qubit_thread_pool/delayed/
scheduled_task.rs

1/*******************************************************************************
2 *
3 *    Copyright (c) 2025 - 2026 Haixing Hu.
4 *
5 *    SPDX-License-Identifier: Apache-2.0
6 *
7 *    Licensed under the Apache License, Version 2.0.
8 *
9 ******************************************************************************/
10use std::{
11    cmp::Ordering as CompareOrdering,
12    sync::{
13        Arc,
14        atomic::AtomicU8,
15    },
16    time::Instant,
17};
18
19/// Task stored in the delayed scheduler heap.
20pub struct ScheduledTask {
21    /// Time at which this task becomes runnable.
22    pub deadline: Instant,
23    /// Insertion order used to make equal deadlines deterministic.
24    pub sequence: usize,
25    /// Shared task state observed by cancellation handles.
26    pub state: Arc<AtomicU8>,
27    /// Scheduled action.
28    pub task: Option<Box<dyn FnOnce() + Send + 'static>>,
29}
30
31impl ScheduledTask {
32    /// Creates a heap entry for a delayed task.
33    ///
34    /// # Parameters
35    ///
36    /// * `deadline` - Instant when the task becomes runnable.
37    /// * `sequence` - Stable insertion sequence.
38    /// * `state` - Shared task lifecycle state.
39    /// * `task` - Action to run when the deadline is reached.
40    ///
41    /// # Returns
42    ///
43    /// A scheduled task heap entry.
44    pub fn new(
45        deadline: Instant,
46        sequence: usize,
47        state: Arc<AtomicU8>,
48        task: Box<dyn FnOnce() + Send + 'static>,
49    ) -> Self {
50        Self {
51            deadline,
52            sequence,
53            state,
54            task: Some(task),
55        }
56    }
57}
58
59impl Eq for ScheduledTask {}
60
61impl PartialEq for ScheduledTask {
62    fn eq(&self, other: &Self) -> bool {
63        self.deadline == other.deadline && self.sequence == other.sequence
64    }
65}
66
67impl Ord for ScheduledTask {
68    fn cmp(&self, other: &Self) -> CompareOrdering {
69        other
70            .deadline
71            .cmp(&self.deadline)
72            .then_with(|| other.sequence.cmp(&self.sequence))
73    }
74}
75
76impl PartialOrd for ScheduledTask {
77    fn partial_cmp(&self, other: &Self) -> Option<CompareOrdering> {
78        Some(self.cmp(other))
79    }
80}
qubit_thread_pool/delayed/scheduled_task.rs

qubit_thread_pool/delayed/
scheduled_task.rs
