<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source to the Rust file `/home/mrh/.cargo/registry/src/github.com-1ecc6299db9ec823/crossbeam-epoch-0.7.1/src/atomic.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>atomic.rs.html -- source</title><link rel="stylesheet" type="text/css" href="../../normalize.css"><link rel="stylesheet" type="text/css" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../dark.css"><link rel="stylesheet" type="text/css" href="../../light.css" id="themeStyle"><script src="../../storage.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="shortcut icon" href="../../favicon.ico"><style type="text/css">#crate-search{background-image:url("../../down-arrow.svg");}</style></head><body class="rustdoc source"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">☰</div><a href='../../crossbeam_epoch/index.html'><div class='logo-container'><img src='../../rust-logo.png' alt='logo'></div></a></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><a id="settings-menu" href="../../settings.html"><img src="../../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><pre class="line-numbers"><span id="1"> 1</span>
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</pre><div class="example-wrap"><pre class="rust ">
<span class="kw">use</span> <span class="ident">alloc</span>::<span class="ident">boxed</span>::<span class="ident">Box</span>;
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">borrow</span>::{<span class="ident">Borrow</span>, <span class="ident">BorrowMut</span>};
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">cmp</span>;
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">fmt</span>;
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">marker</span>::<span class="ident">PhantomData</span>;
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">mem</span>;
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">ops</span>::{<span class="ident">Deref</span>, <span class="ident">DerefMut</span>};
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">ptr</span>;
<span class="kw">use</span> <span class="ident">core</span>::<span class="ident">sync</span>::<span class="ident">atomic</span>::{<span class="ident">AtomicUsize</span>, <span class="ident">Ordering</span>};
<span class="kw">use</span> <span class="ident">crossbeam_utils</span>::<span class="ident">atomic</span>::<span class="ident">AtomicConsume</span>;
<span class="kw">use</span> <span class="ident">guard</span>::<span class="ident">Guard</span>;
<span class="doccomment">/// Given ordering for the success case in a compare-exchange operation, returns the strongest</span>
<span class="doccomment">/// appropriate ordering for the failure case.</span>
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">strongest_failure_ordering</span>(<span class="ident">ord</span>: <span class="ident">Ordering</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Ordering</span> {
<span class="kw">use</span> <span class="self">self</span>::<span class="ident">Ordering</span>::<span class="kw-2">*</span>;
<span class="kw">match</span> <span class="ident">ord</span> {
<span class="ident">Relaxed</span> <span class="op">|</span> <span class="ident">Release</span> <span class="op">=</span><span class="op">></span> <span class="ident">Relaxed</span>,
<span class="ident">Acquire</span> <span class="op">|</span> <span class="ident">AcqRel</span> <span class="op">=</span><span class="op">></span> <span class="ident">Acquire</span>,
<span class="kw">_</span> <span class="op">=</span><span class="op">></span> <span class="ident">SeqCst</span>,
}
}
<span class="doccomment">/// The error returned on failed compare-and-set operation.</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">CompareAndSetError</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span>: <span class="lifetime">'g</span>, <span class="ident">P</span>: <span class="ident">Pointer</span><span class="op"><</span><span class="ident">T</span><span class="op">></span><span class="op">></span> {
<span class="doccomment">/// The value in the atomic pointer at the time of the failed operation.</span>
<span class="kw">pub</span> <span class="ident">current</span>: <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span>,
<span class="doccomment">/// The new value, which the operation failed to store.</span>
<span class="kw">pub</span> <span class="ident">new</span>: <span class="ident">P</span>,
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span>: <span class="lifetime">'g</span>, <span class="ident">P</span>: <span class="ident">Pointer</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="op">+</span> <span class="ident">fmt</span>::<span class="ident">Debug</span><span class="op">></span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">CompareAndSetError</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span>, <span class="ident">P</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-</span><span class="op">></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="ident">f</span>.<span class="ident">debug_struct</span>(<span class="string">"CompareAndSetError"</span>)
.<span class="ident">field</span>(<span class="string">"current"</span>, <span class="kw-2">&</span><span class="self">self</span>.<span class="ident">current</span>)
.<span class="ident">field</span>(<span class="string">"new"</span>, <span class="kw-2">&</span><span class="self">self</span>.<span class="ident">new</span>)
.<span class="ident">finish</span>()
}
}
<span class="doccomment">/// Memory orderings for compare-and-set operations.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// A compare-and-set operation can have different memory orderings depending on whether it</span>
<span class="doccomment">/// succeeds or fails. This trait generalizes different ways of specifying memory orderings.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The two ways of specifying orderings for compare-and-set are:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// 1. Just one `Ordering` for the success case. In case of failure, the strongest appropriate</span>
<span class="doccomment">/// ordering is chosen.</span>
<span class="doccomment">/// 2. A pair of `Ordering`s. The first one is for the success case, while the second one is</span>
<span class="doccomment">/// for the failure case.</span>
<span class="kw">pub</span> <span class="kw">trait</span> <span class="ident">CompareAndSetOrdering</span> {
<span class="doccomment">/// The ordering of the operation when it succeeds.</span>
<span class="kw">fn</span> <span class="ident">success</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Ordering</span>;
<span class="doccomment">/// The ordering of the operation when it fails.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The failure ordering can't be `Release` or `AcqRel` and must be equivalent or weaker than</span>
<span class="doccomment">/// the success ordering.</span>
<span class="kw">fn</span> <span class="ident">failure</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Ordering</span>;
}
<span class="kw">impl</span> <span class="ident">CompareAndSetOrdering</span> <span class="kw">for</span> <span class="ident">Ordering</span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">success</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Ordering</span> {
<span class="kw-2">*</span><span class="self">self</span>
}
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">failure</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Ordering</span> {
<span class="ident">strongest_failure_ordering</span>(<span class="kw-2">*</span><span class="self">self</span>)
}
}
<span class="kw">impl</span> <span class="ident">CompareAndSetOrdering</span> <span class="kw">for</span> (<span class="ident">Ordering</span>, <span class="ident">Ordering</span>) {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">success</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Ordering</span> {
<span class="self">self</span>.<span class="number">0</span>
}
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">failure</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Ordering</span> {
<span class="self">self</span>.<span class="number">1</span>
}
}
<span class="doccomment">/// Panics if the pointer is not properly unaligned.</span>
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">ensure_aligned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="ident">raw</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">T</span>) {
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">raw</span> <span class="kw">as</span> <span class="ident">usize</span> <span class="op">&</span> <span class="ident">low_bits</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(), <span class="number">0</span>, <span class="string">"unaligned pointer"</span>);
}
<span class="doccomment">/// Returns a bitmask containing the unused least significant bits of an aligned pointer to `T`.</span>
