blockfit

This repository implements a basic block-based heap allocator in C to illustrate core ideas in dynamic memory management.

The allocator manages a fixed-size heap using a doubly linked list of metadata blocks and provides heap_alloc and heap_free.

Features

• Fixed-size heap (HEAP_SIZE)
• Fixed-size blocks (BLOCK_SIZE)
• Metadata stored separately from heap payload
• First-fit contiguous block allocation
• Allocation tracking via allocation IDs
• Heap memory obtained using mmap

Heap Layout

A single mmap region is logically divided into:

1. Metadata region: an array of block_metadata structures
2. Heap region: the memory returned to the caller

Each metadata entry corresponds to exactly one fixed-size heap block.