tokio VS zap

Compare tokio vs zap and see what are their differences.


A runtime for writing reliable asynchronous applications with Rust. Provides I/O, networking, scheduling, timers, ... (by tokio-rs)


An asynchronous runtime with a focus on performance and resource efficiency. (by kprotty)
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tokio zap
71 7
14,035 227
2.5% -
9.5 4.5
6 days ago 10 days ago
Rust Zig
MIT License GNU General Public License v3.0 or later
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.


Posts with mentions or reviews of tokio. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2021-12-01.


Posts with mentions or reviews of zap. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2021-09-13.
  • Resource efficient Thread Pools (with Zig)
    3 projects | | 13 Sep 2021
    It is a well-written post on an effective implementation of thread pools — an active area of Rust development — including benchmarks that suggest it may be faster than some of our most popular crates in the area.
    3 projects | | 13 Sep 2021
  • Lock-free, allocation-free, efficient thread pool
    6 projects | | 13 Sep 2021
    This actually can be at the level of a missed optimization. A run queue with a lock-shared queue amongs all the threads scales even worse than the tokio version. Sharding the run queues and changing the notification algorithm, even while keeping locks on the sharded queues improves throughput drastically.

    Tokio is an async runtime, but I don't see why being an async runtime should make it worse from a throughput perspective for a thread pool. I actually started on a Rust version [0] to test out this theory of whether async-rust was the culprit, but realized that I was being nerd-sniped [1] at this point and I should continue my Zig work instead. If you're still interested, I'm open to receiving PRs and questions on that if you want to see that in action.

    It's still correct to benchmark and compare tokio here given the scheduler I was designing was mean to be used with async tasks: a bunch of concurrent and small-executing work units. I mention this in the second paragraph of "Why Build Your Own?".

    The thread pool in the post is meant to be used to distribute I/O bound work. A friend of mine hooked up cross-platform I/O abstractions to the thread pool [2], benchmarked it against tokio to be have greater throughput and slightly worse tail latency under a local load [3]. The thread pool serves it's purpose and the quicksort benchmark is to show how schedulers behave under relatively concurrent work-loads. I could've used a benchmark with smaller tasks than the cpu-bound partition()/insertion_sort() but this worked as a common example.

    I've already mentioned why rayon isn't a good comparison: 1. It doesn't support async root concurrency. 2. scoped() waits for tasks to complete by either blocking the OS thread or using similar inline-scheduler-loop optimizations. This risks stack overflow and isn't available as a use case in other async runtimes due to primarily being a fork-join optimization.





    6 projects | | 13 Sep 2021
    This is not the case, it measures the time between two points in the code at runtime and prints that[1].


  • Question: Does Zig has work-stealing/sharing algorithm in the M:N concurrency model ?
    2 projects | | 5 Jul 2021
    You can implement one:
  • Tokio-uring design proposal
    4 projects | | 8 Apr 2021
    BTW If you're interested in work stealing, i'm writing my own which has a bundle of optimizations for minimal task dispatch overhead and memory efficiency. To appease some of your criteria: yes, it's currently being used in "real world production" for an http server (although not that specific version).
  • MEIO: async actors framework
    5 projects | | 16 Feb 2021
    This is a logical fallacy. Specifically either a "Slippery Slope" or "Either/Or". You assume that fast channel implementations must have originated or have been ported to Rust and are both popular. Things like Stakker and zap are anecdotal examples of where this already isn't the case. Even so, there exists fast synchronized channels both inside and outside of async Rust. Because they aren't popular or aren't tuned to efficient runtimes doesn't mean they don't exist, which was my argument.

What are some alternatives?

When comparing tokio and zap you can also consider the following projects:

async-std - Async version of the Rust standard library

rayon - Rayon: A data parallelism library for Rust

Rocket - A web framework for Rust.

sqlx - 🧰 The Rust SQL Toolkit. An async, pure Rust SQL crate featuring compile-time checked queries without a DSL. Supports PostgreSQL, MySQL, SQLite, and MSSQL.

smol - A small and fast async runtime for Rust

hyper - An HTTP library for Rust

bevy - A refreshingly simple data-driven game engine built in Rust

warp - A super-easy, composable, web server framework for warp speeds.

winit - Window handling library in pure Rust

sled - the champagne of beta embedded databases

reqwest - An easy and powerful Rust HTTP Client

crossbeam - Tools for concurrent programming in Rust