I will start by explaining my issue, and then provide a good portion of the code.
I and filling a queue with a custom class called process. Using this line:
ProcessQueue.push(new Process(inputs[0], inputs[1], inputs[2], inputs[3], inputs[4]));
This all seems well and good, when the loop is done Process queue is filled with pointers.
However upon further inspection I found out they all point to the SAME object?
Finding this curious, I stepped into the constructor on each iteration of the loop.
First iteration: when the constructor is entered all instance variables are null (as expected)
Second iteration: upon entering the constructor, all instance variables contain the values given to the object in the first iteration (ie: the same object)
Furthermore later when I use the queue I have confirmed that every pointer in the queue is referring to the same process object. (I can tell this because process contains a state and if loop through the queue changing the state, I will find the state already changed for the second pointer)
I suspect I must have done something wrong with the creation of me class. so here it is in its entirety.
Process.h
#pragma once
class Process
{
public:
Process(int _processId, int _arrivalTime, int _CPUTime,
int _IOFrequency, int _IODuration);
~Process();
bool HasArrived(int time);
bool HasCompleted();
bool HasFinishedBurst();
bool HasFinishedIO();
int GetQueueNum();
int GetID();
void SetQueueNum(int i);
void SetToReady();
void Run();
void PerformIO();
};
Process.cpp
#include "stdafx.h"
#include "Process.h"
#include <string>
using namespace std;
int processId;
int arrivalTime;
int CPUTime;
int IOFrequency;
int IODuration;
int Ticks;
int CPUConsumption;
int CPUBurstSize;
int queueNumber;
int IOBurstCount;
string state;
Process::Process(int _processId, int _arrivalTime, int _CPUTime,
int _IOFrequency, int _IODuration)
{
processId = _processId;
arrivalTime = _arrivalTime;
CPUTime = _CPUTime;
IOFrequency = _IOFrequency;
IODuration = _IODuration;
IOBurstCount = 0;
CPUConsumption = 0;
Ticks = 0;
queueNumber = 0;
state = "None";
printf("%d: %s\n", processId,state.c_str());
int excess = CPUTime % IOFrequency;
if (excess == 0)
{
CPUBurstSize = CPUTime / IOFrequency;
}
else
{
CPUBurstSize = (CPUTime - excess) / (IOFrequency - 1);
}
}
Process::~Process()
{
}
bool Process::HasArrived(int time)
{
if (arrivalTime <= time)
{
if (state.compare("Newly Arrived") == 0)
{
printf("Already arrived!\n");
}
state = "Newly Arrived";
printf("%d: %s\n", processId, state.c_str());
return true;
}
else
{
return false;
}
}
bool Process::HasCompleted()
{
if (CPUConsumption == CPUTime && IOBurstCount == IOFrequency)
{
state = "Finished";
printf("%d: %s\n", processId, state.c_str());
return true;
}
else
{
return false;
}
}
bool Process::HasFinishedBurst()
{
if (Ticks == CPUBurstSize)
{
Ticks = 0;
state = "Blocked";
printf("%d: %s\n", processId, state.c_str());
return true;
}
else
{
return false;
}
}
bool Process::HasFinishedIO()
{
if (Ticks >= IODuration)
{
IOBurstCount++;
Ticks = 0;
return true;
}
else
{
return false;
}
}
void Process::SetToReady()
{
state = "Ready";
printf("%d: %s\n", processId, state.c_str());
}
void Process::Run()
{
state = "Running";
printf("%d: %s\n", processId, state.c_str());
Ticks++;
CPUConsumption++;
}
void Process::PerformIO()
{
Ticks++;
}
int Process::GetQueueNum()
{
return queueNumber;
}
void Process::SetQueueNum(int i)
{
queueNumber = i;
}
int Process::GetID()
{
return processId;
}
I suspect I have somehow created this as a static class without meaning too...