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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /vendor/tokio/src/runtime/blocking/shutdown.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/tokio/src/runtime/blocking/shutdown.rs')
-rw-r--r-- | vendor/tokio/src/runtime/blocking/shutdown.rs | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/vendor/tokio/src/runtime/blocking/shutdown.rs b/vendor/tokio/src/runtime/blocking/shutdown.rs new file mode 100644 index 000000000..0cf22859b --- /dev/null +++ b/vendor/tokio/src/runtime/blocking/shutdown.rs @@ -0,0 +1,71 @@ +//! A shutdown channel. +//! +//! Each worker holds the `Sender` half. When all the `Sender` halves are +//! dropped, the `Receiver` receives a notification. + +use crate::loom::sync::Arc; +use crate::sync::oneshot; + +use std::time::Duration; + +#[derive(Debug, Clone)] +pub(super) struct Sender { + tx: Arc<oneshot::Sender<()>>, +} + +#[derive(Debug)] +pub(super) struct Receiver { + rx: oneshot::Receiver<()>, +} + +pub(super) fn channel() -> (Sender, Receiver) { + let (tx, rx) = oneshot::channel(); + let tx = Sender { tx: Arc::new(tx) }; + let rx = Receiver { rx }; + + (tx, rx) +} + +impl Receiver { + /// Blocks the current thread until all `Sender` handles drop. + /// + /// If `timeout` is `Some`, the thread is blocked for **at most** `timeout` + /// duration. If `timeout` is `None`, then the thread is blocked until the + /// shutdown signal is received. + /// + /// If the timeout has elapsed, it returns `false`, otherwise it returns `true`. + pub(crate) fn wait(&mut self, timeout: Option<Duration>) -> bool { + use crate::runtime::enter::try_enter; + + if timeout == Some(Duration::from_nanos(0)) { + return false; + } + + let mut e = match try_enter(false) { + Some(enter) => enter, + _ => { + if std::thread::panicking() { + // Don't panic in a panic + return false; + } else { + panic!( + "Cannot drop a runtime in a context where blocking is not allowed. \ + This happens when a runtime is dropped from within an asynchronous context." + ); + } + } + }; + + // The oneshot completes with an Err + // + // If blocking fails to wait, this indicates a problem parking the + // current thread (usually, shutting down a runtime stored in a + // thread-local). + if let Some(timeout) = timeout { + e.block_on_timeout(&mut self.rx, timeout).is_ok() + } else { + let _ = e.block_on(&mut self.rx); + true + } + } +} |