<!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 `libstd/sys/unix/fd.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>fd.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><link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico"></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='../../../../std/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></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"><input class="search-input" name="search" autocomplete="off" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><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><pre class="rust ">
<span class="comment">// Copyright 2015 The Rust Project Developers. See the COPYRIGHT</span>
<span class="comment">// file at the top-level directory of this distribution and at</span>
<span class="comment">// http://rust-lang.org/COPYRIGHT.</span>
<span class="comment">//</span>
<span class="comment">// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or</span>
<span class="comment">// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license</span>
<span class="comment">// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your</span>
<span class="comment">// option. This file may not be copied, modified, or distributed</span>
<span class="comment">// except according to those terms.</span>
<span class="attribute">#![<span class="ident">unstable</span>(<span class="ident">reason</span> <span class="op">=</span> <span class="string">"not public"</span>, <span class="ident">issue</span> <span class="op">=</span> <span class="string">"0"</span>, <span class="ident">feature</span> <span class="op">=</span> <span class="string">"fd"</span>)]</span>
<span class="kw">use</span> <span class="ident">cmp</span>;
<span class="kw">use</span> <span class="ident">io</span>::{<span class="self">self</span>, <span class="ident">Read</span>};
<span class="kw">use</span> <span class="ident">libc</span>::{<span class="self">self</span>, <span class="ident">c_int</span>, <span class="ident">c_void</span>, <span class="ident">ssize_t</span>};
<span class="kw">use</span> <span class="ident">mem</span>;
<span class="kw">use</span> <span class="ident">sync</span>::<span class="ident">atomic</span>::{<span class="ident">AtomicBool</span>, <span class="ident">Ordering</span>};
<span class="kw">use</span> <span class="ident">sys</span>::<span class="ident">cvt</span>;
<span class="kw">use</span> <span class="ident">sys_common</span>::<span class="ident">AsInner</span>;
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">FileDesc</span> {
<span class="ident">fd</span>: <span class="ident">c_int</span>,
}
<span class="kw">fn</span> <span class="ident">max_len</span>() <span class="op">-></span> <span class="ident">usize</span> {
<span class="comment">// The maximum read limit on most posix-like systems is `SSIZE_MAX`,</span>
<span class="comment">// with the man page quoting that if the count of bytes to read is</span>
<span class="comment">// greater than `SSIZE_MAX` the result is "unspecified".</span>
<span class="comment">//</span>
<span class="comment">// On macOS, however, apparently the 64-bit libc is either buggy or</span>
<span class="comment">// intentionally showing odd behavior by rejecting any read with a size</span>
<span class="comment">// larger than or equal to INT_MAX. To handle both of these the read</span>
<span class="comment">// size is capped on both platforms.</span>
<span class="kw">if</span> <span class="macro">cfg</span><span class="macro">!</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"macos"</span>) {
<span class="op"><</span><span class="ident">c_int</span><span class="op">></span>::<span class="ident">max_value</span>() <span class="kw">as</span> <span class="ident">usize</span> <span class="op">-</span> <span class="number">1</span>
} <span class="kw">else</span> {
<span class="op"><</span><span class="ident">ssize_t</span><span class="op">></span>::<span class="ident">max_value</span>() <span class="kw">as</span> <span class="ident">usize</span>
}
}
<span class="kw">impl</span> <span class="ident">FileDesc</span> {
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">fd</span>: <span class="ident">c_int</span>) <span class="op">-></span> <span class="ident">FileDesc</span> {
<span class="ident">FileDesc</span> { <span class="ident">fd</span>: <span class="ident">fd</span> }
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">raw</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">c_int</span> { <span class="self">self</span>.<span class="ident">fd</span> }
<span class="doccomment">/// Extracts the actual filedescriptor without closing it.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">into_raw</span>(<span class="self">self</span>) <span class="op">-></span> <span class="ident">c_int</span> {
<span class="kw">let</span> <span class="ident">fd</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">fd</span>;
<span class="ident">mem</span>::<span class="ident">forget</span>(<span class="self">self</span>);
<span class="ident">fd</span>
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">read</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">buf</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">u8</span>]) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">usize</span><span class="op">></span> {
<span class="kw">let</span> <span class="ident">ret</span> <span class="op">=</span> <span class="ident">cvt</span>(<span class="kw">unsafe</span> {
<span class="ident">libc</span>::<span class="ident">read</span>(<span class="self">self</span>.<span class="ident">fd</span>,
<span class="ident">buf</span>.<span class="ident">as_mut_ptr</span>() <span class="kw">as</span> <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>,
