linux-support 0.0.25

Comprehensive Linux support for namespaces, cgroups, processes, scheduling, parsing /proc, parsing /sys, signals, hyper threads, CPUS, NUMA nodes, unusual file descriptors, PCI devices and much, much more
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60

// This file is part of linux-support. It is subject to the license terms in the COPYRIGHT file found in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/linux-support/master/COPYRIGHT. No part of linux-support, including this file, may be copied, modified, propagated, or distributed except according to the terms contained in the COPYRIGHT file.
// Copyright © 2020 The developers of linux-support. See the COPYRIGHT file in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/linux-support/master/COPYRIGHT.


/// Statistics.
#[derive(Default, Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
#[derive(Deserialize, Serialize)]
#[serde(deny_unknown_fields)]
pub struct Statistics
{
	/// This is the total number of visible (living) descendant cgroups underneath this cgroup.
	///
	/// Known in Linux as `nr_descendants`.
	pub number_of_living_descendants: usize,

	/// This is the total number of dying descendant cgroups underneath this cgroup.
	/// A cgroup enters the dying state after being deleted.
	/// It remains in that state for an undefined period (which will depend on system load) while resources are freed before the cgroup is destroyed.
	/// Note that the presence of some cgroups in the dying state is normal, and is not indicative of any problem.
	///
	/// A process can't be made a member of a dying cgroup, and a dying cgroup can't be brought back to life.
	///
	/// Known in Linux as `nr_dying_descendants`.
	pub number_of_dying_descendants: usize,
}

impl Statistics
{
	#[inline(always)]
	pub(super) fn from_file(file_path: &Path) -> Result<Self, StatisticsParseError>
	{
		let mut number_of_living_descendants = None;
		let mut number_of_dying_descendants = None;
		parse_key_value_statistics(file_path, &mut |name, value| match name
		{
			b"nr_descendants" =>
			{
				number_of_living_descendants = Some(value);
				Ok(())
			}
			
			b"nr_dying_descendants" =>
			{
				number_of_dying_descendants = Some(value);
				Ok(())
			}
			
			_ => Ok(()),
		})?;

		Ok
		(
			Self
			{
				number_of_living_descendants: unwrap_statistic(number_of_living_descendants, b"number_of_living_descendants")?,
				number_of_dying_descendants: unwrap_statistic(number_of_dying_descendants, b"number_of_dying_descendants")?,
			}
		)
	}
}