Struct Subsystem 

pub struct Subsystem { /* private fields */ }

Handler of a Cpuacct subsystem.

Implementations

impl Subsystem

pub fn stat(&self) -> Result<Stat>

Reads the statistics about how much CPU time is consumed by this cgroup (in USER_HZ unit) from cpuacct.stat file. The CPU time is further divided into user and system times.

See the kernel’s documentation for more information about this field.

Errors

Returns an error if failed to read and parse cpuacct.stat file of this cgroup.

Examples

use std::path::PathBuf;
use controlgroup::v1::{cpuacct, Cgroup, CgroupPath, SubsystemKind};

let cgroup = cpuacct::Subsystem::new(
    CgroupPath::new(SubsystemKind::Cpuacct, PathBuf::from("students/charlie")));

let stat = cgroup.stat()?;

pub fn usage(&self) -> Result<u64>

Reads the total CPU time consumed by this cgroup (in nanoseconds) from cpuacct.usage file.

See the kernel’s documentation for more information about this field.

Errors

Returns an error if failed to read and parse cpuacct.usage file of this cgroup.

Examples

use std::path::PathBuf;
use controlgroup::v1::{cpuacct, Cgroup, CgroupPath, SubsystemKind};

let cgroup = cpuacct::Subsystem::new(
    CgroupPath::new(SubsystemKind::Cpuacct, PathBuf::from("students/charlie")));

let usage = cgroup.usage()?;

pub fn usage_all(&self) -> Result<Vec<Stat>>

Reads the per-CPU total CPU time consumed by this cgroup (in nanoseconds) from cpuacct.usage_all file. The CPU time is further divided into user and system times.

See the kernel’s documentation for more information about this field.

Errors

Returns an error if failed to read and parse cpuacct.usage_all file of this cgroup.

Examples

use std::path::PathBuf;
use controlgroup::v1::{cpuacct, Cgroup, CgroupPath, SubsystemKind};

let cgroup = cpuacct::Subsystem::new(
    CgroupPath::new(SubsystemKind::Cpuacct, PathBuf::from("students/charlie")));

let usage_all = cgroup.usage_all()?;

pub fn usage_percpu(&self) -> Result<Vec<u64>>

Reads the per-CPU total CPU times consumed by this cgroup (in nanoseconds) from cpuacct.usage_percpu file.

See the kernel’s documentation for more information about this field.

Errors

Returns an error if failed to read and parse cpuacct.usage_percpu file of this cgroup.

Examples

use std::path::PathBuf;
use controlgroup::v1::{cpuacct, Cgroup, CgroupPath, SubsystemKind};

let cgroup = cpuacct::Subsystem::new(
    CgroupPath::new(SubsystemKind::Cpuacct, PathBuf::from("students/charlie")));

let usage_percpu = cgroup.usage_percpu()?;

pub fn usage_percpu_sys(&self) -> Result<Vec<u64>>

Reads the per-CPU total CPU times consumed by this cgroup in the system (kernel) mode (in nanoseconds) from cpuacct.usage_percpu_sys file.

See the kernel’s documentation for more information about this field.

Errors

Returns an error if failed to read and parse cpuacct.usage_percpu_sys file of this cgroup.

Examples

use std::path::PathBuf;
use controlgroup::v1::{cpuacct, Cgroup, CgroupPath, SubsystemKind};

let cgroup = cpuacct::Subsystem::new(
    CgroupPath::new(SubsystemKind::Cpuacct, PathBuf::from("students/charlie")));

let usage_percpu_sys = cgroup.usage_percpu_sys()?;

pub fn usage_percpu_user(&self) -> Result<Vec<u64>>

Reads the per-CPU total CPU times consumed by this cgroup in the user mode (in nanoseconds) from cpuacct.usage_percpu_user file.

See the kernel’s documentation for more information about this field.

Errors

Returns an error if failed to read and parse cpuacct.usage_percpu_user file of this cgroup.

Examples

use std::path::PathBuf;
use controlgroup::v1::{cpuacct, Cgroup, CgroupPath, SubsystemKind};

let cgroup = cpuacct::Subsystem::new(
    CgroupPath::new(SubsystemKind::Cpuacct, PathBuf::from("students/charlie")));

let usage_percpu_user = cgroup.usage_percpu_user()?;

pub fn usage_sys(&self) -> Result<u64>

Reads the total CPU time consumed by this cgroup in the system (kernel) mode (in nanoseconds) from cpuacct.usage_sys file.

See the kernel’s documentation for more information about this field.

Errors

Returns an error if failed to read and parse cpuacct.usage_sys file of this cgroup.

