containerd/linux/shim/init_state.go
Michael Crosby 967497097a Add procesStates for shim processes
Use the state pattern to handle process transitions from one state to
another and what actions can be performed on a process in a specific
state.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
2017-08-25 14:03:55 -04:00

357 lines
7.4 KiB
Go

// +build !windows
package shim
import (
"context"
"github.com/containerd/console"
shimapi "github.com/containerd/containerd/linux/shim/v1"
"github.com/pkg/errors"
)
type initState interface {
processState
Pause(context.Context) error
Resume(context.Context) error
Update(context.Context, *shimapi.UpdateTaskRequest) error
Checkpoint(context.Context, *shimapi.CheckpointTaskRequest) error
}
type createdState struct {
p *initProcess
}
func (s *createdState) transition(name string) error {
switch name {
case "running":
s.p.initState = &runningState{p: s.p}
case "stopped":
s.p.initState = &stoppedState{p: s.p}
case "deleted":
s.p.initState = &deletedState{}
default:
return errors.Errorf("invalid state transition %q to %q", stateName(s), name)
}
return nil
}
func (s *createdState) Pause(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot pause task in created state")
}
func (s *createdState) Resume(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot resume task in created state")
}
func (s *createdState) Update(context context.Context, r *shimapi.UpdateTaskRequest) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.update(context, r)
}
func (s *createdState) Checkpoint(context context.Context, r *shimapi.CheckpointTaskRequest) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot checkpoint a task in created state")
}
func (s *createdState) Resize(ws console.WinSize) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.resize(ws)
}
func (s *createdState) Start(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
if err := s.p.start(ctx); err != nil {
return err
}
return s.transition("running")
}
func (s *createdState) Delete(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
if err := s.p.delete(ctx); err != nil {
return err
}
return s.transition("deleted")
}
func (s *createdState) Kill(ctx context.Context, sig uint32, all bool) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.kill(ctx, sig, all)
}
func (s *createdState) SetExited(status int) {
s.p.mu.Lock()
defer s.p.mu.Unlock()
s.p.setExited(status)
if err := s.transition("stopped"); err != nil {
panic(err)
}
}
type runningState struct {
p *initProcess
}
func (s *runningState) transition(name string) error {
switch name {
case "stopped":
s.p.initState = &stoppedState{p: s.p}
case "paused":
s.p.initState = &pausedState{p: s.p}
default:
return errors.Errorf("invalid state transition %q to %q", stateName(s), name)
}
return nil
}
func (s *runningState) Pause(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
if err := s.p.pause(ctx); err != nil {
return err
}
return s.transition("paused")
}
func (s *runningState) Resume(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot resume a running process")
}
func (s *runningState) Update(context context.Context, r *shimapi.UpdateTaskRequest) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.update(context, r)
}
func (s *runningState) Checkpoint(ctx context.Context, r *shimapi.CheckpointTaskRequest) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.checkpoint(ctx, r)
}
func (s *runningState) Resize(ws console.WinSize) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.resize(ws)
}
func (s *runningState) Start(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot start a running process")
}
func (s *runningState) Delete(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot delete a running process")
}
func (s *runningState) Kill(ctx context.Context, sig uint32, all bool) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.kill(ctx, sig, all)
}
func (s *runningState) SetExited(status int) {
s.p.mu.Lock()
defer s.p.mu.Unlock()
s.p.setExited(status)
if err := s.transition("stopped"); err != nil {
panic(err)
}
}
type pausedState struct {
p *initProcess
}
func (s *pausedState) transition(name string) error {
switch name {
case "running":
s.p.initState = &runningState{p: s.p}
case "stopped":
s.p.initState = &stoppedState{p: s.p}
default:
return errors.Errorf("invalid state transition %q to %q", stateName(s), name)
}
return nil
}
func (s *pausedState) Pause(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot pause a paused container")
}
func (s *pausedState) Resume(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
if err := s.p.resume(ctx); err != nil {
return err
}
return s.transition("running")
}
func (s *pausedState) Update(context context.Context, r *shimapi.UpdateTaskRequest) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.update(context, r)
}
func (s *pausedState) Checkpoint(ctx context.Context, r *shimapi.CheckpointTaskRequest) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.checkpoint(ctx, r)
}
func (s *pausedState) Resize(ws console.WinSize) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.resize(ws)
}
func (s *pausedState) Start(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot start a paused process")
}
func (s *pausedState) Delete(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot delete a paused process")
}
func (s *pausedState) Kill(ctx context.Context, sig uint32, all bool) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.kill(ctx, sig, all)
}
func (s *pausedState) SetExited(status int) {
s.p.mu.Lock()
defer s.p.mu.Unlock()
s.p.setExited(status)
if err := s.transition("stopped"); err != nil {
panic(err)
}
}
type stoppedState struct {
p *initProcess
}
func (s *stoppedState) transition(name string) error {
switch name {
case "deleted":
s.p.initState = &deletedState{}
default:
return errors.Errorf("invalid state transition %q to %q", stateName(s), name)
}
return nil
}
func (s *stoppedState) Pause(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot pause a stopped container")
}
func (s *stoppedState) Resume(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot resume a stopped container")
}
func (s *stoppedState) Update(context context.Context, r *shimapi.UpdateTaskRequest) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot update a stopped container")
}
func (s *stoppedState) Checkpoint(ctx context.Context, r *shimapi.CheckpointTaskRequest) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot checkpoint a stopped container")
}
func (s *stoppedState) Resize(ws console.WinSize) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot resize a stopped container")
}
func (s *stoppedState) Start(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return errors.Errorf("cannot start a stopped process")
}
func (s *stoppedState) Delete(ctx context.Context) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
if err := s.p.delete(ctx); err != nil {
return err
}
return s.transition("deleted")
}
func (s *stoppedState) Kill(ctx context.Context, sig uint32, all bool) error {
s.p.mu.Lock()
defer s.p.mu.Unlock()
return s.p.kill(ctx, sig, all)
}
func (s *stoppedState) SetExited(status int) {
// no op
}