qubit_executor/service/
rejected_execution.rs

1/*******************************************************************************
2 *
3 *    Copyright (c) 2025 - 2026.
4 *    Haixing Hu, Qubit Co. Ltd.
5 *
6 *    All rights reserved.
7 *
8 ******************************************************************************/
9use std::{
10    io,
11    sync::Arc,
12};
13
14use thiserror::Error;
15
16/// Error returned when an executor service refuses to accept a task.
17///
18/// This error is about task acceptance only. It does not describe task
19/// execution success or failure; accepted tasks report their final result
20/// through the handle returned by the service.
21///
22/// # Author
23///
24/// Haixing Hu
25#[derive(Debug, Clone, Error)]
26pub enum RejectedExecution {
27    /// The service has been shut down and no longer accepts new tasks.
28    #[error("task rejected because the executor service is shut down")]
29    Shutdown,
30
31    /// The service is saturated and cannot accept more tasks.
32    #[error("task rejected because the executor service is saturated")]
33    Saturated,
34
35    /// The service accepted the task conceptually but could not create the
36    /// worker thread required to execute it.
37    #[error("task rejected because the executor service failed to spawn a worker: {source}")]
38    WorkerSpawnFailed {
39        /// I/O error reported while spawning the worker.
40        source: Arc<io::Error>,
41    },
42}
43
44impl PartialEq for RejectedExecution {
45    /// Compares rejection categories.
46    ///
47    /// Worker spawn failures compare equal by variant because [`io::Error`]
48    /// does not provide value equality.
49    ///
50    /// # Parameters
51    ///
52    /// * `other` - Rejection value to compare with this value.
53    ///
54    /// # Returns
55    ///
56    /// `true` when both values have the same rejection category.
57    fn eq(&self, other: &Self) -> bool {
58        matches!(
59            (self, other),
60            (Self::Shutdown, Self::Shutdown)
61                | (Self::Saturated, Self::Saturated)
62                | (
63                    Self::WorkerSpawnFailed { .. },
64                    Self::WorkerSpawnFailed { .. }
65                )
66        )
67    }
68}
69
70impl Eq for RejectedExecution {}
qubit_executor/service/rejected_execution.rs

qubit_executor/service/
rejected_execution.rs
