| <!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 of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.28.2/src/io/split.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>split.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../../tokio/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../tokio/index.html"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="doccomment">//! Split a single value implementing `AsyncRead + AsyncWrite` into separate |
| //! `AsyncRead` and `AsyncWrite` handles. |
| //! |
| //! To restore this read/write object from its `split::ReadHalf` and |
| //! `split::WriteHalf` use `unsplit`. |
| |
| </span><span class="kw">use </span><span class="kw">crate</span>::io::{AsyncRead, AsyncWrite, ReadBuf}; |
| |
| <span class="kw">use </span>std::cell::UnsafeCell; |
| <span class="kw">use </span>std::fmt; |
| <span class="kw">use </span>std::io; |
| <span class="kw">use </span>std::pin::Pin; |
| <span class="kw">use </span>std::sync::atomic::AtomicBool; |
| <span class="kw">use </span>std::sync::atomic::Ordering::{Acquire, Release}; |
| <span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>std::task::{Context, Poll}; |
| |
| <span class="macro">cfg_io_util! </span>{ |
| <span class="doccomment">/// The readable half of a value returned from [`split`](split()). |
| </span><span class="kw">pub struct </span>ReadHalf<T> { |
| inner: Arc<Inner<T>>, |
| } |
| |
| <span class="doccomment">/// The writable half of a value returned from [`split`](split()). |
| </span><span class="kw">pub struct </span>WriteHalf<T> { |
| inner: Arc<Inner<T>>, |
| } |
| |
| <span class="doccomment">/// Splits a single value implementing `AsyncRead + AsyncWrite` into separate |
| /// `AsyncRead` and `AsyncWrite` handles. |
| /// |
| /// To restore this read/write object from its `ReadHalf` and |
| /// `WriteHalf` use [`unsplit`](ReadHalf::unsplit()). |
| </span><span class="kw">pub fn </span>split<T>(stream: T) -> (ReadHalf<T>, WriteHalf<T>) |
| <span class="kw">where |
| </span>T: AsyncRead + AsyncWrite, |
| { |
| <span class="kw">let </span>inner = Arc::new(Inner { |
| locked: AtomicBool::new(<span class="bool-val">false</span>), |
| stream: UnsafeCell::new(stream), |
| }); |
| |
| <span class="kw">let </span>rd = ReadHalf { |
| inner: inner.clone(), |
| }; |
| |
| <span class="kw">let </span>wr = WriteHalf { inner }; |
| |
| (rd, wr) |
| } |
| } |
| |
| <span class="kw">struct </span>Inner<T> { |
| locked: AtomicBool, |
| stream: UnsafeCell<T>, |
| } |
| |
| <span class="kw">struct </span>Guard<<span class="lifetime">'a</span>, T> { |
| inner: <span class="kw-2">&</span><span class="lifetime">'a </span>Inner<T>, |
| } |
| |
| <span class="kw">impl</span><T> ReadHalf<T> { |
| <span class="doccomment">/// Checks if this `ReadHalf` and some `WriteHalf` were split from the same |
| /// stream. |
| </span><span class="kw">pub fn </span>is_pair_of(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span>WriteHalf<T>) -> bool { |
| other.is_pair_of(<span class="self">self</span>) |
| } |
| |
| <span class="doccomment">/// Reunites with a previously split `WriteHalf`. |
| /// |
| /// # Panics |
| /// |
| /// If this `ReadHalf` and the given `WriteHalf` do not originate from the |
| /// same `split` operation this method will panic. |
| /// This can be checked ahead of time by comparing the stream ID |
| /// of the two halves. |
| </span><span class="attribute">#[track_caller] |
| </span><span class="kw">pub fn </span>unsplit(<span class="self">self</span>, wr: WriteHalf<T>) -> T |
| <span class="kw">where |
| </span>T: Unpin, |
| { |
| <span class="kw">if </span><span class="self">self</span>.is_pair_of(<span class="kw-2">&</span>wr) { |
| drop(wr); |
| |
| <span class="kw">let </span>inner = Arc::try_unwrap(<span class="self">self</span>.inner) |
| .ok() |
| .expect(<span class="string">"`Arc::try_unwrap` failed"</span>); |
| |
| inner.stream.into_inner() |
| } <span class="kw">else </span>{ |
| <span class="macro">panic!</span>(<span class="string">"Unrelated `split::Write` passed to `split::Read::unsplit`."</span>) |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><T> WriteHalf<T> { |
| <span class="doccomment">/// Checks if this `WriteHalf` and some `ReadHalf` were split from the same |
| /// stream. |
| </span><span class="kw">pub fn </span>is_pair_of(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span>ReadHalf<T>) -> bool { |
| Arc::ptr_eq(<span class="kw-2">&</span><span class="self">self</span>.inner, <span class="kw-2">&</span>other.inner) |
| } |
| } |
| |
