File: tfrc-sink.cc

package info (click to toggle)
ns2 2.35%2Bdfsg-9
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 79,396 kB
  • sloc: cpp: 172,923; tcl: 107,167; perl: 6,391; sh: 6,143; ansic: 5,846; makefile: 829; awk: 525; csh: 355
file content (1065 lines) | stat: -rw-r--r-- 30,896 bytes parent folder | download | duplicates (7)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
/*
 * Copyright (c) 1999  International Computer Science Institute
 * 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 ACIRI, the AT&T 
 *      Center for Internet Research at ICSI (the International Computer
 *      Science Institute).
 * 4. Neither the name of ACIRI nor of ICSI may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY ICSI 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 ICSI 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.
 */

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <math.h>
 
#include "tfrc-sink.h"
#include "formula-with-inverse.h"
#include "flags.h"

static class TfrcSinkClass : public TclClass {
public:
  	TfrcSinkClass() : TclClass("Agent/TFRCSink") {}
  	TclObject* create(int, const char*const*) {
     		return (new TfrcSinkAgent());
  	}
} class_tfrcSink; 


TfrcSinkAgent::TfrcSinkAgent() : Agent(PT_TFRC_ACK), nack_timer_(this)
{
	bind("packetSize_", &size_);	
	bind("InitHistorySize_", &hsz);
	bind("NumFeedback_", &NumFeedback_);
	bind ("AdjustHistoryAfterSS_", &adjust_history_after_ss);
	bind ("printLoss_", &printLoss_);
	bind ("algo_", &algo); // algo for loss estimation
	bind ("PreciseLoss_", &PreciseLoss_);
	bind ("numPkts_", &numPkts_);
	bind("minDiscountRatio_", &minDiscountRatio_);

	// for WALI ONLY
	bind ("NumSamples_", &numsamples);
	bind ("discount_", &discount);
	bind ("smooth_", &smooth_);
	bind ("ShortIntervals_", &ShortIntervals_);
	bind ("ShortRtts_", &ShortRtts_);

	// EWMA use only
	bind ("history_", &history); // EWMA history

	// for RBPH use only
	bind("minlc_", &minlc); 

	bind("bytes_", &bytes_);
	rtt_ =  0; 
	tzero_ = 0;
	last_timestamp_ = 0;
	last_arrival_ = 0;
	last_report_sent=0;
	total_received_ = 0;
	total_losses_ = 0;
	total_dropped_ = 0;

	maxseq = -1;
	maxseqList = -1;
	rcvd_since_last_report  = 0;
	losses_since_last_report = 0;
	loss_seen_yet = 0;
	lastloss = 0;
	lastloss_round_id = -1 ;
	numPktsSoFar_ = 0;

	rtvec_ = NULL;
	tsvec_ = NULL;
	lossvec_ = NULL;

	// used by WALI and EWMA
	last_sample = 0;

	// used only for WALI 
	false_sample = 0;
	sample = NULL ; 
	weights = NULL ;
	mult = NULL ;
        losses = NULL ;
	count_losses = NULL ;
        num_rtts = NULL ;
	sample_count = 1 ;
	mult_factor_ = 1.0;
	init_WALI_flag = 0;

	// used only for EWMA
	avg_loss_int = -1 ;
	loss_int = 0 ;

	// used only bu RBPH
	sendrate = 0 ; // current send rate
}

/*
 * This is a new loss event if it is at least an RTT after the beginning
 *   of the last one.
 * If PreciseLoss_ is set, the new_loss also checks that there is a
 *     new round_id.
 * The sender updates the round_id when it receives a new report from
 *   the receiver, and when it reduces its rate after no feedback.
 * Sometimes the rtt estimates can be less than the actual RTT, and
 *   the round_id will catch this.  This can be useful if the actual
 *   RTT increases dramatically.
 */
int TfrcSinkAgent::new_loss(int i, double tstamp)
{
	double time_since_last_loss_interval = tsvec_[i%hsz]-lastloss;
	if ((time_since_last_loss_interval > rtt_)
	     && (PreciseLoss_ == 0 || (round_id > lastloss_round_id))) {
		lastloss = tstamp;
		lastloss_round_id = round_id ;
                if (time_since_last_loss_interval < ShortRtts_ * rtt_ &&
				algo == WALI) {
                        count_losses[0] = 1;
                }
                if (rtt_ > 0 && algo == WALI) {
                        num_rtts[0] = (int) ceil(time_since_last_loss_interval / rtt_);
                        if (num_rtts[0] < 1) num_rtts[0] = 1;
                }
		return TRUE;
	} else return FALSE;
}

double TfrcSinkAgent::estimate_tstamp(int before, int after, int i)
{
	double delta = (tsvec_[after%hsz]-tsvec_[before%hsz])/(after-before) ; 
	double tstamp = tsvec_[before%hsz]+(i-before)*delta ;
	return tstamp;
}

