setup_read_cleanup 0.8.0

A library for safely transitioning through the three phases of shared resource access: setup, read, and cleanup.
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
147
148

#[cfg(test)]
mod integration_tests_of_phased_cell_sync {
    use setup_read_cleanup::{PhasedCellSync, PhasedErrorKind};
    use std::{error, fmt, thread};

    #[derive(Debug)]
    struct MyStruct {
        vec: Vec<String>,
    }
    impl MyStruct {
        const fn new() -> Self {
            Self { vec: Vec::new() }
        }
        fn add(&mut self, s: String) {
            self.vec.push(s);
        }
        fn clear(&mut self) {
            self.vec.clear();
        }
    }

    #[derive(Debug)]
    struct MyError {}
    impl fmt::Display for MyError {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            write!(f, "MyError")
        }
    }
    impl error::Error for MyError {}

    static PHASED_CELL: PhasedCellSync<MyStruct> = PhasedCellSync::new(MyStruct::new());

    #[test]
    fn test() {
        let mut join_handlers = Vec::<thread::JoinHandle<_>>::new();
        for i in 0..3 {
            let handler = thread::spawn(move || match PHASED_CELL.lock() {
                Ok(mut data) => {
                    data.add("A-".to_string() + &i.to_string());
                }
                Err(e) => panic!("{e:?}"),
            });
            join_handlers.push(handler);
        }
        while join_handlers.len() > 0 {
            let _ = match join_handlers.remove(0).join() {
                Ok(_) => Ok::<(), MyError>(()),
                Err(e) => panic!("{e:?}"),
            };
        }

        let mut join_handlers = Vec::<thread::JoinHandle<_>>::new();
        for i in 0..3 {
            let handler = thread::spawn(move || {
                if let Err(e) = PHASED_CELL.transition_to_read(|data| {
                    data.add("B-".to_string() + &i.to_string());
                    Ok::<(), MyError>(())
                }) {
                    assert!(
                        e.kind() == PhasedErrorKind::PhaseIsAlreadyRead
                            || e.kind() == PhasedErrorKind::DuringTransitionToRead
                    );
                }
            });
            join_handlers.push(handler);
        }
        while join_handlers.len() > 0 {
            let _ = match join_handlers.remove(0).join() {
                Ok(_) => Ok::<(), MyError>(()),
                Err(e) => panic!("{e:?}"),
            };
        }

        let mut join_handlers = Vec::<thread::JoinHandle<_>>::new();
        for _ in 0..10 {
            let handler = thread::spawn(move || {
                let data = PHASED_CELL.read_relaxed().unwrap();
                assert!(data.vec[0].starts_with("A-"));
                assert!(data.vec[1].starts_with("A-"));
                assert!(data.vec[2].starts_with("A-"));
                assert!(data.vec[3].starts_with("B-"));
            });
            join_handlers.push(handler);
        }
        while join_handlers.len() > 0 {
            let _ = match join_handlers.remove(0).join() {
                Ok(_) => Ok::<(), MyError>(()),
                Err(e) => panic!("{e:?}"),
            };
        }

        let mut join_handlers = Vec::<thread::JoinHandle<_>>::new();
        for i in 0..3 {
            let handler = thread::spawn(move || {
                if let Err(e) = PHASED_CELL.transition_to_cleanup(|data| {
                    data.add("C-".to_string() + &i.to_string());
                    Ok::<(), MyError>(())
                }) {
                    assert!(
                        e.kind() == PhasedErrorKind::PhaseIsAlreadyCleanup
                            || e.kind() == PhasedErrorKind::DuringTransitionToCleanup
                    );
                }
            });
            join_handlers.push(handler);
        }
        while join_handlers.len() > 0 {
            let _ = match join_handlers.remove(0).join() {
                Ok(_) => Ok::<(), MyError>(()),
                Err(e) => panic!("{e:?}"),
            };
        }

        let mut join_handlers = Vec::<thread::JoinHandle<_>>::new();
        for i in 0..4 {
            let handler = thread::spawn(move || match PHASED_CELL.lock() {
                Ok(mut data) => {
                    data.add("D-".to_string() + &i.to_string());
                }
                Err(e) => panic!("{e:?}"),
            });
            join_handlers.push(handler);
        }
        while join_handlers.len() > 0 {
            let _ = match join_handlers.remove(0).join() {
                Ok(_) => Ok::<(), MyError>(()),
                Err(e) => panic!("{e:?}"),
            };
        }

        match PHASED_CELL.lock() {
            Ok(mut data) => {
                assert!(data.vec[0].starts_with("A-"));
                assert!(data.vec[1].starts_with("A-"));
                assert!(data.vec[2].starts_with("A-"));
                assert!(data.vec[3].starts_with("B-"));
                assert!(data.vec[4].starts_with("C-"));
                assert!(data.vec[5].starts_with("D-"));
                assert!(data.vec[6].starts_with("D-"));
                assert!(data.vec[7].starts_with("D-"));
                assert!(data.vec[8].starts_with("D-"));
                data.clear();
                assert_eq!(&data.vec, &[] as &[String]);
            }
            Err(e) => panic!("{e:?}"),
        }
    }
}