Basic Allocation

The Free List

block_header_t *free_list_head = NULL;

// Linked list of ALL blocks
// .free flag marks availability

First-Fit Search

block_header_t *find_first_fit(size_t size) {
    block_header_t *curr = free_list_head;
    while (curr) {
        if (curr->free && curr->size >= size)
            return curr;
        curr = curr->next;
    }
    return NULL;
}

malloc Flow

1. Check size != 0
2. Try find_first_fit()
3. If found: mark used, return payload
4. Else: request_block() from OS
5. Return payload or NULL

Why First-Fit?

• Simple to implement
• Fast (stops at first match)
• Reasonable for most workloads
• Trade-off: fragments at heap start