/*
 * Receive new data packet.  If appropriate, generate a new report.
 */
void TfrcSinkAgent::recv(Packet *pkt, Handler *)
{
	hdr_tfrc *tfrch = hdr_tfrc::access(pkt); 
	hdr_flags* hf = hdr_flags::access(pkt);
	double now = Scheduler::instance().clock();
	double p = -1;
	int ecnEvent = 0;
	int congestionEvent = 0;
	int UrgentFlag = 0;	// send loss report immediately

	if (algo == WALI && !init_WALI_flag) {
		init_WALI () ;
	}
	rcvd_since_last_report ++;
	total_received_ ++;
	// bytes_ was added by Tom Phelan, for reporting bytes received.
	bytes_ += hdr_cmn::access(pkt)->size();

	if (maxseq < 0) {
		// This is the first data packet.
		maxseq = tfrch->seqno - 1 ;
		maxseqList = tfrch->seqno;
		rtvec_=(double *)malloc(sizeof(double)*hsz);
		tsvec_=(double *)malloc(sizeof(double)*hsz);
		lossvec_=(char *)malloc(sizeof(double)*hsz);
		if (rtvec_ && lossvec_) {
			int i;
			for (i = 0; i < hsz ; i ++) {
				lossvec_[i] = UNKNOWN;
				rtvec_[i] = -1; 
				tsvec_[i] = -1; 
			}
		}
		else {
			printf ("error allocating memory for packet buffers\n");
			abort (); 
		}
	}
	/* for the time being, we will ignore out of order and duplicate 
	   packets etc. */
	int seqno = tfrch->seqno ;
	fsize_ = tfrch->fsize;
	int oldmaxseq = maxseq;
	// if this is the highest packet yet, or an unknown packet
	//   between maxseqList and maxseq  
	if ((seqno > maxseq) || 
	  (seqno > maxseqList && lossvec_[seqno%hsz] == UNKNOWN )) {
		if (seqno > maxseqList + 1)
			++ numPktsSoFar_;
		UrgentFlag = tfrch->UrgentFlag;
		round_id = tfrch->round_id ;
		rtt_=tfrch->rtt;
		tzero_=tfrch->tzero;
		psize_=tfrch->psize;
		sendrate = tfrch->rate;
		last_arrival_=now;
		last_timestamp_=tfrch->timestamp;
		rtvec_[seqno%hsz]=now;	
		tsvec_[seqno%hsz]=last_timestamp_;	
		if (hf->ect() == 1 && hf->ce() == 1) {
			// ECN action
			lossvec_[seqno%hsz] = ECN_RCVD;
			++ total_losses_;
			losses_since_last_report++;
			if (new_loss(seqno, tsvec_[seqno%hsz])) {
				ecnEvent = 1;
				lossvec_[seqno%hsz] = ECNLOST;
			} 
			if (algo == WALI) {
                       		++ losses[0];
			}
		} else lossvec_[seqno%hsz] = RCVD;
	}
	if (seqno > maxseq) {
		int i = maxseq + 1;
		while (i < seqno) {
			// Added 3/1/05 in case we have wrapped around
			//   in packet sequence space.
			lossvec_[i%hsz] = UNKNOWN;
			++ i;
			++ total_losses_;
			++ total_dropped_;
		}
	}
	if (seqno > maxseqList && 
	  (ecnEvent || numPktsSoFar_ >= numPkts_ ||
	     tsvec_[seqno%hsz] - tsvec_[maxseqList%hsz] > rtt_)) {
		// numPktsSoFar_ >= numPkts_:
		// Number of pkts since we last entered this procedure
		//   at least equal numPkts_, the number of non-sequential 
		//   packets that must be seen before inferring loss.
		// maxseqList: max seq number checked for dropped packets
		// Decide which losses begin new loss events.
		int i = maxseqList ;
		while(i < seqno) {
			if (lossvec_[i%hsz] == UNKNOWN) {
				rtvec_[i%hsz]=now;	
				tsvec_[i%hsz]=estimate_tstamp(oldmaxseq, seqno, i);	
				if (new_loss(i, tsvec_[i%hsz])) {
					congestionEvent = 1;
					lossvec_[i%hsz] = LOST;
				} else {
					// This lost packet is marked "NOT_RCVD"
					// as it does not begin a loss event.
					lossvec_[i%hsz] = NOT_RCVD; 
				}
				if (algo == WALI) {
			    		++ losses[0];
				}
				losses_since_last_report++;
			}
			i++;
		}
		maxseqList = seqno;
		numPktsSoFar_ = 0;
	} else if (seqno == maxseqList + 1) {
		maxseqList = seqno;
		numPktsSoFar_ = 0;
	} 
	if (seqno > maxseq) {
		maxseq = tfrch->seqno ;
		// if we are in slow start (i.e. (loss_seen_yet ==0)), 
		// and if we saw a loss, report it immediately
		if ((algo == WALI) && (loss_seen_yet ==0) && 
		  (tfrch->seqno - oldmaxseq > 1 || ecnEvent )) {
			UrgentFlag = 1 ; 
			loss_seen_yet = 1;
			if (adjust_history_after_ss) {
				p = adjust_history(tfrch->timestamp);
			}

