@swift-5.10.1 @swift-6.0.3
import Foundation func main() { var calendar = Calendar(identifier: .gregorian) calendar.timeZone = TimeZone(secondsFromGMT: 9 * 3600)! let now = Date() let expected: Int = calendar.component(.hour, from: now) f(calendar) // Copy the calendar here and use it in backgrount thread. for _ in 0...100_000 { let v = calendar.component(.hour, from: now) if v != expected { print("bug! expected=\(expected), actual=\(v)") } } print("end") } func f(_ calendar: Calendar) { let comps = DateComponents( timeZone: TimeZone(secondsFromGMT: 0)!, year: 2022, month: 9, day: 1 ) DispatchQueue.global().async { for _ in 0...100_000 { _ = calendar.date(from: comps) } } } main()
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