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">low_bits</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>() <span class="op">-</span><span class="op">></span> <span class="ident">usize</span> {
(<span class="number">1</span> <span class="op"><</span><span class="op"><</span> <span class="ident">mem</span>::<span class="ident">align_of</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>().<span class="ident">trailing_zeros</span>()) <span class="op">-</span> <span class="number">1</span>
}
<span class="doccomment">/// Given a tagged pointer `data`, returns the same pointer, but tagged with `tag`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// `tag` is truncated to fit into the unused bits of the pointer to `T`.</span>
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">data_with_tag</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="ident">data</span>: <span class="ident">usize</span>, <span class="ident">tag</span>: <span class="ident">usize</span>) <span class="op">-</span><span class="op">></span> <span class="ident">usize</span> {
(<span class="ident">data</span> <span class="op">&</span> <span class="op">!</span><span class="ident">low_bits</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>()) <span class="op">|</span> (<span class="ident">tag</span> <span class="op">&</span> <span class="ident">low_bits</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>())
}
<span class="doccomment">/// Decomposes a tagged pointer `data` into the pointer and the tag.</span>
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">decompose_data</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="ident">data</span>: <span class="ident">usize</span>) <span class="op">-</span><span class="op">></span> (<span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">T</span>, <span class="ident">usize</span>) {
<span class="kw">let</span> <span class="ident">raw</span> <span class="op">=</span> (<span class="ident">data</span> <span class="op">&</span> <span class="op">!</span><span class="ident">low_bits</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>()) <span class="kw">as</span> <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">T</span>;
<span class="kw">let</span> <span class="ident">tag</span> <span class="op">=</span> <span class="ident">data</span> <span class="op">&</span> <span class="ident">low_bits</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>();
(<span class="ident">raw</span>, <span class="ident">tag</span>)
}
<span class="doccomment">/// An atomic pointer that can be safely shared between threads.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The pointer must be properly aligned. Since it is aligned, a tag can be stored into the unused</span>
<span class="doccomment">/// least significant bits of the address. More precisely, a tag should be less than `(1 <<</span>
<span class="doccomment">/// mem::align_of::<T>().trailing_zeros())`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Any method that loads the pointer must be passed a reference to a [`Guard`].</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Guard`]: struct.Guard.html</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="ident">data</span>: <span class="ident">AtomicUsize</span>,
<span class="ident">_marker</span>: <span class="ident">PhantomData</span><span class="op"><</span><span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">T</span><span class="op">></span>,
}
<span class="kw">unsafe</span> <span class="kw">impl</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Send</span> <span class="op">+</span> <span class="ident">Sync</span><span class="op">></span> <span class="ident">Send</span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {}
<span class="kw">unsafe</span> <span class="kw">impl</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Send</span> <span class="op">+</span> <span class="ident">Sync</span><span class="op">></span> <span class="ident">Sync</span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Returns a new atomic pointer pointing to the tagged pointer `data`.</span>
<span class="kw">fn</span> <span class="ident">from_usize</span>(<span class="ident">data</span>: <span class="ident">usize</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="self">Self</span> {
<span class="ident">data</span>: <span class="ident">AtomicUsize</span>::<span class="ident">new</span>(<span class="ident">data</span>),
<span class="ident">_marker</span>: <span class="ident">PhantomData</span>,
}
}
<span class="doccomment">/// Returns a new null atomic pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Atomic;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::<i32>::null();</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">not</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"nightly"</span>))]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">null</span>() <span class="op">-</span><span class="op">></span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="self">Self</span> {
<span class="ident">data</span>: <span class="ident">AtomicUsize</span>::<span class="ident">new</span>(<span class="number">0</span>),
<span class="ident">_marker</span>: <span class="ident">PhantomData</span>,
}
}
<span class="doccomment">/// Returns a new null atomic pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Atomic;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::<i32>::null();</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"nightly"</span>)]</span>
<span class="kw">pub</span> <span class="kw">const</span> <span class="kw">fn</span> <span class="ident">null</span>() <span class="op">-</span><span class="op">></span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="self">Self</span> {
<span class="ident">data</span>: <span class="ident">AtomicUsize</span>::<span class="ident">new</span>(<span class="number">0</span>),
<span class="ident">_marker</span>: <span class="ident">PhantomData</span>,
}
}
<span class="doccomment">/// Allocates `value` on the heap and returns a new atomic pointer pointing to it.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Atomic;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">value</span>: <span class="ident">T</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="self">Self</span>::<span class="ident">from</span>(<span class="ident">Owned</span>::<span class="ident">new</span>(<span class="ident">value</span>))
}
<span class="doccomment">/// Loads a `Shared` from the atomic pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method takes an [`Ordering`] argument which describes the memory ordering of this</span>
<span class="doccomment">/// operation.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Ordering`]: https://doc.rust-lang.org/std/sync/atomic/enum.Ordering.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let p = a.load(SeqCst, guard);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">load</span><span class="op"><</span><span class="lifetime">'g</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">ord</span>: <span class="ident">Ordering</span>, <span class="kw">_</span>: <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">Guard</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">unsafe</span> { <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="self">self</span>.<span class="ident">data</span>.<span class="ident">load</span>(<span class="ident">ord</span>)) }
}
<span class="doccomment">/// Loads a `Shared` from the atomic pointer using a "consume" memory ordering.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This is similar to the "acquire" ordering, except that an ordering is</span>
<span class="doccomment">/// only guaranteed with operations that "depend on" the result of the load.</span>
<span class="doccomment">/// However consume loads are usually much faster than acquire loads on</span>
<span class="doccomment">/// architectures with a weak memory model since they don't require memory</span>
<span class="doccomment">/// fence instructions.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The exact definition of "depend on" is a bit vague, but it works as you</span>
<span class="doccomment">/// would expect in practice since a lot of software, especially the Linux</span>
<span class="doccomment">/// kernel, rely on this behavior.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let p = a.load_consume(guard);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">load_consume</span><span class="op"><</span><span class="lifetime">'g</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="kw">_</span>: <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">Guard</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">unsafe</span> { <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="self">self</span>.<span class="ident">data</span>.<span class="ident">load_consume</span>()) }
}
