我正在寻找一个加权公平排队的调度方法的例子。我找到了这段代码，但它没有运行。而且我不理解“QueueElem”。我应该在课堂上添加什么？谁能帮我？
P.S：我使用netbeans。
由于
import java.util.Scanner;
import java.io.IOException;
import java.util.ArrayList;
public class WFQ
{
public static double compute_VT_Rate(ArrayList<QueueElem>[] Q,
double[] w)
{
double r = 0.0;
for (int i = 0; i < Q.length; i++)
if ( Q[i].size() > 0 )
r += w[i];
if ( r > 0 )
return(1/r);
else
return(0.0);
}
public static void printArrivals(double [] arrTime, int[] flowID,
double[] packetLen)
{
for (int i = 0; i < arrTime.length; i++)
System.out.println(" T = " + arrTime[i]
+ ", flow " + (flowID[i]+1)
+ ", length " + packetLen[i]);
}
public static void printFFS_State(ArrayList<QueueElem>[] Q)
{
// System.out.println("----------------------------------------");
// System.out.println("FFS State:");
int flag = 1;
for (int i = 0; i < Q.length; i++)
{
if ( Q[i].size() > 0 )
{ flag = 0;
System.out.println(" Packet from flow " + i
+ " has remaining VIRTUAL length = "
+ Q[i].get(0).remaining_Virt_len);
// System.out.println(" Q[" + i + "].get(0).remaining_Virt_len = "
// + Q[i].get(0).remaining_Virt_len);
}
}
if ( flag == 1 )
System.out.println(" -- empty");
// System.out.println("----------------------------------------");
}
public static void main(String[] args) throws IOException
{
int Ordering = 1;
Scanner in = new Scanner(System.in);
int i, j, k;
int nFlows; // # Flows
double[] w; // w[i] = weight of flow i
ArrayList<QueueElem> Q[]; // Queue[i] = packet queue of flow i
int nArrs; // # Arrivals
double [] arrTime; // arrTime[i] = arrival time of packet i
int[] flowID; // flowID[i] = ID of the flow of packet i
double[] packetLen; // packetLen[i] = Norm. length of packet i
double new_t = 0.0;
double new_vt = 0.0;
System.out.print("# flows = ");
nFlows = in.nextInt();
w = new double[nFlows];
Q = new ArrayList[nFlows];
for (i = 0; i < nFlows; i++)
{
System.out.print("Weight of flow " + i + " = ");
w[i] = in.nextDouble();
Q[i] = new ArrayList<QueueElem>();
}
System.out.print("# Arrivals = ");
nArrs = in.nextInt();
arrTime = new double[nArrs];
flowID = new int[nArrs];
packetLen = new double[nArrs];
for (i = 0; i < nArrs; i++)
{
System.out.print("Arrival time " + i + " = ");
arrTime[i] = in.nextDouble();
System.out.print("Flow ID " + i + " = ");
flowID[i] = in.nextInt();
flowID[i]--;
System.out.print("Packet len " + i + " = ");
packetLen[i] = in.nextDouble();
}
printArrivals(arrTime, flowID, packetLen);
System.out.println("\n\nBegin WFQ computation");
/* ***********************************************
WFQ Begins here
*********************************************** */
double t = 0.0; // = Now, real time clock
double vt = 0.0; // = Now, virtual time clock
double vt_rate = 0.0; // = speed of virtual time clock
QueueElem PacketQ = null;
// ----------------------------------------
// Variables for packet Arrival
// ----------------------------------------
int nextArrIndex = 0;
double nextArrTime = arrTime[0];
int nextFlowID = -1;
double nextPacketLen = -1.0;
QueueElem q;
// ----------------------------
// Next packet departure
// ----------------------------
double nextDepartureTime = 0.0;
// ----------------------------------------
// Variables for Flow's virtual clocks
// ----------------------------------------
double[] VT_flow = new double[nFlows]; // Max flow TS
double next_FFS_service_end_time;
double last_update_time = 0.0; // Last real time rem len updated
for (i = 0; i < nFlows; i++)
VT_flow[i] = 0.0;
next_FFS_service_end_time = -1.0;
// ------------------------
// Help variables
// ------------------------
/* ---------------------------------------------------------------
Main loop
--------------------------------------------------------------- */
while (true)
{
System.out.println("\n\n\n");
System.out.println("==========================================");
