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authorMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
committerMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
commita031b83a09a8628435317a03f199cdc18b78262f (patch)
treebc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/containerd/cgroups/cgroup.go
parent2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff)
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Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/containerd/cgroups/cgroup.go')
-rw-r--r--vendor/github.com/containerd/cgroups/cgroup.go389
1 files changed, 389 insertions, 0 deletions
diff --git a/vendor/github.com/containerd/cgroups/cgroup.go b/vendor/github.com/containerd/cgroups/cgroup.go
new file mode 100644
index 000000000..74a324f9e
--- /dev/null
+++ b/vendor/github.com/containerd/cgroups/cgroup.go
@@ -0,0 +1,389 @@
+package cgroups
+
+import (
+ "fmt"
+ "io/ioutil"
+ "os"
+ "path/filepath"
+ "strconv"
+ "strings"
+ "sync"
+
+ specs "github.com/opencontainers/runtime-spec/specs-go"
+)
+
+// New returns a new control via the cgroup cgroups interface
+func New(hierarchy Hierarchy, path Path, resources *specs.LinuxResources) (Cgroup, error) {
+ subsystems, err := hierarchy()
+ if err != nil {
+ return nil, err
+ }
+ for _, s := range subsystems {
+ if err := initializeSubsystem(s, path, resources); err != nil {
+ return nil, err
+ }
+ }
+ return &cgroup{
+ path: path,
+ subsystems: subsystems,
+ }, nil
+}
+
+// Load will load an existing cgroup and allow it to be controlled
+func Load(hierarchy Hierarchy, path Path) (Cgroup, error) {
+ subsystems, err := hierarchy()
+ if err != nil {
+ return nil, err
+ }
+ // check the the subsystems still exist
+ for _, s := range pathers(subsystems) {
+ p, err := path(s.Name())
+ if err != nil {
+ return nil, err
+ }
+ if _, err := os.Lstat(s.Path(p)); err != nil {
+ if os.IsNotExist(err) {
+ return nil, ErrCgroupDeleted
+ }
+ return nil, err
+ }
+ }
+ return &cgroup{
+ path: path,
+ subsystems: subsystems,
+ }, nil
+}
+
+type cgroup struct {
+ path Path
+
+ subsystems []Subsystem
+ mu sync.Mutex
+ err error
+}
+
+// New returns a new sub cgroup
+func (c *cgroup) New(name string, resources *specs.LinuxResources) (Cgroup, error) {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return nil, c.err
+ }
+ path := subPath(c.path, name)
+ for _, s := range c.subsystems {
+ if err := initializeSubsystem(s, path, resources); err != nil {
+ return nil, err
+ }
+ }
+ return &cgroup{
+ path: path,
+ subsystems: c.subsystems,
+ }, nil
+}
+
+// Subsystems returns all the subsystems that are currently being
+// consumed by the group
+func (c *cgroup) Subsystems() []Subsystem {
+ return c.subsystems
+}
+
+// Add moves the provided process into the new cgroup
+func (c *cgroup) Add(process Process) error {
+ if process.Pid <= 0 {
+ return ErrInvalidPid
+ }
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return c.err
+ }
+ return c.add(process)
+}
+
+func (c *cgroup) add(process Process) error {
+ for _, s := range pathers(c.subsystems) {
+ p, err := c.path(s.Name())
+ if err != nil {
+ return err
+ }
+ if err := ioutil.WriteFile(
+ filepath.Join(s.Path(p), cgroupProcs),
+ []byte(strconv.Itoa(process.Pid)),
+ defaultFilePerm,
+ ); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+// Delete will remove the control group from each of the subsystems registered
+func (c *cgroup) Delete() error {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return c.err
+ }
+ var errors []string
+ for _, s := range c.subsystems {
+ if d, ok := s.(deleter); ok {
+ sp, err := c.path(s.Name())
+ if err != nil {
+ return err
+ }
+ if err := d.Delete(sp); err != nil {
+ errors = append(errors, string(s.Name()))
+ }
+ continue
+ }
+ if p, ok := s.(pather); ok {
+ sp, err := c.path(s.Name())
+ if err != nil {
+ return err
+ }
+ path := p.Path(sp)
+ if err := remove(path); err != nil {
+ errors = append(errors, path)
+ }
+ }
+ }
+ if len(errors) > 0 {
+ return fmt.Errorf("cgroups: unable to remove paths %s", strings.Join(errors, ", "))
+ }
+ c.err = ErrCgroupDeleted
+ return nil
+}
+
+// Stat returns the current stats for the cgroup
+func (c *cgroup) Stat(handlers ...ErrorHandler) (*Stats, error) {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return nil, c.err
+ }
+ if len(handlers) == 0 {
+ handlers = append(handlers, errPassthrough)
+ }
+ var (
+ stats = &Stats{}
+ wg = &sync.WaitGroup{}
+ errs = make(chan error, len(c.subsystems))
+ )
+ for _, s := range c.subsystems {
+ if ss, ok := s.(stater); ok {
