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
129
130
131
132
133
134

// Copyright 2020 Pierre Krieger
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

use crate::{ctxt_with_diag, log_out};
use pin_project::pin_project;
use std::sync::atomic::{AtomicU64, Ordering};
use std::time::Instant;
use std::{borrow::Cow, fmt, future::Future, mem, pin::Pin, task::Context, task::Poll};

/// Wraps around a `Future` and adds diagnostics.
pub fn diagnose<T>(name: impl Into<Cow<'static, str>>, inner: T) -> DiagnoseFuture<T> {
    if log_out::is_enabled() {
        // TODO: hack, see doc of elapsed_since_abs_time
        crate::absolute_time::elapsed_since_abs_time(Instant::now());
    }

    DiagnoseFuture {
        inner,
        task_name: name.into(),
        task_id: {
            static NEXT_ID: AtomicU64 = AtomicU64::new(0);
            NEXT_ID.fetch_add(1, Ordering::Relaxed)
        },
        first_time_poll: true,
    }
}

/// Wraps around `Future` and adds diagnostics to it.
#[pin_project]
#[derive(Clone)]
pub struct DiagnoseFuture<T> {
    /// The inner future doing the actual work.
    #[pin]
    inner: T,
    task_name: Cow<'static, str>,
    task_id: u64,
    first_time_poll: bool,
}

impl<T> Future for DiagnoseFuture<T>
where
    T: Future,
{
    type Output = T::Output;

    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
        let this = self.project();

        if !log_out::is_enabled() {
            return Future::poll(this.inner, cx);
        }

        let before = Instant::now();

        let waker = ctxt_with_diag::waker_with_diag(
            cx.waker().clone(),
            this.task_name.clone(),
            *this.task_id,
        );
        let mut cx = Context::from_waker(&waker);
        let outcome = Future::poll(this.inner, &mut cx);

        let after = Instant::now();

        log_out::log_poll(
            &this.task_name,
            *this.task_id,
            before,
            after,
            mem::replace(this.first_time_poll, false),
            outcome.is_ready(),
        );

        outcome
    }
}

impl<T> futures01::Future for DiagnoseFuture<T>
where
    T: futures01::Future,
{
    type Item = T::Item;
    type Error = T::Error;

    fn poll(&mut self) -> futures01::Poll<Self::Item, Self::Error> {
        if !log_out::is_enabled() {
            return self.inner.poll();
        }

        let before = Instant::now();
        let outcome = self.inner.poll();
        let after = Instant::now();
        let last_time = match outcome {
            Ok(futures01::Async::Ready(_)) => true,
            Ok(futures01::Async::NotReady) => false,
            Err(_) => true,
        };
        log_out::log_poll(
            &self.task_name,
            self.task_id,
            before,
            after,
            mem::replace(&mut self.first_time_poll, false),
            last_time,
        );
        outcome
    }
}

impl<T> fmt::Debug for DiagnoseFuture<T>
where
    T: fmt::Debug,
{
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        fmt::Debug::fmt(&self.inner, f)
    }
}