System.out.println("last_update_time = " + last_update_time);
System.out.println("(1) Current packet Queue:");
List.print(PacketQ);
System.out.println("(2) Fluid Flow Server State:");
printFFS_State(Q);
System.out.println("------------------------------");
System.out.println("BEGIN processing");
System.out.println("t = " + t + " , vt = " + vt);
/**********************************************************************/
// ----------------------------------------------------------
// Determine next arrival time
// ----------------------------------------------------------
if ( nextArrIndex < nArrs )
{
nextArrTime = arrTime[nextArrIndex];
}
else
{
nextArrTime = 9999999.0;
}
// ----------------------------------------------------------
// Determine next departure time
// ----------------------------------------------------------
if ( PacketQ != null )
{
nextDepartureTime = t + PacketQ.remaining_TransTime;
}
else
{
nextDepartureTime = 9999999.0;
}
// ----------------------------------------------------------
// Determine next FFS finish time
// ----------------------------------------------------------
vt_rate = compute_VT_Rate(Q, w);
// System.out.println("vt_rate = " + vt_rate );
next_FFS_service_end_time = 9999999.0; // Cheap trick
for ( i = 0; i < nFlows; i++ )
{
double h;
double transmit_rate;
if ( Q[i].size() > 0 )
{
h = Q[i].get(0).remaining_Virt_len;
// System.out.println("Flow " + i
// + " Rem. virt len = " + h);
h = h / w[i];
// System.out.println("Flow " + i
// + " Rem. virtual transmit time = " + h);
if ( h < next_FFS_service_end_time )
next_FFS_service_end_time = h;
}
}
next_FFS_service_end_time += t;
// System.out.println("+++ Next FFS service end time = "
// + next_FFS_service_end_time);
/**********************************************************************/
// ******************************************************************
// Print timing information
// ******************************************************************
System.out.println("+++ Next packet arrival time = " + nextArrTime
+ " (flow ID = " + nextFlowID
+ ", packet len = " + nextPacketLen + ")");
System.out.println("+++ Next packet departure time = "
+ nextDepartureTime);
System.out.println("+++ Next FFS service end time = "
+ next_FFS_service_end_time);
System.out.println();
System.out.println("------------------------------------------");
System.out.println("----- Find out Next Event in WFQ ---------");
/**********************************************************************/
// **************************************
// Test first !!!
// **************************************
boolean Arrival, Departure, FFS_fin;
Arrival = Departure = FFS_fin = false;
if ( nextArrTime < 10000 &&
(nextArrTime <= nextDepartureTime) &&
(nextArrTime <= next_FFS_service_end_time) &&
nextArrIndex < nArrs )
{
System.out.println("Next event: packet arrival");
Arrival = true;
new_t = nextArrTime;
}
if ( nextDepartureTime < 10000 &&
(nextDepartureTime<= nextArrTime) &&
(nextDepartureTime <= next_FFS_service_end_time) )
{
System.out.println("Next event: packet departure (real)");
Departure = true;
new_t = nextDepartureTime;
}
if ( next_FFS_service_end_time < 10000 &&
(next_FFS_service_end_time <= nextArrTime) &&
(next_FFS_service_end_time <= nextDepartureTime) )
{
System.out.println("Next event: FFS finishes a packet (virtual packet departure)");
FFS_fin = true;
new_t = next_FFS_service_end_time;
}
System.out.println("------------------------------------------");
vt_rate = compute_VT_Rate(Q, w);
if ( vt_rate > 0 )
new_vt = vt + vt_rate * (new_t - t);
// System.out.println("@@@@@@@@@@@@@@@@ DEBUG: new_t = " + new_t);
// System.out.println("@@@@@@@@@@@@@@@@ DEBUG: new_vt = " + new_vt);
/**********************************************************************/
// PROCESS !!!