<span class="doccomment">/// Stores a `Shared` or `Owned` pointer into the atomic pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method takes an [`Ordering`] argument which describes the memory ordering of this</span>
<span class="doccomment">/// operation.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Ordering`]: https://doc.rust-lang.org/std/sync/atomic/enum.Ordering.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Owned, Shared};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">/// a.store(Shared::null(), SeqCst);</span>
<span class="doccomment">/// a.store(Owned::new(1234), SeqCst);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">store</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">P</span>: <span class="ident">Pointer</span><span class="op"><</span><span class="ident">T</span><span class="op">></span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">new</span>: <span class="ident">P</span>, <span class="ident">ord</span>: <span class="ident">Ordering</span>) {
<span class="self">self</span>.<span class="ident">data</span>.<span class="ident">store</span>(<span class="ident">new</span>.<span class="ident">into_usize</span>(), <span class="ident">ord</span>);
}
<span class="doccomment">/// Stores a `Shared` or `Owned` pointer into the atomic pointer, returning the previous</span>
<span class="doccomment">/// `Shared`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method takes an [`Ordering`] argument which describes the memory ordering of this</span>
<span class="doccomment">/// operation.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Ordering`]: https://doc.rust-lang.org/std/sync/atomic/enum.Ordering.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Owned, Shared};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let p = a.swap(Shared::null(), SeqCst, guard);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">swap</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">P</span>: <span class="ident">Pointer</span><span class="op"><</span><span class="ident">T</span><span class="op">></span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">new</span>: <span class="ident">P</span>, <span class="ident">ord</span>: <span class="ident">Ordering</span>, <span class="kw">_</span>: <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">Guard</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">unsafe</span> { <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="self">self</span>.<span class="ident">data</span>.<span class="ident">swap</span>(<span class="ident">new</span>.<span class="ident">into_usize</span>(), <span class="ident">ord</span>)) }
}
<span class="doccomment">/// Stores the pointer `new` (either `Shared` or `Owned`) into the atomic pointer if the current</span>
<span class="doccomment">/// value is the same as `current`. The tag is also taken into account, so two pointers to the</span>
<span class="doccomment">/// same object, but with different tags, will not be considered equal.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The return value is a result indicating whether the new pointer was written. On success the</span>
<span class="doccomment">/// pointer that was written is returned. On failure the actual current value and `new` are</span>
<span class="doccomment">/// returned.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method takes a [`CompareAndSetOrdering`] argument which describes the memory</span>
<span class="doccomment">/// ordering of this operation.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`CompareAndSetOrdering`]: trait.CompareAndSetOrdering.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Owned, Shared};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let mut curr = a.load(SeqCst, guard);</span>
<span class="doccomment">/// let res1 = a.compare_and_set(curr, Shared::null(), SeqCst, guard);</span>
<span class="doccomment">/// let res2 = a.compare_and_set(curr, Owned::new(5678), SeqCst, guard);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">compare_and_set</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">O</span>, <span class="ident">P</span><span class="op">></span>(
<span class="kw-2">&</span><span class="self">self</span>,
<span class="ident">current</span>: <span class="ident">Shared</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>,
<span class="ident">new</span>: <span class="ident">P</span>,
<span class="ident">ord</span>: <span class="ident">O</span>,
<span class="kw">_</span>: <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">Guard</span>,
) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span>, <span class="ident">CompareAndSetError</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span>, <span class="ident">P</span><span class="op">></span><span class="op">></span>
<span class="kw">where</span>
<span class="ident">O</span>: <span class="ident">CompareAndSetOrdering</span>,
<span class="ident">P</span>: <span class="ident">Pointer</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>,
{
<span class="kw">let</span> <span class="ident">new</span> <span class="op">=</span> <span class="ident">new</span>.<span class="ident">into_usize</span>();
<span class="self">self</span>.<span class="ident">data</span>
.<span class="ident">compare_exchange</span>(<span class="ident">current</span>.<span class="ident">into_usize</span>(), <span class="ident">new</span>, <span class="ident">ord</span>.<span class="ident">success</span>(), <span class="ident">ord</span>.<span class="ident">failure</span>())
.<span class="ident">map</span>(<span class="op">|</span><span class="kw">_</span><span class="op">|</span> <span class="kw">unsafe</span> { <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="ident">new</span>) })
.<span class="ident">map_err</span>(<span class="op">|</span><span class="ident">current</span><span class="op">|</span> <span class="kw">unsafe</span> {
<span class="ident">CompareAndSetError</span> {
<span class="ident">current</span>: <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="ident">current</span>),
<span class="ident">new</span>: <span class="ident">P</span>::<span class="ident">from_usize</span>(<span class="ident">new</span>),
}
})
}
<span class="doccomment">/// Stores the pointer `new` (either `Shared` or `Owned`) into the atomic pointer if the current</span>
<span class="doccomment">/// value is the same as `current`. The tag is also taken into account, so two pointers to the</span>
<span class="doccomment">/// same object, but with different tags, will not be considered equal.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Unlike [`compare_and_set`], this method is allowed to spuriously fail even when comparison</span>
<span class="doccomment">/// succeeds, which can result in more efficient code on some platforms. The return value is a</span>
<span class="doccomment">/// result indicating whether the new pointer was written. On success the pointer that was</span>
<span class="doccomment">/// written is returned. On failure the actual current value and `new` are returned.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method takes a [`CompareAndSetOrdering`] argument which describes the memory</span>
<span class="doccomment">/// ordering of this operation.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`compare_and_set`]: struct.Atomic.html#method.compare_and_set</span>
<span class="doccomment">/// [`CompareAndSetOrdering`]: trait.CompareAndSetOrdering.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Owned, Shared};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let mut new = Owned::new(5678);</span>
<span class="doccomment">/// let mut ptr = a.load(SeqCst, guard);</span>
<span class="doccomment">/// loop {</span>
<span class="doccomment">/// match a.compare_and_set_weak(ptr, new, SeqCst, guard) {</span>
<span class="doccomment">/// Ok(p) => {</span>
<span class="doccomment">/// ptr = p;</span>
<span class="doccomment">/// break;</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// Err(err) => {</span>
<span class="doccomment">/// ptr = err.current;</span>
<span class="doccomment">/// new = err.new;</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let mut curr = a.load(SeqCst, guard);</span>
<span class="doccomment">/// loop {</span>
<span class="doccomment">/// match a.compare_and_set_weak(curr, Shared::null(), SeqCst, guard) {</span>
<span class="doccomment">/// Ok(_) => break,</span>
<span class="doccomment">/// Err(err) => curr = err.current,</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">compare_and_set_weak</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">O</span>, <span class="ident">P</span><span class="op">></span>(
<span class="kw-2">&</span><span class="self">self</span>,
<span class="ident">current</span>: <span class="ident">Shared</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>,
<span class="ident">new</span>: <span class="ident">P</span>,
