fast_able/
unsafe_cell_type.rs

1use std::{
2    cell::UnsafeCell,
3    ops::{Add, Deref, Div, Mul, Sub},
4};
5
6/// unsafe 无锁类型, 请手动保证访问安全, api 与 AtomicCell 一致
7pub struct U<T> {
8    _inner: UnsafeCell<T>,
9}
10
11impl<T> U<T> {
12    pub const fn new(v: T) -> U<T> {
13        U {
14            _inner: UnsafeCell::new(v),
15        }
16    }
17    #[inline(always)]
18    pub fn store(&self, v: T) {
19        let s = unsafe { &mut *self._inner.get() };
20        *s = v;
21    }
22    #[inline(always)]
23    pub fn as_mut(&self) -> &mut T {
24        unsafe { &mut *self._inner.get() }
25    }
26}
27
28impl<T: Clone> Clone for U<T> {
29    fn clone(&self) -> Self {
30        Self {
31            _inner: UnsafeCell::new(self.deref().clone()),
32        }
33    }
34}
35
36impl<T: Eq> Eq for U<T> {}
37
38impl<T: PartialEq> PartialEq for U<T> {
39    fn eq(&self, other: &Self) -> bool {
40        self.deref() == other.deref()
41    }
42}
43
44impl<T: Default> Default for U<T> {
45    fn default() -> Self {
46        Self {
47            _inner: Default::default(),
48        }
49    }
50}
51
52impl<T: Clone> U<T> {
53    pub fn load(&self) -> T {
54        self.deref().clone()
55    }
56    pub fn fetch_end(&self, v: T) -> T {
57        let r = self.deref().clone();
58        self.store(v);
59        r
60    }
61}
62
63impl<T: Add<Output = T> + Clone> U<T> {
64    pub fn fetch_add(&self, v: T) -> T {
65        let r = self.deref().clone();
66        let s = unsafe { &mut *self._inner.get() };
67        *s = self.deref().clone() + v;
68        r
69    }
70}
71
72impl<T: Sub<Output = T> + Clone> U<T> {
73    pub fn fetch_sub(&self, v: T) -> T {
74        let r = self.deref().clone();
75        let s = unsafe { &mut *self._inner.get() };
76        *s = self.deref().clone() - v;
77        r
78    }
79}
80
81use core::fmt::Debug;
82impl<T: Debug> Debug for U<T> {
83    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
84        f.write_fmt(format_args!("{:?}", self.deref()))
85    }
86}
87
88use core::fmt::Display;
89impl<T: Display> Display for U<T> {
90    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
91        f.write_fmt(format_args!("{}", self.deref()))
92    }
93}
94
95impl<T: Add<Output = T> + Clone> Add for U<T> {
96    fn add(self, rhs: Self) -> Self::Output {
97        let v1 = unsafe { &*self._inner.get() };
98        let v2 = unsafe { &*rhs._inner.get() };
99        Self::Output::new(v1.clone() + v2.clone())
100    }
101
102    type Output = U<T>;
103}
104
105impl<T: Sub<Output = T> + Clone> Sub for U<T> {
106    fn sub(self, rhs: Self) -> Self::Output {
107        let v1 = unsafe { &*self._inner.get() };
108        let v2 = unsafe { &*rhs._inner.get() };
109        Self::Output::new(v1.clone() - v2.clone())
110    }
111
112    type Output = U<T>;
113}
114
115impl<T: Div<Output = T> + Clone> Div for U<T> {
116    fn div(self, rhs: Self) -> Self::Output {
117        let v1 = unsafe { &*self._inner.get() };
118        let v2 = unsafe { &*rhs._inner.get() };
119        Self::Output::new(v1.clone() / v2.clone())
120    }
121
122    type Output = U<T>;
123}
124
125impl<T: Mul<Output = T> + Clone> Mul for U<T> {
126    fn mul(self, rhs: Self) -> Self::Output {
127        let v1 = unsafe { &*self._inner.get() };
128        let v2 = unsafe { &*rhs._inner.get() };
129        Self::Output::new(v1.clone() * v2.clone())
130    }
131
132    type Output = U<T>;
133}
134
135unsafe impl<T: Send> Send for U<T> {}
136unsafe impl<T: Sync> Sync for U<T> {}
137
138impl<T> Deref for U<T> {
139    type Target = T;
140    fn deref(&self) -> &Self::Target {
141        unsafe { &*self._inner.get() }
142    }
143}
144
145impl<T> AsRef<T> for U<T> {
146    fn as_ref(&self) -> &T {
147        self.deref()
148    }
149}
150
151impl<T> From<T> for U<T> {
152    fn from(value: T) -> Self {
153        U {
154            _inner: UnsafeCell::new(value),
155        }
156    }
157}
158
159#[test]
160fn test() {
161    let v1 = U::new(1);
162    let v2 = 1.into();
163    let v3 = v1.clone() + v2;
164    println!("r: {}", v3);
165    assert_eq!(v3.load(), 2);
166
167    let v2 = 1.into();
168    let v3 = v1.clone() - v2;
169    println!("r: {}", v3);
170    assert_eq!(v3.load(), 0);
171
172    let v3 = v1.fetch_add(3);
173    println!("r: {}", v3);
174    assert_eq!(v3, 1);
175    assert_eq!(v1.load(), 4);
176
177    let v3 = v1.fetch_end(5);
178    println!("r: {}", v3);
179    assert_eq!(v3, 4);
180
181    let v3 = v1.load();
182    println!("r: {}", v3);
183    assert_eq!(v3, 5);
184
185    v1.store(6);
186    println!("r: {}", v1.load());
187    assert_eq!(v1.load(), 6);
188
189    v1.fetch_sub(5);
190    println!("r: {}", v1.load());
191    assert_eq!(v1.load(), 1);
192}
193
194#[test]
195fn test_mut_thread() {
196    std::env::set_var("RUST_LOG", "debug");
197    env_logger::init();
198
199    static V: U<usize> = U::new(0);
200    std::thread::spawn(move || loop {
201        V.load();
202    });
203    std::thread::spawn(move || loop {
204        V.load();
205    });
206    std::thread::spawn(move || loop {
207        V.load();
208    });
209    std::thread::spawn(move || loop {
210        V.load();
211    });
212    std::thread::spawn(move || loop {
213        V.load();
214    });
215    std::thread::spawn(move || loop {
216        V.load();
217    });
218
219    for i in 0..1000000 {
220        std::thread::sleep(std::time::Duration::from_millis(100));
221        let r = V.fetch_add(i);
222        debug!("loop {}: {r}", i);
223    }
224}
fast_able/unsafe_cell_type.rs

fast_able/
unsafe_cell_type.rs
