1 | use super::Synced; |
2 | |
3 | use crate::runtime::task; |
4 | |
5 | use std::marker::PhantomData; |
6 | |
7 | pub(crate) struct Pop<'a, T: 'static> { |
8 | len: usize, |
9 | synced: &'a mut Synced, |
10 | _p: PhantomData<T>, |
11 | } |
12 | |
13 | impl<'a, T: 'static> Pop<'a, T> { |
14 | pub(super) fn new(len: usize, synced: &'a mut Synced) -> Pop<'a, T> { |
15 | Pop { |
16 | len, |
17 | synced, |
18 | _p: PhantomData, |
19 | } |
20 | } |
21 | } |
22 | |
23 | impl<'a, T: 'static> Iterator for Pop<'a, T> { |
24 | type Item = task::Notified<T>; |
25 | |
26 | fn next(&mut self) -> Option<Self::Item> { |
27 | if self.len == 0 { |
28 | return None; |
29 | } |
30 | |
31 | let ret = self.synced.pop(); |
32 | |
33 | // Should be `Some` when `len > 0` |
34 | debug_assert!(ret.is_some()); |
35 | |
36 | self.len -= 1; |
37 | ret |
38 | } |
39 | |
40 | fn size_hint(&self) -> (usize, Option<usize>) { |
41 | (self.len, Some(self.len)) |
42 | } |
43 | } |
44 | |
45 | impl<'a, T: 'static> ExactSizeIterator for Pop<'a, T> { |
46 | fn len(&self) -> usize { |
47 | self.len |
48 | } |
49 | } |
50 | |
51 | impl<'a, T: 'static> Drop for Pop<'a, T> { |
52 | fn drop(&mut self) { |
53 | for _ in self.by_ref() {} |
54 | } |
55 | } |
56 | |