<span class="ident">ord</span>: <span class="ident">O</span>,
<span class="kw">_</span>: <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">Guard</span>,
) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span>, <span class="ident">CompareAndSetError</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span>, <span class="ident">P</span><span class="op">></span><span class="op">></span>
<span class="kw">where</span>
<span class="ident">O</span>: <span class="ident">CompareAndSetOrdering</span>,
<span class="ident">P</span>: <span class="ident">Pointer</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>,
{
<span class="kw">let</span> <span class="ident">new</span> <span class="op">=</span> <span class="ident">new</span>.<span class="ident">into_usize</span>();
<span class="self">self</span>.<span class="ident">data</span>
.<span class="ident">compare_exchange_weak</span>(<span class="ident">current</span>.<span class="ident">into_usize</span>(), <span class="ident">new</span>, <span class="ident">ord</span>.<span class="ident">success</span>(), <span class="ident">ord</span>.<span class="ident">failure</span>())
.<span class="ident">map</span>(<span class="op">|</span><span class="kw">_</span><span class="op">|</span> <span class="kw">unsafe</span> { <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="ident">new</span>) })
.<span class="ident">map_err</span>(<span class="op">|</span><span class="ident">current</span><span class="op">|</span> <span class="kw">unsafe</span> {
<span class="ident">CompareAndSetError</span> {
<span class="ident">current</span>: <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="ident">current</span>),
<span class="ident">new</span>: <span class="ident">P</span>::<span class="ident">from_usize</span>(<span class="ident">new</span>),
}
})
}
<span class="doccomment">/// Bitwise "and" with the current tag.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Performs a bitwise "and" operation on the current tag and the argument `val`, and sets the</span>
<span class="doccomment">/// new tag to the result. Returns the previous pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method takes an [`Ordering`] argument which describes the memory ordering of this</span>
<span class="doccomment">/// operation.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Ordering`]: https://doc.rust-lang.org/std/sync/atomic/enum.Ordering.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Shared};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::<i32>::from(Shared::null().with_tag(3));</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// assert_eq!(a.fetch_and(2, SeqCst, guard).tag(), 3);</span>
<span class="doccomment">/// assert_eq!(a.load(SeqCst, guard).tag(), 2);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">fetch_and</span><span class="op"><</span><span class="lifetime">'g</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">val</span>: <span class="ident">usize</span>, <span class="ident">ord</span>: <span class="ident">Ordering</span>, <span class="kw">_</span>: <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">Guard</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">unsafe</span> { <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="self">self</span>.<span class="ident">data</span>.<span class="ident">fetch_and</span>(<span class="ident">val</span> <span class="op">|</span> <span class="op">!</span><span class="ident">low_bits</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(), <span class="ident">ord</span>)) }
}
<span class="doccomment">/// Bitwise "or" with the current tag.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Performs a bitwise "or" operation on the current tag and the argument `val`, and sets the</span>
<span class="doccomment">/// new tag to the result. Returns the previous pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method takes an [`Ordering`] argument which describes the memory ordering of this</span>
<span class="doccomment">/// operation.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Ordering`]: https://doc.rust-lang.org/std/sync/atomic/enum.Ordering.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Shared};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::<i32>::from(Shared::null().with_tag(1));</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// assert_eq!(a.fetch_or(2, SeqCst, guard).tag(), 1);</span>
<span class="doccomment">/// assert_eq!(a.load(SeqCst, guard).tag(), 3);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">fetch_or</span><span class="op"><</span><span class="lifetime">'g</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">val</span>: <span class="ident">usize</span>, <span class="ident">ord</span>: <span class="ident">Ordering</span>, <span class="kw">_</span>: <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">Guard</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">unsafe</span> { <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="self">self</span>.<span class="ident">data</span>.<span class="ident">fetch_or</span>(<span class="ident">val</span> <span class="op">&</span> <span class="ident">low_bits</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(), <span class="ident">ord</span>)) }
}
<span class="doccomment">/// Bitwise "xor" with the current tag.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Performs a bitwise "xor" operation on the current tag and the argument `val`, and sets the</span>
<span class="doccomment">/// new tag to the result. Returns the previous pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method takes an [`Ordering`] argument which describes the memory ordering of this</span>
<span class="doccomment">/// operation.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Ordering`]: https://doc.rust-lang.org/std/sync/atomic/enum.Ordering.html</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Shared};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::<i32>::from(Shared::null().with_tag(1));</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// assert_eq!(a.fetch_xor(3, SeqCst, guard).tag(), 1);</span>
<span class="doccomment">/// assert_eq!(a.load(SeqCst, guard).tag(), 2);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">fetch_xor</span><span class="op"><</span><span class="lifetime">'g</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">val</span>: <span class="ident">usize</span>, <span class="ident">ord</span>: <span class="ident">Ordering</span>, <span class="kw">_</span>: <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">Guard</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">unsafe</span> { <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="self">self</span>.<span class="ident">data</span>.<span class="ident">fetch_xor</span>(<span class="ident">val</span> <span class="op">&</span> <span class="ident">low_bits</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(), <span class="ident">ord</span>)) }
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-</span><span class="op">></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="kw">let</span> <span class="ident">data</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">data</span>.<span class="ident">load</span>(<span class="ident">Ordering</span>::<span class="ident">SeqCst</span>);
<span class="kw">let</span> (<span class="ident">raw</span>, <span class="ident">tag</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="ident">data</span>);
<span class="ident">f</span>.<span class="ident">debug_struct</span>(<span class="string">"Atomic"</span>)
.<span class="ident">field</span>(<span class="string">"raw"</span>, <span class="kw-2">&</span><span class="ident">raw</span>)
.<span class="ident">field</span>(<span class="string">"tag"</span>, <span class="kw-2">&</span><span class="ident">tag</span>)
.<span class="ident">finish</span>()
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">fmt</span>::<span class="ident">Pointer</span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-</span><span class="op">></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="kw">let</span> <span class="ident">data</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">data</span>.<span class="ident">load</span>(<span class="ident">Ordering</span>::<span class="ident">SeqCst</span>);
<span class="kw">let</span> (<span class="ident">raw</span>, <span class="kw">_</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="ident">data</span>);
<span class="ident">fmt</span>::<span class="ident">Pointer</span>::<span class="ident">fmt</span>(<span class="kw-2">&</span><span class="ident">raw</span>, <span class="ident">f</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">Clone</span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Returns a copy of the atomic value.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Note that a `Relaxed` load is used here. If you need synchronization, use it with other</span>
