Programming Homework Help. C Programming Impact of Linux versus Windows in Memory Allocation Discussion
Sources
This assignment covers material presented in the chapter ‘Memory Management & Operating Systems’. You can refer particularly to the following lessons in order to help you working through your solution:
Memory Allocation Schemes: Definition & Uses
Paged Memory Allocation: Definition, Purpose & Structure
Page Replacement: Definition & Algorithms
Prompt
- Consider the below settings to begin this project and keep them in mind:
Total Memory size = 20 Kbyte
- Page size = 1 Kbyte
Run the following list of jobs given the above considerations.
- Job IDStart TimeJob required sizeExecution intervalJob state at the end of the interval1127End2238Sleep3346End4436Sleep5529Sleep6636Sleep7726Sleep
Using the functions you studied in the previously mentioned code that implement the different allocation, deallocation and replacement schemes, try three different scenarios in order to manage memory allocation for the following jobs
Job IDStart TimeJob required sizeExecution intervalJob state at the end of the interval8834Sleep9955Sleep101028Sleep111146End121265Sleep21336End41334Sleep131353End71323End91744Sleep1019211End61936End520210Sleep421312Sleep1222613End82239End928511End53323Sleep434310End538210End
Show the memory state for the different scenarios and analyze which choice is the best. Discuss the impact that Linux verses Windows might have on the ending memory state.
Here’s the sample code:
#include <stdio.h>
//Process struct to create an object with the attributes needed
struct Process {
int processID;
int processingTime;
int waitTime;
int turnAroundTime;
//add arrivingTime;
int arrivingTime;
//add is Processing
int isProcessing;
};
//This will calculate the Wait Time for each Process according to the algorithm
struct Process * calculateWaitTime (struct Process queue[], int size) {
for (int i = 1; i < size; i++) {
queue[i].waitTime = queue[i – 1].processingTime + queue[i – 1].waitTime;
}
return queue;
}
//This will calculate how much time it takes for a process to wait and be executed
struct Process * calculateTurnAround (struct Process queue[], int size) {
for (int i = 0; i < size; i++) {
queue[i].turnAroundTime = queue[i].processingTime + queue[i].waitTime;
}
return queue;
}
//This will give us an average of the waiting time for each process
void averageWaitingTime (struct Process queue[], int size) {
float average = 0;
int count = 0;
for (int i = 0; i < size; i++) {
average += queue[i].waitTime;
count++;
}
average = average / count;
printf(“Average Waiting Time: %fn”, average);
}
//This function helps to swap items in an array
void swap(struct Process *a, struct Process *b) {
struct Process t = *a;
a = b;
*b = t;
}
//This method aids the pivot for Quick Sort
int partition (struct Process queue[], int low, int high) {
int pivot = queue[high].processingTime;
int i = low – 1;
for (int j = low; j <= high – 1; j++) {
if (queue[j].processingTime <= pivot) {
i++;
swap(&queue[i],&queue[j]);
}
}
swap(&queue[i + 1], &queue[high]);
return (i + 1);
}
//This is a recursive implementation of the Quick Sort
void quickSort (struct Process queue[], int low, int high) {
if (low < high) {
int pi = partition(queue, low, high);
quickSort(queue, low, pi – 1);
quickSort(queue, pi + 1, high);
}
}
//First Server First Come scheduling algorithm
// void firstServeFirstCome (struct Process queue[], int size) {
// queue = calculateWaitTime(queue, size);
// queue = calculateTurnAround(queue, size);
// averageWaitingTime(queue, size);
// }
//Shortest Job Next scheduling algorithm
void shortestJobNext (struct Process queue[], int size) {
quickSort(queue, 0, size – 1);
queue = calculateWaitTime(queue, size);
queue = calculateTurnAround(queue, size);
averageWaitingTime(queue, size);
}
// Round Robin
struct Process * roundRobin (struct Process queue[], int size, int quantum) {
int iterator = 0;
int flag = 0;
int time = 0; //The time variable to manage waiting, turnaround and incoming processes
quickSort(queue, 0, size – 1);
//This while loop is to control the whole scheduling
while (flag == 0) {
//This loop is to make sure every process is only executed within the quantum
for (int k = 0; k < quantum; k++) {
queue[iterator].isProcessing = 1;
int flagProcessingTime = 0;
//Since we are not using Threading, this loop is to make sure every process is considered within each time unit
for (int i = 0; i < size; i++) {
//This will make sure that we only affect the process that has actually arrive at the scheduler
if (queue[i].arrivingTime <= time && queue[i].processingTime > 0) {
flagProcessingTime++;
/**
* If the process isProcessing, remove processing time.
* It is not processing, just add to the wait time.
*/
switch (queue[i].isProcessing) {
case 1:
queue[i].processingTime–;
queue[i].turnAroundTime++;
break;
case 0:
queue[i].waitTime++;
queue[i].turnAroundTime++;
break;
}
}
}
time++;
queue[iterator].isProcessing = 0;
//Once all processes get to 0, this will finish execution of the scheduler
if (flagProcessingTime == 0) {
flag = 1;
break;
}
}
iterator++;
iterator = iterator % size;
}
averageWaitingTime(queue, size);
return 0;
}
//main
int main() {
//Array with processes with their id and processing time
struct Process queue[] ={ {1, 6, 0, 0}, {2, 8, 0, 0}, {3, 7, 0, 0}, {4, 3, 0, 0}, {5, 1, 0, 0}};
//This will help determine the number of items in the array
//int size = sizeof(queue)/sizeof(struct Process);
int size = 5;
//firstServeFirstCome(queue, size);
shortestJobNext(queue, size);
//roundRobin(queue, size, 1);
printf(“ProcessID Processing Time Wait Time Turnaround Time n”);
for (int i = 0; i < size; i++) {
printf(“t %d ttt %d tttt %d ttt %d n”, queue[i].processID, queue[i].processingTime, queue[i].waitTime, queue[i].turnAroundTime);
}
return 0;
}
