 0.5 * edp_.q_w * (f - f_old);
}
f_old = f;
f += f_sl;
f *= 1.0 - edp_.q_w;
f += edp_.q_w * nqueued;
f_sl *= 1.0 - 0.5 * edp_.q_w;
f_sl += 0.5 * edp_.q_w * (f - f_old);
#endif
edv_.v_ave = f;
edv_.v_slope = f_sl;
}
/*
* Return the next packet in the queue for transmission.
*/
Packet* REDQueue::deque()
{
printf("3 edp_.max_p_inv is %f\n", edp_.max_p_inv); /* Hussein*/
Packet *p;
p = q_->deque();
if (p != 0) {
idle_ = 0;
bcount_ -= ((hdr_cmn*)p->access(off_cmn_))->size();
} else {
idle_ = 1;
// deque() may invoked by Queue::reset at init
// time (before the scheduler is instantiated).
// deal with this case
if (&Scheduler::instance() != NULL)
idletime_ = Scheduler::instance().clock();
else
idletime_ = 0.0;
}
return (p);
}
/*
* should the packet be dropped/marked due to a probabilistic drop?
*/
int
REDQueue::drop_early(Packet* pkt)
{
printf("4 edp_.max_p_inv is %f\n", edp_.max_p_inv); /* Hussein*/
hdr_cmn* ch = (hdr_cmn*)pkt->access(off_cmn_);
double p = edv_.v_a * edv_.v_ave + edv_.v_b;
p /= edp_.max_p_inv;
edv_.v_prob1 = p;
if (edv_.v_prob1 > 1.0)
edv_.v_prob1 = 1.0;
double count1 = edv_.count;
if (edp_.bytes)
count1 = (double) (edv_.count_bytes/edp_.mean_pktsize);
if (edp_.wait) {
if (count1 * p < 1.0)
p = 0.0;
else if (count1 * p < 2.0)
p /= (2 - count1 * p);
else
p = 1.0;
} else {
if (count1 * p < 1.0)
p /= (1.0 - count1 * p);
else
p = 1.0;
}
if (edp_.bytes && p < 1.0) {
p = p * ch->size() / edp_.mean_pktsize;
}
if (p > 1.0)
p = 1.0;
edv_.v_prob = p;
// drop probability is computed, pick random number and act
double u = Random::uniform();
if (u <= edv_.v_prob) {
// DROP or MARK
edv_.count = 0;
edv_.count_bytes = 0;
hdr_flags* hf =
(hdr_flags*)pickPacketForECN(pkt)->access(off_flags_);
if (edp_.setbit && hf->ect()) {
hf->ce() = 1; // mark Congestion Experienced bit
return (0); // no drop
} else {
return (1); // drop
}
}
return (0); // no DROP/mark
}
/*
* Pick packet for early congestion notification (ECN). This packet is then
* marked or dropped. Having a separate function do this is convenient for
* supporting derived classes that use the standard RED algorithm to compute
* average queue size but use a different algorithm for choosing the packet
for
* ECN notification.
*/
Packet*
REDQueue::pickPacketForECN(Packet* pkt)
{
return pkt; /* pick the packet that just arrived */
}
/*
* Pick packet to drop. Having a separate function do this is convenient for
* supporting derived classes that use the standard RED algorithm to compute
* average queue size but use a different algorithm for choosing the victim.
*/
Packet*
REDQueue::pickPacketToDrop()
{
printf("5 edp_.max_p_inv is %f\n", edp_.max_p_inv); /* Hussein*/
int victim;
if (drop_front_)
victim = min(1, q_->length()-1);
else if (drop_rand_)
victim = Random::integer(q_->length());
else /* default is drop_tail_ */
victim = q_->length() - 1;
return(q_->lookup(victim));
}
/*
* Receive a new packet arriving at the queue.
* The average queue size is computed. If the average size
* exceeds the threshold, then the dropping probability is computed,
* and the newly-arriving packet is dropped with that probability.
* The packet is also dropped if the maximum queue size is exceeded.
*
* "Forced" drops mean a packet arrived when the underlying queue was
* full or when the average q size exceeded maxthresh.
