atomex 0.1.1

Atomics extensions in Rust
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159

use core::{
    borrow::BorrowMut,
    convert::AsRef,
    fmt::{self, Debug},
    marker::PhantomData,
};

use crate::{
    CmpxchResult, PhantomAtomicPtr, StrictOrderings,
    TrAtomicCell, TrAtomicData, TrCmpxchOrderings,
};

pub trait TrAtomicFlags<T, O = StrictOrderings>
where
    Self: AsRef<<T as TrAtomicData>::AtomicCell>,
    T: TrAtomicData + Copy,
    <T as TrAtomicData>::AtomicCell: TrAtomicCell<Value = T>,
    O: TrCmpxchOrderings,
{
    fn value(&self) -> T {
        self.as_ref().load(O::LOAD_ORDERING)
    }

    fn try_spin_compare_exchange_weak<FnExpect, FnDesire>(
        &self,
        mut expect: FnExpect,
        mut desire: FnDesire,
    ) -> CmpxchResult<T>
    where
        FnExpect: FnMut(T) -> bool,
        FnDesire: FnMut(T) -> T,
    {
        let atomic = self.as_ref();
        let mut current = atomic.load(O::LOAD_ORDERING);
        loop {
            let r = self.try_once_compare_exchange_weak(
                current,
                &mut expect,
                &mut desire,
            );
            if let CmpxchResult::Fail(x) = r {
                current = x;
            } else {
                break r;
            }
        }
    }

    fn try_once_compare_exchange_weak<FnExpect, FnDesire>(
        &self,
        current: T,
        mut expect: FnExpect,
        mut desire: FnDesire,
    ) -> CmpxchResult<T>
    where
        FnExpect: FnMut(T) -> bool,
        FnDesire: FnMut(T) -> T,
    {
        let atomic = self.as_ref();
        if !expect(current) {
            return CmpxchResult::Unexpected(current);
        };
        let desired = desire(current);
        match atomic.compare_exchange_weak(
            current,
            desired,
            O::SUCC_ORDERING,
            O::FAIL_ORDERING,
        ) {
            Result::Ok(x) => CmpxchResult::Succ(x),
            Result::Err(x) => CmpxchResult::Fail(x),
        }
    }
}

pub struct AtomicFlags<
    T,
    B = <T as TrAtomicData>::AtomicCell,
    O = StrictOrderings,
>(B, PhantomData<T>, PhantomAtomicPtr<O>)
where
    T: TrAtomicData + Copy,
    <T as TrAtomicData>::AtomicCell: TrAtomicCell<Value = T>,
    B: BorrowMut<<T as TrAtomicData>::AtomicCell>,
    O: TrCmpxchOrderings;

impl<T, B, O> AtomicFlags<T, B, O>
where
    T: TrAtomicData + Copy,
    <T as TrAtomicData>::AtomicCell: TrAtomicCell<Value = T>,
    B: BorrowMut<<T as TrAtomicData>::AtomicCell>,
    O: TrCmpxchOrderings,
{
    pub const fn new(cell: B) -> Self {
        AtomicFlags(cell, PhantomData, PhantomData)
    }

    #[inline(always)]
    pub fn value(&self) -> T {
        TrAtomicFlags::<T, O>::value(self)
    }

    #[inline(always)]
    pub fn try_once_compare_exchange_weak(
        &self,
        current: T,
        expect: impl FnMut(T) -> bool,
        desire: impl FnMut(T) -> T,
    ) -> CmpxchResult<T> {
        TrAtomicFlags::try_once_compare_exchange_weak(
            self,
            current,
            expect,
            desire
        )
    }

    #[inline(always)]
    pub fn try_spin_compare_exchange_weak(
        &self,
        expect: impl FnMut(T) -> bool,
        desire: impl FnMut(T) -> T,
    ) -> CmpxchResult<T> {
        TrAtomicFlags::try_spin_compare_exchange_weak(self, expect, desire)
    }
}

impl<T, B, O> AsRef<<T as TrAtomicData>::AtomicCell>
for AtomicFlags<T, B, O>
where
    T: TrAtomicData + Copy,
    <T as TrAtomicData>::AtomicCell: TrAtomicCell<Value = T>,
    B: BorrowMut<<T as TrAtomicData>::AtomicCell>,
    O: TrCmpxchOrderings,
{
    fn as_ref(&self) -> &<T as TrAtomicData>::AtomicCell {
        self.0.borrow()
    }
}

impl<T, B, O> TrAtomicFlags<T, O> for AtomicFlags<T, B, O>
where
    T: TrAtomicData + Copy,
    <T as TrAtomicData>::AtomicCell: TrAtomicCell<Value = T>,
    B: BorrowMut<<T as TrAtomicData>::AtomicCell>,
    O: TrCmpxchOrderings,
{}

impl<T, B, O> Debug for AtomicFlags<T, B, O>
where
    T: TrAtomicData + Copy,
    <T as TrAtomicData>::AtomicCell: TrAtomicCell<Value = T> + Debug,
    B: BorrowMut<<T as TrAtomicData>::AtomicCell>,
    O: TrCmpxchOrderings,
{
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        self.0.borrow().fmt(f)
    }
}