<!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 `src/pid1.rs`."><title>pid1.rs - source</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../../static.files/rustdoc-492a78a4a87dcc01.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="monitord" data-themes="" data-resource-suffix="" data-rustdoc-version="1.82.0 (f6e511eec 2024-10-15)" data-channel="1.82.0" data-search-js="search-a99f1315e7cc5121.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../../static.files/storage-118b08c4c78b968e.js"></script><script defer src="../../static.files/src-script-e66d777a5a92e9b2.js"></script><script defer src="../../src-files.js"></script><script defer src="../../static.files/main-921df33f47b8780c.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-3b12f09e550e0385.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc src"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="src-sidebar-title"><h2>Files</h2></div></nav><div class="sidebar-resizer"></div><main><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="example-wrap"><div data-nosnippet><pre class="src-line-numbers"><a href="#1" id="1">1</a>
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</pre></div><pre class="rust"><code><span class="doccomment">//! # pid1 module
//!
//! `pid1` uses procfs to get some statistics on Linux's more important
//! process pid1. These metrics can help ensure newer systemds don't regress
//! or show stange behavior. E.g. more file descriptors without more units.

</span><span class="kw">use </span>std::sync::Arc;

<span class="kw">use </span>procfs::process::Process;
<span class="kw">use </span>tokio::sync::RwLock;
<span class="kw">use </span>tracing::error;

<span class="kw">use </span><span class="kw">crate</span>::MachineStats;

<span class="attr">#[derive(serde::Serialize, serde::Deserialize, Clone, Debug, Default, Eq, PartialEq)]
</span><span class="kw">pub struct </span>Pid1Stats {
    <span class="kw">pub </span>cpu_time_kernel: u64,
    <span class="kw">pub </span>cpu_time_user: u64,
    <span class="kw">pub </span>memory_usage_bytes: u64,
    <span class="kw">pub </span>fd_count: u64,
    <span class="kw">pub </span>tasks: u64,
}

<span class="doccomment">/// Get procfs info on pid 1 - &lt;https://manpages.debian.org/buster/manpages/procfs.5.en.html&gt;
</span><span class="kw">pub fn </span>get_pid_stats(pid: i32) -&gt; anyhow::Result&lt;Pid1Stats&gt; {
    <span class="kw">let </span>bytes_per_page = procfs::page_size();
    <span class="kw">let </span>ticks_per_second = procfs::ticks_per_second();

    <span class="kw">let </span>pid1_proc = Process::new(pid)<span class="question-mark">?</span>;
    <span class="kw">let </span>stat_file = pid1_proc.stat()<span class="question-mark">?</span>;

    <span class="comment">// Living with integer rounding
    </span><span class="prelude-val">Ok</span>(Pid1Stats {
        cpu_time_kernel: (stat_file.stime) / (ticks_per_second),
        cpu_time_user: (stat_file.utime) / (ticks_per_second),
        memory_usage_bytes: (stat_file.rss) * (bytes_per_page),
        fd_count: pid1_proc.fd_count()<span class="question-mark">?</span>.try_into()<span class="question-mark">?</span>,
        <span class="comment">// Using 0 as impossible number of tasks
        </span>tasks: pid1_proc
            .tasks()<span class="question-mark">?
            </span>.flatten()
            .collect::&lt;Vec&lt;<span class="kw">_</span>&gt;&gt;()
            .len()
            .try_into()<span class="question-mark">?</span>,
    })
}

<span class="doccomment">/// Async wrapper than can update PID1 stats when passed a locked struct
</span><span class="kw">pub async fn </span>update_pid1_stats(
    pid: i32,
    locked_machine_stats: Arc&lt;RwLock&lt;MachineStats&gt;&gt;,
) -&gt; anyhow::Result&lt;()&gt; {
    <span class="kw">let </span>pid1_stats = <span class="kw">match </span>tokio::task::spawn_blocking(<span class="kw">move </span>|| get_pid_stats(pid)).<span class="kw">await </span>{
        <span class="prelude-val">Ok</span>(p1s) =&gt; p1s,
        <span class="prelude-val">Err</span>(err) =&gt; <span class="kw">return </span><span class="prelude-val">Err</span>(err.into()),
    };

    <span class="kw">let </span><span class="kw-2">mut </span>machine_stats = locked_machine_stats.write().<span class="kw">await</span>;
    machine_stats.pid1 = <span class="kw">match </span>pid1_stats {
        <span class="prelude-val">Ok</span>(s) =&gt; <span class="prelude-val">Some</span>(s),
        <span class="prelude-val">Err</span>(err) =&gt; {
            <span class="macro">error!</span>(<span class="string">"Unable to set pid1 stats: {:?}"</span>, err);
            <span class="prelude-val">None
        </span>}
    };

    <span class="prelude-val">Ok</span>(())
}

<span class="attr">#[cfg(test)]
</span><span class="kw">pub mod </span>tests {
    <span class="kw">use super</span>::<span class="kw-2">*</span>;

    <span class="attr">#[test]
    </span><span class="kw">pub fn </span>test_get_stats() -&gt; anyhow::Result&lt;()&gt; {
        <span class="kw">let </span>pid1_stats = get_pid_stats(<span class="number">1</span>)<span class="question-mark">?</span>;
        <span class="macro">assert!</span>(pid1_stats.tasks &gt; <span class="number">0</span>);
        <span class="prelude-val">Ok</span>(())
    }
}
</code></pre></div></section></main></body></html>