go-sandbox/pkg/cgroup/v2_linux.go

234 lines
5.3 KiB
Go

package cgroup
import (
"bufio"
"bytes"
"os"
"path/filepath"
"strconv"
"strings"
"sync"
)
// V2 provides cgroup interface for v2
type V2 struct {
path string
control *Controllers
subtreeOnce sync.Once
subtreeErr error
existing bool
}
var _ Cgroup = &V2{}
func (c *V2) Open() (*os.File, error) {
return os.OpenFile(c.path, 0, dirPerm)
}
func (c *V2) String() string {
ct, _ := getAvailableControllerV2path(filepath.Join(c.path, cgroupControllers))
return "v2(" + c.path + ")" + ct.String()
}
// AddProc adds processes into the cgroup
func (c *V2) AddProc(pids ...int) error {
return AddProcesses(filepath.Join(c.path, cgroupProcs), pids)
}
// Processes returns all processes within the cgroup
func (c *V2) Processes() ([]int, error) {
return ReadProcesses(filepath.Join(c.path, cgroupProcs))
}
// New creates a sub-cgroup based on the existing one
func (c *V2) New(name string) (Cgroup, error) {
if err := c.enableSubtreeControl(); err != nil {
return nil, err
}
v2 := &V2{
path: filepath.Join(c.path, name),
control: c.control,
}
if err := os.Mkdir(v2.path, dirPerm); err != nil {
if !os.IsExist(err) {
return nil, err
}
v2.existing = true
}
return v2, nil
}
// Nest creates a sub-cgroup, moves current process into that cgroup
func (c *V2) Nest(name string) (Cgroup, error) {
v2 := &V2{
path: filepath.Join(c.path, name),
control: c.control,
}
if err := os.Mkdir(v2.path, dirPerm); err != nil {
if !os.IsExist(err) {
return nil, err
}
v2.existing = true
}
p, err := c.Processes()
if err != nil {
return nil, err
}
if err := v2.AddProc(p...); err != nil {
return nil, err
}
if err := c.enableSubtreeControl(); err != nil {
return nil, err
}
return v2, nil
}
func (c *V2) enableSubtreeControl() error {
c.subtreeOnce.Do(func() {
ct, err := getAvailableControllerV2path(filepath.Join(c.path, cgroupControllers))
if err != nil {
c.subtreeErr = err
return
}
ect, err := getAvailableControllerV2path(filepath.Join(c.path, cgroupSubtreeControl))
if err != nil {
c.subtreeErr = err
return
}
if ect.Contains(ct) {
return
}
s := ct.Names()
controlMsg := []byte("+" + strings.Join(s, " +"))
c.subtreeErr = writeFile(filepath.Join(c.path, cgroupSubtreeControl), controlMsg, filePerm)
})
return c.subtreeErr
}
// Random creates a sub-cgroup based on the existing one but the name is randomly generated
func (c *V2) Random(pattern string) (Cgroup, error) {
return randomBuild(pattern, c.New)
}
// Destroy destroys the cgroup
func (c *V2) Destroy() error {
if !c.existing {
return remove(c.path)
}
return nil
}
// Existing returns true if the cgroup was opened rather than created
func (c *V2) Existing() bool {
return c.existing
}
// CPUUsage reads cpu.stat usage_usec
func (c *V2) CPUUsage() (uint64, error) {
b, err := c.ReadFile("cpu.stat")
if err != nil {
return 0, err
}
s := bufio.NewScanner(bytes.NewReader(b))
for s.Scan() {
parts := strings.Fields(s.Text())
if len(parts) == 2 && parts[0] == "usage_usec" {
v, err := strconv.Atoi(parts[1])
if err != nil {
return 0, err
}
return uint64(v) * 1000, nil // to ns
}
}
return 0, os.ErrNotExist
}
// MemoryUsage reads memory.current
func (c *V2) MemoryUsage() (uint64, error) {
if !c.control.Memory {
return 0, ErrNotInitialized
}
return c.ReadUint("memory.current")
}
// MemoryMaxUsage reads memory.peak
func (c *V2) MemoryMaxUsage() (uint64, error) {
if !c.control.Memory {
return 0, ErrNotInitialized
}
return c.ReadUint("memory.peak")
}
// ProcessPeak reads pids.peak
func (c *V2) ProcessPeak() (uint64, error) {
if !c.control.Pids {
return 0, ErrNotInitialized
}
return c.ReadUint("pids.peak")
}
// SetCPUBandwidth set cpu.max quota period
func (c *V2) SetCPUBandwidth(quota, period uint64) error {
if !c.control.CPU {
return ErrNotInitialized
}
content := strconv.FormatUint(quota, 10) + " " + strconv.FormatUint(period, 10)
return c.WriteFile("cpu.max", []byte(content))
}
// SetCPUSet sets cpuset.cpus
func (c *V2) SetCPUSet(content []byte) error {
if !c.control.CPUSet {
return ErrNotInitialized
}
return c.WriteFile("cpuset.cpus", content)
}
// SetMemoryLimit memory.max
func (c *V2) SetMemoryLimit(l uint64) error {
if !c.control.Memory {
return ErrNotInitialized
}
return c.WriteUint("memory.max", l)
}
// SetProcLimit pids.max
func (c *V2) SetProcLimit(l uint64) error {
if !c.control.Pids {
return ErrNotInitialized
}
return c.WriteUint("pids.max", l)
}
// WriteUint writes uint64 into given file
func (c *V2) WriteUint(filename string, i uint64) error {
return c.WriteFile(filename, []byte(strconv.FormatUint(i, 10)))
}
// ReadUint read uint64 from given file
func (c *V2) ReadUint(filename string) (uint64, error) {
b, err := c.ReadFile(filename)
if err != nil {
return 0, err
}
s, err := strconv.ParseUint(strings.TrimSpace(string(b)), 10, 64)
if err != nil {
return 0, err
}
return s, nil
}
// WriteFile writes cgroup file and handles potential EINTR error while writes to
// the slow device (cgroup)
func (c *V2) WriteFile(name string, content []byte) error {
p := filepath.Join(c.path, name)
return writeFile(p, content, filePerm)
}
// ReadFile reads cgroup file and handles potential EINTR error while read to
// the slow device (cgroup)
func (c *V2) ReadFile(name string) ([]byte, error) {
p := filepath.Join(c.path, name)
return readFile(p)
}