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>
2017-08-24 16:27:35 -04:00
parent a6ce1ef2a1
commit 967497097a
7 changed files with 716 additions and 108 deletions
--- a/linux/shim/init_state.go
+++ b/linux/shim/init_state.go
@@ -0,0 +1,356 @@
+// +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
+}