revert some changes

tokio/src/runtime/time/mod.rs

@@ -190,18 +190,22 @@ impl Driver {
  assert!(!handle.is_shutdown());
 
  // Finds out the min expiration time to park.
- let expiration_time = (0..rt_handle.time().inner.get_shard_size())
- .filter_map(|id| {
- let lock = rt_handle.time().inner.lock_sharded_wheel(id);
- lock.next_expiration_time()
- })
+ let locks = (0..rt_handle.time().inner.get_shard_size())
+ .map(|id| rt_handle.time().inner.lock_sharded_wheel(id))
+ .collect::<Vec<_>>();
+
+ let expiration_time = locks
+ .iter()
+ .filter_map(|lock| lock.next_expiration_time())
  .min();
 
  rt_handle
  .time()
  .inner
  .next_wake
  .store(next_wake_time(expiration_time));
+ // Safety: After updating the `next_wake`, we drop all the locks.
+ drop(locks);
 
  match expiration_time {
  Some(when) => {

tokio/src/runtime/time/tests/mod.rs

@@ -219,7 +219,6 @@ fn reset_timer_and_drop() {
  .poll_elapsed(&mut Context::from_waker(futures::task::noop_waker_ref()));
 
  entry.as_mut().reset(start + Duration::from_secs(1), true);
- drop(entry);
  }
  });
 }

tokio/src/runtime/time/wheel/mod.rs

@@ -190,7 +190,7 @@ impl Wheel {
  }
 
  /// Inserts the `entry` to the `Wheel`.
- /// Returns the level and slot which `entry` insert into.
+ /// Returns the level and the slot which `entry` insert into.
  ///
  /// Safety: The `cached_when` of this `entry`` must have been updated to `when`.
  unsafe fn inner_insert(