		}
		if ((rtt_ > SMALLFLOAT) && 
			(now - last_report_sent >= rtt_/NumFeedback_)) {
			UrgentFlag = 1 ;
		}
	}
	if (UrgentFlag || ecnEvent || congestionEvent) {
		nextpkt(p);
	}
	Packet::free(pkt);
}

double TfrcSinkAgent::est_loss () 
{	
	double p = 0 ;
	switch (algo) {
		case WALI:
			p = est_loss_WALI () ;
			break;
		case EWMA:
			p = est_loss_EWMA () ;
			break;
		case RBPH:
			p = est_loss_RBPH () ;
			break;
		case EBPH:
			p = est_loss_EBPH () ;
			break;
		default:
			printf ("invalid algo specified\n");
			abort();
			break ; 
	}
	return p;
}

/*
 * compute estimated throughput in packets per RTT for report.
 */
double TfrcSinkAgent::est_thput () 
{
	double time_for_rcv_rate;
	double now = Scheduler::instance().clock();
	double thput = 1 ;

	if ((rtt_ > 0) && ((now - last_report_sent) >= rtt_)) {
		// more than an RTT since the last report
		time_for_rcv_rate = (now - last_report_sent);
		if (rcvd_since_last_report > 0) {
			thput = rcvd_since_last_report/time_for_rcv_rate;
		}
	}
	else {
		// count number of packets received in the last RTT
		if (rtt_ > 0){
			double last = rtvec_[maxseq%hsz]; 
			int rcvd = 0;
			int i = maxseq;
			while (i > 0) {
				if (lossvec_[i%hsz] == RCVD) {
					if ((rtvec_[i%hsz] + rtt_) > last) 
						rcvd++; 
					else
						break ;
				}
				i--; 
			}
			if (rcvd > 0)
				thput = rcvd/rtt_; 
		}
	}
	return thput ;
}

/*
 * Schedule sending this report, and set timer for the next one.
 */
void TfrcSinkAgent::nextpkt(double p) {

	sendpkt(p);

	/* schedule next report rtt/NumFeedback_ later */
	/* note from Sally: why is this 1.5 instead of 1.0? */
	if (rtt_ > 0.0 && NumFeedback_ > 0) 
		nack_timer_.resched(1.5*rtt_/NumFeedback_);
}

/*
 * Create report message, and send it.
 */
void TfrcSinkAgent::sendpkt(double p)
{
	double now = Scheduler::instance().clock();

	/*don't send an ACK unless we've received new data*/
	/*if we're sending slower than one packet per RTT, don't need*/
	/*multiple responses per data packet.*/
        /*
	 * Do we want to send a report even if we have not received
	 * any new data?
         */ 

	if (last_arrival_ >= last_report_sent) {

		Packet* pkt = allocpkt();
		if (pkt == NULL) {
			printf ("error allocating packet\n");
			abort(); 
		}
	
		hdr_tfrc_ack *tfrc_ackh = hdr_tfrc_ack::access(pkt);
	
		tfrc_ackh->seqno=maxseq;
		tfrc_ackh->timestamp_echo=last_timestamp_;
		tfrc_ackh->timestamp_offset=now-last_arrival_;
		tfrc_ackh->timestamp=now;
		tfrc_ackh->NumFeedback_ = NumFeedback_;
		if (p < 0) 
			tfrc_ackh->flost = est_loss (); 
		else
			tfrc_ackh->flost = p;
		tfrc_ackh->rate_since_last_report = est_thput ();
		tfrc_ackh->losses = losses_since_last_report;
		if (total_received_ <= 0) 
			tfrc_ackh->true_loss = 0.0;
		else 
			tfrc_ackh->true_loss = 1.0 * 
			    total_losses_/(total_received_+total_dropped_);
		last_report_sent = now; 
		rcvd_since_last_report = 0;
		losses_since_last_report = 0;
		send(pkt, 0);
	}
}

