Array of STL Queues

[icpsvt]

Hi, small problem I'm having.

I've created an array of queues:

queue<Process> pqueue[NUM_PRIORITY_LEVELS];

I know I could have used a vector of queues, but I think this will be easier to debug.

I can insert elements into the first element of the array:

pqueue[0].push(p);

But when I attempt to push into any other element, it doesn't put them in.
ie,

pqueue[2].push(p);  //executes, but it doesn't actually appear

I'm using Visual Studio .NET 2003. In the debugger, it shows pqueue[0].c's _MAP as being referenced, but any of the other elements _MAP is shown as an undefined value.

Why? And How do I fix it?

Thanks for any help,
Jason

#include <string>
#include <vector>
#include <queue>
#include <cmath>
#include "EXPQueue.h"
#include "Process.h"
#include "state.h"
#include "SchedulerProcess.h"
using namespace std;


//EXPQueue::EXPQueue() : ReadyState("Ready State (EXP)"){
EXPQueue::EXPQueue() : state("Ready State (EXP)"){
    for(int i=0; i<NUM_PRIORITY_LEVELS; i++)
        this->pqueue[i].size();
}

EXPQueue::~EXPQueue(){
}


// What to do when the clock ticks
void EXPQueue::clockTick(long currentTime) {
    this->currentTime = currentTime;


}


// Store an existing process in the right queue
void EXPQueue::storeIntoQueue(Process p) {
    //first determine what the new priority level should be and set it
    int level = p.getTimeSliceLevel();
    int start = p.getTimeSliceStart();
    int end = p.getTimeSliceEnd();
    int runTime = (int)(pow(2,level)*10);
    int actualTime = end - start;
    //runTime is how long it could have run for
    if(runTime == actualTime) {
        if(level<NUM_PRIORITY_LEVELS)
            p.setTimeSliceLevel(++level);
    } 
    else if(((double)actualTime/(double)runTime)<.5)
        if(level>0)
            p.setTimeSliceLevel(--level);


    //then store it in the right level at the end
    this->pqueue[p.getTimeSliceLevel()].push(p);
}

// Load what should be the next process from the Queue
 Process EXPQueue::loadFromQueue() {
    Process p;
    // If the queues are not empty, load the first process, and store a copy in copy
    if(!this->isEmpty()) {
        p = this->getFront();    
        this->copy = p;
    }
    return p;
}

 //Check if there are any processes
 bool EXPQueue::isEmpty() {
     for(int i=0; i<NUM_PRIORITY_LEVELS; i++) 
        if(!this->pqueue[i].empty()) 
            return false;

    return true;
 }

 //Check if there is more work to do (Keeps syntax similar in opening loop)
 bool EXPQueue::getMoreToDo() {
    for(int i=0; i<NUM_PRIORITY_LEVELS; i++) 
            if(!this->pqueue[i].empty()) 
                return true;

    return false;
 }

 //Return a copy of what's up front
 Process EXPQueue::getFront() {
    Process p;
    //Get the first available process
    for(int i=0; i<NUM_PRIORITY_LEVELS; i++) 
        if(!this->pqueue[i].empty()) {
            p = this->pqueue[i].front();
            this->pqueue[i].pop();
            return p;
        }
    return p;
 }

// Describe the state
string EXPQueue::toString() {
    char temp[ARRAY_SIZE];
    char temp2[20];
    int nums[8];
    
    int size = 0;
    for(int i=0; i<NUM_PRIORITY_LEVELS; i++)
        size += this->pqueue[i].size();

    string info = this->name + ": Queued Processes = ";
    info += itoa(size, temp, NUM_BASE);

    if(!this->isEmpty()) {
        info += this->getFront().toString();
        for(int i=0; i<NUM_PRIORITY_LEVELS; i++)
            nums[i] = this->pqueue[i].size();
    }
    sprintf(temp2, "%d %d %d %d %d %d %d %d",nums[0],nums[1],nums[2],nums[3],nums[4],nums[5],nums[6],nums[7]);
    info += temp2;

    return info + "\n";
}

 

[ArkM]

Your getFront() member function has (unwilling?) side effect: it removes the last element of the queue by pop() member function. May be you want top() member function?..