Whirlwind – Async concurrent hashmap for Rust
Hey HN, this is Will and David from Fortress (https://news.ycombinator.com/item?id=41426998). We use a lot of async Rust internally, and created this library out of a need for an async-aware concurrent hashmap since there weren’t many available in the Rust ecosystem. Whirlwind is a sharded HashMap with a fully asynchronous API. Just as dashmap is a replacement for std::sync::RwLock, whirlwind aims to be a replacement for tokio::sync::RwLock. It has a similar design and performance characteristics to dashmap, but seems to perform better in read-heavy workloads with tokio's…
Whirlwind – Async concurrent hashmap for Rust launched on November 5, 2024 with 140 votes, #317 of 4,990 launches that month and more than 95% of that year's launches. The site was still online in September 2026, 1 year on.
In plain words
Whirlwind is a sharded concurrent hashmap library for Rust with a fully asynchronous API. Built by developers at Fortress, it provides an async-aware alternative to wrapping hashmaps in tokio synchronization primitives. The library uses similar sharding design to dashmap but is optimized for read-heavy workloads in async contexts. It runs unsafe code verification through Miri in continuous integration and includes benchmark comparisons in its documentation.
written from the facts on this page · September 2026
From the sources
🌀 Async-first sharded hashmap for Rust. Contribute to willothy/whirlwind development by creating an account on GitHub.
An asynchronous, sharded HashMap for high-performance concurrent data access in Rust. This crate is in development, and breaking changes may be made up until a 1.0 release. [ dependencies ] whirlwind = " 0.1.1 " 🔧 Usage Here's a quick example to get youfrom github.com
In the maker’s words, at launch
Hey HN, this is Will and David from Fortress (https://news.ycombinator.com/item?id=41426998). We use a lot of async Rust internally, and created this library out of a need for an async-aware concurrent hashmap since there weren’t many available in the Rust ecosystem. Whirlwind is a sharded HashMap with…
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