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https://github.com/denoland/deno.git
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1b355d8a87
Introduces a `SyncReadAsyncWriteLock` to make it harder to write to the npm resolution without first waiting async in a queue. For the npm resolution, reading synchronously is fine, but when updating, someone should wait async, clone the data, then write the data at the end back.
35 lines
822 B
Rust
35 lines
822 B
Rust
// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
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use std::sync::atomic::AtomicBool;
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use std::sync::atomic::Ordering;
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/// Simplifies the use of an atomic boolean as a flag.
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#[derive(Debug, Default)]
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pub struct AtomicFlag(AtomicBool);
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impl AtomicFlag {
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/// Raises the flag returning if the raise was successful.
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pub fn raise(&self) -> bool {
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!self.0.swap(true, Ordering::SeqCst)
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}
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/// Gets if the flag is raised.
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pub fn is_raised(&self) -> bool {
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self.0.load(Ordering::SeqCst)
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}
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}
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#[cfg(test)]
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mod test {
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use super::*;
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#[test]
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fn atomic_flag_raises() {
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let flag = AtomicFlag::default();
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assert!(!flag.is_raised()); // false by default
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assert!(flag.raise());
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assert!(flag.is_raised());
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assert!(!flag.raise());
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assert!(flag.is_raised());
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}
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}
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