<!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/process/process_unix.rs`."> <meta name="keywords" content="rust, rustlang, rust-lang"> <title>process_unix.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="../../../../../main.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"> </div> </form> </nav> <section id='main' class="content"><pre class="line-numbers"><span id="1"> 1</span> <span id="2"> 2</span> <span id="3"> 3</span> <span id="4"> 4</span> <span id="5"> 5</span> <span id="6"> 6</span> <span id="7"> 7</span> <span id="8"> 8</span> <span id="9"> 9</span> <span id="10"> 10</span> <span id="11"> 11</span> <span id="12"> 12</span> <span id="13"> 13</span> <span id="14"> 14</span> <span id="15"> 15</span> <span id="16"> 16</span> <span id="17"> 17</span> <span id="18"> 18</span> <span id="19"> 19</span> <span id="20"> 20</span> <span id="21"> 21</span> <span id="22"> 22</span> <span id="23"> 23</span> <span id="24"> 24</span> <span id="25"> 25</span> <span id="26"> 26</span> <span id="27"> 27</span> <span id="28"> 28</span> <span id="29"> 29</span> <span id="30"> 30</span> <span id="31"> 31</span> <span id="32"> 32</span> <span id="33"> 33</span> <span id="34"> 34</span> <span id="35"> 35</span> <span id="36"> 36</span> <span id="37"> 37</span> <span id="38"> 38</span> <span id="39"> 39</span> <span id="40"> 40</span> <span id="41"> 41</span> <span id="42"> 42</span> <span id="43"> 43</span> <span id="44"> 44</span> <span id="45"> 45</span> <span id="46"> 46</span> <span id="47"> 47</span> <span id="48"> 48</span> <span id="49"> 49</span> <span id="50"> 50</span> <span id="51"> 51</span> <span id="52"> 52</span> <span id="53"> 53</span> <span id="54"> 54</span> <span id="55"> 55</span> <span id="56"> 56</span> <span id="57"> 57</span> <span id="58"> 58</span> <span id="59"> 59</span> <span id="60"> 60</span> <span id="61"> 61</span> <span id="62"> 62</span> <span id="63"> 63</span> <span id="64"> 64</span> <span id="65"> 65</span> <span id="66"> 66</span> <span id="67"> 67</span> <span id="68"> 68</span> <span id="69"> 69</span> <span id="70"> 70</span> <span id="71"> 71</span> <span id="72"> 72</span> <span id="73"> 73</span> <span id="74"> 74</span> <span id="75"> 75</span> <span id="76"> 76</span> <span id="77"> 77</span> <span id="78"> 78</span> <span id="79"> 79</span> <span id="80"> 80</span> <span id="81"> 81</span> <span id="82"> 82</span> <span id="83"> 83</span> <span id="84"> 84</span> <span id="85"> 85</span> <span id="86"> 86</span> <span id="87"> 87</span> <span id="88"> 88</span> <span id="89"> 89</span> <span id="90"> 90</span> <span id="91"> 91</span> <span id="92"> 92</span> <span id="93"> 93</span> <span id="94"> 94</span> <span id="95"> 95</span> <span id="96"> 96</span> <span id="97"> 97</span> <span id="98"> 98</span> <span id="99"> 99</span> <span id="100">100</span> <span id="101">101</span> <span id="102">102</span> <span id="103">103</span> <span id="104">104</span> <span id="105">105</span> <span id="106">106</span> <span id="107">107</span> <span id="108">108</span> <span id="109">109</span> <span id="110">110</span> <span id="111">111</span> <span id="112">112</span> <span id="113">113</span> <span id="114">114</span> <span id="115">115</span> <span id="116">116</span> <span id="117">117</span> <span id="118">118</span> <span id="119">119</span> <span id="120">120</span> <span id="121">121</span> <span id="122">122</span> <span id="123">123</span> <span id="124">124</span> <span id="125">125</span> <span id="126">126</span> <span id="127">127</span> <span id="128">128</span> <span id="129">129</span> <span id="130">130</span> <span id="131">131</span> <span id="132">132</span> <span id="133">133</span> <span id="134">134</span> <span id="135">135</span> <span id="136">136</span> <span id="137">137</span> <span id="138">138</span> <span id="139">139</span> <span id="140">140</span> <span id="141">141</span> <span id="142">142</span> <span id="143">143</span> <span id="144">144</span> <span id="145">145</span> <span id="146">146</span> <span id="147">147</span> <span id="148">148</span> <span id="149">149</span> <span id="150">150</span> <span id="151">151</span> <span id="152">152</span> <span id="153">153</span> <span id="154">154</span> <span id="155">155</span> <span id="156">156</span> <span id="157">157</span> <span id="158">158</span> <span id="159">159</span> <span id="160">160</span> <span id="161">161</span> <span id="162">162</span> <span id="163">163</span> <span id="164">164</span> <span id="165">165</span> <span id="166">166</span> <span id="167">167</span> <span