PrabalMinotra / Assignment_3_OS

MeMS [CSE231 OS Assignment 3]

MeMS: Memory Management System [CSE231 OS Assignment 3]

Documentation

How to run the example.c

After implementing functions in mems.h follow the below steps to run example.c file

$ make
$ ./example

Table of Contents

1. Problem Statement
2. Prerequisites
3. Code Structure
   • Header Files
   • Data Structures
   • Global Variables
4. Code Walkthrough
5. Output

Problem Statment

• Implement a custom memory management system (MeMS) using the C programming language. MeMS should utilize the system calls mmap and munmap for memory allocation and deallocation, respectively

Prerequisites

• C compiler (e.g., GCC)
• POSIX-compliant system (Linux, Unix, macOS): Parallels VM for this case

Code Structure

Header Files

#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>

Data Structures

struct node {
// Structure members
};

Global Variables

struct node *headPtr;
int currIndex, totalNodes, pageMultiple;
int sizeNode = sizeof(struct node);
#define PAGE_SIZE 4096

Code Walkthrough

mems_init()

void mems_init() {
    // Initialization code
}

mems_malloc(size_t reqSize)

void *mems_malloc(size_t reqSize) {
    // Memory allocation code
}

mems_free(void *vPtr)

void mems_free(void *vPtr) {
    // Memory deallocation code
}

mems_print_stats()

void mems_print_stats() {
    // Print memory statistics
}

mems_get(void *vPtr)

void *mems_get(void *vPtr) {
    // Get physical memory address
}

mergeCo()

void mergeCo() {
    // Merge contiguous holes
}

To Run

• locate to the folder named "2022357_2022293"

$ make
$ ./example

Output

------- Allocated virtual addresses [mems_malloc] -------
Virtual address: 0
Virtual address: 1000
Virtual address: 2000
Virtual address: 3000
Virtual address: 4096
Virtual address: 5096
Virtual address: 6096
Virtual address: 7096
Virtual address: 8192
Virtual address: 9192

------ Assigning value to Virtual address [mems_get] -----
Virtual address: 0	 Physical Address: 281473053999104
Value written: 200

--------- Printing Stats [mems_print_stats] --------
----- MeMS SYSTEM STATS ----
MAIN[0:4095]-> P[0:999]<->P[1000:1999]<->P[2000:2999]<->P[3000:3999]<->P[4000:4095]
MAIN[4096:8191]-> P[4096:5095]<->P[5096:6095]<->P[6096:7095]<->P[7096:8095]<->P[8096:8191]
MAIN[8192:12287]-> P[8192:9191]<->P[9192:10191]<->P[10192:12287]-> NULL

Pages Used : 3
Space unused : 2288
Main Chain Length: 3
Sub-Chain Length Array: [5 ,5 ,3 ,]


--------- Freeing up the memory [mems_free] --------
----- MeMS SYSTEM STATS ----
MAIN[0:4095]-> P[0:999]<->P[1000:1999]<->P[2000:2999]<->P[3000:4095]
MAIN[4096:8191]-> P[4096:5095]<->P[5096:6095]<->P[6096:7095]<->P[7096:8095]<->P[8096:8191]
MAIN[8192:12287]-> P[8192:9191]<->P[9192:10191]<->P[10192:12287]-> NULL

Pages Used : 3
Space unused : 3288
Main Chain Length: 3
Sub-Chain Length Array: [4 ,5 ,3 ,]

----- MeMS SYSTEM STATS ----
MAIN[0:4095]-> P[0:999]<->P[1000:1999]<->P[2000:2999]<->P[3000:3999]<->P[4000:4095]
MAIN[4096:8191]-> P[4096:5095]<->P[5096:6095]<->P[6096:7095]<->P[7096:8095]<->P[8096:8191]
MAIN[8192:12287]-> P[8192:9191]<->P[9192:10191]<->P[10192:12287]-> NULL

Pages Used : 3
Space unused : 2288
Main Chain Length: 3
Sub-Chain Length Array: [5 ,5 ,3 ,]


--------- Unmapping all memory [mems_finish] --------