mitchellh/libxev

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libxev is a cross-platform, high-performance event loop that provides abstractions for non-blocking IO, timers, events, and more and works on Linux (io_uring or epoll), macOS (kqueue), and Wasm + WASI. Available as both a Zig and C API.

Stars: 3.6k
Forks: 191
Open beginner issues: 0
Indexed issues: 41

Dominant language: Zig
License: MIT
Last GitHub push: May 6, 2026
Latest indexed: Sep 21, 2026
Contributing guide: No contributing guide
Code of conduct: No code of conduct
Beginner labels: No beginner labels indexed
PR merge metrics: No merged PRs in 30d

Beginner friendly Everything

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41 open issues indexed

kqueue: xev.UDP.poll hits unreachable in Stream.poll Open

Difficulty 2/5 1-3 hours Newbie friendliness 86/100

mitchellh/libxev#242 · Opened Sep 14, 2026
kqueue: UDP read reports a truncated source address for IPv6 senders Open

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

mitchellh/libxev#241 · Opened Sep 14, 2026
epoll: dispatch loop invokes callbacks for completions the owning queue no longer holds, crashing queueWrite's callback on head.? (the epoll counterpart of #169/#224/#227) Open

Difficulty 5/5 Over a week Newbie friendliness 32/100

mitchellh/libxev#234 · 2 comments · 1 reaction · Opened Aug 18, 2026
io_uring: `cancel()` matches on reused `user_data`; under completion reuse, both `success` and `NotFound` are ambiguous about which request was canceled Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

mitchellh/libxev#233 · Opened Jul 29, 2026
kqueue: close(2) returns EBADF inside `thread_perform`; something closed the fd first, and the cancel path can't say who (it ignores `flags.threadpool` entirely) Open

Difficulty 5/5 Over a week Newbie friendliness 42/100

mitchellh/libxev#232 · 1 comment · Opened Jul 29, 2026
epoll: canceled TCP operations leak the duplicated fd and keep the peer's connection alive; cancellation isn't the only leaky path Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

mitchellh/libxev#231 · Opened Jul 29, 2026
epoll: `start()`'s cancel branch guards on the cancel's own `state == .adding` instead of the target's; canceling a dead or never-registered completion panics, and on a recycled fd it silently deregisters a live one Open

Difficulty 3/5 1-2 days Newbie friendliness 68/100

mitchellh/libxev#230 · Opened Jul 29, 2026
IOCP: reusing a completion while it is still queued corrupts the loop (null-result panic + orphaned completions) — the IOCP counterpart of #169/#224 Open

Difficulty 5/5 Over a week Newbie friendliness 42/100

mitchellh/libxev#227 · Opened Jul 2, 2026
Implement `std.Io` interface Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

mitchellh/libxev#219 · 1 comment · 1 reaction · Opened Apr 14, 2026
CPUs with high iowait seem to be a reporting issue Open

Difficulty 2/5 1-3 hours Newbie friendliness 54/100

mitchellh/libxev#216 · 1 comment · 1 reaction · Opened Apr 8, 2026
Add batch send and recv support Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

mitchellh/libxev#182 · 3 comments · 1 reaction · Opened Jul 18, 2025
Shutting down an event loop in a thread Open

Difficulty 4/5 3-5 days Newbie friendliness 32/100

mitchellh/libxev#173 · 3 comments · Opened Jul 9, 2025
[bug] v.next is not proper cleared for re-enqueue a completion between different queues Open

Difficulty 4/5 3-5 days Newbie friendliness 42/100

mitchellh/libxev#169 · Opened Jun 20, 2025
Support BSDs Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

mitchellh/libxev#163 · 2 comments · 3 reactions · Opened May 18, 2025
support Windows iocp now? Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

mitchellh/libxev#162 · Opened May 16, 2025
win: prefer LPFN_CONNECTEX for asynchronous connect calls Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

mitchellh/libxev#151 · Opened Mar 9, 2025
Redesign `Watcher` initialization Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

mitchellh/libxev#150 · 2 reactions · Opened Mar 9, 2025
Panic on windows when running ping-pongs Open