id="168">168</span> <span id="169">169</span> <span id="170">170</span> <span id="171">171</span> <span id="172">172</span> <span id="173">173</span> <span id="174">174</span> <span id="175">175</span> <span id="176">176</span> <span id="177">177</span> <span id="178">178</span> <span id="179">179</span> <span id="180">180</span> <span id="181">181</span> <span id="182">182</span> <span id="183">183</span> <span id="184">184</span> <span id="185">185</span> <span id="186">186</span> <span id="187">187</span> <span id="188">188</span> <span id="189">189</span> <span id="190">190</span> <span id="191">191</span> <span id="192">192</span> <span id="193">193</span> <span id="194">194</span> <span id="195">195</span> <span id="196">196</span> <span id="197">197</span> <span id="198">198</span> <span id="199">199</span> <span id="200">200</span> <span id="201">201</span> <span id="202">202</span> <span id="203">203</span> <span id="204">204</span> <span id="205">205</span> <span id="206">206</span> <span id="207">207</span> <span id="208">208</span> <span id="209">209</span> <span id="210">210</span> <span id="211">211</span> <span id="212">212</span> <span id="213">213</span> <span id="214">214</span> <span id="215">215</span> <span id="216">216</span> <span id="217">217</span> <span id="218">218</span> <span id="219">219</span> <span id="220">220</span> <span id="221">221</span> <span id="222">222</span> <span id="223">223</span> <span id="224">224</span> <span id="225">225</span> <span id="226">226</span> <span id="227">227</span> <span id="228">228</span> <span id="229">229</span> <span id="230">230</span> <span id="231">231</span> <span id="232">232</span> <span id="233">233</span> <span id="234">234</span> <span id="235">235</span> <span id="236">236</span> <span id="237">237</span> <span id="238">238</span> <span id="239">239</span> <span id="240">240</span> <span id="241">241</span> <span id="242">242</span> <span id="243">243</span> <span id="244">244</span> <span id="245">245</span> <span id="246">246</span> <span id="247">247</span> <span id="248">248</span> <span id="249">249</span> <span id="250">250</span> <span id="251">251</span> <span id="252">252</span> <span id="253">253</span> <span id="254">254</span> <span id="255">255</span> <span id="256">256</span> <span id="257">257</span> <span id="258">258</span> <span id="259">259</span> <span id="260">260</span> <span id="261">261</span> <span id="262">262</span> <span id="263">263</span> <span id="264">264</span> <span id="265">265</span> <span id="266">266</span> <span id="267">267</span> <span id="268">268</span> <span id="269">269</span> <span id="270">270</span> <span id="271">271</span> <span id="272">272</span> <span id="273">273</span> <span id="274">274</span> <span id="275">275</span> <span id="276">276</span> <span id="277">277</span> <span id="278">278</span> <span id="279">279</span> <span id="280">280</span> <span id="281">281</span> <span id="282">282</span> <span id="283">283</span> <span id="284">284</span> <span id="285">285</span> <span id="286">286</span> <span id="287">287</span> </pre><pre class="rust "> <span class="comment">// Copyright 2014-2015 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="kw">use</span> <span class="ident">io</span>::{<span class="self">self</span>, <span class="ident">Error</span>, <span class="ident">ErrorKind</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">gid_t</span>, <span class="ident">pid_t</span>, <span class="ident">uid_t</span>}; <span class="kw">use</span> <span class="ident">ptr</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</span>::<span class="ident">process</span>::<span class="ident">process_common</span>::<span class="kw-2">*</span>; <span class="comment">////////////////////////////////////////////////////////////////////////////////</span> <span class="comment">// Command</span> <span class="comment">////////////////////////////////////////////////////////////////////////////////</span> <span class="kw">impl</span> <span class="ident">Command</span> { <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">spawn</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">default</span>: <span class="ident">Stdio</span>, <span class="ident">needs_stdin</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="ident">Process</span>, <span class="ident">StdioPipes</span>)<span class="op">></span> { <span class="kw">use</span> <span class="ident">sys</span>; <span class="kw">const</span> <span class="ident">CLOEXEC_MSG_FOOTER</span>: <span class="kw-2">&</span><span class="lifetime">'static</span> [<span class="ident">u8</span>] <span class="op">=</span> <span class="string">b"NOEX"</span>; <span class="kw">let</span> <span class="ident">envp</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">capture_env</span>(); <span class="kw">if</span> <span class="self">self</span>.