winit_runtime/
timer.rs

1/*
2 * Created on Thu Aug 10 2023
3 *
4 * Copyright (c) storycraft. Licensed under the MIT Licence.
5 */
6
7use std::{
8    num::NonZeroU64,
9    sync::atomic::{AtomicU64, Ordering},
10};
11
12use futures_intrusive::timer::{Clock, Timer, TimerService};
13
14pub use futures_intrusive::timer::TimerFuture;
15use instant::Duration;
16
17use crate::executor::executor_handle;
18
19#[derive(Debug)]
20pub(crate) struct ExecutorTimer {
21    service: TimerService,
22    next_expiration: AtomicU64,
23}
24
25impl ExecutorTimer {
26    pub fn new() -> Self {
27        struct InstantClock;
28
29        impl Clock for InstantClock {
30            fn now(&self) -> u64 {
31                instant::now() as u64
32            }
33        }
34
35        Self {
36            service: TimerService::new(&InstantClock),
37            next_expiration: AtomicU64::new(0),
38        }
39    }
40
41    pub fn update_next(&self) -> UpdateState {
42        let next = self.next_expiration.load(Ordering::Acquire);
43        if next == 0 {
44            return UpdateState::None;
45        }
46
47        let now = instant::now() as u64;
48
49        if next <= now {
50            self.service.check_expirations();
51            self.next_expiration.store(
52                self.service.next_expiration().unwrap_or(0),
53                Ordering::Release,
54            );
55
56            UpdateState::Triggered
57        } else {
58            UpdateState::WaitTimeout(NonZeroU64::new(next - now).unwrap())
59        }
60    }
61
62    pub fn delay(&self, delay: Duration) -> TimerFuture {
63        self.deadline(instant::now() as u64 + delay.as_millis() as u64)
64    }
65
66    pub fn deadline(&self, timestamp: u64) -> TimerFuture {
67        let future = self.service.deadline(timestamp);
68
69        let _ = self
70            .next_expiration
71            .fetch_update(Ordering::Release, Ordering::Acquire, |next| {
72                if next == 0 || next > timestamp {
73                    Some(timestamp)
74                } else {
75                    None
76                }
77            });
78
79        future
80    }
81}
82
83#[derive(Debug, Clone, Copy)]
84pub(crate) enum UpdateState {
85    None,
86    Triggered,
87    WaitTimeout(NonZeroU64),
88}
89
90/// Create Future waiting for given duration
91pub fn wait(delay: Duration) -> TimerFuture<'static> {
92    executor_handle().wait(delay)
93}
94
95/// Create Future waiting for given timestamp
96pub fn wait_deadline(timestamp: u64) -> TimerFuture<'static> {
97    executor_handle().wait_deadline(timestamp)
98}
winit_runtime/timer.rs

winit_runtime/
timer.rs
