{"schemaVersion":"2.0.0","locale":"en","title":"Blocking call on a critical executor","description":"Rule ID: concurrency.main-actor-blocking@1.0.0. Availability below refers to source-scan at product 524fa07e.","htmlUrl":"https://docs.swift-analyzer.com/catalog/concurrency.main-actor-blocking/","markdownUrl":"https://docs.swift-analyzer.com/catalog/concurrency.main-actor-blocking/index.md","productRevision":"524fa07e0ae4153c84ac12ae9eb6559df89ec2be","catalogRevision":"4558458d","docsRevision":"1f17ba58ab08627e0de898f1442067b09e960b48cd5605d6529e9275f8930d68","channel":"pre-prod","maturity":"experimental","access":"owner-provided-checkout","markdown":"# Blocking call on a critical executor\n\nRule ID: concurrency.main-actor-blocking@1.0.0. Availability below refers to source-scan at product 524fa07e.\n\n## V-EXEC-09 — Blocking call on a critical executor\n\nBlocking call on a critical executor. It examines isolation, executor, scheduler, and execution-domain relationships.\n\n### Availability\n\nNot available in source-scan. There is no source-scan flag to activate this condition.\n\nA separate [experimental source preview](https://docs.swift-analyzer.com/guides/experimental/) recognizes a limited local pattern for this condition:\n\n```text\n\"$ANALYZER\" experimental-scan <path> --rule execution.blocking-in-concurrency-context --format json\n```\n\nUse the terminal from [Installation](https://docs.swift-analyzer.com/get-started/installation/), with ANALYZER set, and replace `<path>` with a Swift file or directory. This preview is not compiler-backed source-scan coverage.\n\n### Example and action\n\nIllustrative pattern only. This is not a complete runnable package or a reproduced source-scan result. Helper APIs and omitted context must be supplied by the application.\n\n```swift\n@MainActor func refresh() {\n    Thread.sleep(forTimeInterval: 2)\n}\n```\n\nMake the required context explicit at the boundary. Review ordering, lifetime and transferred values before adding a task or changing isolation.\n\n```swift\n@MainActor func refresh() async throws {\n    try await Task.sleep(for: .seconds(2))\n}\n```\n\n### Intended analysis\n\nIntended reasoning: Compare the required execution or isolation context with recognized context transitions and use sites. Actor context, task context and physical thread identity are different facts; suspension alone does not prove a thread hop. Required evidence: isolation, executor, scheduler, and path facts\n\n### Assumptions and unknown\n\nThe relevant facts must be admitted for the selected immutable build world. Unknown aliases, external effects, unsupported source forms or incomplete consumers can prevent a conclusion. Availability in this workflow is stated above; the illustration does not expand that availability.\n\n### Evidence and interpretation\n\nThe target catalog describes the intended condition. It is not evidence of an active source-scan diagnostic.\n\nHistorical evidence at 4558458d: recovery-required (historical qualification is incomplete and needs further evidence). That evidence has not been requalified for this product revision.\n\n[How we validate checks](https://docs.swift-analyzer.com/concepts/validation/) explains the evidence boundary. [Foundations](https://docs.swift-analyzer.com/concepts/foundations/) separates method assumptions from implementation claims.\n","anchors":["blocking-call-on-a-critical-executor","V-EXEC-09","availability","example-and-action","intended-analysis","assumptions-and-unknown","evidence-and-interpretation"]}