<span class="ident">saw_nul</span>() { <span class="kw">return</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">ErrorKind</span>::<span class="ident">InvalidInput</span>, <span class="string">"nul byte found in provided data"</span>)); } <span class="kw">let</span> (<span class="ident">ours</span>, <span class="ident">theirs</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">setup_io</span>(<span class="ident">default</span>, <span class="ident">needs_stdin</span>)<span class="question-mark">?</span>; <span class="kw">let</span> (<span class="ident">input</span>, <span class="ident">output</span>) <span class="op">=</span> <span class="ident">sys</span>::<span class="ident">pipe</span>::<span class="ident">anon_pipe</span>()<span class="question-mark">?</span>; <span class="kw">let</span> <span class="ident">pid</span> <span class="op">=</span> <span class="kw">unsafe</span> { <span class="kw">match</span> <span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">fork</span>())<span class="question-mark">?</span> { <span class="number">0</span> <span class="op">=></span> { <span class="ident">drop</span>(<span class="ident">input</span>); <span class="kw">let</span> <span class="ident">err</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">do_exec</span>(<span class="ident">theirs</span>, <span class="ident">envp</span>.<span class="ident">as_ref</span>()); <span class="kw">let</span> <span class="ident">errno</span> <span class="op">=</span> <span class="ident">err</span>.<span class="ident">raw_os_error</span>().<span class="ident">unwrap_or</span>(<span class="ident">libc</span>::<span class="ident">EINVAL</span>) <span class="kw">as</span> <span class="ident">u32</span>; <span class="kw">let</span> <span class="ident">bytes</span> <span class="op">=</span> [ (<span class="ident">errno</span> <span class="op">>></span> <span class="number">24</span>) <span class="kw">as</span> <span class="ident">u8</span>, (<span class="ident">errno</span> <span class="op">>></span> <span class="number">16</span>) <span class="kw">as</span> <span class="ident">u8</span>, (<span class="ident">errno</span> <span class="op">>></span> <span class="number">8</span>) <span class="kw">as</span> <span class="ident">u8</span>, (<span class="ident">errno</span> <span class="op">>></span> <span class="number">0</span>) <span class="kw">as</span> <span class="ident">u8</span>, <span class="ident">CLOEXEC_MSG_FOOTER</span>[<span class="number">0</span>], <span class="ident">CLOEXEC_MSG_FOOTER</span>[<span class="number">1</span>], <span class="ident">CLOEXEC_MSG_FOOTER</span>[<span class="number">2</span>], <span class="ident">CLOEXEC_MSG_FOOTER</span>[<span class="number">3</span>] ]; <span class="comment">// pipe I/O up to PIPE_BUF bytes should be atomic, and then</span> <span class="comment">// we want to be sure we *don't* run at_exit destructors as</span> <span class="comment">// we're being torn down regardless</span> <span class="macro">assert</span><span class="macro">!</span>(<span class="ident">output</span>.<span class="ident">write</span>(<span class="kw-2">&</span><span class="ident">bytes</span>).<span class="ident">is_ok</span>()); <span class="ident">libc</span>::<span class="ident">_exit</span>(<span class="number">1</span>) } <span class="ident">n</span> <span class="op">=></span> <span class="ident">n</span>, } }; <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">p</span> <span class="op">=</span> <span class="ident">Process</span> { <span class="ident">pid</span>: <span class="ident">pid</span>, <span class="ident">status</span>: <span class="prelude-val">None</span> }; <span class="ident">drop</span>(<span class="ident">output</span>); <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">bytes</span> <span class="op">=</span> [<span class="number">0</span>; <span class="number">8</span>]; <span class="comment">// loop to handle EINTR</span> <span class="kw">loop</span> { <span class="kw">match</span> <span class="ident">input</span>.<span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">bytes</span>) { <span class="prelude-val">Ok</span>(<span class="number">0</span>) <span class="op">=></span> <span class="kw">return</span> <span class="prelude-val">Ok</span>((<span class="ident">p</span>, <span class="ident">ours</span>)), <span class="prelude-val">Ok</span>(<span class="number">8</span>) <span class="op">=></span> { <span class="macro">assert</span><span class="macro">!