<span class="doccomment">/// atomics or fences.</span>
<span class="kw">fn</span> <span class="ident">clone</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="kw">let</span> <span class="ident">data</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">data</span>.<span class="ident">load</span>(<span class="ident">Ordering</span>::<span class="ident">Relaxed</span>);
<span class="ident">Atomic</span>::<span class="ident">from_usize</span>(<span class="ident">data</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">Default</span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">default</span>() <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="ident">Atomic</span>::<span class="ident">null</span>()
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">From</span><span class="op"><</span><span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span><span class="op">></span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Returns a new atomic pointer pointing to `owned`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{Atomic, Owned};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::<i32>::from(Owned::new(1234));</span>
<span class="doccomment">/// ```</span>
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">owned</span>: <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="kw">let</span> <span class="ident">data</span> <span class="op">=</span> <span class="ident">owned</span>.<span class="ident">data</span>;
<span class="ident">mem</span>::<span class="ident">forget</span>(<span class="ident">owned</span>);
<span class="self">Self</span>::<span class="ident">from_usize</span>(<span class="ident">data</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">From</span><span class="op"><</span><span class="ident">Box</span><span class="op"><</span><span class="ident">T</span><span class="op">></span><span class="op">></span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">b</span>: <span class="ident">Box</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="self">Self</span>::<span class="ident">from</span>(<span class="ident">Owned</span>::<span class="ident">from</span>(<span class="ident">b</span>))
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">From</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">t</span>: <span class="ident">T</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="self">Self</span>::<span class="ident">new</span>(<span class="ident">t</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">From</span><span class="op"><</span><span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span><span class="op">></span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Returns a new atomic pointer pointing to `ptr`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{Atomic, Shared};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::<i32>::from(Shared::<i32>::null());</span>
<span class="doccomment">/// ```</span>
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">ptr</span>: <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="self">Self</span>::<span class="ident">from_usize</span>(<span class="ident">ptr</span>.<span class="ident">data</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">From</span><span class="op"><</span><span class="kw-2">*</span><span class="kw">const</span> <span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Atomic</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Returns a new atomic pointer pointing to `raw`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::ptr;</span>
<span class="doccomment">/// use crossbeam_epoch::Atomic;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::<i32>::from(ptr::null::<i32>());</span>
<span class="doccomment">/// ```</span>
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">raw</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">T</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="self">Self</span>::<span class="ident">from_usize</span>(<span class="ident">raw</span> <span class="kw">as</span> <span class="ident">usize</span>)
}
}
<span class="doccomment">/// A trait for either `Owned` or `Shared` pointers.</span>
<span class="kw">pub</span> <span class="kw">trait</span> <span class="ident">Pointer</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Returns the machine representation of the pointer.</span>
<span class="kw">fn</span> <span class="ident">into_usize</span>(<span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">usize</span>;
<span class="doccomment">/// Returns a new pointer pointing to the tagged pointer `data`.</span>
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">from_usize</span>(<span class="ident">data</span>: <span class="ident">usize</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span>;
}
<span class="doccomment">/// An owned heap-allocated object.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This type is very similar to `Box<T>`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The pointer must be properly aligned. Since it is aligned, a tag can be stored into the unused</span>
<span class="doccomment">/// least significant bits of the address.</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="ident">data</span>: <span class="ident">usize</span>,
<span class="ident">_marker</span>: <span class="ident">PhantomData</span><span class="op"><</span><span class="ident">Box</span><span class="op"><</span><span class="ident">T</span><span class="op">></span><span class="op">></span>,
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">Pointer</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">into_usize</span>(<span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">usize</span> {
<span class="kw">let</span> <span class="ident">data</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">data</span>;
<span class="ident">mem</span>::<span class="ident">forget</span>(<span class="self">self</span>);
<span class="ident">data</span>
}
<span class="doccomment">/// Returns a new pointer pointing to the tagged pointer `data`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Panics</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Panics if the data is zero in debug mode.</span>
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">from_usize</span>(<span class="ident">data</span>: <span class="ident">usize</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="macro">debug_assert</span><span class="macro">!</span>(<span class="ident">data</span> <span class="op">!</span><span class="op">=</span> <span class="number">0</span>, <span class="string">"converting zero into `Owned`"</span>);
<span class="ident">Owned</span> {
<span class="ident">data</span>: <span class="ident">data</span>,
<span class="ident">_marker</span>: <span class="ident">PhantomData</span>,
}
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Allocates `value` on the heap and returns a new owned pointer pointing to it.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Owned;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let o = Owned::new(1234);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">value</span>: <span class="ident">T</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="self">Self</span>::<span class="ident">from</span>(<span class="ident">Box</span>::<span class="ident">new</span>(<span class="ident">value</span>))
}
<span class="doccomment">/// Returns a new owned pointer pointing to `raw`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function is unsafe because improper use may lead to memory problems. Argument `raw`</span>
<span class="doccomment">/// must be a valid pointer. Also, a double-free may occur if the function is called twice on</span>
<span class="doccomment">/// the same raw pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Panics</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Panics if `raw` is not properly aligned.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Owned;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let o = unsafe { Owned::from_raw(Box::into_raw(Box::new(1234))) };</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">from_raw</span>(<span class="ident">raw</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">T</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="ident">ensure_aligned</span>(<span class="ident">raw</span>);
<span class="self">Self</span>::<span class="ident">from_usize</span>(<span class="ident">raw</span> <span class="kw">as</span> <span class="ident">usize</span>)
}
