deadpool 0.9.2

Dead simple async pool
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
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255

#![cfg(feature = "managed")]

use std::{convert::Infallible, time::Duration};

use async_trait::async_trait;
use tokio::time;

use deadpool::managed::{self, Object, PoolError, RecycleResult};

type Pool = managed::Pool<Manager>;

struct Manager {}

#[async_trait]
impl managed::Manager for Manager {
    type Type = usize;
    type Error = Infallible;

    async fn create(&self) -> Result<usize, Infallible> {
        Ok(0)
    }

    async fn recycle(&self, _conn: &mut usize) -> RecycleResult<Infallible> {
        Ok(())
    }
}

#[tokio::test]
async fn basic() {
    let mgr = Manager {};
    let pool = Pool::builder(mgr).max_size(16).build().unwrap();

    let status = pool.status();
    assert_eq!(status.size, 0);
    assert_eq!(status.available, 0);

    let obj0 = pool.get().await.unwrap();
    let status = pool.status();
    assert_eq!(status.size, 1);
    assert_eq!(status.available, 0);

    let obj1 = pool.get().await.unwrap();
    let status = pool.status();
    assert_eq!(status.size, 2);
    assert_eq!(status.available, 0);

    let obj2 = pool.get().await.unwrap();
    let status = pool.status();
    assert_eq!(status.size, 3);
    assert_eq!(status.available, 0);

    drop(obj0);
    let status = pool.status();
    assert_eq!(status.size, 3);
    assert_eq!(status.available, 1);

    drop(obj1);
    let status = pool.status();
    assert_eq!(status.size, 3);
    assert_eq!(status.available, 2);

    drop(obj2);
    let status = pool.status();
    assert_eq!(status.size, 3);
    assert_eq!(status.available, 3);
}

#[tokio::test]
async fn closing() {
    let mgr = Manager {};
    let pool = Pool::builder(mgr).max_size(1).build().unwrap();

    // fetch the only object from the pool
    let obj = pool.get().await;
    let join_handle = {
        let pool = pool.clone();
        tokio::spawn(async move { pool.get().await })
    };

    tokio::task::yield_now().await;
    assert_eq!(pool.status().available, -1);

    pool.close();
    tokio::task::yield_now().await;
    assert_eq!(pool.status().available, 0);

    assert!(matches!(join_handle.await.unwrap(), Err(PoolError::Closed)));
    assert!(matches!(pool.get().await, Err(PoolError::Closed)));
    assert!(matches!(pool.try_get().await, Err(PoolError::Closed)));

    drop(obj);
    tokio::task::yield_now().await;
    assert_eq!(pool.status().available, 0);
}

#[tokio::test]
async fn close_resize() {
    let mgr = Manager {};
    let pool = Pool::builder(mgr).max_size(1).build().unwrap();
    pool.close();
    pool.resize(16);
    assert_eq!(pool.status().size, 0);
    assert_eq!(pool.status().max_size, 0);
}

#[tokio::test(flavor = "multi_thread")]
async fn concurrent() {
    let mgr = Manager {};
    let pool = Pool::builder(mgr).max_size(3).build().unwrap();

    // Spawn tasks
    let futures = (0..100)
        .map(|_| {
            let pool = pool.clone();
            tokio::spawn(async move {
                let mut obj = pool.get().await.unwrap();
                *obj += 1;
                time::sleep(Duration::from_millis(1)).await;
            })
        })
        .collect::<Vec<_>>();

    // Await tasks to finish
    for future in futures {
        future.await.unwrap();
    }

