±H¥óªÌ: <huanglin@sjtu.edu.cn>
¦¬¥óªÌ: <smallko@ee.ncku.edu.tw>
¥D¦®: A Bug of Q&A Q5 -- From Huang Lin
¤é´Á: 2006¦~8¤ë11¤é ¤U¤È 08:43

Hi, Mr. Ke.

I have read your Q&A part of your website. It is quite useful. Yet it seems that you missed a part in question 5 -- a modification of command function. I put my supplyment and my tcl file below. It is ok when I test this tcl file.

2.­×§ïqueue/ priqueue.cc
PriQueue::PriQueue() : DropTail()
{
        bind("curq_",&curq_);
        tchan_=0;
        bind("Prefer_Routing_Protocols", &Prefer_Routing_Protocols);
                LIST_INSERT_HEAD(&prhead, this, link);
}

void PriQueue::recv(Packet *p, Handler *h)
{
    struct hdr_cmn *ch = HDR_CMN(p);
      curq_ = q_->length();
          if(Prefer_Routing_Protocols) {
    ¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­¡­
}

//add by Huang Lin, 2006-8-9,21:59
int PriQueue::command(int argc, const char*const* argv)
{
  if (argc == 2 && strcasecmp(argv[1], "reset") == 0) {
    	Terminate();
      //FALL-THROUGH to give parents a chance to reset
   }
  else if(argc == 3 &&strcmp(argv[1], "attach") == 0) {
	int mode;
	const char* id = argv[2];
	Tcl& tcl = Tcl::instance();
	tchan_ = Tcl_GetChannel(tcl.interp(), (char*)id,
					  &mode);
	if (tchan_ == 0) {
		tcl.resultf("trace: can't attach %s for writing", id);
		return (TCL_ERROR);
	}
	return (TCL_OK);
    }
  return DropTail::command(argc, argv);
}


void PriQueue::trace(TracedVar* v)
{
        char wrk[500], *p;

        if (((p = strstr(v->name(), "curq")) == NULL) ) {
                fprintf(stderr, "PriQueue:unknown trace var %s\n", v->name());
                return;
        }

        if (tchan_) {
                int n;
                double t = Scheduler::instance().clock();
                              if (strstr(v->name(), "curq") != NULL) {
                        sprintf(wrk, "Q %g %d", t, int(*((TracedInt*) v)));
                }
                              n = strlen(wrk);
                wrk[n] = '\n';
                wrk[n+1] = 0;
                (void)Tcl_Write(tchan_, wrk, n+1);
        }
        return;
}

5.      Huang LinµÄtcl™n°¸ # globals and flags
set ns [new Simulator]

debug 1
#number of nodes
set num_mobile_nodes 3

# Parameter for wireless nodes
set opt(chan)           Channel/WirelessChannel    ;# channel type
set opt(prop)           Propagation/TwoRayGround   ;# radio-propagation model
set opt(netif)          Phy/WirelessPhy            ;# network interface type
set opt(mac)            Mac/802_11                 ;# MAC type
set opt(ifq)            Queue/DropTail/PriQueue    ;# interface queue type
set opt(ifqlen)         50
set opt(ll)             LL                         ;# link layer type
set opt(ant)            Antenna/OmniAntenna        ;# antenna model
set opt(ifqlen)         50                        ;# max packet in ifq
set opt(adhocRouting)   DumbAgent                       ;# routing protocol
set opt(x)          670  ;# X dimension of the topography
set opt(y)          670          ;# Y dimension of the topography

#smallko add the following two lines
Mac/802_11 set dataRate_  1Mb
Mac/802_11 set basicRate_  1Mb

set ntr [open out_rc_3.tr w]
$ns trace-all $ntr

set chan    [new $opt(chan)]
set topo    [new Topography]

$topo load_flatgrid $opt(x) $opt(y)

# Create God
create-god $num_mobile_nodes

# config node
$ns node-config -adhocRouting $opt(adhocRouting) \
                 -llType $opt(ll) \
                 -macType $opt(mac) \
                 -ifqType $opt(ifq) \
                 -ifqLen $opt(ifqlen) \
                 -antType $opt(ant) \
                 -propType $opt(prop)    \
                 -phyType $opt(netif) \
                 -channel $chan      \
                 -topoInstance $topo \
                 -wiredRouting OFF \
                 -agentTrace ON \
                 -routerTrace OFF \
                 -macTrace OFF    \
                 -movementTrace OFF

# creating mobile nodes
Mac/802_11 set RTSThreshold_ 3000
for {set i 0} {$i < $num_mobile_nodes} {incr i} {
    set wl_node_($i) [$ns node]         $wl_node_($i) random-motion 0               ;# disable random motion
    puts "wireless node $i created ..."
    $wl_node_($i) set X_ [expr $i * 10.0]
    $wl_node_($i) set Y_ [expr $i * 10.0]
    $wl_node_($i) set Z_ 0.0
}

set wl_ifq [$wl_node_(0) set ifq_(0)]
set queuechan [open qlen.tr w]
$wl_ifq trace curq_
$wl_ifq attach $queuechan

for {set i 0} {$i < $num_mobile_nodes} {incr i} {
    set src_udp_($i) [new Agent/UDP]
    $src_udp_($i) set class_ $i
    set dst_udp_($i) [new Agent/Null]
    $ns attach-agent $wl_node_($i) $src_udp_($i)
    $ns attach-agent $wl_node_([expr ($i+1)%($num_mobile_nodes)]) $dst_udp_($i)
    set app_($i) [new Application/Traffic/CBR]
    $app_($i) set packetSize_ 1025
    $app_($i) set interval_ 0.005
    $app_($i) attach-agent $src_udp_($i)
    $ns connect $src_udp_($i) $dst_udp_($i)
    $ns set fid_ $i
    $ns at 0.$i "$app_($i) start"
}

# Define node initial position in nam
for {set i 0} {$i < $num_mobile_nodes} {incr i} {
    $ns initial_node_pos $wl_node_($i) 20
   }

# Tell nodes when the simulation ends
for {set i 0} {$i < $num_mobile_nodes } {incr i} {
    $ns at 10.0 "$wl_node_($i) reset";
}

for {set i 0} {$i < $num_mobile_nodes} {incr i} {
    $ns at 100.0 "$app_($i) stop"
}

$ns at 110.0 "puts \"NS EXITING...\" ; $ns halt"

proc stop {} {
    global ns ntr queuechan
    close $ntr
    close $queuechan
}

# run the simulation
$ns run

If convenient, please send me your solution, check my method and update the website.

Best wishes.

Huang Lin