int TfrcSinkAgent::command(int argc, const char*const* argv) 
{
	if (argc == 3) {
		if (strcmp(argv[1], "weights") == 0) {
			/* 
			 * weights is a string of numbers, seperated by + signs
			 * the firs number is the total number of weights.
			 * the rest of them are the actual weights
			 * this overrides the defaults
			 */
			char *w ;
			w = (char *)calloc(strlen(argv[2])+1, sizeof(char)) ;
			if (w == NULL) {
				printf ("error allocating w\n");
				abort();
			}
			strcpy(w, (char *)argv[2]);
			numsamples = atoi(strtok(w,"+"));
			sample = (int *)malloc((numsamples+1)*sizeof(int));
			losses = (int *)malloc((numsamples+1)*sizeof(int));
                        count_losses = (int *)malloc((numsamples+1)*sizeof(int));
                        num_rtts = (int *)malloc((numsamples+1)*sizeof(int));
			weights = (double *)malloc((numsamples+1)*sizeof(double));
			mult = (double *)malloc((numsamples+1)*sizeof(double));
			fflush(stdout);
			if (sample && weights) {
				int count = 0 ;
				while (count < numsamples) {
					sample[count] = 0;
					losses[count] = 1;
					count_losses[count] = 0;
                                        num_rtts[count] = 0;
					mult[count] = 1;
					char *w;
					w = strtok(NULL, "+");
					if (w == NULL)
						break ; 
					else {
						weights[count++] = atof(w);
					}	
				}
				if (count < numsamples) {
					printf ("error in weights string %s\n", argv[2]);
					abort();
				}
				sample[count] = 0;
				losses[count] = 1;
				count_losses[count] = 0;
				num_rtts[count] = 0;
				weights[count] = 0;
				mult[count] = 1;
				free(w);
				return (TCL_OK);
			}
			else {
				printf ("error allocating memory for smaple and weights:2\n");
				abort();
			}
		}
	}
	return (Agent::command(argc, argv));
}

void TfrcNackTimer::expire(Event *) {
	a_->nextpkt(-1);
}

void TfrcSinkAgent::print_loss(int sample, double ave_interval)
{
	double now = Scheduler::instance().clock();
	double drops = 1/ave_interval;
	// This is ugly to include this twice, but the first one is
	//   for backward compatibility with earlier scripts. 
	printf ("time: %7.5f loss_rate: %7.5f \n", now, drops);
	printf ("time: %7.5f sample 0: %5d loss_rate: %7.5f \n", 
		now, sample, drops);
	//printf ("time: %7.5f send_rate: %7.5f\n", now, sendrate);
	//printf ("time: %7.5f maxseq: %d\n", now, maxseq);
}

void TfrcSinkAgent::print_loss_all(int *sample) 
{
	double now = Scheduler::instance().clock();
	printf ("%f: sample 0: %5d 1: %5d 2: %5d 3: %5d 4: %5d\n", 
		now, sample[0], sample[1], sample[2], sample[3], sample[4]); 
}

void TfrcSinkAgent::print_losses_all(int *losses) 
{
	double now = Scheduler::instance().clock();
	printf ("%f: losses 0: %5d 1: %5d 2: %5d 3: %5d 4: %5d\n", 
		now, losses[0], losses[1], losses[2], losses[3], losses[4]); 
}

void TfrcSinkAgent::print_count_losses_all(int *count_losses) 
{
	double now = Scheduler::instance().clock();
	printf ("%f: count? 0: %5d 1: %5d 2: %5d 3: %5d 4: %5d\n", 
		now, count_losses[0], count_losses[1], count_losses[2], count_losses[3], count_losses[4]); 
}

void TfrcSinkAgent::print_num_rtts_all(int *) 
{
	double now = Scheduler::instance().clock();
	printf ("%f: rtts 0: %5d 1: %5d 2: %5d 3: %5d 4: %5d\n", 
 	   now, num_rtts[0], num_rtts[1], num_rtts[2], num_rtts[3], num_rtts[4]); 
}

////////////////////////////////////////
// algo specific code /////////////////
///////////////////////////////////////


