1 use std::cell::Cell;
2 use std::mem;
3
4 use crossbeam_utils::CachePadded;
5
6 #[test]
default()7 fn default() {
8 let x: CachePadded<u64> = Default::default();
9 assert_eq!(*x, 0);
10 }
11
12 #[test]
store_u64()13 fn store_u64() {
14 let x: CachePadded<u64> = CachePadded::new(17);
15 assert_eq!(*x, 17);
16 }
17
18 #[test]
store_pair()19 fn store_pair() {
20 let x: CachePadded<(u64, u64)> = CachePadded::new((17, 37));
21 assert_eq!(x.0, 17);
22 assert_eq!(x.1, 37);
23 }
24
25 #[test]
distance()26 fn distance() {
27 let arr = [CachePadded::new(17u8), CachePadded::new(37u8)];
28 let a = &*arr[0] as *const u8;
29 let b = &*arr[1] as *const u8;
30 let align = mem::align_of::<CachePadded<()>>();
31 assert!(align >= 32);
32 assert_eq!(unsafe { a.add(align) }, b);
33 }
34
35 #[test]
different_sizes()36 fn different_sizes() {
37 CachePadded::new(17u8);
38 CachePadded::new(17u16);
39 CachePadded::new(17u32);
40 CachePadded::new([17u64; 0]);
41 CachePadded::new([17u64; 1]);
42 CachePadded::new([17u64; 2]);
43 CachePadded::new([17u64; 3]);
44 CachePadded::new([17u64; 4]);
45 CachePadded::new([17u64; 5]);
46 CachePadded::new([17u64; 6]);
47 CachePadded::new([17u64; 7]);
48 CachePadded::new([17u64; 8]);
49 }
50
51 #[test]
large()52 fn large() {
53 let a = [17u64; 9];
54 let b = CachePadded::new(a);
55 assert!(mem::size_of_val(&a) <= mem::size_of_val(&b));
56 }
57
58 #[test]
debug()59 fn debug() {
60 assert_eq!(
61 format!("{:?}", CachePadded::new(17u64)),
62 "CachePadded { value: 17 }"
63 );
64 }
65
66 #[test]
drops()67 fn drops() {
68 let count = Cell::new(0);
69
70 struct Foo<'a>(&'a Cell<usize>);
71
72 impl<'a> Drop for Foo<'a> {
73 fn drop(&mut self) {
74 self.0.set(self.0.get() + 1);
75 }
76 }
77
78 let a = CachePadded::new(Foo(&count));
79 let b = CachePadded::new(Foo(&count));
80
81 assert_eq!(count.get(), 0);
82 drop(a);
83 assert_eq!(count.get(), 1);
84 drop(b);
85 assert_eq!(count.get(), 2);
86 }
87
88 #[allow(clippy::clone_on_copy)] // This is intentional.
89 #[test]
clone()90 fn clone() {
91 let a = CachePadded::new(17);
92 let b = a.clone();
93 assert_eq!(*a, *b);
94 }
95
96 #[test]
runs_custom_clone()97 fn runs_custom_clone() {
98 let count = Cell::new(0);
99
100 struct Foo<'a>(&'a Cell<usize>);
101
102 impl<'a> Clone for Foo<'a> {
103 fn clone(&self) -> Foo<'a> {
104 self.0.set(self.0.get() + 1);
105 Foo::<'a>(self.0)
106 }
107 }
108
109 let a = CachePadded::new(Foo(&count));
110 let _ = a.clone();
111
112 assert_eq!(count.get(), 1);
113 }
114