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moby--moby/daemon/state.go
David Calavera 4f2a5ba360 Decouple daemon and container to stop and kill containers.
Signed-off-by: David Calavera <david.calavera@gmail.com>
2015-11-04 12:27:47 -05:00

265 lines
5.9 KiB
Go

package daemon
import (
"fmt"
"sync"
"time"
"github.com/docker/docker/daemon/execdriver"
derr "github.com/docker/docker/errors"
"github.com/docker/docker/pkg/units"
)
// State holds the current container state, and has methods to get and
// set the state. Container has an embed, which allows all of the
// functions defined against State to run against Container.
type State struct {
sync.Mutex
// FIXME: Why do we have both paused and running if a
// container cannot be paused and running at the same time?
Running bool
Paused bool
Restarting bool
OOMKilled bool
removalInProgress bool // Not need for this to be persistent on disk.
Dead bool
Pid int
ExitCode int
Error string // contains last known error when starting the container
StartedAt time.Time
FinishedAt time.Time
waitChan chan struct{}
}
// NewState creates a default state object with a fresh channel for state changes.
func NewState() *State {
return &State{
waitChan: make(chan struct{}),
}
}
// String returns a human-readable description of the state
func (s *State) String() string {
if s.Running {
if s.Paused {
return fmt.Sprintf("Up %s (Paused)", units.HumanDuration(time.Now().UTC().Sub(s.StartedAt)))
}
if s.Restarting {
return fmt.Sprintf("Restarting (%d) %s ago", s.ExitCode, units.HumanDuration(time.Now().UTC().Sub(s.FinishedAt)))
}
return fmt.Sprintf("Up %s", units.HumanDuration(time.Now().UTC().Sub(s.StartedAt)))
}
if s.removalInProgress {
return "Removal In Progress"
}
if s.Dead {
return "Dead"
}
if s.StartedAt.IsZero() {
return "Created"
}
if s.FinishedAt.IsZero() {
return ""
}
return fmt.Sprintf("Exited (%d) %s ago", s.ExitCode, units.HumanDuration(time.Now().UTC().Sub(s.FinishedAt)))
}
// StateString returns a single string to describe state
func (s *State) StateString() string {
if s.Running {
if s.Paused {
return "paused"
}
if s.Restarting {
return "restarting"
}
return "running"
}
if s.Dead {
return "dead"
}
if s.StartedAt.IsZero() {
return "created"
}
return "exited"
}
func isValidStateString(s string) bool {
if s != "paused" &&
s != "restarting" &&
s != "running" &&
s != "dead" &&
s != "created" &&
s != "exited" {
return false
}
return true
}
func wait(waitChan <-chan struct{}, timeout time.Duration) error {
if timeout < 0 {
<-waitChan
return nil
}
select {
case <-time.After(timeout):
return derr.ErrorCodeTimedOut.WithArgs(timeout)
case <-waitChan:
return nil
}
}
// waitRunning waits until state is running. If state is already
// running it returns immediately. If you want wait forever you must
// supply negative timeout. Returns pid, that was passed to
// setRunning.
func (s *State) waitRunning(timeout time.Duration) (int, error) {
s.Lock()
if s.Running {
pid := s.Pid
s.Unlock()
return pid, nil
}
waitChan := s.waitChan
s.Unlock()
if err := wait(waitChan, timeout); err != nil {
return -1, err
}
return s.GetPID(), nil
}
// WaitStop waits until state is stopped. If state already stopped it returns
// immediately. If you want wait forever you must supply negative timeout.
// Returns exit code, that was passed to setStoppedLocking
func (s *State) WaitStop(timeout time.Duration) (int, error) {
s.Lock()
if !s.Running {
exitCode := s.ExitCode
s.Unlock()
return exitCode, nil
}
waitChan := s.waitChan
s.Unlock()
if err := wait(waitChan, timeout); err != nil {
return -1, err
}
return s.getExitCode(), nil
}
// IsRunning returns whether the running flag is set. Used by Container to check whether a container is running.
func (s *State) IsRunning() bool {
s.Lock()
res := s.Running
s.Unlock()
return res
}
// GetPID holds the process id of a container.
func (s *State) GetPID() int {
s.Lock()
res := s.Pid
s.Unlock()
return res
}
func (s *State) getExitCode() int {
s.Lock()
res := s.ExitCode
s.Unlock()
return res
}
func (s *State) setRunning(pid int) {
s.Error = ""
s.Running = true
s.Paused = false
s.Restarting = false
s.ExitCode = 0
s.Pid = pid
s.StartedAt = time.Now().UTC()
close(s.waitChan) // fire waiters for start
s.waitChan = make(chan struct{})
}
func (s *State) setStoppedLocking(exitStatus *execdriver.ExitStatus) {
s.Lock()
s.setStopped(exitStatus)
s.Unlock()
}
func (s *State) setStopped(exitStatus *execdriver.ExitStatus) {
s.Running = false
s.Restarting = false
s.Pid = 0
s.FinishedAt = time.Now().UTC()
s.ExitCode = exitStatus.ExitCode
s.OOMKilled = exitStatus.OOMKilled
close(s.waitChan) // fire waiters for stop
s.waitChan = make(chan struct{})
}
// setRestarting is when docker handles the auto restart of containers when they are
// in the middle of a stop and being restarted again
func (s *State) setRestartingLocking(exitStatus *execdriver.ExitStatus) {
s.Lock()
s.setRestarting(exitStatus)
s.Unlock()
}
func (s *State) setRestarting(exitStatus *execdriver.ExitStatus) {
// we should consider the container running when it is restarting because of
// all the checks in docker around rm/stop/etc
s.Running = true
s.Restarting = true
s.Pid = 0
s.FinishedAt = time.Now().UTC()
s.ExitCode = exitStatus.ExitCode
s.OOMKilled = exitStatus.OOMKilled
close(s.waitChan) // fire waiters for stop
s.waitChan = make(chan struct{})
}
// setError sets the container's error state. This is useful when we want to
// know the error that occurred when container transits to another state
// when inspecting it
func (s *State) setError(err error) {
s.Error = err.Error()
}
func (s *State) isPaused() bool {
s.Lock()
res := s.Paused
s.Unlock()
return res
}
func (s *State) setRemovalInProgress() error {
s.Lock()
defer s.Unlock()
if s.removalInProgress {
return derr.ErrorCodeAlreadyRemoving
}
s.removalInProgress = true
return nil
}
func (s *State) resetRemovalInProgress() {
s.Lock()
s.removalInProgress = false
s.Unlock()
}
func (s *State) setDead() {
s.Lock()
s.Dead = true
s.Unlock()
}