I'm using NS-2 version 2.29 on a Fedora Linux PC. I'm using a MAC
protocol, and I want to find the average delay time. I heard that I need
to do that with changes to the C++ code, rather than a tcl script.
I want to write the enqueue packet time to file1, and dequeue packet time
to file2. Then, with a perl script, subtract the times in file1 from file2
to get the delay times. But I'm not sure where to make the changes to the
C++ code (I tried modifying queue.cc; See below), and I'm having a problem
using Scheduler::instance().clock() when writing the time to a file
because I get arbitrarily large numbers and negative numbers.
Any suggestions would be appreciated.
Thanks,
Mark
_____________________________________________
Mark C. Wood
Graduate Student, Computer Science Department
Washington University in St. Louis
_____________________________________________
/* -*- Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t
-*- */
/*
* Copyright (c) 1996-1997 The 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 Network Research
* Group at Lawrence Berkeley National 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.
*/
// added for average delay graph - MW
#include <stdlib.h> // for exit()
#include <stdio.h> // for fprintf
FILE *fd_enq_out; // output file for enqueue time
FILE *fd_deq_out; // output file for dequeue time
//
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/queue/queue.cc,v 1.29
2004/10/28 01:22:48 sfloyd Exp $ (LBL)";
#endif
#include "queue.h"
#include <math.h>
#include <stdio.h>
void PacketQueue::remove(Packet* target)
{
for (Packet *pp= 0, *p= head_; p; pp= p, p= p->next_) {
if (p == target) {
if (!pp) deque();
else {
if (p == tail_)
tail_= pp;
pp->next_= p->next_;
--len_;
bytes_ -= hdr_cmn::access(p)->size();
}
return;
}
}
fprintf(stderr, "PacketQueue:: remove() couldn't find target\n");
abort();
}
/*
* Remove packet pkt located after packet prev on the queue. Either p or
prev
* could be NULL. If prev is NULL then pkt must be the head of the queue.
*/
void PacketQueue::remove(Packet* pkt, Packet *prev) //XXX: screwy
{
if (pkt) {
if (head_ == pkt)
PacketQueue::deque(); /* decrements len_
internally */
else {
prev->next_ = pkt->next_;
if (tail_ == pkt)
tail_ = prev;
--len_;
bytes_ -= hdr_cmn::access(pkt)->size();
}
}
return;
}
void QueueHandler::handle(Event*)
{
queue_.resume();
}
Queue::~Queue() {
}
Queue::Queue() : Connector(), blocked_(0), unblock_on_resume_(1), qh_(*this),
pq_(0),
last_change_(0), /* temporarily NULL */
old_util_(0), period_begin_(0), cur_util_(0), buf_slot_(0),
util_buf_(NULL)
{
bind("limit_", &qlim_);
bind("util_weight_", &util_weight_);
bind_bool("blocked_", &blocked_);
bind_bool("unblock_on_resume_", &unblock_on_resume_);
bind("util_check_intv_", &util_check_intv_);
bind("util_records_", &util_records_);
if (util_records_ > 0) {
util_buf_ = new double[util_records_];
if (util_buf_ == NULL) {
printf("Error allocating util_bufs!");
util_records_ = 0;
}
for (int i = 0; i < util_records_; i++) {
util_buf_[i] = 0;
}
}
}
void Queue::recv(Packet* p, Handler*)
{
// added for average delay graph - MW
if (fd_enq_out == NULL) {
if ((fd_enq_out = fopen("file1", "w")) == NULL) {
fprintf(stderr, "\n********** Cannot open file1
for output!**********\n");
exit(1);
} else {
fprintf(stderr, "\n********** file1 opened
successfully **********\n");
}
}
double now = Scheduler::instance().clock();
fprintf(fd_enq_out, "%d\t%.17g\n", p->uid_, now);
//
enque(p);
if (!blocked_) {
/*
* We're not blocked. Get a packet and send it on.
* We perform an extra check because the queue
* might drop the packet even if it was
* previously empty! (e.g., RED can do this.)
*/
// added for average delay graph - MW
if (fd_deq_out == NULL) {
if ((fd_deq_out = fopen("file2", "w")) == NULL) {
fprintf(stderr, "\n********** Cannot open
file2 for output!
**********\n");
exit(1);
} else {
fprintf(stderr,"\n********** file2 opened
successfully **********\n");
}
}
//
p = deque();
// added for average delay graph - MW
now = Scheduler::instance().clock();
fprintf(fd_deq_out, "%d\t%.17g\n", p->uid_, now);
//
if (p != 0) {
utilUpdate(last_change_, now, blocked_);
last_change_ = now;
blocked_ = 1;
target_->recv(p, &qh_);
}
}
}
void Queue::utilUpdate(double int_begin, double int_end, int link_state) {
double decay;
decay = exp(-util_weight_ * (int_end - int_begin));
old_util_ = link_state + (old_util_ - link_state) * decay;
// PS: measuring peak utilization
if (util_records_ == 0)
return; // We don't track peak utilization
double intv = int_end - int_begin;
double tot_intv = int_begin - period_begin_;
if (intv || tot_intv) {
int guard = 0; // for protecting against long while loops
cur_util_ = (link_state * intv + cur_util_ * tot_intv) /
(intv + tot_intv);
while (tot_intv + intv > util_check_intv_ &&
guard++ < util_records_) {
period_begin_ = int_end;
util_buf_[buf_slot_] = cur_util_;
buf_slot_ = (buf_slot_ + 1) % util_records_;
cur_util_ = link_state;
intv -= util_check_intv_;
}
}
}
double Queue::utilization(void)
{
double now = Scheduler::instance().clock();
utilUpdate(last_change_, now, blocked_);
last_change_ = now;
return old_util_;
}
double Queue::peak_utilization(void)
{
double now = Scheduler::instance().clock();
double peak = 0;
int i;
// PS: if peak_utilization tracking is disabled,
// return the weighed avg instead
if (util_records_ == 0)
return utilization();
utilUpdate(last_change_, now, blocked_);
last_change_ = now;
for (i = 0; i < util_records_; i++) {
if (util_buf_[i] > peak)
peak = util_buf_[i];
}
return peak;
}
void Queue::updateStats(int queuesize)
{
double now = Scheduler::instance().clock();
double newtime = now - total_time_;
if (newtime > 0.0) {
double oldave = true_ave_;
double oldtime = total_time_;
double newtime = now - total_time_;
true_ave_ = (oldtime * oldave + newtime * queuesize) /now;
total_time_ = now;
}
}
void Queue::resume()
{
double now = Scheduler::instance().clock();
Packet* p = deque();
if (p != 0) {
target_->recv(p, &qh_);
} else {
if (unblock_on_resume_) {
utilUpdate(last_change_, now, blocked_);
last_change_ = now;
blocked_ = 0;
}
else {
utilUpdate(last_change_, now, blocked_);
last_change_ = now;
blocked_ = 1;
}
}
}
void Queue::reset()
{
Packet* p;
total_time_ = 0.0;
true_ave_ = 0.0;
while ((p = deque()) != 0)
drop(p);
}
----------------------------------------------------------------