////
/// WALI Code
////
double TfrcSinkAgent::est_loss_WALI () 
{
	int i;
	double ave_interval1, ave_interval2; 
	int ds ; 
		
	if (!init_WALI_flag) {
		init_WALI () ;
	}
	// sample[i] counts the number of packets in the i-th loss interval
	// sample[0] contains the most recent sample.
        // losses[i] contains the number of losses in the i-th loss interval
        // count_losses[i] is 1 if the i-th loss interval is short.
        // num_rtts[i] contains the number of rtts in the i-th loss interval
	for (i = last_sample; i <= maxseq ; i ++) {
		sample[0]++;
		if (lossvec_[i%hsz] == LOST || lossvec_[i%hsz] == ECNLOST) {
		        //  new loss event
			sample_count ++;
			shift_array (sample, numsamples+1, 0); 
			shift_array (losses, numsamples+1, 1); 
			shift_array (count_losses, numsamples+1, 1); 
			shift_array (num_rtts, numsamples+1, 0); 
			multiply_array(mult, numsamples+1, mult_factor_);
			shift_array (mult, numsamples+1, 1.0); 
			mult_factor_ = 1.0;
		}
	}
	last_sample = maxseq+1 ; 
	double now = Scheduler::instance().clock();
        //if (ShortIntervals_ > 0 && printLoss_ > 0) {
        //    printf ("now: %5.2f lastloss: %5.2f ShortRtts_: %d rtt_: %5.2f\n",
        //         now, lastloss, ShortRtts_, rtt_);
        //}
        if (ShortIntervals_ > 0 && 
            now - lastloss > ShortRtts_ * rtt_) {
              // Check if the current loss interval is short.
              count_losses[0] = 0;
        }
        if (ShortIntervals_ > 0 && rtt_ > 0) {
              // Count number of rtts in current loss interval.
              num_rtts[0] = (int) ceil((now - lastloss) / rtt_);
              if (num_rtts[0] < 1) num_rtts[0] = 1;
        }
	if (sample_count>numsamples+1)
		// The array of loss intervals is full.
		ds=numsamples+1;
    	else
		ds=sample_count;

	if (sample_count == 1 && false_sample == 0) 
		// no losses yet
		return 0; 
	/* do we need to discount weights? */
	if (sample_count > 1 && discount && sample[0] > 0) {
                double ave = weighted_average1(1, ds, 1.0, mult, weights, sample, ShortIntervals_, losses, count_losses, num_rtts);
		int factor = 2;
		double ratio = (factor*ave)/sample[0];
		if ( ratio < 1.0) {
			// the most recent loss interval is very large
			mult_factor_ = ratio;
			double min_ratio = minDiscountRatio_;
			if (mult_factor_ < min_ratio) 
				mult_factor_ = min_ratio;
		}
	}
	// Calculations including the most recent loss interval.
        ave_interval1 = weighted_average1(0, ds, mult_factor_, mult, weights, sample, ShortIntervals_, losses, count_losses, num_rtts);
        // Calculations not including the most recent loss interval.
        ave_interval2 = weighted_average1(1, ds, mult_factor_, mult, weights, sample, ShortIntervals_, losses, count_losses, num_rtts);
	// The most recent loss interval does not end in a loss
	// event.  Include the most recent interval in the 
	// calculations only if this increases the estimated loss
	// interval. 
        // If ShortIntervals is less than 10, do not count the most
        //   recent interval if it is a short interval.
        //   Values of ShortIntervals greater than 10 are only for
        //   validation purposes, and for backwards compatibility.
        //
	if (ave_interval2 > ave_interval1 ||
             (ShortIntervals_ > 1 && ShortIntervals_ < 10 
                     && count_losses[0] == 1))
                // The second condition is to check if the first interval
                //  is a short interval.  If so, we must use ave_interval2.
		ave_interval1 = ave_interval2;
	if (ave_interval1 > 0) { 
		if (printLoss_ > 0) {
			print_loss(sample[0], ave_interval1);
			print_loss_all(sample);
			if (ShortIntervals_ > 0) {
				print_losses_all(losses);
				print_count_losses_all(count_losses);
                                print_num_rtts_all(num_rtts);
			}
		}
		return 1/ave_interval1; 
	} else return 999;     
}