</span>(<span class="ident">combine</span>(<span class="ident">CLOEXEC_MSG_FOOTER</span>) <span class="op">==</span> <span class="ident">combine</span>(<span class="kw-2">&</span><span class="ident">bytes</span>[<span class="number">4</span>.. <span class="number">8</span>]), <span class="string">"Validation on the CLOEXEC pipe failed: {:?}"</span>, <span class="ident">bytes</span>); <span class="kw">let</span> <span class="ident">errno</span> <span class="op">=</span> <span class="ident">combine</span>(<span class="kw-2">&</span><span class="ident">bytes</span>[<span class="number">0</span>.. <span class="number">4</span>]); <span class="macro">assert</span><span class="macro">!</span>(<span class="ident">p</span>.<span class="ident">wait</span>().<span class="ident">is_ok</span>(), <span class="string">"wait() should either return Ok or panic"</span>); <span class="kw">return</span> <span class="prelude-val">Err</span>(<span class="ident">Error</span>::<span class="ident">from_raw_os_error</span>(<span class="ident">errno</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">kind</span>() <span class="op">==</span> <span class="ident">ErrorKind</span>::<span class="ident">Interrupted</span> <span class="op">=></span> {} <span class="prelude-val">Err</span>(<span class="ident">e</span>) <span class="op">=></span> { <span class="macro">assert</span><span class="macro">!</span>(<span class="ident">p</span>.<span class="ident">wait</span>().<span class="ident">is_ok</span>(), <span class="string">"wait() should either return Ok or panic"</span>); <span class="macro">panic</span><span class="macro">!</span>(<span class="string">"the CLOEXEC pipe failed: {:?}"</span>, <span class="ident">e</span>) }, <span class="prelude-val">Ok</span>(..) <span class="op">=></span> { <span class="comment">// pipe I/O up to PIPE_BUF bytes should be atomic</span> <span class="macro">assert</span><span class="macro">!</span>(<span class="ident">p</span>.<span class="ident">wait</span>().<span class="ident">is_ok</span>(), <span class="string">"wait() should either return Ok or panic"</span>); <span class="macro">panic</span><span class="macro">!</span>(<span class="string">"short read on the CLOEXEC pipe"</span>) } } } <span class="kw">fn</span> <span class="ident">combine</span>(<span class="ident">arr</span>: <span class="kw-2">&</span>[<span class="ident">u8</span>]) <span class="op">-></span> <span class="ident">i32</span> { <span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> <span class="ident">arr</span>[<span class="number">0</span>] <span class="kw">as</span> <span class="ident">u32</span>; <span class="kw">let</span> <span class="ident">b</span> <span class="op">=</span> <span class="ident">arr</span>[<span class="number">1</span>] <span class="kw">as</span> <span class="ident">u32</span>; <span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">arr</span>[<span class="number">2</span>] <span class="kw">as</span> <span class="ident">u32</span>; <span class="kw">let</span> <span class="ident">d</span> <span class="op">=</span> <span class="ident">arr</span>[<span class="number">3</span>] <span class="kw">as</span> <span class="ident">u32</span>; ((<span class="ident">a</span> <span class="op"><<</span> <span class="number">24</span>) <span class="op">|</span> (<span class="ident">b</span> <span class="op"><<</span> <span class="number">16</span>) <span class="op">|</span> (<span class="ident">c</span> <span class="op"><<</span> <span class="number">8</span>) <span class="op">|</span> (<span class="ident">d</span> <span class="op"><<</span> <span class="number">0</span>)) <span class="kw">as</span> <span class="ident">i32</span> } } <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">exec</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">default</span>: <span class="ident">Stdio</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="ident">Error</span> { <span class="kw">let</span> <span class="ident">envp</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">capture_env</span>(); <span class="kw">if</span> <span class="self">self</span>.<span class="ident">saw_nul</span>() { <span class="kw">return</span> <span class="ident">io</span>::<span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">ErrorKind</span>::<span class="ident">InvalidInput</span>, <span class="string">"nul byte found in provided data"</span>) } <span class="kw">match</span> <span class="self">self</span>.