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.setFromExitStatus(exitStatus) 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.setFromExitStatus(exitStatus) 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() }