Linux

Type-safe wrappers for Linux-specific kernel mechanisms. Provides epoll event notification and io_uring async I/O with typed throws and full Sendable compliance.

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Key Features

• epoll support – Scalable I/O event notification via epoll_create1, epoll_ctl, epoll_wait
• io_uring support – High-performance async I/O (Linux kernel 5.1+) with submission/completion queues
• Runtime detection – isSupported check for io_uring availability with environment variable override
• Typed throws end-to-end – Every error type is statically known; no any Error escapes the API surface
• Swift 6 strict concurrency – Full Sendable compliance with documented thread-safety guarantees
• Policy-free design – Raw syscall wrappers without opinions on scheduling, buffering, or lifecycle

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Installation

Package.swift dependency

dependencies: [
    .package(url: "https://github.com/swift-compositions/swift-linux.git", from: "0.1.0")
]

Target dependency

.target(
    name: "YourTarget",
    dependencies: [
        .product(name: "Linux Kernel", package: "swift-linux")
    ]
)

Requirements

• Swift 6.2+
• Linux (glibc or musl)
• Kernel 5.1+ for io_uring support

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Quick Start

import Linux_Kernel

// Check io_uring availability
if Kernel.IO.Uring.isSupported {
    // Create an io_uring instance
    var params = Kernel.IO.Uring.Params()
    let ringFd = try Kernel.IO.Uring.setup(entries: 256, params: &params)
    defer { Kernel.IO.Uring.close(ringFd) }

    print("io_uring ready: \(params.sqEntries) SQ entries, \(params.cqEntries) CQ entries")
} else {
    // Fall back to epoll
    let epfd = try Kernel.Event.Poll.create()
    defer { try? Kernel.Close.close(epfd) }

    print("Using epoll fallback")
}

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Architecture

Type	Description
Linux	Linux platform namespace
Kernel.Event.Poll	epoll syscall wrappers (create, ctl, wait)
Kernel.Event.Poll.Event	Event structure with event mask and user data
Kernel.Event.Poll.Error	Typed errors for epoll operations
Kernel.IO.Uring	io_uring syscall wrappers (setup, enter, register, close)
Kernel.IO.Uring.Params	Setup parameters and kernel-returned ring configuration
Kernel.IO.Uring.Submission.Queue.Entry	SQE wrapper for describing I/O operations
Kernel.IO.Uring.Completion.Queue.Entry	CQE wrapper for operation results
Kernel.IO.Uring.Opcode	Operation codes for io_uring submissions
Kernel.IO.Uring.Error	Typed errors for io_uring operations

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Platform Support

Platform	CI	Status
Linux	✅	Full support
macOS	—	Not supported
iOS/tvOS/watchOS	—	Not supported
Windows	—	Not supported

This package provides Linux-specific kernel mechanisms. For cross-platform kernel primitives, see swift-kernel-primitives.

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Related Packages

Dependencies

• swift-kernel-primitives: Cross-platform kernel syscall wrappers
• swift-posix: POSIX kernel bindings
• swift-standards: Binary data types and standards

Used By

• swift-io: Async I/O executor built on kernel primitives

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License

This project is licensed under the Apache License v2.0. See LICENSE.md for details.