<span class="ident">setup_io</span>(<span class="ident">default</span>, <span class="bool-val">true</span>) { <span class="prelude-val">Ok</span>((_, <span class="ident">theirs</span>)) <span class="op">=></span> <span class="kw">unsafe</span> { <span class="self">self</span>.<span class="ident">do_exec</span>(<span class="ident">theirs</span>, <span class="ident">envp</span>.<span class="ident">as_ref</span>()) }, <span class="prelude-val">Err</span>(<span class="ident">e</span>) <span class="op">=></span> <span class="ident">e</span>, } } <span class="comment">// And at this point we've reached a special time in the life of the</span> <span class="comment">// child. The child must now be considered hamstrung and unable to</span> <span class="comment">// do anything other than syscalls really. Consider the following</span> <span class="comment">// scenario:</span> <span class="comment">//</span> <span class="comment">// 1. Thread A of process 1 grabs the malloc() mutex</span> <span class="comment">// 2. Thread B of process 1 forks(), creating thread C</span> <span class="comment">// 3. Thread C of process 2 then attempts to malloc()</span> <span class="comment">// 4. The memory of process 2 is the same as the memory of</span> <span class="comment">// process 1, so the mutex is locked.</span> <span class="comment">//</span> <span class="comment">// This situation looks a lot like deadlock, right? It turns out</span> <span class="comment">// that this is what pthread_atfork() takes care of, which is</span> <span class="comment">// presumably implemented across platforms. The first thing that</span> <span class="comment">// threads to *before* forking is to do things like grab the malloc</span> <span class="comment">// mutex, and then after the fork they unlock it.</span> <span class="comment">//</span> <span class="comment">// Despite this information, libnative's spawn has been witnessed to</span> <span class="comment">// deadlock on both macOS and FreeBSD. I'm not entirely sure why, but</span> <span class="comment">// all collected backtraces point at malloc/free traffic in the</span> <span class="comment">// child spawned process.</span> <span class="comment">//</span> <span class="comment">// For this reason, the block of code below should contain 0</span> <span class="comment">// invocations of either malloc of free (or their related friends).</span> <span class="comment">//</span> <span class="comment">// As an example of not having malloc/free traffic, we don't close</span> <span class="comment">// this file descriptor by dropping the FileDesc (which contains an</span> <span class="comment">// allocation). Instead we just close it manually. This will never</span> <span class="comment">// have the drop glue anyway because this code never returns (the</span> <span class="comment">// child will either exec() or invoke libc::exit)</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">do_exec</span>( <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">stdio</span>: <span class="ident">ChildPipes</span>, <span class="ident">maybe_envp</span>: <span class="prelude-ty">Option</span><span class="op"><</span><span class="kw-2">&</span><span class="ident">CStringArray</span><span class="op">></span> ) <span class="op">-></span> <span class="ident">io</span>::<span class="ident">Error</span> { <span class="kw">use</span> <span class="ident">sys</span>::{<span class="self">self</span>, <span class="ident">cvt_r</span>}; <span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">t</span> { (<span class="macro-nonterminal">$</span><span class="macro-nonterminal">e</span>:<span class="ident">expr</span>) <span class="op">=></span> (<span class="kw">match</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">e</span> { <span class="prelude-val">Ok</span>(<span class="ident">e</span>) <span class="op">=></span> <span class="ident">e</span>, <span class="prelude-val">Err</span>(<span class="ident">e</span>) <span class="op">=></span> <span class="kw">return</span> <span class="ident">e</span>, }) } <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">fd</span>) <span class="op">=</span> <span class="ident">stdio</span>.<span class="ident">stdin</span>.<span class="ident">fd</span>() { <span class="macro">t</span><span class="macro">!</span>(<span class="ident">cvt_r</span>(<span class="op">||</span> <span class="ident">libc</span>::<span class="ident">dup2</span>(<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">STDIN_FILENO</span>))); } <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">fd</span>) <span class="op">=</span> <span class="ident">stdio</span>.