50 lines
1.4 KiB
Rust
50 lines
1.4 KiB
Rust
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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/// Simple refcount structure for cloning handles
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///
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/// This is meant to be an unintrusive solution to cloning handles in rustuv.
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/// The handles themselves shouldn't be sharing memory because there are bits of
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/// state in the rust objects which shouldn't be shared across multiple users of
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/// the same underlying uv object, hence Rc is not used and this simple counter
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/// should suffice.
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use std::sync::arc::UnsafeArc;
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pub struct Refcount {
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rc: UnsafeArc<uint>,
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}
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impl Refcount {
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/// Creates a new refcount of 1
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pub fn new() -> Refcount {
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Refcount { rc: UnsafeArc::new(1) }
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}
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fn increment(&self) {
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unsafe { *self.rc.get() += 1; }
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}
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/// Returns whether the refcount just hit 0 or not
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pub fn decrement(&self) -> bool {
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unsafe {
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*self.rc.get() -= 1;
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*self.rc.get() == 0
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}
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}
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}
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impl Clone for Refcount {
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fn clone(&self) -> Refcount {
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self.increment();
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Refcount { rc: self.rc.clone() }
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}
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}
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