47 lines
1.2 KiB
Rust
47 lines
1.2 KiB
Rust
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// Copyright 2016 Mozilla
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//
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// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
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// this file except in compliance with the License. You may obtain a copy of the
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// License at http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing, software distributed
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// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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// CONDITIONS OF ANY KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations under the License.
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use std::rc::Rc;
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use std::sync::atomic::{
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AtomicUsize,
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Ordering,
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};
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#[derive(Clone)]
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pub struct RcCounter {
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c: Rc<AtomicUsize>,
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}
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impl RcCounter {
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pub fn new() -> Self {
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RcCounter { c: Rc::new(AtomicUsize::new(0)) }
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}
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pub fn next(&self) -> usize {
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self.c.fetch_add(1, Ordering::SeqCst)
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}
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}
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#[cfg(test)]
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mod tests {
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use super::RcCounter;
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#[test]
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fn test_rc_counter() {
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let c = RcCounter::new();
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assert_eq!(c.next(), 0);
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assert_eq!(c.next(), 1);
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let d = c.clone();
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assert_eq!(d.next(), 2);
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assert_eq!(c.next(), 3);
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}
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}
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