<span class="ident">stdout</span>.<span class="ident">fd</span>() { <span class="macro">t</span><span class="macro">!</span>(<span class="ident">cvt_r</span>(<span class="op">||</span> <span class="ident">libc</span>::<span class="ident">dup2</span>(<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">STDOUT_FILENO</span>))); } <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">fd</span>) <span class="op">=</span> <span class="ident">stdio</span>.<span class="ident">stderr</span>.<span class="ident">fd</span>() { <span class="macro">t</span><span class="macro">!</span>(<span class="ident">cvt_r</span>(<span class="op">||</span> <span class="ident">libc</span>::<span class="ident">dup2</span>(<span class="ident">fd</span>, <span class="ident">libc</span>::<span class="ident">STDERR_FILENO</span>))); } <span class="kw">if</span> <span class="macro">cfg</span><span class="macro">!</span>(<span class="ident">not</span>(<span class="ident">any</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"l4re"</span>))) { <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">u</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">get_gid</span>() { <span class="macro">t</span><span class="macro">!</span>(<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">setgid</span>(<span class="ident">u</span> <span class="kw">as</span> <span class="ident">gid_t</span>))); } <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">u</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">get_uid</span>() { <span class="comment">// When dropping privileges from root, the `setgroups` call</span> <span class="comment">// will remove any extraneous groups. If we don't call this,</span> <span class="comment">// then even though our uid has dropped, we may still have</span> <span class="comment">// groups that enable us to do super-user things. This will</span> <span class="comment">// fail if we aren't root, so don't bother checking the</span> <span class="comment">// return value, this is just done as an optimistic</span> <span class="comment">// privilege dropping function.</span> <span class="kw">let</span> _ <span class="op">=</span> <span class="ident">libc</span>::<span class="ident">setgroups</span>(<span class="number">0</span>, <span class="ident">ptr</span>::<span class="ident">null</span>()); <span class="macro">t</span><span class="macro">!</span>(<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">setuid</span>(<span class="ident">u</span> <span class="kw">as</span> <span class="ident">uid_t</span>))); } } <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="kw-2">ref</span> <span class="ident">cwd</span>) <span class="op">=</span> <span class="kw-2">*</span><span class="self">self</span>.<span class="ident">get_cwd</span>() { <span class="macro">t</span><span class="macro">!</span>(<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">chdir</span>(<span class="ident">cwd</span>.<span class="ident">as_ptr</span>()))); } <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">envp</span>) <span class="op">=</span> <span class="ident">maybe_envp</span> { <span class="kw-2">*</span><span class="ident">sys</span>::<span class="ident">os</span>::<span class="ident">environ</span>() <span class="op">=</span> <span class="ident">envp</span>.<span class="ident">as_ptr</span>(); } <span class="comment">// emscripten has no signal support.</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">"emscripten"</span>)))]</span> { <span class="kw">use</span> <span class="ident">mem</span>; <span class="comment">// Reset signal handling so the child process starts in a</span> <span class="comment">// standardized state. libstd ignores SIGPIPE, and signal-handling</span> <span class="comment">// libraries often set a mask. Child processes inherit ignored</span> <span class="comment">// signals and the signal mask from their parent, but most</span> <span class="comment">// UNIX programs do not reset these things on their own, so we</span> <span class="comment">// need to clean things up now to avoid confusing the program</span> <span class="comment">// we're about to run.