zrx_executor/executor/
strategy.rs

1// Copyright (c) 2025-2026 Zensical and contributors
2
3// SPDX-License-Identifier: MIT
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24// ----------------------------------------------------------------------------
25
26//! Execution strategies.
27
28use std::fmt::Debug;
29
30use super::error::Result;
31use super::signal::Signal;
32use super::task::Task;
33
34mod immediate;
35mod worker;
36
37pub use immediate::Immediate;
38pub use worker::{WorkSharing, WorkStealing};
39
40// ----------------------------------------------------------------------------
41// Traits
42// ----------------------------------------------------------------------------
43
44/// Execution strategy.
45///
46/// Besides task submission, strategies must also allow to inspect the number of
47/// workers, as well as the number of running and pending tasks, which might be
48/// useful for implementing more fine-grained execution strategies. It's also
49/// used to determine whether an [`Executor`][] is idle or at capacity.
50///
51/// [`Executor`]: crate::executor::Executor
52pub trait Strategy: Debug {
53    /// Submits a task.
54    ///
55    /// This method submits a [`Task`], which should be executed by one of the
56    /// worker threads as soon as possible. How and when the task is executed,
57    /// and in what order tasks are executed, is entirely up to the strategy
58    /// implementation.
59    ///
60    /// # Errors
61    ///
62    /// This method should return an error when a problem is encountered trying
63    /// to submit the given task, but not within the task itself.
64    fn submit(&self, task: Box<dyn Task>) -> Result;
65
66    /// Returns the number of workers.
67    fn num_workers(&self) -> usize;
68
69    /// Returns the number of running tasks.
70    fn num_tasks_running(&self) -> usize;
71
72    /// Returns the number of pending tasks.
73    fn num_tasks_pending(&self) -> usize;
74
75    /// Returns the capacity.
76    fn capacity(&self) -> usize;
77}
zrx_executor/executor/strategy.rs

zrx_executor/executor/
strategy.rs
