Swift concurrency inakuwezesha kuandika asynchronous code inayosomeka kama synchronous code ukitumia async/await, huku compiler ikitekeleza usalama dhidi ya data-race. Task huanzisha kazi ya concurrent, actors hulinda mutable state, na huhakikisha UI code inaendeshwa kwenye main thread.
@MainActorawait huweka alama ya suspension point: function inaweza kusimama hapo, ikiachilia thread kwa kazi nyingine, na kuendelea wakati thamani inayosubiriwa iko tayari — hakuna callbacks, hakuna kuzuia thread.
func loadProfile() async throws -> Profile {
let user = try await fetchUser() // suspends, thread reused
let posts = try await fetchPosts(user) // runs after user resolves
return Profile(user: user, posts: posts)
}
// Start async work from a sync context
Task {
let profile = try await loadProfile()
await MainActor.run { render(profile) } // UI update on main thread
}
Actor hupanga upatikanaji wa mutable state yake kwa mfululizo — task moja tu huigusa kwa wakati mmoja, hivyo hakuna locks na hakuna data races.
actor ImageCache {
private var store: [URL: Image] = [:]
func image(for url: URL) -> Image? { store[url] } // isolated
func insert(_ img: Image, for url: URL) { store[url] = img }
}
@MainActor
final class ViewModel: ObservableObject { // all members run on main thread
@Published var title = ""
}
async let na TaskGroup huendesha watoto kwa sambamba (parallel) na kuwasubiri pamoja; kukatiza parent hukatiza watoto.
async let a = fetchA() // both start immediately, in parallel
async let b = fetchB()
let (x, y) = try await (a, b)
@MainActor kwenye UI updates husababisha maonyo ya "Publishing changes from background thread".Task { } hurithi actor context; Task.detached hairithi — itumie kwa uangalifu.async/await ilibadilisha completion handlers zilizowekwa kwa kina ("callback hell") na sasa compiler hukamata data races wakati wa build. Wahojaji huangalia kama unaelewa suspension points, actor isolation, na @MainActor — mfumo unaofanya iOS concurrency ya kisasa kuwa yenye kusomeka na salama.
Maktaba ya maswali ya mahojiano ya IT yenye majibu ya kina — kutoka Junior hadi Senior.
Changia