</span> <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">set</span>: <span class="ident">libc</span>::<span class="ident">sigset_t</span> <span class="op">=</span> <span class="ident">mem</span>::<span class="ident">uninitialized</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">"android"</span>) { <span class="comment">// Implementing sigemptyset allow us to support older Android</span> <span class="comment">// versions. See the comment about Android and sig* functions in</span> <span class="comment">// process_common.rs</span> <span class="ident">libc</span>::<span class="ident">memset</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">set</span> <span class="kw">as</span> <span class="kw-2">*</span><span class="kw-2">mut</span> _ <span class="kw">as</span> <span class="kw-2">*</span><span class="kw-2">mut</span> _, <span class="number">0</span>, <span class="ident">mem</span>::<span class="ident">size_of</span>::<span class="op"><</span><span class="ident">libc</span>::<span class="ident">sigset_t</span><span class="op">></span>()); } <span class="kw">else</span> { <span class="macro">t</span><span class="macro">!</span>(<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">sigemptyset</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">set</span>))); } <span class="macro">t</span><span class="macro">!</span>(<span class="ident">cvt</span>(<span class="ident">libc</span>::<span class="ident">pthread_sigmask</span>(<span class="ident">libc</span>::<span class="ident">SIG_SETMASK</span>, <span class="kw-2">&</span><span class="ident">set</span>, <span class="ident">ptr</span>::<span class="ident">null_mut</span>()))); <span class="kw">let</span> <span class="ident">ret</span> <span class="op">=</span> <span class="ident">sys</span>::<span class="ident">signal</span>(<span class="ident">libc</span>::<span class="ident">SIGPIPE</span>, <span class="ident">libc</span>::<span class="ident">SIG_DFL</span>); <span class="kw">if</span> <span class="ident">ret</span> <span class="op">==</span> <span class="ident">libc</span>::<span class="ident">SIG_ERR</span> { <span class="kw">return</span> <span class="ident">io</span>::<span class="ident">Error</span>::<span class="ident">last_os_error</span>() } } <span class="kw">for</span> <span class="ident">callback</span> <span class="kw">in</span> <span class="self">self</span>.<span class="ident">get_closures</span>().<span class="ident">iter_mut</span>() { <span class="macro">t</span><span class="macro">!</span>(<span class="ident">callback</span>()); } <span class="ident">libc</span>::<span class="ident">execvp</span>(<span class="self">self</span>.<span class="ident">get_argv</span>()[<span class="number">0</span>], <span class="self">self</span>.<span class="ident">get_argv</span>().<span class="ident">as_ptr</span>()); <span class="ident">io</span>::<span class="ident">Error</span>::<span class="ident">last_os_error</span>() } } <span class="comment">////////////////////////////////////////////////////////////////////////////////</span> <span class="comment">// Processes</span> <span class="comment">////////////////////////////////////////////////////////////////////////////////</span> <span class="doccomment">/// The unique id of the process (this should never be negative).</span> <span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Process</span> { <span class="ident">pid</span>: <span class="ident">pid_t</span>, <span class="ident">status</span>: <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">ExitStatus</span><span class="op">></span>, } <span class="kw">impl</span> <span class="ident">Process</span> { <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">id</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">u32</span> { <span class="self">self</span>.<span class="ident">pid</span> <span class="kw">as</span> <span class="ident">u32</span> } <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">kill</span>(<span class="kw-2">&</span><span class="kw-2">mut</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="comment">// If we've already waited on this process then the pid can be recycled</span> <span class="comment">// and used for another process, and we probably shouldn't be killing</span> <span class="comment">// random processes, so just return an error.</span> <span class="kw">if</span> <span class="self">self</span>.<span class="ident">status</span>.<span class="ident">is_some</span>() { <span class="prelude-val">Err</span>(<span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">ErrorKind</span>::<span class="ident">InvalidInput</span>, <span class="string">"invalid argument: can't kill an exited process"</span>)) } <span class="kw">else</span> { <span class="ident">cvt</span>(<span class="kw">unsafe</span> { <span class="ident">libc</span>::<span class="ident">kill</span>(<span class="self">self</span>.<span class="ident">pid</span>, <span class="ident">libc</span>::<span class="ident">SIGKILL</span>) }).