+ sp, err := c.path(s.Name())
+ if err != nil {
+ return nil, err
+ }
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ if err := ss.Stat(sp, stats); err != nil {
+ for _, eh := range handlers {
+ if herr := eh(err); herr != nil {
+ errs <- herr
+ }
+ }
+ }
+ }()
+ }
+ }
+ wg.Wait()
+ close(errs)
+ for err := range errs {
+ return nil, err
+ }
+ return stats, nil
+}
+
+// Update updates the cgroup with the new resource values provided
+//
+// Be prepared to handle EBUSY when trying to update a cgroup with
+// live processes and other operations like Stats being performed at the
+// same time
+func (c *cgroup) Update(resources *specs.LinuxResources) error {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return c.err
+ }
+ for _, s := range c.subsystems {
+ if u, ok := s.(updater); ok {
+ sp, err := c.path(s.Name())
+ if err != nil {
+ return err
+ }
+ if err := u.Update(sp, resources); err != nil {
+ return err
+ }
+ }
+ }
+ return nil
+}
+
+// Processes returns the processes running inside the cgroup along
+// with the subsystem used, pid, and path
+func (c *cgroup) Processes(subsystem Name, recursive bool) ([]Process, error) {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return nil, c.err
+ }
+ return c.processes(subsystem, recursive)
+}
+
+func (c *cgroup) processes(subsystem Name, recursive bool) ([]Process, error) {
+ s := c.getSubsystem(subsystem)
+ sp, err := c.path(subsystem)
+ if err != nil {
+ return nil, err
+ }
+ path := s.(pather).Path(sp)
+ var processes []Process
+ err = filepath.Walk(path, func(p string, info os.FileInfo, err error) error {
+ if err != nil {
+ return err
+ }
+ if !recursive && info.IsDir() {
+ if p == path {
+ return nil
+ }
+ return filepath.SkipDir
+ }
+ dir, name := filepath.Split(p)
+ if name != cgroupProcs {
+ return nil
+ }
+ procs, err := readPids(dir, subsystem)
+ if err != nil {
+ return err
+ }
+ processes = append(processes, procs...)
+ return nil
+ })
+ return processes, err
+}
+
+// Freeze freezes the entire cgroup and all the processes inside it
+func (c *cgroup) Freeze() error {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return c.err
+ }
+ s := c.getSubsystem(Freezer)
+ if s == nil {
+ return ErrFreezerNotSupported
+ }
+ sp, err := c.path(Freezer)
+ if err != nil {
+ return err
+ }
+ return s.(*freezerController).Freeze(sp)
+}
+
+// Thaw thaws out the cgroup and all the processes inside it
+func (c *cgroup) Thaw() error {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return c.err
+ }
+ s := c.getSubsystem(Freezer)
+ if s == nil {
+ return ErrFreezerNotSupported
+ }
+ sp, err := c.path(Freezer)
+ if err != nil {
+ return err
+ }
+ return s.(*freezerController).Thaw(sp)
+}
+
+// OOMEventFD returns the memory cgroup's out of memory event fd that triggers
+// when processes inside the cgroup receive an oom event
+func (c *cgroup) OOMEventFD() (uintptr, error) {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return 0, c.err
+ }
+ s := c.getSubsystem(Memory)
+ if s == nil {
+ return 0, ErrMemoryNotSupported
+ }
+ sp, err := c.path(Memory)
+ if err != nil {
+ return 0, err
+ }
+ return s.(*memoryController).OOMEventFD(sp)
+}
+
+// State returns the state of the cgroup and its processes
+func (c *cgroup) State() State {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ c.checkExists()
+ if c.err != nil && c.err == ErrCgroupDeleted {
+ return Deleted
+ }
+ s := c.getSubsystem(Freezer)
+ if s == nil {
+ return Thawed
+ }
+ sp, err := c.path(Freezer)
+ if err != nil {
+ return Unknown
+ }
+ state, err := s.(*freezerController).state(sp)
+ if err != nil {
+ return Unknown
+ }
+ return state
+}
+
+// MoveTo does a recursive move subsystem by subsystem of all the processes
+// inside the group
+func (c *cgroup) MoveTo(destination Cgroup) error {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+ if c.err != nil {
+ return c.err
+ }
+ for _, s := range c.subsystems {
+ processes, err := c.processes(s.Name(), true)
+ if err != nil {
+ return err
+ }
+ for _, p := range processes {
+ if err := destination.Add(p); err != nil {
+ return err
+ }
+ }
+ }
+ return nil
+}
+
+func (c *cgroup) getSubsystem(n Name) Subsystem {
+ for _, s := range c.subsystems {
+ if s.Name() == n {
+ return s
+ }
+ }
+ return nil
+}
+
+func (c *cgroup) checkExists() {
+ for _, s := range pathers(c.subsystems) {
+ p, err := c.path(s.Name())
+ if err != nil {
+ return
+ }
+ if _, err := os.Lstat(s.Path(p)); err != nil {
+ if os.IsNotExist(err) {
+ c.err = ErrCgroupDeleted
+ return
+ }
+ }
+ }
+}