oneringbuf 0.7.0

A lock-free single-producer, single-consumer (SPSC) ring buffer with in-place mutability, asynchronous support, and virtual memory optimisation.
Documentation 
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

use core::cell::UnsafeCell;

use crate::{
    iters_components::NonMutIterComp,
    ring_buffer::iters_components::{IterComponent, PIterComponent},
};

/// Non-mutable iterators component usable in single-threaded environments.
pub struct LocalComp {
    prod_idx: UnsafeCell<usize>,
    cons_idx: UnsafeCell<usize>,

    alive_iters: UnsafeCell<u8>,
}

impl NonMutIterComp for LocalComp {}

impl LocalComp {
    pub const fn default() -> Self {
        Self {
            prod_idx: UnsafeCell::new(0),
            cons_idx: UnsafeCell::new(0),
            alive_iters: UnsafeCell::new(2),
        }
    }
}

impl PIterComponent for LocalComp {
    #[inline(always)]
    fn middle_iter_idx(&self) -> usize {
        self.prod_index()
    }

    fn drop_iter(&self) -> u8 {
        unsafe {
            let ret = *self.alive_iters.get();
            *self.alive_iters.get() -= 1;
            ret
        }
    }

    fn acquire_fence(&self) {}

    #[inline]
    fn prod_index(&self) -> usize {
        unsafe { *self.prod_idx.get() }
    }

    #[inline]
    fn work_index(&self) -> usize {
        0
    }

    #[inline]
    fn cons_index(&self) -> usize {
        unsafe { *self.cons_idx.get() }
    }

    #[inline]
    fn set_prod_index(&self, index: usize) {
        unsafe {
            *self.prod_idx.get() = index;
        }
    }

    #[inline]
    fn set_work_index(&self, _index: usize) {}

    #[inline]
    fn set_cons_index(&self, index: usize) {
        unsafe {
            *self.cons_idx.get() = index;
        }
    }

    fn alive_iters(&self) -> u8 {
        unsafe { *self.alive_iters.get() }
    }
}

impl IterComponent for LocalComp {}