<span class="ident">cmp</span>::<span class="ident">min</span>(<span class="ident">buf</span>.<span class="ident">len</span>(), <span class="ident">max_len</span>()))
})<span class="question-mark">?</span>;
<span class="prelude-val">Ok</span>(<span class="ident">ret</span> <span class="kw">as</span> <span class="ident">usize</span>)
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">read_to_end</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">buf</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">Vec</span><span class="op"><</span><span class="ident">u8</span><span class="op">></span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">usize</span><span class="op">></span> {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">me</span> <span class="op">=</span> <span class="self">self</span>;
(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">me</span>).<span class="ident">read_to_end</span>(<span class="ident">buf</span>)
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">read_at</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">buf</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">u8</span>], <span class="ident">offset</span>: <span class="ident">u64</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">usize</span><span class="op">></span> {
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"android"</span>)]</span>
<span class="kw">use</span> <span class="kw">super</span>::<span class="ident">android</span>::<span class="ident">cvt_pread64</span>;
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>)]</span>
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">cvt_pread64</span>(<span class="ident">fd</span>: <span class="ident">c_int</span>, <span class="ident">buf</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>, <span class="ident">count</span>: <span class="ident">usize</span>, <span class="ident">offset</span>: <span class="ident">i64</span>)
<span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">isize</span><span class="op">></span>
{
<span class="kw">use</span> <span class="ident">convert</span>::<span class="ident">TryInto</span>;
<span class="kw">use</span> <span class="ident">libc</span>::<span class="ident">pread64</span>;
<span class="comment">// pread64 on emscripten actually takes a 32 bit offset</span>
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Ok</span>(<span class="ident">o</span>) <span class="op">=</span> <span class="ident">offset</span>.<span class="ident">try_into</span>() {
<span class="ident">cvt</span>(<span class="ident">pread64</span>(<span class="ident">fd</span>, <span class="ident">buf</span>, <span class="ident">count</span>, <span class="ident">o</span>))
} <span class="kw">else</span> {
<span class="prelude-val">Err</span>(<span class="ident">io</span>::<span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">io</span>::<span class="ident">ErrorKind</span>::<span class="ident">InvalidInput</span>,
<span class="string">"cannot pread >2GB"</span>))
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">not</span>(<span class="ident">any</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"android"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>)))]</span>
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">cvt_pread64</span>(<span class="ident">fd</span>: <span class="ident">c_int</span>, <span class="ident">buf</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>, <span class="ident">count</span>: <span class="ident">usize</span>, <span class="ident">offset</span>: <span class="ident">i64</span>)
<span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">isize</span><span class="op">></span>
{
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"linux"</span>)]</span>
<span class="kw">use</span> <span class="ident">libc</span>::<span class="ident">pread64</span>;
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">not</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"linux"</span>))]</span>
<span class="kw">use</span> <span class="ident">libc</span>::<span class="ident">pread</span> <span class="kw">as</span> <span class="ident">pread64</span>;
<span class="ident">cvt</span>(<span class="ident">pread64</span>(<span class="ident">fd</span>, <span class="ident">buf</span>, <span class="ident">count</span>, <span class="ident">offset</span>))
}
<span class="kw">unsafe</span> {
<span class="ident">cvt_pread64</span>(<span class="self">self</span>.<span class="ident">fd</span>,
<span class="ident">buf</span>.<span class="ident">as_mut_ptr</span>() <span class="kw">as</span> <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>,
<span class="ident">cmp</span>::<span class="ident">min</span>(<span class="ident">buf</span>.<span class="ident">len</span>(), <span class="ident">max_len</span>()),
<span class="ident">offset</span> <span class="kw">as</span> <span class="ident">i64</span>)
.<span class="ident">map</span>(<span class="op">|</span><span class="ident">n</span><span class="op">|</span> <span class="ident">n</span> <span class="kw">as</span> <span class="ident">usize</span>)
}
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">write</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">buf</span>: <span class="kw-2">&</span>[<span class="ident">u8</span>]) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">usize</span><span class="op">></span> {
<span class="kw">let</span> <span class="ident">ret</span> <span class="op">=</span> <span class="ident">cvt</span>(<span class="kw">unsafe</span> {
<span class="ident">libc</span>::<span class="ident">write</span>(<span class="self">self</span>.<span class="ident">fd</span>,
<span class="ident">buf</span>.<span class="ident">as_ptr</span>() <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">c_void</span>,
<span class="ident">cmp</span>::<span class="ident">min</span>(<span class="ident">buf</span>.<span class="ident">len</span>(), <span class="ident">max_len</span>()))
