13 pub(super) struct Snapshot(usize);  struct
15 type UpdateResult = Result<Snapshot, Snapshot>;
109     pub(super) fn load(&self) -> Snapshot {  in load()  argument
110         Snapshot(self.val.load(Acquire))  in load()
183     pub(super) fn transition_to_complete(&self) -> Snapshot {  in transition_to_complete()  argument
186         let prev = Snapshot(self.val.fetch_xor(DELTA, AcqRel));  in transition_to_complete()
190         Snapshot(prev.0 ^ DELTA)  in transition_to_complete()
198         let prev = Snapshot(self.val.fetch_sub(count * REF_ONE, AcqRel));  in transition_to_terminal()
215         self.fetch_update_action(|mut snapshot| {  in transition_to_notified_by_val()
218             if snapshot.is_running() {  in transition_to_notified_by_val()
222                 snapshot.set_notified();  in transition_to_notified_by_val()
223                 snapshot.ref_dec();  in transition_to_notified_by_val()
226                 assert!(snapshot.ref_count() > 0);  in transition_to_notified_by_val()
229             } else if snapshot.is_complete() || snapshot.is_notified() {  in transition_to_notified_by_val()
232                 snapshot.ref_dec();  in transition_to_notified_by_val()
234                 if snapshot.ref_count() == 0 {  in transition_to_notified_by_val()
242                 snapshot.set_notified();  in transition_to_notified_by_val()
243                 snapshot.ref_inc();  in transition_to_notified_by_val()
247             (action, Some(snapshot))  in transition_to_notified_by_val()
253         self.fetch_update_action(|mut snapshot| {  in transition_to_notified_by_ref()
254             if snapshot.is_complete() || snapshot.is_notified() {  in transition_to_notified_by_ref()
257             } else if snapshot.is_running() {  in transition_to_notified_by_ref()
261                 snapshot.set_notified();  in transition_to_notified_by_ref()
262                 (TransitionToNotifiedByRef::DoNothing, Some(snapshot))  in transition_to_notified_by_ref()
266                 snapshot.set_notified();  in transition_to_notified_by_ref()
267                 snapshot.ref_inc();  in transition_to_notified_by_ref()
268                 (TransitionToNotifiedByRef::Submit, Some(snapshot))  in transition_to_notified_by_ref()
278         self.fetch_update_action(|mut snapshot| {  in transition_to_notified_and_cancel()
279             if snapshot.is_cancelled() || snapshot.is_complete() {  in transition_to_notified_and_cancel()
282             } else if snapshot.is_running() {  in transition_to_notified_and_cancel()
290                 snapshot.set_notified();  in transition_to_notified_and_cancel()
291                 snapshot.set_cancelled();  in transition_to_notified_and_cancel()
292                 (false, Some(snapshot))  in transition_to_notified_and_cancel()
297                 snapshot.set_cancelled();  in transition_to_notified_and_cancel()
298                 if !snapshot.is_notified() {  in transition_to_notified_and_cancel()
299                     snapshot.set_notified();  in transition_to_notified_and_cancel()
300                     snapshot.ref_inc();  in transition_to_notified_and_cancel()
301                     (true, Some(snapshot))  in transition_to_notified_and_cancel()
303                     (false, Some(snapshot))  in transition_to_notified_and_cancel()
313         let mut prev = Snapshot(0);  in transition_to_shutdown()
315         let _ = self.fetch_update(|mut snapshot| {  in transition_to_shutdown()
316             prev = snapshot;  in transition_to_shutdown()
318             if snapshot.is_idle() {  in transition_to_shutdown()
319                 snapshot.set_running();  in transition_to_shutdown()
325             snapshot.set_cancelled();  in transition_to_shutdown()
326             Some(snapshot)  in transition_to_shutdown()
439         let prev = Snapshot(self.val.fetch_sub(REF_ONE, AcqRel));  in ref_dec()
446         let prev = Snapshot(self.val.fetch_sub(2 * REF_ONE, AcqRel));  in ref_dec_twice()
453         F: FnMut(Snapshot) -> (T, Option<Snapshot>),  in fetch_update_action()  argument
468                 Err(actual) => curr = Snapshot(actual),  in fetch_update_action()
473     fn fetch_update<F>(&self, mut f: F) -> Result<Snapshot, Snapshot>  in fetch_update()  argument
475         F: FnMut(Snapshot) -> Option<Snapshot>,  in fetch_update()  argument
489                 Err(actual) => curr = Snapshot(actual),  in fetch_update()
495 // ===== impl Snapshot =====
497 impl Snapshot {  implementation
578         let snapshot = self.load();  in fmt()  localVariable
579         snapshot.fmt(fmt)  in fmt()
583 impl fmt::Debug for Snapshot {  implementation
585         fmt.debug_struct("Snapshot")  in fmt()