* "Unforced" means a RED random drop.
*
* For forced drops, either the arriving packet is dropped or one in the
* queue is dropped, depending on the setting of drop_tail_.
* For unforced drops, the arriving packet is always the victim.
*/
#define DTYPE_NONE 0 /* ok, no drop */
#define DTYPE_FORCED 1 /* a "forced" drop */
#define DTYPE_UNFORCED 2 /* an "unforced" (random) drop */
void REDQueue::enque(Packet* pkt)
{
printf("5 edp_.max_p_inv is %f\n", edp_.max_p_inv); /* Hussein*/
/*
* if we were idle, we pretend that m packets arrived during
* the idle period. m is set to be the ptc times the amount
* of time we've been idle for
*/
int m = 0;
if (idle_) {
double now = Scheduler::instance().clock();
/* To account for the period when the queue was empty. */
idle_ = 0;
m = int(edp_.ptc * (now - idletime_));
}
/*
* Run the estimator with either 1 new packet arrival, or with
* the scaled version above [scaled by m due to idle time]
* (bcount_ maintains the byte count in the underlying queue).
* If the underlying queue is able to delete packets without
* us knowing, then bcount_ will not be maintained properly!
*/
run_estimator(qib_ ? bcount_ : q_->length(), m + 1);
/*
* count and count_bytes keeps a tally of arriving traffic
* that has not been dropped (i.e. how long, in terms of traffic,
* it has been since the last early drop)
*/
hdr_cmn* ch = (hdr_cmn*)pkt->access(off_cmn_);
++edv_.count;
edv_.count_bytes += ch->size();
/*
* DROP LOGIC:
* q = current q size, ~q = averaged q size
* 1> if ~q > maxthresh, this is a FORCED drop
* 2> if minthresh < ~q < maxthresh, this may be an UNFORCED
drop
* 3> if (q+1) > hard q limit, this is a FORCED drop
*/
register double qavg = edv_.v_ave;
int droptype = DTYPE_NONE;
int qlen = qib_ ? bcount_ : q_->length();
int qlim = qib_ ? (qlim_ * edp_.mean_pktsize) : qlim_;
curq_ = qlen; // helps to trace queue during arrival, if enabled
if (qavg >= edp_.th_min && qlen > 1) {
if (qavg >= edp_.th_max) {
droptype = DTYPE_FORCED;
} else if (edv_.old == 0) {
/*
* The average queue size has just crossed the
* threshold from below to above "minthresh", or
* from above "minthresh" with an empty queue to
* above "minthresh" with a nonempty queue.
*/
edv_.count = 1;
edv_.count_bytes = ch->size();
edv_.old = 1;
} else if (drop_early(pkt)) {
droptype = DTYPE_UNFORCED;
}
} else {
/* No packets are being dropped. */
edv_.v_prob = 0.0;
edv_.old = 0;
}
if (qlen >= qlim) {
// see if we've exceeded the queue size
droptype = DTYPE_FORCED;
}
if (droptype == DTYPE_UNFORCED) {
/* pick packet for ECN, which is dropping in this case */
Packet *pkt_to_drop = pickPacketForECN(pkt);
/*
* If the packet picked is different that the one that just
arrived,
* add it to the queue and remove the chosen packet.
