Memory Management Simulator

A CLI-based Operating Systems memory management simulator that models how modern OS kernels manage physical memory allocation, buddy allocation, CPU cache hierarchy, and virtual memory with paging.

The simulator emphasizes systems-level design, algorithmic correctness, and performance trade-offs in memory management.

---

Demo Video

07.01.2026_05.18.17_REC.mp4

📌 Features Overview

1. Physical Memory Allocation

• Simulates a contiguous block of physical memory
• Dynamic allocation and deallocation
• Allocation strategies:
  • First Fit
  • Best Fit
  • Worst Fit
• Block splitting and coalescing
• Real-time statistics:
  • Used / free memory
  • Internal fragmentation
  • External fragmentation
  • Allocation success rate
  • Memory utilization

---

2. Buddy Memory Allocator

• Power-of-two memory management
• Allocation rounded to nearest power of two
• Recursive block splitting
• Buddy coalescing using XOR-based address computation
• Free lists maintained per block size
• Visualization via buddy_dump

---

3. Multi-Level Cache Simulation

• Simulates a two-level CPU cache hierarchy consisting of L1 and L2 caches, integrated with physical memory access.
• Features
• Configurable L1 and L2 cache sizes
• Set-associative cache design
• FIFO replacement policy
• Real-time tracking of:
• Cache hits and misses per level
• Miss propagation from L1 → L2 → main memory
• Total memory access cycles (miss penalty modeling)
• Behavior
• L1 is checked first for every access
• On L1 miss, request is forwarded to L2
• On L2 miss, access is forwarded to main memory
• Blocks are inserted back into upper cache levels following FIFO policy
• This module demonstrates realistic cache behavior and clearly visualizes performance trade-offs in hierarchical memory systems.

---

4. Virtual Memory Simulation

• Paging-based virtual memory model
• Virtual → Physical address translation
• Page table management
• Page fault detection and handling
• FIFO page replacement
• Integrated pipeline:

---

Simulator Commands

Memory Allocation

init memory <size>
set <firstfit | bestfit | worstfit>
malloc <size>
free <block_id>
dump memory
stats

Buddy Allocator

buddy_malloc <size>
buddy_free <address> <size>
buddy_dump

Cache

cache_init <l1_size> <l2_size>
cache_access <address>
cache_stats

Virtual Memory

vm_init <pages> <frames> <page_size>
vm_access <virtual_address>
vm_stats

Integrated Access

access <virtual_address>
---

🛠 Build Instructions (Windows / MinGW)

Requirements

1. MinGW (g++)
2. mingw32-make

Commands

1)cd file
2)mingw32-make
3).\memsim.exe

---

📁 Project Structure

memory-simulator/
├── src/
│   ├── allocator/
│   ├── buddy/
│   ├── cache/
│   ├── virtual_memory/
│   └── main.cpp
│
├── include/
│   ├── allocator/
│   ├── buddy/
│   ├── cache/
│   └── virtual_memory/
│
├── tests/
│   ├── allocator_test.txt
│   ├── buddy_test.txt
│   ├── cache_test.txt
│   └── vm_test.txt
│
├── docs/
│   └── DESIGN.md
│
├── Makefile
└── README.md

---

🎯 Learning Outcomes

Understanding memory allocation strategies

Fragmentation analysis

Cache hierarchy behavior

Virtual memory and paging

OS-level abstraction design in user space

---

🧠 Design Highlights

Modular separation of allocation strategies

Clear abstraction between memory model and CLI

Efficient coalescing of free blocks

Buddy allocator uses XOR-based buddy computation

Easily extensible for cache and virtual memory modules

---

⚠️ Assumptions & Limitations

Simulation runs entirely in user space

No real hardware interaction

Cache and virtual memory extensions are conceptual / optional

Focus is on correctness and visualization, not raw performance