<span class="ident">map</span>(<span class="op">|</span>_<span class="op">|</span> ()) } } <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">wait</span>(<span class="kw-2">&</span><span class="kw-2">mut</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">ExitStatus</span><span class="op">></span> { <span class="kw">use</span> <span class="ident">sys</span>::<span class="ident">cvt_r</span>; <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">status</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">status</span> { <span class="kw">return</span> <span class="prelude-val">Ok</span>(<span class="ident">status</span>) } <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">status</span> <span class="op">=</span> <span class="number">0</span> <span class="kw">as</span> <span class="ident">c_int</span>; <span class="ident">cvt_r</span>(<span class="op">||</span> <span class="kw">unsafe</span> { <span class="ident">libc</span>::<span class="ident">waitpid</span>(<span class="self">self</span>.<span class="ident">pid</span>, <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">status</span>, <span class="number">0</span>) })<span class="question-mark">?</span>; <span class="self">self</span>.<span class="ident">status</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="ident">ExitStatus</span>::<span class="ident">new</span>(<span class="ident">status</span>)); <span class="prelude-val">Ok</span>(<span class="ident">ExitStatus</span>::<span class="ident">new</span>(<span class="ident">status</span>)) } <span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">try_wait</span>(<span class="kw-2">&</span><span class="kw-2">mut</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="prelude-ty">Option</span><span class="op"><</span><span class="ident">ExitStatus</span><span class="op">>></span> { <span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">status</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">status</span> { <span class="kw">return</span> <span class="prelude-val">Ok</span>(<span class="prelude-val">Some</span>(<span class="ident">status</span>)) } <span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">status</span> <span class="op">=</span> <span class="number">0</span> <span class="kw">as</span> <span class="ident">c_int</span>; <span class="kw">let</span> <span class="ident">pid</span> <span class="op">=</span> <span class="ident">cvt</span>(<span class="kw">unsafe</span> { <span class="ident">libc</span>::<span class="ident">waitpid</span>(<span class="self">self</span>.<span class="ident">pid</span>, <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">status</span>, <span class="ident">libc</span>::<span class="ident">WNOHANG</span>) })<span class="question-mark">?</span>; <span class="kw">if</span> <span class="ident">pid</span> <span class="op">==</span> <span class="number">0</span> { <span class="prelude-val">Ok</span>(<span class="prelude-val">None</span>) } <span class="kw">else</span> { <span class="self">self</span>.<span class="ident">status</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="ident">ExitStatus</span>::<span class="ident">new</span>(<span class="ident">status</span>)); <span class="prelude-val">Ok</span>(<span class="prelude-val">Some</span>(<span class="ident">ExitStatus</span>::<span class="ident">new</span>(<span class="ident">status</span>))) } } } </pre> </section> <section id='search' class="content hidden"></section> <section class="footer"></section> <aside id="help" class="hidden"> <div> <h1 class="hidden">Help</h1> <div class="shortcuts"> <h2>Keyboard Shortcuts</h2> <dl> <dt><kbd>?</kbd></dt> <dd>Show this help dialog</dd> <dt><kbd>S</kbd></dt> <dd>Focus the search field</dd> <dt><kbd>↑</kbd></dt> <dd>Move up in search results</dd> <dt><kbd>↓</kbd></dt> <dd>Move down in search results</dd> <dt><kbd>↹</kbd></dt> <dd>Switch tab</dd> <dt><kbd>⏎</kbd></dt> <dd>Go to active search result</dd> <dt><kbd>+</kbd></dt> <dd>Expand all sections</dd> <dt><kbd>-</kbd></dt> <dd>Collapse all sections</dd> </dl> </div> <div class="infos"> <h2>Search Tricks</h2> <p> Prefix searches with a type followed by a colon (e.g. <code>fn:</code>) to restrict the search to a given type. </p> <p> Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>. </p> <p> Search functions by type signature (e.g. <code>vec -> usize</code> or <code>* -> vec</code>) </p> </div> </div> </aside> <script> window.rootPath = "../../../../../"; window.currentCrate = "std"; </script> <script src="../../../../../main.js"></script> <script defer src="../../../../../search-index.js"></script> </body> </html>