Difficulty 4/5 3-5 days Newbie friendliness 28/100

mitchellh/libxev#137 · Opened Jan 23, 2025
Using completion in multi-threaded application Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

mitchellh/libxev#134 · Opened Jan 16, 2025
close without callback Open

Difficulty 4/5 3-5 days Newbie friendliness 30/100

mitchellh/libxev#126 · Opened Nov 8, 2024
kqueue: wrong API usage Open

backend/kqueue bug

Difficulty 5/5 Over a week Newbie friendliness 35/100

mitchellh/libxev#125 · 13 reactions · Opened Oct 30, 2024
Allow watchers to generate completions without adding them to the loop. Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

mitchellh/libxev#123 · Opened Oct 19, 2024
[kqueue] hits unreachable code with high completion loads Open

Difficulty 4/5 3-5 days Newbie friendliness 42/100

mitchellh/libxev#122 · 7 comments · Opened Oct 15, 2024
Support for deadline/timeout Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

mitchellh/libxev#106 · 2 reactions · Opened Jul 29, 2024
"Ghost" send callback in macOS (kqueue) Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mitchellh/libxev#105 · Opened Jul 25, 2024
c# iocp Open

Difficulty 5/5 Over a week Newbie friendliness 10/100

mitchellh/libxev#93 · Opened Apr 14, 2024
Simple question Open

Difficulty 5/5 Over a week Newbie friendliness 15/100

mitchellh/libxev#92 · 1 comment · Opened Apr 3, 2024
too much stuff included in the package Open

Difficulty 2/5 1-3 hours Newbie friendliness 48/100

mitchellh/libxev#87 · Opened Feb 23, 2024
api: add generic cancelation function to all backends Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mitchellh/libxev#85 · Opened Jan 28, 2024
std.ArrayList support for [Read/Write]Buffers Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

mitchellh/libxev#83 · 1 comment · Opened Jan 13, 2024
Windows - thread panic: integer overflow Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

mitchellh/libxev#81 · 8 comments · Opened Dec 14, 2023
Embedding libxev with freestanding targets Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

mitchellh/libxev#74 · 1 reaction · Opened Nov 3, 2023
Windows bug? Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

mitchellh/libxev#70 · 6 comments · Opened Sep 28, 2023
Need more examples: C Server Open

bug

Difficulty 4/5 3-5 days Newbie friendliness 30/100

mitchellh/libxev#62 · 2 comments · Opened Aug 22, 2023
Pre-allocating buffers and registering them to io_uring Open

backend/io_uring enhancement

Difficulty 5/5 Over a week Newbie friendliness 20/100

mitchellh/libxev#58 · 1 reaction · Opened Aug 6, 2023
Feature request: profile benchmarking "mode" Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

mitchellh/libxev#46 · Opened May 16, 2023
How to embed this in wasi Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

mitchellh/libxev#43 · 1 comment · Opened May 1, 2023
Potential issue in UDP ping-pong benchmark Open

bug core

Difficulty 4/5 3-5 days Newbie friendliness 35/100

mitchellh/libxev#38 · Opened Apr 6, 2023
Feature Request: async dns Open

enhancement question

Difficulty 5/5 Over a week Newbie friendliness 20/100

mitchellh/libxev#37 · 3 comments · Opened Apr 4, 2023
Wasm freestanding (i.e. browser) via extern loop Open

core enhancement

Difficulty 5/5 Over a week Newbie friendliness 25/100

mitchellh/libxev#5 · 1 reaction · Opened Jan 18, 2023
website content + deploy Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

mitchellh/libxev#1 · 2 comments · Opened Jan 18, 2023

mitchellh/libxev

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