swift-concurrency

Implement and migrate Swift concurrent code under Swift 6 strict concurrency.

1|Updated Jun 9, 2026
One-click install
npx skills add https://github.com/Emasoft/emasoft-complete-ios-app-authoring --skill swift-concurrency-emasoft
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: swift-concurrency
Source: https://github.com/Emasoft/emasoft-complete-ios-app-authoring/tree/main/skills/swift-concurrency
Command: npx skills add https://github.com/Emasoft/emasoft-complete-ios-app-authoring --skill swift-concurrency-emasoft

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

Writing and maintaining Swift concurrent code for Apple platforms under Swift 6 strict concurrency introduces common, high-severity pitfalls: data races, deadlocks, runtime isolation crashes, and painful migration work from older Swift versions. This Skill eliminates guesswork by providing production-tested rules, decision trees, and fix mappings distilled from real shipping app bugs, so you can write safe, performant concurrent code without trial and error.

Core Features & Use Cases

  • Isolation Decision Trees: Step-by-step guides to choose the right isolation strategy (actors, @MainActor, Mutex) and concurrency structure (async let, TaskGroup, @concurrent) for any use case.
  • Crash & Hang Pattern Library: Exact signatures and fixes for production issues like continuation misuse, cooperative-pool deadlocks, actor reentrancy corruption, and runtime isolation crashes on warning-free builds.
  • Swift 6.2 Migration Guidance: Full walkthrough of Approachable Concurrency changes, silent runtime behavior shifts, and incremental migration paths from Swift 5.x through 6.0 to 6.2, including per-target SPM configuration.
  • Code Quality Checklists: Pre-finalization checklists and anti-rationalization guides to ensure all output is data-race-free, deadlock-free, and compliant with Swift 6 strict concurrency rules.
  • Use Case Example: A developer migrating an iOS app to Swift 6.2 can use this Skill to audit their codebase for Sendable errors, fix main-thread hangs from changed nonisolated async behavior, and configure CI with Thread Sanitizer and strict concurrency flags.

Quick Start

Use the swift-concurrency skill to audit your existing iOS project for Swift 6 strict concurrency violations and get a prioritized list of fixes for crashes, data races, and migration blockers.

Frequently Asked Questions about swift-concurrency

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I migrate my iOS app to Swift 6 strict concurrency without runtime isolation crashes?▼

Migrating to Swift 6 strict concurrency without crashes requires an incremental approach using per-target SPM configuration, auditing Sendable compliance, and applying actor isolation patterns to achieve data-race-free code.

What's the best way to choose between actors and MainActor for Swift concurrency isolation?▼

Choosing the right Swift concurrency isolation strategy involves using decision trees to evaluate actors, @MainActor, or Mutex based on your specific use case, ensuring safe structured concurrency without deadlocks.

Why does my Swift AsyncStream cause continuation misuse crashes during execution?▼

AsyncStream continuation misuse crashes occur when lifecycle management is handled improperly; fixing them requires applying exact crash pattern signatures and following structured concurrency guidelines to prevent runtime isolation failures.

Does Swift 6.2 Approachable Concurrency support gradual adoption from Swift 5.x projects?▼

Swift 6.2 Approachable Concurrency supports gradual adoption from Swift 5.x through incremental migration paths, allowing per-target configuration to silence strict concurrency warnings while preventing data races.

How do I fix cooperative-pool deadlocks and actor reentrancy corruption in iOS development?▼

Fixing cooperative-pool deadlocks and actor reentrancy corruption involves identifying exact crash signatures from a pattern library and applying production-tested fix mappings to ensure deadlock-free concurrent code.

Can I configure Thread Sanitizer and strict concurrency flags in a CI pipeline for Swift 6?▼

Configuring Thread Sanitizer and strict concurrency flags in a CI pipeline for Swift 6 is fully supported, allowing automated detection of data races and validation of Sendable type compliance during iOS and macOS builds.