})<span class="question-mark">?</span>;
<span class="prelude-val">Ok</span>(<span class="ident">ret</span> <span class="kw">as</span> <span class="ident">usize</span>)
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">write_at</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">buf</span>: <span class="kw-2">&</span>[<span class="ident">u8</span>], <span class="ident">offset</span>: <span class="ident">u64</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">usize</span><span class="op">></span> {
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"android"</span>)]</span>
<span class="kw">use</span> <span class="kw">super</span>::<span class="ident">android</span>::<span class="ident">cvt_pwrite64</span>;
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>)]</span>
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">cvt_pwrite64</span>(<span class="ident">fd</span>: <span class="ident">c_int</span>, <span class="ident">buf</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">c_void</span>, <span class="ident">count</span>: <span class="ident">usize</span>, <span class="ident">offset</span>: <span class="ident">i64</span>)
<span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">isize</span><span class="op">></span>
{
<span class="kw">use</span> <span class="ident">convert</span>::<span class="ident">TryInto</span>;
<span class="kw">use</span> <span class="ident">libc</span>::<span class="ident">pwrite64</span>;
<span class="comment">// pwrite64 on emscripten actually takes a 32 bit offset</span>
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Ok</span>(<span class="ident">o</span>) <span class="op">=</span> <span class="ident">offset</span>.<span class="ident">try_into</span>() {
<span class="ident">cvt</span>(<span class="ident">pwrite64</span>(<span class="ident">fd</span>, <span class="ident">buf</span>, <span class="ident">count</span>, <span class="ident">o</span>))
} <span class="kw">else</span> {
<span class="prelude-val">Err</span>(<span class="ident">io</span>::<span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">io</span>::<span class="ident">ErrorKind</span>::<span class="ident">InvalidInput</span>,
<span class="string">"cannot pwrite >2GB"</span>))
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">not</span>(<span class="ident">any</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"android"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>)))]</span>
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">cvt_pwrite64</span>(<span class="ident">fd</span>: <span class="ident">c_int</span>, <span class="ident">buf</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">c_void</span>, <span class="ident">count</span>: <span class="ident">usize</span>, <span class="ident">offset</span>: <span class="ident">i64</span>)
<span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">isize</span><span class="op">></span>
{
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"linux"</span>)]</span>
<span class="kw">use</span> <span class="ident">libc</span>::<span class="ident">pwrite64</span>;
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">not</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"linux"</span>))]</span>
<span class="kw">use</span> <span class="ident">libc</span>::<span class="ident">pwrite</span> <span class="kw">as</span> <span class="ident">pwrite64</span>;
<span class="ident">cvt</span>(<span class="ident">pwrite64</span>(<span class="ident">fd</span>, <span class="ident">buf</span>, <span class="ident">count</span>, <span class="ident">offset</span>))
}
<span class="kw">unsafe</span> {
<span class="ident">cvt_pwrite64</span>(<span class="self">self</span>.<span class="ident">fd</span>,
<span class="ident">buf</span>.<span class="ident">as_ptr</span>() <span class="kw">as</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">c_void</span>,
<span class="ident">cmp</span>::<span class="ident">min</span>(<span class="ident">buf</span>.<span class="ident">len</span>(), <span class="ident">max_len</span>()),
<span class="ident">offset</span> <span class="kw">as</span> <span class="ident">i64</span>)
.<span class="ident">map</span>(<span class="op">|</span><span class="ident">n</span><span class="op">|</span> <span class="ident">n</span> <span class="kw">as</span> <span class="ident">usize</span>)
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"linux"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">get_cloexec</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">bool</span><span class="op">></span> {
<span class="kw">unsafe</span> {
<span class="prelude-val">Ok</span>((<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">fcntl</span>(<span class="self">self</span>.<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">F_GETFD</span>))<span class="question-mark">?</span> <span class="op">&</span> <span class="ident">libc</span>::<span class="ident">FD_CLOEXEC</span>) <span class="op">!=</span> <span class="number">0</span>)
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">not</span>(<span class="ident">any</span>(<span class="ident">target_env</span> <span class="op">=</span> <span class="string">"newlib"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"solaris"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"fuchsia"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"l4re"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"haiku"</span>)))]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">set_cloexec</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span>()<span class="op">></span> {
<span class="kw">unsafe</span> {
<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">ioctl</span>(<span class="self">self</span>.<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">FIOCLEX</span>))<span class="question-mark">?</span>;
