pulse/
barrier.rs

1//   Copyright 2015 Colin Sherratt
2//
3//   Licensed under the Apache License, Version 2.0 (the "License");
4//   you may not use this file except in compliance with the License.
5//   You may obtain a copy of the License at
6//
7//       http://www.apache.org/licenses/LICENSE-2.0
8//
9//   Unless required by applicable law or agreed to in writing, software
10//   distributed under the License is distributed on an "AS IS" BASIS,
11//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12//   See the License for the specific language governing permissions and
13//   limitations under the License.
14
15use std::sync::atomic::{AtomicUsize, Ordering};
16use std::sync::{Arc, Mutex};
17
18use {Pulse, Signal, Waiting, Signals};
19
20pub struct Inner {
21    pub count: AtomicUsize,
22    pub trigger: Mutex<Option<Pulse>>,
23}
24
25/// A `Barrier` can listen for 1 or more `Signals`. It will only transition
26/// to a `Pulsed` state once all the `Signals` have `Pulsed`.
27pub struct Barrier {
28    inner: Arc<Inner>,
29}
30
31pub struct Handle(pub Arc<Inner>);
32
33impl Barrier {
34    /// Create a new Barrier from an Vector of `Siganl`s
35    pub fn new(pulses: &[Signal]) -> Barrier {
36        // count items
37        let inner = Arc::new(Inner {
38            count: AtomicUsize::new(pulses.len()),
39            trigger: Mutex::new(None),
40        });
41
42        for pulse in pulses {
43            pulse.clone().arm(Waiting::barrier(Handle(inner.clone())));
44        }
45
46        Barrier { inner: inner }
47    }
48}
49
50impl Signals for Barrier {
51    fn signal(&self) -> Signal {
52        let (p, t) = Signal::new();
53
54        let mut guard = self.inner.trigger.lock().unwrap();
55        if self.inner.count.load(Ordering::Relaxed) == 0 {
56            t.pulse();
57        } else {
58            *guard = Some(t);
59        }
60        p
61    }
62}
pulse/barrier.rs

pulse/
barrier.rs