Examples

use std::path::PathBuf;
use controlgroup::v1::{cpuacct, Cgroup, CgroupPath, SubsystemKind};

let cgroup = cpuacct::Subsystem::new(
    CgroupPath::new(SubsystemKind::Cpuacct, PathBuf::from("students/charlie")));

let usage_sys = cgroup.usage_sys()?;

pub fn usage_user(&self) -> Result<u64>

Reads the total CPU time consumed by this cgroup in the user mode (in nanoseconds) from cpuacct.usage_user file.

See the kernel’s documentation for more information about this field.

Errors

Returns an error if failed to read and parse cpuacct.usage_user file of this cgroup.

Examples

use std::path::PathBuf;
use controlgroup::v1::{cpuacct, Cgroup, CgroupPath, SubsystemKind};

let cgroup = cpuacct::Subsystem::new(
    CgroupPath::new(SubsystemKind::Cpuacct, PathBuf::from("students/charlie")));

let usage_user = cgroup.usage_user()?;

pub fn reset(&mut self) -> Result<()>

Resets the accounted CPU time of this cgroup by writing to cpuacct.usage file.

Errors

Returns an error if failed to write to cpuacct.usage file of this cgroup.

Examples

use std::path::PathBuf;
use controlgroup::v1::{cpuacct, Cgroup, CgroupPath, SubsystemKind};

let mut cgroup = cpuacct::Subsystem::new(
    CgroupPath::new(SubsystemKind::Cpuacct, PathBuf::from("students/charlie")));

cgroup.reset()?;

Trait Implementations

impl Cgroup for Subsystem

fn apply(&mut self, _resources: &Resources) -> Result<()>

Does nothing as a Cpuacct subsystem is basically read-only.

fn new(path: CgroupPath) -> Self

Defines a new cgroup with a path.

fn subsystem(&self) -> SubsystemKind

Returns the subsystem to which this cgroup belongs.

fn path(&self) -> PathBuf

Returns the absolute path to this cgroup.

fn is_root(&self) -> bool

Returns whether this cgroup is the root cgroup of a subsystem.

fn root_cgroup(&self) -> Box<Self>

Returns the definition of the root cgroup for the subsystem of this cgroup.

fn create(&mut self) -> Result<()>

Creates a new directory for this cgroup.

fn delete(&mut self) -> Result<()>

Deletes the directory of this cgroup.

fn tasks(&self) -> Result<Vec<Pid>>

Reads a list of tasks attached to this cgroup, from tasks file. The resulting tasks are represented by their thread IDs.

fn add_task(&mut self, pid: impl Into<Pid>) -> Result<()>

Attaches a task to this cgroup by writing a thread ID to tasks file.

fn remove_task(&mut self, pid: impl Into<Pid>) -> Result<()>

Removes a task from this cgroup by writing a thread ID to tasks file of the root cgroup.

fn procs(&self) -> Result<Vec<Pid>>

Reads a list of processes attached to this cgroup, from cgroup.procs file. The resulting tasks are represented by their PIDs.

fn add_proc(&mut self, pid: impl Into<Pid>) -> Result<()>

Attaches a process to this cgroup, with all threads in the same thread group at once, by writing a PID to cgroup.procs file.

fn remove_proc(&mut self, pid: impl Into<Pid>) -> Result<()>

Removes a process from this cgroup, with all threads in the same thread group at once, by writing a PID to cgroup.procs file of the root cgroup.

fn notify_on_release(&self) -> Result<bool>

Reads whether the system executes the executable written in release_agent file when this cgroup no longer has any task, from notify_on_release file.

fn set_notify_on_release(&mut self, enable: bool) -> Result<()>

Sets whether the system executes the executable written in release_agent file when this cgroup no longer has any task, by writing to notify_on_release file.

fn release_agent(&self) -> Result<String>

Reads the command to be executed when “notify on release” is triggered, i.e. this cgroup is emptied of all tasks, from release_agent file.

fn set_release_agent(&mut self, agent_path: impl AsRef<[u8]>) -> Result<()>

Sets a command to be executed when “notify on release” is triggered, i.e. this cgroup is emptied of all tasks, by writing to release_agent file.

fn sane_behavior(&self) -> Result<bool>

Reads whether the subsystem of this cgroup is forced to follow “sane behavior”, from cgroup.sane_behavior file.

fn file_exists(&self, name: &str) -> bool

Returns whether a file with the given name exists in this cgroup.

fn open_file_read(&self, name: &str) -> Result<File>

Low-level API that opens a file with read access.

fn open_file_write(&mut self, name: &str) -> Result<File>

Low-level API that opens a file with write access.

impl Debug for Subsystem

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.