/**********************************************************************/
// System.out.println(" + + + + PROCESSING !!! + + + + + +");
// *******************
// Virtual progress
// *******************
// System.out.println("********************************");
// System.out.println("Processing VIRTUAL progress\n");
// System.out.println("********************************");
// System.out.println("vt_rate= " + vt_rate);
for (i = 0; i < nFlows; i++)
{
if ( Q[i].size() > 0 )
{
QueueElem x = Q[i].get(0);
x.remaining_Virt_len -= w[i] * vt_rate *
(new_t - x.last_update_time);
x.last_update_time = new_t;
// System.out.println("Flow " + i + " remaining_Virt_len = "
// + x.remaining_Virt_len);
// System.out.println("Flow " + i + " remaining_Virt_len/w = "
// + x.remaining_Virt_len/w[i]);
}
}
// *******************
// Real progress
// *******************
// System.out.println("********************************");
// System.out.println("Processing REAL progress\n");
// System.out.println("********************************");
if ( PacketQ != null )
{
PacketQ.remaining_TransTime -= (new_t - last_update_time);
// System.out.println("!!!! Packet Q, remaining trans time = "
// + PacketQ.remaining_TransTime);
}
// ********************************
// Remember the current time and compute curret VT rate
// ********************************
last_update_time = new_t;
// **************************************
// Check if next event = packet arrival
// **************************************
if ( Arrival )
{
System.out.println("***** Processing packet arrival");
// Packet arrival
// System.out.println("nextArrIndex = " + nextArrIndex);
// System.out.println("nextArrTime = " + nextArrTime);
nextFlowID = flowID[nextArrIndex];
nextPacketLen = packetLen[nextArrIndex];
q = new QueueElem();
q.flowID = nextFlowID;
q.packetLen = nextPacketLen;
q.remaining_TransTime = q.packetLen;
q.remaining_Virt_len = q.packetLen;
q.last_update_time = new_t;
q.virtualFinTime = ( (VT_flow[nextFlowID] > new_vt) ?
VT_flow[nextFlowID] : new_vt ) +
q.remaining_Virt_len/w[nextFlowID];
VT_flow[nextFlowID] = q.virtualFinTime;
Q[nextFlowID].add(q);
// *********************************
// Insert in Packet Q
// *********************************
PacketQ = List.insert(PacketQ, q);
nextArrIndex++; // go to Next arrival
}
// **************************************
// Check if next event = packet departure
// **************************************
if ( Departure )
{
System.out.println("***** Processing packet departure");
System.out.println(">>>>>> Output order " + Ordering
+ " --> flow ID = " + (PacketQ.flowID +1)
+ " (packet len = " + PacketQ.packetLen + ")");
Ordering++;
PacketQ = List.delete(PacketQ);
if ( PacketQ != null )
{
PacketQ.remaining_TransTime = PacketQ.packetLen;
PacketQ.last_update_time = new_t;
}
// System.out.println("--- PacketQ after processing packet departure");
// if ( PacketQ != null )
// {
// List.print(PacketQ);
// }
}
// **************************************
// Check if next event = FFS fin packet
// **************************************
if ( FFS_fin )
{
System.out.println("***** Processing FFS Finish");
for ( i = 0; i < nFlows; i++ )
{
if ( Q[i].size() > 0 )
{
if ( Q[i].get(0).remaining_Virt_len < 0.00001 )
{
Q[i].remove(0);
if ( Q[i].size() > 0 )
{
Q[i].get(0).remaining_Virt_len =
Q[i].get(0).packetLen;
}
}
}
}
}
/* --------------------------------------------
t ------------> new_t
vt_rate
-------------------------------------------- */
vt_rate = compute_VT_Rate(Q, w);
if ( vt_rate > 0 )
new_vt = vt + vt_rate * (new_t - t);
t = new_t;
vt = new_vt;
if ( nextArrTime > 10000 &&
nextDepartureTime > 10000 &&
next_FFS_service_end_time > 10000 )
{
System.out.println("t = " + t + " ----- END");
break;
}
System.out.println();
System.out.println("vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv");
System.out.println("END processing: result");
System.out.println("t = " + t);
System.out.println("vt = " + vt);
System.out.println("(1) Current packet Queue:");
List.print(PacketQ);
System.out.println("(2) Fluid Flow Server State:");
printFFS_State(Q);
System.out.println("^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^");
System.out.println("\n\n");
}
}
}