compact-waitgroup 0.1.3

A compact asynchronous WaitGroup synchronization primitive.
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
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

use core::{
    borrow::Borrow,
    fmt::Debug,
    panic::{RefUnwindSafe, UnwindSafe},
};

use derive_more::Deref;

use crate::{
    core_impl::{WaitGroupData, WaitGroupType, WaitGroupUtil},
    twin_ref::{ClonableTwinRefType, TwinRef, TwinRefType},
    utils::*,
};

pub(crate) struct MonoWgInner {
    twin_count: AtomicU8,
    state: AtomicU8,
    data: UnsafeCell<WaitGroupData>,
}

#[cfg(not(loom))]
const _: () = {
    assert!(core::mem::size_of::<MonoWgInner>() == core::mem::size_of::<usize>() * 3);
    assert!(core::mem::align_of::<MonoWgInner>() == core::mem::size_of::<usize>());
};

unsafe impl Send for MonoWgInner {}
unsafe impl Sync for MonoWgInner {}
impl UnwindSafe for MonoWgInner {}
impl RefUnwindSafe for MonoWgInner {}

impl MonoWgInner {
    #[cfg(not(loom))]
    #[inline]
    pub const fn new() -> Self {
        Self {
            twin_count: AtomicU8::new(2),
            state: AtomicU8::new(0),
            data: UnsafeCell::new(WaitGroupData::None),
        }
    }

    #[cfg(loom)]
    pub fn new() -> Self {
        Self {
            twin_count: AtomicU8::new(2),
            state: AtomicU8::new(0),
            data: UnsafeCell::new(WaitGroupData::None),
        }
    }
}

#[derive(Deref)]
pub(crate) struct SharedWgInner {
    cloned_count: AtomicUsize,
    #[deref]
    inner: MonoWgInner,
}

#[cfg(not(loom))]
const _: () = {
    assert!(core::mem::size_of::<SharedWgInner>() == core::mem::size_of::<usize>() * 4);
    assert!(core::mem::align_of::<SharedWgInner>() == core::mem::size_of::<usize>());
};

impl SharedWgInner {
    #[cfg(not(loom))]
    #[inline]
    pub const fn new() -> Self {
        Self {
            cloned_count: AtomicUsize::new(1),
            inner: MonoWgInner::new(),
        }
    }

    #[cfg(loom)]
    pub fn new() -> Self {
        Self {
            cloned_count: AtomicUsize::new(1),
            inner: MonoWgInner::new(),
        }
    }
}

impl Debug for MonoWgInner {
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        f.debug_struct("WaitGroupInner")
            .field("done", &self.is_done())
            .finish()
    }
}

impl Debug for SharedWgInner {
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        f.debug_struct("SharedWaitGroupInner")
            .field("done", &self.is_done())
            .finish()
    }
}

impl Borrow<MonoWgInner> for SharedWgInner {
    #[inline]
    fn borrow(&self) -> &MonoWgInner {
        self
    }
}

impl Borrow<MonoWgInner> for TwinRef<SharedWgInner> {
    #[inline]
    fn borrow(&self) -> &MonoWgInner {
        self
    }
}

unsafe impl<T: Borrow<MonoWgInner>> TwinRefType for T {
    #[inline]
    fn count(&self) -> &AtomicU8 {
        &self.borrow().twin_count
    }
}

unsafe impl<T: Borrow<MonoWgInner>> WaitGroupType for T {
    #[inline]
    fn state(&self) -> &AtomicU8 {
        &self.borrow().state
    }

    #[inline]
    unsafe fn slot(&self) -> &UnsafeCell<WaitGroupData> {
        &self.borrow().data
    }
}

unsafe impl<T: Borrow<SharedWgInner>> ClonableTwinRefType for T {
    #[inline]
    fn cloned_count(&self) -> &AtomicUsize {
        &self.borrow().cloned_count
    }

    #[inline]
    fn action_on_zero(&self) {
        unsafe {
            self.borrow().send_done();
        }
    }
}