ranked-semaphore 0.1.4

A high-performance ranked semaphore with priority support
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

use ranked_semaphore::{PriorityConfig, QueueStrategy, RankedSemaphore};
use std::sync::Arc;
use std::time::Duration;

#[test]
fn test_smol_runtime_basic_usage() {
    smol::block_on(async {
        let sem = RankedSemaphore::new_fifo(3);
        
        // Test basic acquire/release
        let permit1 = sem.acquire().await.unwrap();
        assert_eq!(sem.available_permits(), 2);
        
        let permit2 = sem.acquire_many(2).await.unwrap();
        assert_eq!(sem.available_permits(), 0);
        
        // Should fail when no permits available
        assert!(sem.try_acquire().is_err());
        
        // Release permits
        drop(permit1);
        assert_eq!(sem.available_permits(), 1);
        
        drop(permit2);
        assert_eq!(sem.available_permits(), 3);
    });
}

#[test]
fn test_smol_runtime_priority_access() {
    smol::block_on(async {
        let config = PriorityConfig::new()
            .default_strategy(QueueStrategy::Fifo)
            .greater_or_equal(5, QueueStrategy::Lifo);
        
        let sem = Arc::new(RankedSemaphore::new_with_config(1, config));
        
        // Hold the permit initially
        let _hold_permit = sem.acquire_with_priority(10).await.unwrap();
        
        let mut handles = vec![];
        let results: Arc<smol::lock::Mutex<Vec<isize>>> = Arc::new(smol::lock::Mutex::new(Vec::new()));
        
        // Spawn tasks with different priorities
        for priority in [0, 5, 10] {
            let sem_clone = Arc::clone(&sem);
            let results_clone = Arc::clone(&results);
            
            let handle = smol::spawn(async move {
                let _permit = sem_clone.acquire_with_priority(priority).await.unwrap();
                results_clone.lock().await.push(priority);
            });
            
            handles.push(handle);
            smol::Timer::after(Duration::from_millis(10)).await;
        }
        
        // Release the initial permit to start the queue
        drop(_hold_permit);
        
        // Wait for all tasks to complete
        for handle in handles {
            handle.await;
        }
        
        let results = results.lock().await;
        // Higher priorities should complete first
        assert_eq!(results[0], 10);
    });
}

#[test]
fn test_smol_runtime_concurrent_operations() {
    smol::block_on(async {
        let sem = Arc::new(RankedSemaphore::new_fifo(5));
        let mut handles = vec![];
        
        // Spawn multiple concurrent tasks
        for i in 0..10 {
            let sem_clone = Arc::clone(&sem);
            let handle = smol::spawn(async move {
                let _permit = sem_clone.acquire().await.unwrap();
                smol::Timer::after(Duration::from_millis(50)).await;
                i
            });
            handles.push(handle);
        }
        
        // All tasks should complete successfully
        for (i, handle) in handles.into_iter().enumerate() {
            let result = handle.await;
            assert_eq!(result, i);
        }
        
        // All permits should be available again
        assert_eq!(sem.available_permits(), 5);
    });
}

#[test]
fn test_smol_runtime_semaphore_close() {
    smol::block_on(async {
        let sem = Arc::new(RankedSemaphore::new_fifo(0));
        let sem_clone = Arc::clone(&sem);
        
        // Spawn a task that will wait
        let handle = smol::spawn(async move {
            sem_clone.acquire_owned().await
        });
        
        // Give the task time to start waiting
        smol::Timer::after(Duration::from_millis(10)).await;
        
        // Close the semaphore
        sem.close();
        
        // The waiting task should receive an error
        let result = handle.await;
        assert!(result.is_err());
    });
}