gtsocial-umbx

Unnamed repository; edit this file 'description' to name the repository.
Log | Files | Refs | README | LICENSE

freezer.go (1946B)

      1 /*
      2    Copyright The containerd Authors.
      3 
      4    Licensed under the Apache License, Version 2.0 (the "License");
      5    you may not use this file except in compliance with the License.
      6    You may obtain a copy of the License at
      7 
      8        http://www.apache.org/licenses/LICENSE-2.0
      9 
     10    Unless required by applicable law or agreed to in writing, software
     11    distributed under the License is distributed on an "AS IS" BASIS,
     12    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13    See the License for the specific language governing permissions and
     14    limitations under the License.
     15 */
     16 
     17 package cgroup1
     18 
     19 import (
     20 	"os"
     21 	"path/filepath"
     22 	"strings"
     23 	"time"
     24 )
     25 
     26 func NewFreezer(root string) *freezerController {
     27 	return &freezerController{
     28 		root: filepath.Join(root, string(Freezer)),
     29 	}
     30 }
     31 
     32 type freezerController struct {
     33 	root string
     34 }
     35 
     36 func (f *freezerController) Name() Name {
     37 	return Freezer
     38 }
     39 
     40 func (f *freezerController) Path(path string) string {
     41 	return filepath.Join(f.root, path)
     42 }
     43 
     44 func (f *freezerController) Freeze(path string) error {
     45 	return f.waitState(path, Frozen)
     46 }
     47 
     48 func (f *freezerController) Thaw(path string) error {
     49 	return f.waitState(path, Thawed)
     50 }
     51 
     52 func (f *freezerController) changeState(path string, state State) error {
     53 	return os.WriteFile(
     54 		filepath.Join(f.root, path, "freezer.state"),
     55 		[]byte(strings.ToUpper(string(state))),
     56 		defaultFilePerm,
     57 	)
     58 }
     59 
     60 func (f *freezerController) state(path string) (State, error) {
     61 	current, err := os.ReadFile(filepath.Join(f.root, path, "freezer.state"))
     62 	if err != nil {
     63 		return "", err
     64 	}
     65 	return State(strings.ToLower(strings.TrimSpace(string(current)))), nil
     66 }
     67 
     68 func (f *freezerController) waitState(path string, state State) error {
     69 	for {
     70 		if err := f.changeState(path, state); err != nil {
     71 			return err
     72 		}
     73 		current, err := f.state(path)
     74 		if err != nil {
     75 			return err
     76 		}
     77 		if current == state {
     78 			return nil
     79 		}
     80 		time.Sleep(1 * time.Millisecond)
     81 	}
     82 }