| <span class="kw">impl</span><T: AsyncRead> AsyncRead <span class="kw">for </span>ReadHalf<T> { |
| <span class="kw">fn </span>poll_read( |
| <span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, |
| cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>, |
| buf: <span class="kw-2">&mut </span>ReadBuf<<span class="lifetime">'_</span>>, |
| ) -> Poll<io::Result<()>> { |
| <span class="kw">let </span><span class="kw-2">mut </span>inner = <span class="macro">ready!</span>(<span class="self">self</span>.inner.poll_lock(cx)); |
| inner.stream_pin().poll_read(cx, buf) |
| } |
| } |
| |
| <span class="kw">impl</span><T: AsyncWrite> AsyncWrite <span class="kw">for </span>WriteHalf<T> { |
| <span class="kw">fn </span>poll_write( |
| <span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, |
| cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>, |
| buf: <span class="kw-2">&</span>[u8], |
| ) -> Poll<<span class="prelude-ty">Result</span><usize, io::Error>> { |
| <span class="kw">let </span><span class="kw-2">mut </span>inner = <span class="macro">ready!</span>(<span class="self">self</span>.inner.poll_lock(cx)); |
| inner.stream_pin().poll_write(cx, buf) |
| } |
| |
| <span class="kw">fn </span>poll_flush(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<<span class="prelude-ty">Result</span><(), io::Error>> { |
| <span class="kw">let </span><span class="kw-2">mut </span>inner = <span class="macro">ready!</span>(<span class="self">self</span>.inner.poll_lock(cx)); |
| inner.stream_pin().poll_flush(cx) |
| } |
| |
| <span class="kw">fn </span>poll_shutdown(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<<span class="prelude-ty">Result</span><(), io::Error>> { |
| <span class="kw">let </span><span class="kw-2">mut </span>inner = <span class="macro">ready!</span>(<span class="self">self</span>.inner.poll_lock(cx)); |
| inner.stream_pin().poll_shutdown(cx) |
| } |
| } |
| |
| <span class="kw">impl</span><T> Inner<T> { |
| <span class="kw">fn </span>poll_lock(<span class="kw-2">&</span><span class="self">self</span>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<Guard<<span class="lifetime">'_</span>, T>> { |
| <span class="kw">if </span><span class="self">self |
| </span>.locked |
| .compare_exchange(<span class="bool-val">false</span>, <span class="bool-val">true</span>, Acquire, Acquire) |
| .is_ok() |
| { |
| Poll::Ready(Guard { inner: <span class="self">self </span>}) |
| } <span class="kw">else </span>{ |
| <span class="comment">// Spin... but investigate a better strategy |
| |
| </span>std::thread::yield_now(); |
| cx.waker().wake_by_ref(); |
| |
| Poll::Pending |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><T> Guard<<span class="lifetime">'_</span>, T> { |
| <span class="kw">fn </span>stream_pin(<span class="kw-2">&mut </span><span class="self">self</span>) -> Pin<<span class="kw-2">&mut </span>T> { |
| <span class="comment">// safety: the stream is pinned in `Arc` and the `Guard` ensures mutual |
| // exclusion. |
| </span><span class="kw">unsafe </span>{ Pin::new_unchecked(<span class="kw-2">&mut *</span><span class="self">self</span>.inner.stream.get()) } |
| } |
| } |
| |
| <span class="kw">impl</span><T> Drop <span class="kw">for </span>Guard<<span class="lifetime">'_</span>, T> { |
| <span class="kw">fn </span>drop(<span class="kw-2">&mut </span><span class="self">self</span>) { |
| <span class="self">self</span>.inner.locked.store(<span class="bool-val">false</span>, Release); |
| } |
| } |
| |
| <span class="kw">unsafe impl</span><T: Send> Send <span class="kw">for </span>ReadHalf<T> {} |
| <span class="kw">unsafe impl</span><T: Send> Send <span class="kw">for </span>WriteHalf<T> {} |
| <span class="kw">unsafe impl</span><T: Sync> Sync <span class="kw">for </span>ReadHalf<T> {} |
| <span class="kw">unsafe impl</span><T: Sync> Sync <span class="kw">for </span>WriteHalf<T> {} |
| |
| <span class="kw">impl</span><T: fmt::Debug> fmt::Debug <span class="kw">for </span>ReadHalf<T> { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, fmt: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { |
| fmt.debug_struct(<span class="string">"split::ReadHalf"</span>).finish() |
| } |
| } |
| |
| <span class="kw">impl</span><T: fmt::Debug> fmt::Debug <span class="kw">for </span>WriteHalf<T> { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, fmt: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { |
| fmt.debug_struct(<span class="string">"split::WriteHalf"</span>).finish() |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="tokio" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
