summaryrefslogtreecommitdiffstats
path: root/third_party/rust/hyper/src/server/shutdown.rs
blob: 96937d0827afb8eb65cacdfc16649c5bfff5c678 (plain)
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
122
123
124
125
126
127
128
use std::error::Error as StdError;

use pin_project_lite::pin_project;
use tokio::io::{AsyncRead, AsyncWrite};
use tracing::debug;

use super::accept::Accept;
use super::conn::UpgradeableConnection;
use super::server::{Server, Watcher};
use crate::body::{Body, HttpBody};
use crate::common::drain::{self, Draining, Signal, Watch, Watching};
use crate::common::exec::{ConnStreamExec, NewSvcExec};
use crate::common::{task, Future, Pin, Poll, Unpin};
use crate::service::{HttpService, MakeServiceRef};

pin_project! {
    #[allow(missing_debug_implementations)]
    pub struct Graceful<I, S, F, E> {
        #[pin]
        state: State<I, S, F, E>,
    }
}

pin_project! {
    #[project = StateProj]
    pub(super) enum State<I, S, F, E> {
        Running {
            drain: Option<(Signal, Watch)>,
            #[pin]
            server: Server<I, S, E>,
            #[pin]
            signal: F,
        },
        Draining { draining: Draining },
    }
}

impl<I, S, F, E> Graceful<I, S, F, E> {
    pub(super) fn new(server: Server<I, S, E>, signal: F) -> Self {
        let drain = Some(drain::channel());
        Graceful {
            state: State::Running {
                drain,
                server,
                signal,
            },
        }
    }
}

impl<I, IO, IE, S, B, F, E> Future for Graceful<I, S, F, E>
where
    I: Accept<Conn = IO, Error = IE>,
    IE: Into<Box<dyn StdError + Send + Sync>>,
    IO: AsyncRead + AsyncWrite + Unpin + Send + 'static,
    S: MakeServiceRef<IO, Body, ResBody = B>,
    S::Error: Into<Box<dyn StdError + Send + Sync>>,
    B: HttpBody + 'static,
    B::Error: Into<Box<dyn StdError + Send + Sync>>,
    F: Future<Output = ()>,
    E: ConnStreamExec<<S::Service as HttpService<Body>>::Future, B>,
    E: NewSvcExec<IO, S::Future, S::Service, E, GracefulWatcher>,
{
    type Output = crate::Result<()>;

    fn poll(self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
        let mut me = self.project();
        loop {
            let next = {
                match me.state.as_mut().project() {
                    StateProj::Running {
                        drain,
                        server,
                        signal,
                    } => match signal.poll(cx) {
                        Poll::Ready(()) => {
                            debug!("signal received, starting graceful shutdown");
                            let sig = drain.take().expect("drain channel").0;
                            State::Draining {
                                draining: sig.drain(),
                            }
                        }
                        Poll::Pending => {
                            let watch = drain.as_ref().expect("drain channel").1.clone();
                            return server.poll_watch(cx, &GracefulWatcher(watch));
                        }
                    },
                    StateProj::Draining { ref mut draining } => {
                        return Pin::new(draining).poll(cx).map(Ok);
                    }
                }
            };
            me.state.set(next);
        }
    }
}

#[allow(missing_debug_implementations)]
#[derive(Clone)]
pub struct GracefulWatcher(Watch);

impl<I, S, E> Watcher<I, S, E> for GracefulWatcher
where
    I: AsyncRead + AsyncWrite + Unpin + Send + 'static,
    S: HttpService<Body>,
    E: ConnStreamExec<S::Future, S::ResBody>,
    S::ResBody: 'static,
    <S::ResBody as HttpBody>::Error: Into<Box<dyn StdError + Send + Sync>>,
{
    type Future =
        Watching<UpgradeableConnection<I, S, E>, fn(Pin<&mut UpgradeableConnection<I, S, E>>)>;

    fn watch(&self, conn: UpgradeableConnection<I, S, E>) -> Self::Future {
        self.0.clone().watch(conn, on_drain)
    }
}

fn on_drain<I, S, E>(conn: Pin<&mut UpgradeableConnection<I, S, E>>)
where
    S: HttpService<Body>,
    S::Error: Into<Box<dyn StdError + Send + Sync>>,
    I: AsyncRead + AsyncWrite + Unpin,
    S::ResBody: HttpBody + 'static,
    <S::ResBody as HttpBody>::Error: Into<Box<dyn StdError + Send + Sync>>,
    E: ConnStreamExec<S::Future, S::ResBody>,
{
    conn.graceful_shutdown()
}