<span class="doccomment">/// Converts the owned pointer into a [`Shared`].</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Owned};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let o = Owned::new(1234);</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let p = o.into_shared(guard);</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Shared`]: struct.Shared.html</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">into_shared</span><span class="op"><</span><span class="lifetime">'g</span><span class="op">></span>(<span class="self">self</span>, <span class="kw">_</span>: <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">Guard</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">unsafe</span> { <span class="ident">Shared</span>::<span class="ident">from_usize</span>(<span class="self">self</span>.<span class="ident">into_usize</span>()) }
}
<span class="doccomment">/// Converts the owned pointer into a `Box`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Owned};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let o = Owned::new(1234);</span>
<span class="doccomment">/// let b: Box<i32> = o.into_box();</span>
<span class="doccomment">/// assert_eq!(*b, 1234);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">into_box</span>(<span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Box</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">let</span> (<span class="ident">raw</span>, <span class="kw">_</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>);
<span class="ident">mem</span>::<span class="ident">forget</span>(<span class="self">self</span>);
<span class="kw">unsafe</span> { <span class="ident">Box</span>::<span class="ident">from_raw</span>(<span class="ident">raw</span>) }
}
<span class="doccomment">/// Returns the tag stored within the pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Owned;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!(Owned::new(1234).tag(), 0);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">tag</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">usize</span> {
<span class="kw">let</span> (<span class="kw">_</span>, <span class="ident">tag</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>);
<span class="ident">tag</span>
}
<span class="doccomment">/// Returns the same pointer, but tagged with `tag`. `tag` is truncated to be fit into the</span>
<span class="doccomment">/// unused bits of the pointer to `T`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Owned;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let o = Owned::new(0u64);</span>
<span class="doccomment">/// assert_eq!(o.tag(), 0);</span>
<span class="doccomment">/// let o = o.with_tag(2);</span>
<span class="doccomment">/// assert_eq!(o.tag(), 2);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">with_tag</span>(<span class="self">self</span>, <span class="ident">tag</span>: <span class="ident">usize</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">let</span> <span class="ident">data</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">into_usize</span>();
<span class="kw">unsafe</span> { <span class="self">Self</span>::<span class="ident">from_usize</span>(<span class="ident">data_with_tag</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="ident">data</span>, <span class="ident">tag</span>)) }
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">Drop</span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">drop</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) {
<span class="kw">let</span> (<span class="ident">raw</span>, <span class="kw">_</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>);
<span class="kw">unsafe</span> {
<span class="ident">drop</span>(<span class="ident">Box</span>::<span class="ident">from_raw</span>(<span class="ident">raw</span>));
}
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-</span><span class="op">></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="kw">let</span> (<span class="ident">raw</span>, <span class="ident">tag</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>);
<span class="ident">f</span>.<span class="ident">debug_struct</span>(<span class="string">"Owned"</span>)
.<span class="ident">field</span>(<span class="string">"raw"</span>, <span class="kw-2">&</span><span class="ident">raw</span>)
.<span class="ident">field</span>(<span class="string">"tag"</span>, <span class="kw-2">&</span><span class="ident">tag</span>)
.<span class="ident">finish</span>()
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Clone</span><span class="op">></span> <span class="ident">Clone</span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">clone</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="ident">Owned</span>::<span class="ident">new</span>((<span class="kw-2">*</span><span class="kw-2">*</span><span class="self">self</span>).<span class="ident">clone</span>()).<span class="ident">with_tag</span>(<span class="self">self</span>.<span class="ident">tag</span>())
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">Deref</span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">type</span> <span class="ident">Target</span> <span class="op">=</span> <span class="ident">T</span>;
<span class="kw">fn</span> <span class="ident">deref</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="kw-2">&</span><span class="ident">T</span> {
<span class="kw">let</span> (<span class="ident">raw</span>, <span class="kw">_</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>);
<span class="kw">unsafe</span> { <span class="kw-2">&</span><span class="kw-2">*</span><span class="ident">raw</span> }
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">DerefMut</span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">deref_mut</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">T</span> {
<span class="kw">let</span> (<span class="ident">raw</span>, <span class="kw">_</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>);
<span class="kw">unsafe</span> { <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="kw-2">*</span><span class="ident">raw</span> }
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">From</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">t</span>: <span class="ident">T</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="ident">Owned</span>::<span class="ident">new</span>(<span class="ident">t</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">From</span><span class="op"><</span><span class="ident">Box</span><span class="op"><</span><span class="ident">T</span><span class="op">></span><span class="op">></span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Returns a new owned pointer pointing to `b`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Panics</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Panics if the pointer (the `Box`) is not properly aligned.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Owned;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let o = unsafe { Owned::from_raw(Box::into_raw(Box::new(1234))) };</span>
<span class="doccomment">/// ```</span>
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">b</span>: <span class="ident">Box</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="kw">unsafe</span> { <span class="self">Self</span>::<span class="ident">from_raw</span>(<span class="ident">Box</span>::<span class="ident">into_raw</span>(<span class="ident">b</span>)) }
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">Borrow</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">borrow</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="kw-2">&</span><span class="ident">T</span> {
<span class="kw-2">&</span><span class="kw-2">*</span><span class="kw-2">*</span><span class="self">self</span>
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">BorrowMut</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">borrow_mut</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">T</span> {
<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="kw-2">*</span><span class="kw-2">*</span><span class="self">self</span>
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">AsRef</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">as_ref</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="kw-2">&</span><span class="ident">T</span> {
<span class="kw-2">&</span><span class="kw-2">*</span><span class="kw-2">*</span><span class="self">self</span>
}
}
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">AsMut</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">as_mut</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">T</span> {
<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="kw-2">*</span><span class="kw-2">*</span><span class="self">self</span>
}
}
<span class="doccomment">/// A pointer to an object protected by the epoch GC.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The pointer is valid for use only during the lifetime `'g`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The pointer must be properly aligned. Since it is aligned, a tag can be stored into the unused</span>
<span class="doccomment">/// least significant bits of the address.</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span>: <span class="lifetime">'g</span><span class="op">></span> {
<span class="ident">data</span>: <span class="ident">usize</span>,