*/
if (pkt_to_drop != pkt) {
q_->enque(pkt);
bcount_ += ch->size();
q_->remove(pkt_to_drop);
bcount_ -=
((hdr_cmn*)pkt_to_drop->access(off_cmn_))->size();
pkt = pkt_to_drop; /* XXX okay because pkt is not
needed anymore */
}
// deliver to special "edrop" target, if defined
if (de_drop_ != NULL)
de_drop_->recv(pkt);
else
drop(pkt);
} else {
/* forced drop, or not a drop: first enqueue pkt */
q_->enque(pkt);
bcount_ += ch->size();
/* drop a packet if we were told to */
if (droptype == DTYPE_FORCED) {
/* drop random victim or last one */
pkt = pickPacketToDrop();
q_->remove(pkt);
bcount_ -=
((hdr_cmn*)pkt->access(off_cmn_))->size();
drop(pkt);
}
}
return;
}
int REDQueue::command(int argc, const char*const* argv)
{
printf("7 edp_.max_p_inv is %f\n", edp_.max_p_inv); /* Hussein*/
Tcl& tcl = Tcl::instance();
if (argc == 2) {
if (strcmp(argv[1], "reset") == 0) {
reset();
return (TCL_OK);
}
if (strcmp(argv[1], "early-drop-target") == 0) {
if (de_drop_ != NULL)
tcl.resultf("%s", de_drop_->name());
return (TCL_OK);
}
} else if (argc == 3) {
// attach a file for variable tracing
if (strcmp(argv[1], "attach") == 0) {
int mode;
const char* id = argv[2];
tchan_ = Tcl_GetChannel(tcl.interp(), (char*)id,
&mode);
if (tchan_ == 0) {
tcl.resultf("RED: trace: can't attach %s for
writing", id);
return (TCL_ERROR);
}
return (TCL_OK);
}
// tell RED about link stats
if (strcmp(argv[1], "link") == 0) {
LinkDelay* del =
(LinkDelay*)TclObject::lookup(argv[2]);
if (del == 0) {
tcl.resultf("RED: no LinkDelay object %s",
argv[2]);
return(TCL_ERROR);
}
// set ptc now
link_ = del;
edp_.ptc = link_->bandwidth() /
(8. * edp_.mean_pktsize);
return (TCL_OK);
}
if (strcmp(argv[1], "early-drop-target") == 0) {
NsObject* p = (NsObject*)TclObject::lookup(argv[2]);
if (p == 0) {
tcl.resultf("no object %s", argv[2]);
return (TCL_ERROR);
}
de_drop_ = p;
return (TCL_OK);
}
if (!strcmp(argv[1], "packetqueue-attach")) {
delete q_;
if (!(q_ = (PacketQueue*)
TclObject::lookup(argv[2])))
return (TCL_ERROR);
else {
pq_ = q_;
return (TCL_OK);
}
}
}
return (Queue::command(argc, argv));
}
/*
* Routine called by TracedVar facility when variables change values.
* Currently used to trace values of avg queue size, drop probability,
* and the instantaneous queue size seen by arriving packets.
* Note that the tracing of each var must be enabled in tcl to work.
*/
void
REDQueue::trace(TracedVar* v)
{
char wrk[500], *p;
if (((p = strstr(v->name(), "ave")) == NULL) &&
((p = strstr(v->name(), "prob")) == NULL) &&
((p = strstr(v->name(), "curq")) == NULL)) {
fprintf(stderr, "RED:unknown trace var %s\n",
v->name());
return;
}
if (tchan_) {
int n;
double t = Scheduler::instance().clock();
// XXX: be compatible with nsv1 RED trace entries
if (*p == 'c') {
sprintf(wrk, "Q %g %d", t, int(*((TracedInt*) v)));
} else {
sprintf(wrk, "%c %g %g", *p, t,
double(*((TracedDouble*) v)));
}
n = strlen(wrk);
wrk[n] = '\n';
wrk[n+1] = 0;
(void)Tcl_Write(tchan_, wrk, n+1);
}
return;
}
/* for debugging help */
void REDQueue::print_edp()
{
printf("8 edp_.max_p_inv is %f\n", edp_.max_p_inv); /* Hussein*/
printf("mean_pktsz: %d\n", edp_.mean_pktsize);
printf("bytes: %d, wait: %d, setbit: %d\n",
edp_.bytes, edp_.wait, edp_.setbit);
printf("minth: %f, maxth: %f\n", edp_.th_min, edp_.th_max);
printf("max_p_inv: %f, qw: %f, ptc: %f\n",
edp_.max_p_inv, edp_.q_w, edp_.ptc);
printf("qlim: %d, idletime: %f\n", qlim_, idletime_);
printf("=========\n");
}
void REDQueue::print_edv()
{
printf("v_a: %f, v_b: %f\n", edv_.v_a, edv_.v_b);
}
---------------------------------------------
Regards.
AA.
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