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

use std::future::Future;

use async_std::task;

use crate::timer::sleep;

#[cfg(feature = "task_unstable")]
pub use async_std::task::spawn_local;

/// run future and wait forever
/// this is typically used in the server
pub fn run<F>(spawn_closure: F)
where
    F: Future<Output = ()> + Send + 'static,
{
    task::block_on(spawn_closure);
}

/// run future and wait forever
/// this is typically used in the server
pub fn main<F>(spawn_closure: F)
where
    F: Future<Output = ()> + Send + 'static,
{
    use std::time::Duration;

    task::block_on(async {
        spawn_closure.await;
        // do infinite loop for now
        loop {
            cfg_if::cfg_if! {
                if #[cfg(target_arch = "wasm32")] {
                    sleep(Duration::from_secs(3600)).await.unwrap();
                } else {
                    sleep(Duration::from_secs(3600)).await;
                }
            }
        }
    });
}

cfg_if::cfg_if! {
    if #[cfg(target_arch = "wasm32")] {
        pub use async_std::task::spawn_local as spawn;
    } else {
        pub use async_std::task::spawn;
    }
}

#[cfg(feature = "task_unstable")]
#[cfg(not(target_arch = "wasm32"))]
pub use async_std::task::spawn_blocking;

cfg_if::cfg_if! {
    if #[cfg(target_arch = "wasm32")] {
        pub fn run_block_on<F, T>(f: F)
            where
                F: Future<Output = T> + 'static,
                T: 'static,
            {
                task::block_on(f)
            }
    } else {
        pub use async_std::task::block_on as run_block_on;
    }
}

#[cfg(test)]
mod basic_test {

    use std::io::Error;
    use std::thread;
    use std::time;

    use futures_lite::future::zip;
    use log::debug;

    use crate::task::spawn;
    use crate::test_async;

    #[test_async]
    async fn future_join() -> Result<(), Error> {
        // with join, futures are dispatched on same thread
        // since ft1 starts first and
        // blocks on thread, it will block future2
        // should see ft1,ft1,ft2,ft2

        //let mut ft_id = 0;

        let ft1 = async {
            debug!("ft1: starting sleeping for 1000ms");
            // this will block ft2.  both ft1 and ft2 share same thread
            thread::sleep(time::Duration::from_millis(1000));
            debug!("ft1: woke from sleep");
            //  ft_id = 1;
            Ok(()) as Result<(), ()>
        };

        let ft2 = async {
            debug!("ft2: starting sleeping for 500ms");
            thread::sleep(time::Duration::from_millis(500));
            debug!("ft2: woke up");
            //   ft_id = 2;
            Ok(()) as Result<(), ()>
        };

        let core_threads = num_cpus::get().max(1);
        debug!("num threads: {}", core_threads);
        let _ = zip(ft1, ft2).await;
        Ok(())
    }

    #[test_async]
    async fn future_spawn() -> Result<(), Error> {
        // with spawn, futures are dispatched on separate thread
        // in this case, thread sleep on ft1 won't block
        // should see  ft1, ft2, ft2, ft1

        let ft1 = async {
            debug!("ft1: starting sleeping for 1000ms");
            thread::sleep(time::Duration::from_millis(1000)); // give time for server to come up
            debug!("ft1: woke from sleep");
        };

        let ft2 = async {
            debug!("ft2: starting sleeping for 500ms");
            thread::sleep(time::Duration::from_millis(500));
            debug!("ft2: woke up");
        };

        let core_threads = num_cpus::get().max(1);
        debug!("num threads: {}", core_threads);

        spawn(ft1);
        spawn(ft2);
        // wait for all futures complete
        thread::sleep(time::Duration::from_millis(2000));

        Ok(())
    }
}