forked from mirror/async-std
83 lines
2.1 KiB
Rust
83 lines
2.1 KiB
Rust
use log::log_enabled;
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use std::future::Future;
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use crate::io;
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use crate::task::executor;
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use crate::task::{JoinHandle, Task};
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use crate::utils::abort_on_panic;
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/// Task builder that configures the settings of a new task.
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#[derive(Debug, Default)]
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pub struct Builder {
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pub(crate) name: Option<String>,
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}
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impl Builder {
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/// Creates a new builder.
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#[inline]
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pub fn new() -> Builder {
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Builder { name: None }
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}
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/// Configures the name of the task.
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#[inline]
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pub fn name(mut self, name: String) -> Builder {
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self.name = Some(name);
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self
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}
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/// Spawns a task with the configured settings.
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pub fn spawn<F, T>(self, future: F) -> io::Result<JoinHandle<T>>
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where
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F: Future<Output = T> + Send + 'static,
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T: Send + 'static,
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{
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// Create a new task handle.
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let task = Task::new(self.name);
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// Log this `spawn` operation.
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if log_enabled!(log::Level::Trace) {
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log::trace!("spawn", {
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task_id: task.id().0,
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parent_task_id: Task::get_current(|t| t.id().0).unwrap_or(0),
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});
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}
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let future = async move {
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// Drop task-locals on exit.
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defer! {
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Task::get_current(|t| unsafe { t.drop_locals() });
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}
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// Log completion on exit.
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defer! {
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if log_enabled!(log::Level::Trace) {
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Task::get_current(|t| {
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log::trace!("completed", {
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task_id: t.id().0,
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});
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});
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}
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}
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future.await
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};
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let schedule = move |t| executor::schedule(Runnable(t));
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let (task, handle) = async_task::spawn(future, schedule, task);
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task.schedule();
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Ok(JoinHandle::new(handle))
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}
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}
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/// A runnable task.
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pub(crate) struct Runnable(async_task::Task<Task>);
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impl Runnable {
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/// Runs the task by polling its future once.
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pub fn run(self) {
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unsafe {
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Task::set_current(self.0.tag(), || abort_on_panic(|| self.0.run()));
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}
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}
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}
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