rocketmq-runtime 1.0.0

Unofficial Rust implementation of Apache RocketMQ
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

// Copyright 2023 The RocketMQ Rust Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::future::Future;

use parking_lot::Mutex;
use tokio::sync::Notify;
use tokio::sync::OnceCell;

use crate::shutdown_deadline::ShutdownDeadline;
use crate::shutdown_report::ShutdownReport;

#[derive(Debug)]
pub(super) struct ShutdownTimeout;

#[derive(Debug)]
pub(super) struct ShutdownCoordinator {
    deadline: Mutex<Option<ShutdownDeadline>>,
    changed: Notify,
    pub(super) report: OnceCell<ShutdownReport>,
    pub(super) report_ready: Notify,
}

impl ShutdownCoordinator {
    pub(super) fn new() -> Self {
        Self {
            deadline: Mutex::new(None),
            changed: Notify::new(),
            report: OnceCell::new(),
            report_ready: Notify::new(),
        }
    }

    pub(super) fn deadline(&self) -> Option<ShutdownDeadline> {
        *self.deadline.lock()
    }

    pub(super) async fn wait_report(&self) -> &ShutdownReport {
        loop {
            let ready = self.report_ready.notified();
            if let Some(report) = self.report.get() {
                return report;
            }
            ready.await;
        }
    }

    pub(super) fn tighten(&self, deadline: ShutdownDeadline) -> ShutdownDeadline {
        let (installed, changed) = {
            let mut current = self.deadline.lock();
            let installed = current.map_or(deadline, |existing| existing.earliest(deadline));
            let changed = current.is_none_or(|existing| installed.instant() < existing.instant());
            *current = Some(installed);
            (installed, changed)
        };

        if changed {
            self.changed.notify_waiters();
        }
        installed
    }

    pub(super) async fn run_until<F>(&self, future: F) -> Result<F::Output, ShutdownTimeout>
    where
        F: Future,
    {
        tokio::pin!(future);
        loop {
            let changed = self.changed.notified();
            let Some(deadline) = self.deadline() else {
                return Ok(future.await);
            };
            let deadline_elapsed = tokio::time::sleep(deadline.remaining());
            tokio::pin!(changed);
            tokio::pin!(deadline_elapsed);

            tokio::select! {
                biased;
                output = &mut future => return Ok(output),
                () = &mut changed => {}
                () = &mut deadline_elapsed => return Err(ShutdownTimeout),
            }
        }
    }
}