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 cgroups 18 19 import ( 20 "os" 21 22 v1 "github.com/containerd/cgroups/stats/v1" 23 specs "github.com/opencontainers/runtime-spec/specs-go" 24 ) 25 26 type procType = string 27 28 const ( 29 cgroupProcs procType = "cgroup.procs" 30 cgroupTasks procType = "tasks" 31 defaultDirPerm = 0755 32 ) 33 34 // defaultFilePerm is a var so that the test framework can change the filemode 35 // of all files created when the tests are running. The difference between the 36 // tests and real world use is that files like "cgroup.procs" will exist when writing 37 // to a read cgroup filesystem and do not exist prior when running in the tests. 38 // this is set to a non 0 value in the test code 39 var defaultFilePerm = os.FileMode(0) 40 41 type Process struct { 42 // Subsystem is the name of the subsystem that the process / task is in. 43 Subsystem Name 44 // Pid is the process id of the process / task. 45 Pid int 46 // Path is the full path of the subsystem and location that the process / task is in. 47 Path string 48 } 49 50 type Task = Process 51 52 // Cgroup handles interactions with the individual groups to perform 53 // actions on them as them main interface to this cgroup package 54 type Cgroup interface { 55 // New creates a new cgroup under the calling cgroup 56 New(string, *specs.LinuxResources) (Cgroup, error) 57 // Add adds a process to the cgroup (cgroup.procs). Without additional arguments, 58 // the process is added to all the cgroup subsystems. When giving Add a list of 59 // subsystem names, the process is only added to those subsystems, provided that 60 // they are active in the targeted cgroup. 61 Add(Process, ...Name) error 62 // AddProc adds the process with the given id to the cgroup (cgroup.procs). 63 // Without additional arguments, the process with the given id is added to all 64 // the cgroup subsystems. When giving AddProc a list of subsystem names, the process 65 // id is only added to those subsystems, provided that they are active in the targeted 66 // cgroup. 67 AddProc(uint64, ...Name) error 68 // AddTask adds a process to the cgroup (tasks). Without additional arguments, the 69 // task is added to all the cgroup subsystems. When giving AddTask a list of subsystem 70 // names, the task is only added to those subsystems, provided that they are active in 71 // the targeted cgroup. 72 AddTask(Process, ...Name) error 73 // Delete removes the cgroup as a whole 74 Delete() error 75 // MoveTo moves all the processes under the calling cgroup to the provided one 76 // subsystems are moved one at a time 77 MoveTo(Cgroup) error 78 // Stat returns the stats for all subsystems in the cgroup 79 Stat(...ErrorHandler) (*v1.Metrics, error) 80 // Update updates all the subsystems with the provided resource changes 81 Update(resources *specs.LinuxResources) error 82 // Processes returns all the processes in a select subsystem for the cgroup 83 Processes(Name, bool) ([]Process, error) 84 // Tasks returns all the tasks in a select subsystem for the cgroup 85 Tasks(Name, bool) ([]Task, error) 86 // Freeze freezes or pauses all processes inside the cgroup 87 Freeze() error 88 // Thaw thaw or resumes all processes inside the cgroup 89 Thaw() error 90 // OOMEventFD returns the memory subsystem's event fd for OOM events 91 OOMEventFD() (uintptr, error) 92 // RegisterMemoryEvent returns the memory subsystems event fd for whatever memory event was 93 // registered for. Can alternatively register for the oom event with this method. 94 RegisterMemoryEvent(MemoryEvent) (uintptr, error) 95 // State returns the cgroups current state 96 State() State 97 // Subsystems returns all the subsystems in the cgroup 98 Subsystems() []Subsystem 99 } 100