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
use std::ops::Deref;
use tokio::sync::mpsc::Sender;
use crate::FnId;
/// A reference to the function, which also signals when the reference is
/// dropped.
#[derive(Debug)]
pub struct FnRef<'f, F> {
/// Graph ID of the function this references.
pub(crate) fn_id: FnId,
/// Reference to the function.
pub(crate) r#fn: &'f F,
/// Channel to notify when this reference is dropped.
pub(crate) fn_done_tx: Sender<FnId>,
}
impl<F> Deref for FnRef<'_, F> {
type Target = F;
fn deref(&self) -> &Self::Target {
self.r#fn
}
}
impl<F> Drop for FnRef<'_, F> {
fn drop(&mut self) {
// Notify that this function is no longer used.
// We ignore the result because the receiver may be closed before the reference
// to the last function is dropped.
let _ = self.fn_done_tx.try_send(self.fn_id);
}
}
#[cfg(test)]
mod tests {
use tokio::sync::mpsc;
use crate::FnId;
use super::FnRef;
#[test]
fn debug() {
let (fn_done_tx, _fn_done_rx) = mpsc::channel(1);
let fn_ref = FnRef {
fn_id: FnId::new(1),
r#fn: &(),
fn_done_tx,
};
assert!(format!("{fn_ref:?}")
.starts_with("FnRef { fn_id: NodeIndex(FnIdInner(1)), fn: (), fn_done_tx: Sender"));
}
}