// Calculate the weighted average.
double TfrcSinkAgent::weighted_average(int start, int end, double factor, double *m, double *w, int *sample)
{
	int i; 
	double wsum = 0;
	double answer = 0;
	if (smooth_ == 1 && start == 0) {
		if (end == numsamples+1) {
			// the array is full, but we don't want to uses
			//  the last loss interval in the array
			end = end-1;
		} 
		// effectively shift the weight arrays 
		for (i = start ; i < end; i++) 
			if (i==0)
				wsum += m[i]*w[i+1];
			else 
				wsum += factor*m[i]*w[i+1];
		for (i = start ; i < end; i++)  
			if (i==0)
			 	answer += m[i]*w[i+1]*sample[i]/wsum;
			else 
				answer += factor*m[i]*w[i+1]*sample[i]/wsum;
	        return answer;

	} else {
		for (i = start ; i < end; i++) 
			if (i==0)
				wsum += m[i]*w[i];
			else 
				wsum += factor*m[i]*w[i];
		for (i = start ; i < end; i++)  
			if (i==0)
			 	answer += m[i]*w[i]*sample[i]/wsum;
			else 
				answer += factor*m[i]*w[i]*sample[i]/wsum;
	        return answer;
	}
}

int TfrcSinkAgent::get_sample(int oldSample, int numLosses) 
{
	int newSample;
	if (numLosses == 0) {
		newSample = oldSample;
	} else {
		newSample = oldSample / numLosses;
	}
	return newSample;
}

int TfrcSinkAgent::get_sample_rtts(int oldSample, int numLosses, int rtts) 
{
	int newSample;
	if (numLosses == 0) {
		newSample = oldSample;
                //printf ("sample: %d numLosses: %d\n", oldSample, numLosses);
	} else {
                double fraction;
                if (ShortRtts_ != 0)
                     fraction = (ShortRtts_ + 1.0 - rtts) / ShortRtts_;
                else fraction = 1.0;
		int numLoss = (int) (floor(fraction * numLosses ));
                if (numLoss != 0)
		  newSample = oldSample / numLoss;
                else newSample = oldSample;
                //printf ("sample: %d rtts: %d numLosses: %d newSample: %d fraction: %5.2f numLoss %d\n",
                //  oldSample, rtts, numLosses, newSample, fraction, numLoss);
	}
	return newSample;
}

// Calculate the weighted average, factor*m[i]*w[i]*sample[i]/wsum.
// "factor" is "mult_factor_", for weighting the most recent interval
//    when it is very large
// "m[i]" is "mult[]", for old values of "mult_factor_".
//
// When ShortIntervals_%10 is 1, the length of a loss interval is
//   "sample[i]/losses[i]" for short intervals, not just "sample[i]".
//   This is equivalent to a loss event rate of "losses[i]/sample[i]",
//   instead of "1/sample[i]".
//
// When ShortIntervals_%10 is 2, it is like ShortIntervals_ of 1,
//   except that the number of losses per loss interval is at
//   most 1460/byte-size-of-small-packets.
//
// When ShortIntervals_%10 is 3, short intervals are up to three RTTs,
//   and the number of losses counted is a function of the interval size.
//
double TfrcSinkAgent::weighted_average1(int start, int end, double factor, double *m, double *w, int *sample, int ShortIntervals, int *losses, int *count_losses, int *num_rtts)
{
        int i;
        int ThisSample;
        double wsum = 0;
        double answer = 0;
        if (smooth_ == 1 && start == 0) {
                if (end == numsamples+1) {
                        // the array is full, but we don't want to use
                        //  the last loss interval in the array
                        end = end-1;
                }
                // effectively shift the weight arrays
                for (i = start ; i < end; i++)
                        if (i==0)
                                wsum += m[i]*w[i+1];
                        else
                                wsum += factor*m[i]*w[i+1];
                for (i = start ; i < end; i++) {
                        ThisSample = sample[i];
                        if (ShortIntervals%10 == 1 && count_losses[i] == 1) {
			       ThisSample = get_sample(sample[i], losses[i]);
                        }
                        if (ShortIntervals%10 == 2 && count_losses[i] == 1) {
			       int adjusted_losses = int(fsize_/size_);
			       if (losses[i] < adjusted_losses) {
					adjusted_losses = losses[i];
			       }
			       ThisSample = get_sample(sample[i], adjusted_losses);
                        }
                        if (ShortIntervals%10 == 3 && count_losses[i] == 1) {
			       ThisSample = get_sample_rtts(sample[i], losses[i], num_rtts[i]);
                        }
                        if (i==0)
                                answer += m[i]*w[i+1]*ThisSample/wsum;
                                //answer += m[i]*w[i+1]*sample[i]/wsum;
                        else
                                answer += factor*m[i]*w[i+1]*ThisSample/wsum;
                                //answer += factor*m[i]*w[i+1]*sample[i]/wsum;
		}
                return answer;

