I wrote a minimal memory allocator in C
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A fun toy memory allocator (not thread safe, that's a future TODO). I also wanted to explain how I approached it, so I also wrote a tutorial blog post (~20 minute read) covering the code which you can find the link to in the README.
HN · launched Nov 23, 2025 · 137 upvotes (top 7%) · 0 views
Niche: specialized algorithms and computing libraries · 230 launches, 4 in the last 7 days ▼ -73% · Explore this niche →
Category and tags
- Horizontal
- Dev tools
- Developer
- Not AI
- Hobby / open-source project
Visit website ↗ Source listing ↗
More like this: all 230 launches in specialized algorithms and computing libraries →
Could you build this?
Yes A non-thread-safe toy memory allocator using basic `sbrk` or `mmap` syscalls in C is a standard computer science educational project that LLMs can generate and explain flawlessly.
Discussion
20 comments analyzed.
Competitors mentioned: C standard library malloc/free, jemalloc, tcmalloc, mimalloc
Concerns raised: Unspecified/non-portable behavior mixing brk()/sbrk() with other memory functions, realloc() has inconsistencies and corner cases with mmapped blocks, Missing overflow checks on size+META_SIZE in multiple spots, Not suitable for general-purpose library use due to application-specific assumptions, Single-threaded only, performance concerns with large fragmentation scenarios
Feature requests: Add static keyword to internal functions and constants for proper encapsulation, Add overflow checks for size+META_SIZE operations, Improve realloc() handling of mmapped blocks during shrinking, Only track freed nodes in free_list, not all nodes, Add more const qualifiers for clarity
Competitors
Other products that read as similar to this one : 251 launches clear the similarity bar, closest 8 shown.
Attention rank: #24 of 252 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).
Launched 23 days after the earliest competitor.
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- Nibble · hn · 2026-05-14 · 102 upvotes · similarity 0.48
- C/C++ Cheatsheet · hn · 2026-01-23 · 10 upvotes · similarity 0.47
- helloworld-bruteforced · github · 2026-09-10 · 38 upvotes · similarity 0.47
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