actix 0.5.7

Actor framework for Rust
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

extern crate actix;

use actix::prelude::*;

struct CounterActor;

struct Count(u32);

// Maximum number of items to keep alive
const MAX_ITEMS: u32 = 256;

// Number of items to keep alive
static mut N_ITEMS: u32 = 0;

// Keeps track of instances alive
struct TrackableItem;

impl TrackableItem {
    fn new() -> TrackableItem {
        unsafe {
            N_ITEMS += 1;
        }
        TrackableItem {}
    }

    fn count() -> u32 {
        unsafe { N_ITEMS }
    }
}

impl Drop for TrackableItem {
    fn drop(&mut self) {
        unsafe {
            N_ITEMS -= 1;
        }
    }
}

impl Message for Count {
    type Result = TrackableItem;
}

impl Actor for CounterActor {
    type Context = Context<Self>;
}

impl Handler<Count> for CounterActor {
    type Result = MessageResult<Count>;

    fn handle(&mut self, msg: Count, ctx: &mut Self::Context) -> Self::Result {
        assert!(TrackableItem::count() <= MAX_ITEMS);

        // send a message to self,
        // creating sorta async recursion
        let my_address: Addr<Unsync, CounterActor> = ctx.address();

        my_address.do_send(Count(msg.0 + 1));
        MessageResult(TrackableItem::new())
    }
}

// When actor sends messages to itself recursively,
// results of the Handler should not stack up indefinitely
#[test]
#[should_panic]
fn test_recursion() {
    let system = actix::System::new("test");
    let addr: Addr<Unsync, _> = CounterActor.start();
    addr.do_send(Count(0));
    system.run();
}