        } else {
                for (i = start ; i < end; i++)
                        if (i==0)
                                wsum += m[i]*w[i];
                        else
                                wsum += factor*m[i]*w[i];
                for (i = start ; i < end; i++) {
                       ThisSample = sample[i];
                       if (ShortIntervals%10 == 1 && count_losses[i] == 1) {
			       ThisSample = get_sample(sample[i], losses[i]);
                       }
                       if (ShortIntervals%10 == 2 && count_losses[i] == 1) {
			       ThisSample = get_sample(sample[i], 7);
			       // Replace 7 by 1460/packet size.
                               // NOT FINISHED.
                       }
                        if (ShortIntervals%10 == 3 && count_losses[i] == 1) {
			       ThisSample = get_sample_rtts(sample[i], losses[i], (int) num_rtts[i]);
                        }
                       if (i==0)
                                answer += m[i]*w[i]*ThisSample/wsum;
                                //answer += m[i]*w[i]*sample[i]/wsum;
                        else
                                answer += factor*m[i]*w[i]*ThisSample/wsum;
                                //answer += factor*m[i]*w[i]*sample[i]/wsum;
		}
                return answer;
        }
}

// Shift array a[] up, starting with a[sz-2] -> a[sz-1].
void TfrcSinkAgent::shift_array(int *a, int sz, int defval) 
{
	int i ;
	for (i = sz-2 ; i >= 0 ; i--) {
		a[i+1] = a[i] ;
	}
	a[0] = defval;
}
void TfrcSinkAgent::shift_array(double *a, int sz, double defval) {
	int i ;
	for (i = sz-2 ; i >= 0 ; i--) {
		a[i+1] = a[i] ;
	}
	a[0] = defval;
}

// Multiply array by value, starting with array index 1.
// Array index 0 of the unshifted array contains the most recent interval.
void TfrcSinkAgent::multiply_array(double *a, int sz, double multiplier) {
	int i ;
	for (i = 1; i <= sz-1; i++) {
		double old = a[i];
		a[i] = old * multiplier ;
	}
}

/*
 * We just received our first loss, and need to adjust our history.
 */
double TfrcSinkAgent::adjust_history (double ts)
{
	int i;
	double p;
	for (i = maxseq; i >= 0 ; i --) {
		if (lossvec_[i%hsz] == LOST || lossvec_[i%hsz] == ECNLOST ) {
			lossvec_[i%hsz] = NOT_RCVD; 
		}
	}
	lastloss = ts; 
	lastloss_round_id = round_id ;
	p=b_to_p(est_thput()*psize_, rtt_, tzero_, fsize_, 1);
	false_sample = (int)(1.0/p);
	sample[1] = false_sample;
	sample[0] = 0;
	losses[1] = 0;
	losses[0] = 1;
	count_losses[1] = 0;
	count_losses[0] = 0;
        num_rtts[0]=0;
        num_rtts[1]=0;
	sample_count++; 
	if (printLoss_) {
		print_loss_all (sample);
		if (ShortIntervals_ > 0) {
			print_losses_all(losses);
			print_count_losses_all(count_losses);
			print_num_rtts_all(num_rtts);
		}
	}
	false_sample = -1 ; 
	return p;
}


/*
 * Initialize data structures for weights.
 */
void TfrcSinkAgent::init_WALI () {
	int i;
	if (numsamples < 0)
		numsamples = DEFAULT_NUMSAMPLES ;	
	if (smooth_ == 1) {
		numsamples = numsamples + 1;
	}
	sample = (int *)malloc((numsamples+1)*sizeof(int));
        losses = (int *)malloc((numsamples+1)*sizeof(int));
        count_losses = (int *)malloc((numsamples+1)*sizeof(int));
        num_rtts = (int *)malloc((numsamples+1)*sizeof(int));
	weights = (double *)malloc((numsamples+1)*sizeof(double));
	mult = (double *)malloc((numsamples+1)*sizeof(double));
	for (i = 0 ; i < numsamples+1 ; i ++) {
		sample[i] = 0 ; 
	}
	if (smooth_ == 1) {
		int mid = int(numsamples/2);
		for (i = 0; i < mid; i ++) {
			weights[i] = 1.0;
		}
		for (i = mid; i <= numsamples; i ++){
			weights[i] = 1.0 - (i-mid)/(mid + 1.0);
		}
	} else {
		int mid = int(numsamples/2);
		for (i = 0; i < mid; i ++) {
			weights[i] = 1.0;
		}
		for (i = mid; i <= numsamples; i ++){
			weights[i] = 1.0 - (i+1-mid)/(mid + 1.0);
		}
	}
	for (i = 0; i < numsamples+1; i ++) {
		mult[i] = 1.0 ; 
	}
	init_WALI_flag = 1;  /* initialization done */
}