<span class="prelude-val">Ok</span>(())
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">any</span>(<span class="ident">target_env</span> <span class="op">=</span> <span class="string">"newlib"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"solaris"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"emscripten"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"fuchsia"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"l4re"</span>,
<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"haiku"</span>))]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">set_cloexec</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span>()<span class="op">></span> {
<span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="ident">previous</span> <span class="op">=</span> <span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">fcntl</span>(<span class="self">self</span>.<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">F_GETFD</span>))<span class="question-mark">?</span>;
<span class="kw">let</span> <span class="ident">new</span> <span class="op">=</span> <span class="ident">previous</span> <span class="op">|</span> <span class="ident">libc</span>::<span class="ident">FD_CLOEXEC</span>;
<span class="kw">if</span> <span class="ident">new</span> <span class="op">!=</span> <span class="ident">previous</span> {
<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">fcntl</span>(<span class="self">self</span>.<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">F_SETFD</span>, <span class="ident">new</span>))<span class="question-mark">?</span>;
}
<span class="prelude-val">Ok</span>(())
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"linux"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">set_nonblocking</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">nonblocking</span>: <span class="ident">bool</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span>()<span class="op">></span> {
<span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="ident">v</span> <span class="op">=</span> <span class="ident">nonblocking</span> <span class="kw">as</span> <span class="ident">c_int</span>;
<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">ioctl</span>(<span class="self">self</span>.<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">FIONBIO</span>, <span class="kw-2">&</span><span class="ident">v</span>))<span class="question-mark">?</span>;
<span class="prelude-val">Ok</span>(())
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">not</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"linux"</span>))]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">set_nonblocking</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">nonblocking</span>: <span class="ident">bool</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span>()<span class="op">></span> {
<span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="ident">previous</span> <span class="op">=</span> <span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">fcntl</span>(<span class="self">self</span>.<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">F_GETFL</span>))<span class="question-mark">?</span>;
<span class="kw">let</span> <span class="ident">new</span> <span class="op">=</span> <span class="kw">if</span> <span class="ident">nonblocking</span> {
<span class="ident">previous</span> <span class="op">|</span> <span class="ident">libc</span>::<span class="ident">O_NONBLOCK</span>
} <span class="kw">else</span> {
<span class="ident">previous</span> <span class="op">&</span> <span class="op">!</span><span class="ident">libc</span>::<span class="ident">O_NONBLOCK</span>
};
<span class="kw">if</span> <span class="ident">new</span> <span class="op">!=</span> <span class="ident">previous</span> {
<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">fcntl</span>(<span class="self">self</span>.<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">F_SETFL</span>, <span class="ident">new</span>))<span class="question-mark">?</span>;
}
<span class="prelude-val">Ok</span>(())
}
}
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">duplicate</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">FileDesc</span><span class="op">></span> {
<span class="comment">// We want to atomically duplicate this file descriptor and set the</span>
<span class="comment">// CLOEXEC flag, and currently that's done via F_DUPFD_CLOEXEC. This</span>
<span class="comment">// flag, however, isn't supported on older Linux kernels (earlier than</span>
<span class="comment">// 2.6.24).</span>
<span class="comment">//</span>
<span class="comment">// To detect this and ensure that CLOEXEC is still set, we</span>
<span class="comment">// follow a strategy similar to musl [1] where if passing</span>
<span class="comment">// F_DUPFD_CLOEXEC causes `fcntl` to return EINVAL it means it's not</span>
<span class="comment">// supported (the third parameter, 0, is always valid), so we stop</span>
<span class="comment">// trying that.</span>
<span class="comment">//</span>
<span class="comment">// Also note that Android doesn't have F_DUPFD_CLOEXEC, but get it to</span>
<span class="comment">// resolve so we at least compile this.</span>
<span class="comment">//</span>
<span class="comment">// [1]: http://comments.gmane.org/gmane.linux.lib.musl.general/2963</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">any</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"android"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"haiku"</span>))]</span>
<span class="kw">use</span> <span class="ident">libc</span>::<span class="ident">F_DUPFD</span> <span class="kw">as</span> <span class="ident">F_DUPFD_CLOEXEC</span>;