<span class="ident">_marker</span>: <span class="ident">PhantomData</span><span class="op"><</span>(<span class="kw-2">&</span><span class="lifetime">'g</span> (), <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">T</span>)<span class="op">></span>,
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">Clone</span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">clone</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="ident">Shared</span> {
<span class="ident">data</span>: <span class="self">self</span>.<span class="ident">data</span>,
<span class="ident">_marker</span>: <span class="ident">PhantomData</span>,
}
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">Copy</span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">Pointer</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">into_usize</span>(<span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">usize</span> {
<span class="self">self</span>.<span class="ident">data</span>
}
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">from_usize</span>(<span class="ident">data</span>: <span class="ident">usize</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="ident">Shared</span> {
<span class="ident">data</span>: <span class="ident">data</span>,
<span class="ident">_marker</span>: <span class="ident">PhantomData</span>,
}
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Returns a new null pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Shared;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let p = Shared::<i32>::null();</span>
<span class="doccomment">/// assert!(p.is_null());</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">null</span>() <span class="op">-</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="ident">Shared</span> {
<span class="ident">data</span>: <span class="number">0</span>,
<span class="ident">_marker</span>: <span class="ident">PhantomData</span>,
}
}
<span class="doccomment">/// Returns `true` if the pointer is null.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Owned};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::null();</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// assert!(a.load(SeqCst, guard).is_null());</span>
<span class="doccomment">/// a.store(Owned::new(1234), SeqCst);</span>
<span class="doccomment">/// assert!(!a.load(SeqCst, guard).is_null());</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">is_null</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">bool</span> {
<span class="self">self</span>.<span class="ident">as_raw</span>().<span class="ident">is_null</span>()
}
<span class="doccomment">/// Converts the pointer to a raw pointer (without the tag).</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Owned};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let o = Owned::new(1234);</span>
<span class="doccomment">/// let raw = &*o as *const _;</span>
<span class="doccomment">/// let a = Atomic::from(o);</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let p = a.load(SeqCst, guard);</span>
<span class="doccomment">/// assert_eq!(p.as_raw(), raw);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">as_raw</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">T</span> {
<span class="kw">let</span> (<span class="ident">raw</span>, <span class="kw">_</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>);
<span class="ident">raw</span>
}
<span class="doccomment">/// Dereferences the pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Returns a reference to the pointee that is valid during the lifetime `'g`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Safety</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Dereferencing a pointer is unsafe because it could be pointing to invalid memory.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Another concern is the possiblity of data races due to lack of proper synchronization.</span>
<span class="doccomment">/// For example, consider the following scenario:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// 1. A thread creates a new object: `a.store(Owned::new(10), Relaxed)`</span>
<span class="doccomment">/// 2. Another thread reads it: `*a.load(Relaxed, guard).as_ref().unwrap()`</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The problem is that relaxed orderings don't synchronize initialization of the object with</span>
<span class="doccomment">/// the read from the second thread. This is a data race. A possible solution would be to use</span>
<span class="doccomment">/// `Release` and `Acquire` orderings.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let p = a.load(SeqCst, guard);</span>
<span class="doccomment">/// unsafe {</span>
<span class="doccomment">/// assert_eq!(p.deref(), &1234);</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">deref</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">T</span> {
<span class="kw-2">&</span><span class="kw-2">*</span><span class="self">self</span>.<span class="ident">as_raw</span>()
}
<span class="doccomment">/// Dereferences the pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Returns a mutable reference to the pointee that is valid during the lifetime `'g`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Safety</span>
<span class="doccomment">///</span>
<span class="doccomment">/// * There is no guarantee that there are no more threads attempting to read/write from/to the</span>
<span class="doccomment">/// actual object at the same time.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The user must know that there are no concurrent accesses towards the object itself.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// * Other than the above, all safety concerns of `deref()` applies here.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(vec![1, 2, 3, 4]);</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let mut p = a.load(SeqCst, guard);</span>
<span class="doccomment">/// unsafe {</span>
<span class="doccomment">/// assert!(!p.is_null());</span>
<span class="doccomment">/// let b = p.deref_mut();</span>
<span class="doccomment">/// assert_eq!(b, &vec![1, 2, 3, 4]);</span>
<span class="doccomment">/// b.push(5);</span>
<span class="doccomment">/// assert_eq!(b, &vec![1, 2, 3, 4, 5]);</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let p = a.load(SeqCst, guard);</span>
<span class="doccomment">/// unsafe {</span>
<span class="doccomment">/// assert_eq!(p.deref(), &vec![1, 2, 3, 4, 5]);</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">deref_mut</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="kw-2">&</span><span class="lifetime">'g</span> <span class="kw-2">mut</span> <span class="ident">T</span> {
<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="kw-2">*</span>(<span class="self">self</span>.<span class="ident">as_raw</span>() <span class="kw">as</span> <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">T</span>)
}
<span class="doccomment">/// Converts the pointer to a reference.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Returns `None` if the pointer is null, or else a reference to the object wrapped in `Some`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Safety</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Dereferencing a pointer is unsafe because it could be pointing to invalid memory.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Another concern is the possiblity of data races due to lack of proper synchronization.</span>
<span class="doccomment">/// For example, consider the following scenario:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// 1. A thread creates a new object: `a.store(Owned::new(10), Relaxed)`</span>
<span class="doccomment">/// 2. Another thread reads it: `*a.load(Relaxed, guard).as_ref().unwrap()`</span>
<span class="doccomment">///</span>
<span class="doccomment">/// The problem is that relaxed orderings don't synchronize initialization of the object with</span>
<span class="doccomment">/// the read from the second thread. This is a data race. A possible solution would be to use</span>
<span class="doccomment">/// `Release` and `Acquire` orderings.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let p = a.load(SeqCst, guard);</span>
<span class="doccomment">/// unsafe {</span>
<span class="doccomment">/// assert_eq!(p.as_ref(), Some(&1234));</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">as_ref</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="kw-2">&</span><span class="lifetime">'g</span> <span class="ident">T</span><span class="op">></span> {
<span class="self">self</span>.<span class="ident">as_raw</span>().<span class="ident">as_ref</span>()
}
<span class="doccomment">/// Takes ownership of the pointee.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Panics</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Panics if this pointer is null, but only in debug mode.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Safety</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This method may be called only if the pointer is valid and nobody else is holding a</span>