    // Verify
    let status = pool.status();
    assert_eq!(status.size, 3);
    assert_eq!(status.available, 3);

    let values = [
        pool.get().await.unwrap(),
        pool.get().await.unwrap(),
        pool.get().await.unwrap(),
    ];

    assert_eq!(values.iter().map(|obj| **obj).sum::<usize>(), 100);
}

#[tokio::test(flavor = "multi_thread")]
async fn object_take() {
    let mgr = Manager {};
    let pool = Pool::builder(mgr).max_size(2).build().unwrap();
    let obj0 = pool.get().await.unwrap();
    let obj1 = pool.get().await.unwrap();

    let status = pool.status();
    assert_eq!(status.size, 2);
    assert_eq!(status.available, 0);

    drop(Object::take(obj0));
    let status = pool.status();
    assert_eq!(status.size, 1);
    assert_eq!(status.available, 0);

    drop(Object::take(obj1));
    let status = pool.status();
    assert_eq!(status.size, 0);
    assert_eq!(status.available, 0);

    let obj0 = pool.get().await.unwrap();
    let obj1 = pool.get().await.unwrap();
    let status = pool.status();
    assert_eq!(status.size, 2);
    assert_eq!(status.available, 0);

    drop(obj0);
    drop(obj1);
    let status = pool.status();
    assert_eq!(status.size, 2);
    assert_eq!(status.available, 2);
}

#[tokio::test]
async fn resize_pool_shrink() {
    let mgr = Manager {};
    let pool = Pool::builder(mgr).max_size(2).build().unwrap();
    let obj0 = pool.get().await.unwrap();
    let obj1 = pool.get().await.unwrap();
    pool.resize(1);
    assert_eq!(pool.status().max_size, 1);
    assert_eq!(pool.status().size, 2);
    drop(obj1);
    assert_eq!(pool.status().max_size, 1);
    assert_eq!(pool.status().size, 1);
    drop(obj0);
    assert_eq!(pool.status().max_size, 1);
    assert_eq!(pool.status().size, 1);
}

#[tokio::test]
async fn resize_pool_grow() {
    let mgr = Manager {};
    let pool = Pool::builder(mgr).max_size(1).build().unwrap();
    let obj0 = pool.get().await.unwrap();
    pool.resize(2);
    assert_eq!(pool.status().max_size, 2);
    assert_eq!(pool.status().size, 1);
    let obj1 = pool.get().await.unwrap();
    assert_eq!(pool.status().max_size, 2);
    assert_eq!(pool.status().size, 2);
    drop(obj1);
    assert_eq!(pool.status().max_size, 2);
    assert_eq!(pool.status().size, 2);
    drop(obj0);
    assert_eq!(pool.status().max_size, 2);
    assert_eq!(pool.status().size, 2);
}

#[tokio::test]
async fn resize_pool_shrink_grow() {
    let mgr = Manager {};
    let pool = Pool::builder(mgr).max_size(1).build().unwrap();
    let obj0 = pool.get().await.unwrap();
    pool.resize(2);
    pool.resize(0);
    pool.resize(5);
    assert_eq!(pool.status().max_size, 5);
    assert_eq!(pool.status().size, 1);
    drop(obj0);
    assert_eq!(pool.status().max_size, 5);
    assert_eq!(pool.status().size, 1);
}

#[tokio::test]
async fn resize_pool_grow_concurrent() {
    let mgr = Manager {};
    let pool = Pool::builder(mgr).max_size(0).build().unwrap();
    let join_handle = {
        let pool = pool.clone();
        tokio::spawn(async move { pool.get().await })
    };
    tokio::task::yield_now().await;
    assert_eq!(pool.status().max_size, 0);
    assert_eq!(pool.status().size, 0);
    assert_eq!(pool.status().available, -1);
    pool.resize(1);
    assert_eq!(pool.status().max_size, 1);
    assert_eq!(pool.status().size, 0);
    assert_eq!(pool.status().available, -1);
    tokio::task::yield_now().await;
    assert_eq!(pool.status().max_size, 1);
    assert_eq!(pool.status().size, 1);
    assert_eq!(pool.status().available, 0);
    let obj0 = join_handle.await.unwrap().unwrap();
    assert_eq!(pool.status().max_size, 1);
    assert_eq!(pool.status().size, 1);
    assert_eq!(pool.status().available, 0);
    drop(obj0);
    assert_eq!(pool.status().max_size, 1);
    assert_eq!(pool.status().size, 1);
    assert_eq!(pool.status().available, 1);
}