1111//===----------------------------------------------------------------------===//
1212import Swift
1313
14- /// A mechanism in which to measure time, and delay work until a given point
14+ /// A mechanism in which to measure time, and delay work until a given point
1515/// in time.
1616///
17- /// Types that conform to the `Clock` protocol define a concept of "now" which
17+ /// Types that conform to the `Clock` protocol define a concept of "now" which
1818/// is the specific instant in time that property is accessed. Any pair of calls
1919/// to the `now` property may have a minimum duration between them - this
2020/// minimum resolution is exposed by the `minimumResolution` property to inform
21- /// any user of the type the expected granularity of accuracy.
21+ /// any user of the type the expected granularity of accuracy.
2222///
2323/// One of the primary uses for clocks is to schedule task sleeping. This method
2424/// resumes the calling task after a given deadline has been met or passed with
25- /// a given tolerance value. The tolerance is expected as a leeway around the
26- /// deadline. The clock may reschedule tasks within the tolerance to ensure
25+ /// a given tolerance value. The tolerance is expected as a leeway around the
26+ /// deadline. The clock may reschedule tasks within the tolerance to ensure
2727/// efficient execution of resumptions by reducing potential operating system
2828/// wake-ups. If no tolerance is specified (i.e. nil is passed in) the sleep
29- /// function is expected to schedule with a default tolerance strategy.
29+ /// function is expected to schedule with a default tolerance strategy.
3030///
31- /// For more information about specific clocks see `ContinuousClock` and
31+ /// For more information about specific clocks see `ContinuousClock` and
3232/// `SuspendingClock`.
3333@available ( SwiftStdlib 5 . 7 , * )
3434public protocol Clock < Duration> : Sendable {
@@ -41,8 +41,56 @@ public protocol Clock<Duration>: Sendable {
4141#if !SWIFT_STDLIB_TASK_TO_THREAD_MODEL_CONCURRENCY
4242 func sleep( until deadline: Instant , tolerance: Instant . Duration ? ) async throws
4343#endif
44- }
4544
45+ #if !$Embedded
46+ /// Choose which Dispatch clock to use with DispatchExecutor
47+ ///
48+ /// This controls which Dispatch clock is used to enqueue delayed jobs
49+ /// when using this Clock.
50+ @available ( SwiftStdlib 6 . 2 , * )
51+ var dispatchClockID : DispatchClockID { get }
52+ #endif
53+
54+ /// Convert a Clock-specific Duration to a Swift Duration
55+ ///
56+ /// Some clocks may define `C.Duration` to be something other than a
57+ /// `Swift.Duration`, but that makes it tricky to convert timestamps
58+ /// between clocks, which is something we want to be able to support.
59+ /// This method will convert whatever `C.Duration` is to a `Swift.Duration`.
60+ ///
61+ /// Parameters:
62+ ///
63+ /// - from duration: The `Duration` to convert
64+ ///
65+ /// Returns: A `Swift.Duration` representing the equivalent duration, or
66+ /// `nil` if this function is not supported.
67+ @available ( SwiftStdlib 6 . 2 , * )
68+ func convert( from duration: Duration ) -> Swift . Duration ?
69+
70+ /// Convert a Swift Duration to a Clock-specific Duration
71+ ///
72+ /// Parameters:
73+ ///
74+ /// - from duration: The `Swift.Duration` to convert.
75+ ///
76+ /// Returns: A `Duration` representing the equivalent duration, or
77+ /// `nil` if this function is not supported.
78+ @available ( SwiftStdlib 6 . 2 , * )
79+ func convert( from duration: Swift . Duration ) -> Duration ?
80+
81+ /// Convert an `Instant` from some other clock's `Instant`
82+ ///
83+ /// Parameters:
84+ ///
85+ /// - instant: The instant to convert.
86+ // - from clock: The clock to convert from.
87+ ///
88+ /// Returns: An `Instant` representing the equivalent instant, or
89+ /// `nil` if this function is not supported.
90+ @available ( SwiftStdlib 6 . 2 , * )
91+ func convert< OtherClock: Clock > ( instant: OtherClock . Instant ,
92+ from clock: OtherClock ) -> Instant ?
93+ }
4694
4795@available ( SwiftStdlib 5 . 7 , * )
4896extension Clock {
@@ -88,6 +136,50 @@ extension Clock {
88136 }
89137}
90138
139+ @available ( SwiftStdlib 6 . 2 , * )
140+ extension Clock {
141+ #if !$Embedded
142+ public var dispatchClockID : DispatchClockID {
143+ return . suspending
144+ }
145+ #endif
146+
147+ // For compatibility, return `nil` if this is not implemented
148+ public func convert( from duration: Duration ) -> Swift . Duration ? {
149+ return nil
150+ }
151+
152+ public func convert( from duration: Swift . Duration ) -> Duration ? {
153+ return nil
154+ }
155+
156+ public func convert< OtherClock: Clock > ( instant: OtherClock . Instant ,
157+ from clock: OtherClock ) -> Instant ? {
158+ let ourNow = now
159+ let otherNow = clock. now
160+ let otherDuration = otherNow. duration ( to: instant)
161+
162+ // Convert to `Swift.Duration`
163+ guard let duration = clock. convert ( from: otherDuration) else {
164+ return nil
165+ }
166+
167+ // Convert from `Swift.Duration`
168+ guard let ourDuration = convert ( from: duration) else {
169+ return nil
170+ }
171+
172+ return ourNow. advanced ( by: ourDuration)
173+ }
174+ }
175+
176+ @available ( SwiftStdlib 6 . 2 , * )
177+ extension Clock where Duration == Swift . Duration {
178+ public func convert( from duration: Duration ) -> Duration ? {
179+ return duration
180+ }
181+ }
182+
91183#if !SWIFT_STDLIB_TASK_TO_THREAD_MODEL_CONCURRENCY
92184@available ( SwiftStdlib 5 . 7 , * )
93185extension Clock {
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