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">not</span>(<span class="ident">any</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"android"</span>, <span class="ident">target_os</span><span class="op">=</span><span class="string">"haiku"</span>)))]</span>
<span class="kw">use</span> <span class="ident">libc</span>::<span class="ident">F_DUPFD_CLOEXEC</span>;
<span class="kw">let</span> <span class="ident">make_filedesc</span> <span class="op">=</span> <span class="op">|</span><span class="ident">fd</span><span class="op">|</span> {
<span class="kw">let</span> <span class="ident">fd</span> <span class="op">=</span> <span class="ident">FileDesc</span>::<span class="ident">new</span>(<span class="ident">fd</span>);
<span class="ident">fd</span>.<span class="ident">set_cloexec</span>()<span class="question-mark">?</span>;
<span class="prelude-val">Ok</span>(<span class="ident">fd</span>)
};
<span class="kw">static</span> <span class="ident">TRY_CLOEXEC</span>: <span class="ident">AtomicBool</span> <span class="op">=</span>
<span class="ident">AtomicBool</span>::<span class="ident">new</span>(<span class="op">!</span><span class="macro">cfg</span><span class="macro">!</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"android"</span>));
<span class="kw">let</span> <span class="ident">fd</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">raw</span>();
<span class="kw">if</span> <span class="ident">TRY_CLOEXEC</span>.<span class="ident">load</span>(<span class="ident">Ordering</span>::<span class="ident">Relaxed</span>) {
<span class="kw">match</span> <span class="ident">cvt</span>(<span class="kw">unsafe</span> { <span class="ident">libc</span>::<span class="ident">fcntl</span>(<span class="ident">fd</span>, <span class="ident">F_DUPFD_CLOEXEC</span>, <span class="number">0</span>) }) {
<span class="comment">// We *still* call the `set_cloexec` method as apparently some</span>
<span class="comment">// linux kernel at some point stopped setting CLOEXEC even</span>
<span class="comment">// though it reported doing so on F_DUPFD_CLOEXEC.</span>
<span class="prelude-val">Ok</span>(<span class="ident">fd</span>) <span class="op">=></span> {
<span class="kw">return</span> <span class="prelude-val">Ok</span>(<span class="kw">if</span> <span class="macro">cfg</span><span class="macro">!</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"linux"</span>) {
<span class="ident">make_filedesc</span>(<span class="ident">fd</span>)<span class="question-mark">?</span>
} <span class="kw">else</span> {
<span class="ident">FileDesc</span>::<span class="ident">new</span>(<span class="ident">fd</span>)
})
}
<span class="prelude-val">Err</span>(<span class="kw-2">ref</span> <span class="ident">e</span>) <span class="kw">if</span> <span class="ident">e</span>.<span class="ident">raw_os_error</span>() <span class="op">==</span> <span class="prelude-val">Some</span>(<span class="ident">libc</span>::<span class="ident">EINVAL</span>) <span class="op">=></span> {
<span class="ident">TRY_CLOEXEC</span>.<span class="ident">store</span>(<span class="bool-val">false</span>, <span class="ident">Ordering</span>::<span class="ident">Relaxed</span>);
}
<span class="prelude-val">Err</span>(<span class="ident">e</span>) <span class="op">=></span> <span class="kw">return</span> <span class="prelude-val">Err</span>(<span class="ident">e</span>),
}
}
<span class="ident">cvt</span>(<span class="kw">unsafe</span> { <span class="ident">libc</span>::<span class="ident">fcntl</span>(<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">F_DUPFD</span>, <span class="number">0</span>) }).<span class="ident">and_then</span>(<span class="ident">make_filedesc</span>)
}
}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> <span class="ident">Read</span> <span class="kw">for</span> <span class="kw-2">&</span><span class="lifetime">'a</span> <span class="ident">FileDesc</span> {
<span class="kw">fn</span> <span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">buf</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">u8</span>]) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">usize</span><span class="op">></span> {
(<span class="kw-2">*</span><span class="kw-2">*</span><span class="self">self</span>).<span class="ident">read</span>(<span class="ident">buf</span>)
}
}
<span class="kw">impl</span> <span class="ident">AsInner</span><span class="op"><</span><span class="ident">c_int</span><span class="op">></span> <span class="kw">for</span> <span class="ident">FileDesc</span> {
<span class="kw">fn</span> <span class="ident">as_inner</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="kw-2">&</span><span class="ident">c_int</span> { <span class="kw-2">&</span><span class="self">self</span>.<span class="ident">fd</span> }
}
<span class="kw">impl</span> <span class="ident">Drop</span> <span class="kw">for</span> <span class="ident">FileDesc</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="comment">// Note that errors are ignored when closing a file descriptor. The</span>
<span class="comment">// reason for this is that if an error occurs we don't actually know if</span>
<span class="comment">// the file descriptor was closed or not, and if we retried (for</span>
<span class="comment">// something like EINTR), we might close another valid file descriptor</span>
<span class="comment">// (opened after we closed ours.</span>
<span class="kw">let</span> <span class="kw">_</span> <span class="op">=</span> <span class="kw">unsafe</span> { <span class="ident">libc</span>::<span class="ident">close</span>(<span class="self">self</span>.<span class="ident">fd</span>) };
}
}
</pre>
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distrib
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armv7hl
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core-updates
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4e2dbb669434a7691662cb2f0ad38972
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11852