<span class="doccomment">/// reference to the same object.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(1234);</span>
<span class="doccomment">/// unsafe {</span>
<span class="doccomment">/// let guard = &epoch::unprotected();</span>
<span class="doccomment">/// let p = a.load(SeqCst, guard);</span>
<span class="doccomment">/// drop(p.into_owned());</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">into_owned</span>(<span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Owned</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> {
<span class="macro">debug_assert</span><span class="macro">!</span>(
<span class="self">self</span>.<span class="ident">as_raw</span>() <span class="op">!</span><span class="op">=</span> <span class="ident">ptr</span>::<span class="ident">null</span>(),
<span class="string">"converting a null `Shared` into `Owned`"</span>
);
<span class="ident">Owned</span>::<span class="ident">from_usize</span>(<span class="self">self</span>.<span class="ident">data</span>)
}
<span class="doccomment">/// Returns the tag stored within the pointer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic, Owned};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::<u64>::from(Owned::new(0u64).with_tag(2));</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let p = a.load(SeqCst, guard);</span>
<span class="doccomment">/// assert_eq!(p.tag(), 2);</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">tag</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">usize</span> {
<span class="kw">let</span> (<span class="kw">_</span>, <span class="ident">tag</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>);
<span class="ident">tag</span>
}
<span class="doccomment">/// Returns the same pointer, but tagged with `tag`. `tag` is truncated to be fit into the</span>
<span class="doccomment">/// unused bits of the pointer to `T`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::{self as epoch, Atomic};</span>
<span class="doccomment">/// use std::sync::atomic::Ordering::SeqCst;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let a = Atomic::new(0u64);</span>
<span class="doccomment">/// let guard = &epoch::pin();</span>
<span class="doccomment">/// let p1 = a.load(SeqCst, guard);</span>
<span class="doccomment">/// let p2 = p1.with_tag(2);</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!(p1.tag(), 0);</span>
<span class="doccomment">/// assert_eq!(p2.tag(), 2);</span>
<span class="doccomment">/// assert_eq!(p1.as_raw(), p2.as_raw());</span>
<span class="doccomment">/// ```</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">with_tag</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">tag</span>: <span class="ident">usize</span>) <span class="op">-</span><span class="op">></span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">unsafe</span> { <span class="self">Self</span>::<span class="ident">from_usize</span>(<span class="ident">data_with_tag</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>, <span class="ident">tag</span>)) }
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">From</span><span class="op"><</span><span class="kw-2">*</span><span class="kw">const</span> <span class="ident">T</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="doccomment">/// Returns a new pointer pointing to `raw`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Panics</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Panics if `raw` is not properly aligned.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use crossbeam_epoch::Shared;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let p = unsafe { Shared::from(Box::into_raw(Box::new(1234)) as *const _) };</span>
<span class="doccomment">/// assert!(!p.is_null());</span>
<span class="doccomment">/// ```</span>
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">raw</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">T</span>) <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="ident">ensure_aligned</span>(<span class="ident">raw</span>);
<span class="kw">unsafe</span> { <span class="self">Self</span>::<span class="ident">from_usize</span>(<span class="ident">raw</span> <span class="kw">as</span> <span class="ident">usize</span>) }
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">PartialEq</span><span class="op"><</span><span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span><span class="op">></span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">eq</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">other</span>: <span class="kw-2">&</span><span class="self">Self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">bool</span> {
<span class="self">self</span>.<span class="ident">data</span> <span class="op">=</span><span class="op">=</span> <span class="ident">other</span>.<span class="ident">data</span>
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">Eq</span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">PartialOrd</span><span class="op"><</span><span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span><span class="op">></span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">partial_cmp</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">other</span>: <span class="kw-2">&</span><span class="self">Self</span>) <span class="op">-</span><span class="op">></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">cmp</span>::<span class="ident">Ordering</span><span class="op">></span> {
<span class="self">self</span>.<span class="ident">data</span>.<span class="ident">partial_cmp</span>(<span class="kw-2">&</span><span class="ident">other</span>.<span class="ident">data</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">Ord</span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">cmp</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">other</span>: <span class="kw-2">&</span><span class="self">Self</span>) <span class="op">-</span><span class="op">></span> <span class="ident">cmp</span>::<span class="ident">Ordering</span> {
<span class="self">self</span>.<span class="ident">data</span>.<span class="ident">cmp</span>(<span class="kw-2">&</span><span class="ident">other</span>.<span class="ident">data</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-</span><span class="op">></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="kw">let</span> (<span class="ident">raw</span>, <span class="ident">tag</span>) <span class="op">=</span> <span class="ident">decompose_data</span>::<span class="op"><</span><span class="ident">T</span><span class="op">></span>(<span class="self">self</span>.<span class="ident">data</span>);
<span class="ident">f</span>.<span class="ident">debug_struct</span>(<span class="string">"Shared"</span>)
.<span class="ident">field</span>(<span class="string">"raw"</span>, <span class="kw-2">&</span><span class="ident">raw</span>)
.<span class="ident">field</span>(<span class="string">"tag"</span>, <span class="kw-2">&</span><span class="ident">tag</span>)
.<span class="ident">finish</span>()
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">fmt</span>::<span class="ident">Pointer</span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-</span><span class="op">></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="ident">fmt</span>::<span class="ident">Pointer</span>::<span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>.<span class="ident">as_raw</span>(), <span class="ident">f</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> <span class="ident">Default</span> <span class="kw">for</span> <span class="ident">Shared</span><span class="op"><</span><span class="lifetime">'g</span>, <span class="ident">T</span><span class="op">></span> {
<span class="kw">fn</span> <span class="ident">default</span>() <span class="op">-</span><span class="op">></span> <span class="self">Self</span> {
<span class="ident">Shared</span>::<span class="ident">null</span>()
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span>
<span class="kw">mod</span> <span class="ident">tests</span> {
<span class="kw">use</span> <span class="kw">super</span>::<span class="ident">Shared</span>;
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">valid_tag_i8</span>() {
<span class="ident">Shared</span>::<span class="op"><</span><span class="ident">i8</span><span class="op">></span>::<span class="ident">null</span>().<span class="ident">with_tag</span>(<span class="number">0</span>);
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">valid_tag_i64</span>() {
<span class="ident">Shared</span>::<span class="op"><</span><span class="ident">i64</span><span class="op">></span>::<span class="ident">null</span>().<span class="ident">with_tag</span>(<span class="number">7</span>);
}
}
</pre></div>
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