Most developers use malloc without thinking much about what happens underneath.

This project is an attempt to explore that layer by building a memory allocator from scratch in C.

The allocator implements malloc , free , calloc , and realloc without relying on libc’s heap functions. It focuses on:

Thread safety

Per-thread caching (tcache)

Efficient free block management using bins

mmap-based memory growth

Handling large allocations separately

This article breaks down the design, implementation decisions, performance characteristics, and limitations of the allocator.

What is a Memory Allocator?

A memory allocator is responsible for managing dynamic memory at runtime.

Functions like malloc , free , calloc , and realloc are part of this layer.

At a high level, an allocator:

Requests memory from the operating system (e.g., using mmap )

Splits that memory into smaller blocks

Tracks which blocks are free or in use

Reuses freed blocks to avoid unnecessary system calls

This layer sits between user…