///////////////////////////
// EWMA //////////////////
//////////////////////////

double TfrcSinkAgent::est_loss_EWMA () {
	double p1, p2 ;
	for (int i = last_sample; i <= maxseq ; i ++) {
		loss_int++; 
		if (lossvec_[i%hsz] == LOST || lossvec_[i%hsz] == ECNLOST ) {
			if (avg_loss_int < 0) {
				avg_loss_int = loss_int ; 
			} else {
				avg_loss_int = history*avg_loss_int + (1-history)*loss_int ;
			}
			loss_int = 0 ;
		}
	}
	last_sample = maxseq+1 ; 

	if (avg_loss_int < 0) { 
		p1 = 0;
	} else {
		p1 = 1.0/avg_loss_int ; 
	}
	if (loss_int == 0 
	    || avg_loss_int < 0){ //XXX this last check was added by a
				  //person who knows nothing of this
				  //code just to stop FP div by zero.
				  //Values were history=.75,
				  //avg_loss_int=-1, loss_int=3.  If
				  //you know what should be here,
				  //please cleanup and remove this
				  //comment.

		p2 = p1 ; 
	} else {
		p2 = 1.0/(history*avg_loss_int + (1-history)*loss_int) ;
	}
	if (p2 < p1) {
		p1 = p2 ; 
	}
	if (printLoss_ > 0) {
		if (p1 > 0) 
			print_loss(loss_int, 1.0/p1);
		else
			print_loss(loss_int, 0.00001);
		print_loss_all(sample);
	}
	return p1 ;
}

///////////////////////////
// RBPH //////////////////
//////////////////////////
double TfrcSinkAgent::est_loss_RBPH () {

	double numpkts = hsz ;
	double p ; 

	// how many pkts we should go back?
	if (sendrate > 0 && rtt_ > 0) {
		double x = b_to_p(sendrate, rtt_, tzero_, psize_, 1);
		if (x > 0) 
			numpkts = minlc/x ; 
		else
			numpkts = hsz ;
	}

	// that number must be below maxseq and hsz 
	if (numpkts > maxseq)
		numpkts = maxseq ;
	if (numpkts > hsz)
		numpkts = hsz ;

	int lc = 0;
	int pc = 0;
	int i = maxseq ;

	// first see if how many lc's we find in numpkts 
	while (pc < numpkts) {
		pc ++ ;
		if (lossvec_[i%hsz] == LOST || lossvec_[i%hsz] == ECNLOST )
			lc ++ ; 
		i -- ;
	}

	// if not enough lsos events, keep going back ...
	if (lc < minlc) {

		// but only as far as the history allows ...
		numpkts = maxseq ;
		if (numpkts > hsz)
			numpkts = hsz ;

		while ((lc < minlc) && (pc < numpkts)) {
			pc ++ ;
			if (lossvec_[i%hsz] == LOST || lossvec_[i%hsz] == ECNLOST )
				lc ++ ;
			i -- ;
		
		}
	}

	if (pc == 0) 
		p = 0; 
	else
		p = (double)lc/(double)pc ; 
	if (printLoss_ > 0) {
		if (p > 0) 
			print_loss(0, 1.0/p);
		else
			print_loss(0, 0.00001);
		print_loss_all(sample);
	}
	return p ;
}

///////////////////////////
// EBPH //////////////////
//////////////////////////
double TfrcSinkAgent::est_loss_EBPH () {

	double numpkts = hsz ;
	double p ; 

	int lc = 0;
	int pc = 0;
	int i = maxseq ;

	numpkts = maxseq ;
	if (numpkts > hsz)
		numpkts = hsz ;

	while ((lc < minlc) && (pc < numpkts)) {
		pc ++ ;
		if (lossvec_[i%hsz] == LOST || lossvec_[i%hsz] == ECNLOST)
			lc ++ ;
		i -- ;
	}

	if (pc == 0) 
		p = 0; 
	else
		p = (double)lc/(double)pc ; 
	if (printLoss_ > 0) {
		if (p > 0) 
			print_loss(0, 1.0/p);
		else
			print_loss(0, 0.00001);
		print_loss_all(sample);
	}
	return p ;
}