コード例 #1
0
ファイル: taskrunner_test.go プロジェクト: niemeyer/snapd
func (ts *taskRunnerSuite) TestExternalAbort(c *C) {
	sb := &stateBackend{}
	st := state.New(sb)
	r := state.NewTaskRunner(st)
	defer r.Stop()

	ch := make(chan bool)
	r.AddHandler("blocking", func(t *state.Task, tb *tomb.Tomb) error {
		ch <- true
		<-tb.Dying()
		return nil
	}, nil)

	st.Lock()
	chg := st.NewChange("install", "...")
	t := st.NewTask("blocking", "...")
	chg.AddTask(t)
	st.Unlock()

	r.Ensure()
	<-ch

	st.Lock()
	chg.Abort()
	st.Unlock()

	// The Abort above must make Ensure kill the task, or this will never end.
	ensureChange(c, r, sb, chg)
}
コード例 #2
0
ファイル: taskrunner_test.go プロジェクト: niemeyer/snapd
func (ts *taskRunnerSuite) TestStopHandlerJustFinishing(c *C) {
	sb := &stateBackend{}
	st := state.New(sb)
	r := state.NewTaskRunner(st)
	defer r.Stop()

	ch := make(chan bool)
	r.AddHandler("just-finish", func(t *state.Task, tb *tomb.Tomb) error {
		ch <- true
		<-tb.Dying()
		// just ignore and actually finishes
		return nil
	}, nil)

	st.Lock()
	chg := st.NewChange("install", "...")
	t := st.NewTask("just-finish", "...")
	chg.AddTask(t)
	st.Unlock()

	r.Ensure()
	<-ch
	r.Stop()

	st.Lock()
	defer st.Unlock()
	c.Check(t.Status(), Equals, state.DoneStatus)
}
コード例 #3
0
ファイル: taskrunner_test.go プロジェクト: niemeyer/snapd
func (ts *taskRunnerSuite) TestStopAskForRetry(c *C) {
	sb := &stateBackend{}
	st := state.New(sb)
	r := state.NewTaskRunner(st)
	defer r.Stop()

	ch := make(chan bool)
	r.AddHandler("ask-for-retry", func(t *state.Task, tb *tomb.Tomb) error {
		ch <- true
		<-tb.Dying()
		// ask for retry
		return &state.Retry{}
	}, nil)

	st.Lock()
	chg := st.NewChange("install", "...")
	t := st.NewTask("ask-for-retry", "...")
	chg.AddTask(t)
	st.Unlock()

	r.Ensure()
	<-ch
	r.Stop()

	st.Lock()
	defer st.Unlock()
	c.Check(t.Status(), Equals, state.DoingStatus)
}
コード例 #4
0
ファイル: overlord_test.go プロジェクト: niemeyer/snapd
func newRunnerManager(s *state.State) *runnerManager {
	rm := &runnerManager{
		runner: state.NewTaskRunner(s),
	}

	rm.runner.AddHandler("runMgr1", func(t *state.Task, _ *tomb.Tomb) error {
		s := t.State()
		s.Lock()
		defer s.Unlock()
		s.Set("runMgr1Mark", 1)
		return nil
	}, nil)
	rm.runner.AddHandler("runMgr2", func(t *state.Task, _ *tomb.Tomb) error {
		s := t.State()
		s.Lock()
		defer s.Unlock()
		s.Set("runMgr2Mark", 1)
		return nil
	}, nil)
	rm.runner.AddHandler("runMgrEnsureBefore", func(t *state.Task, _ *tomb.Tomb) error {
		s := t.State()
		s.Lock()
		defer s.Unlock()
		s.EnsureBefore(20 * time.Millisecond)
		return nil
	}, nil)

	return rm
}
コード例 #5
0
ファイル: snapmgr.go プロジェクト: pedronis/snappy
// Manager returns a new snap manager.
func Manager(st *state.State) (*SnapManager, error) {
	runner := state.NewTaskRunner(st)

	m := &SnapManager{
		state:   st,
		backend: backend.Backend{},
		runner:  runner,
	}

	// this handler does nothing
	runner.AddHandler("nop", func(t *state.Task, _ *tomb.Tomb) error {
		return nil
	}, nil)

	// install/update related
	runner.AddHandler("prepare-snap", m.doPrepareSnap, m.undoPrepareSnap)
	runner.AddHandler("download-snap", m.doDownloadSnap, m.undoPrepareSnap)
	runner.AddHandler("mount-snap", m.doMountSnap, m.undoMountSnap)
	runner.AddHandler("unlink-current-snap", m.doUnlinkCurrentSnap, m.undoUnlinkCurrentSnap)
	runner.AddHandler("copy-snap-data", m.doCopySnapData, m.undoCopySnapData)
	runner.AddCleanup("copy-snap-data", m.cleanupCopySnapData)
	runner.AddHandler("link-snap", m.doLinkSnap, m.undoLinkSnap)
	runner.AddHandler("start-snap-services", m.startSnapServices, m.stopSnapServices)

	// FIXME: drop the task entirely after a while
	// (having this wart here avoids yet-another-patch)
	runner.AddHandler("cleanup", func(*state.Task, *tomb.Tomb) error { return nil }, nil)

	// remove related
	runner.AddHandler("stop-snap-services", m.stopSnapServices, m.startSnapServices)
	runner.AddHandler("unlink-snap", m.doUnlinkSnap, nil)
	runner.AddHandler("clear-snap", m.doClearSnapData, nil)
	runner.AddHandler("discard-snap", m.doDiscardSnap, nil)

	// alias related
	runner.AddHandler("alias", m.doAlias, m.undoAlias)
	runner.AddHandler("clear-aliases", m.doClearAliases, m.undoClearAliases)
	runner.AddHandler("set-auto-aliases", m.doSetAutoAliases, m.undoClearAliases)
	runner.AddHandler("setup-aliases", m.doSetupAliases, m.undoSetupAliases)
	runner.AddHandler("remove-aliases", m.doRemoveAliases, m.doSetupAliases)

	// control serialisation
	runner.SetBlocked(m.blockedTask)

	// test handlers
	runner.AddHandler("fake-install-snap", func(t *state.Task, _ *tomb.Tomb) error {
		return nil
	}, nil)
	runner.AddHandler("fake-install-snap-error", func(t *state.Task, _ *tomb.Tomb) error {
		return fmt.Errorf("fake-install-snap-error errored")
	}, nil)

	return m, nil
}
コード例 #6
0
ファイル: hookmgr.go プロジェクト: clobrano/snappy
// Manager returns a new HookManager.
func Manager(s *state.State) (*HookManager, error) {
	runner := state.NewTaskRunner(s)
	manager := &HookManager{
		state:      s,
		runner:     runner,
		repository: newRepository(),
		contexts:   make(map[string]*Context),
	}

	runner.AddHandler("run-hook", manager.doRunHook, nil)

	return manager, nil
}
コード例 #7
0
ファイル: snapmgr.go プロジェクト: niemeyer/snapd
// Manager returns a new snap manager.
func Manager(s *state.State) (*SnapManager, error) {
	runner := state.NewTaskRunner(s)

	m := &SnapManager{
		state:   s,
		backend: backend.Backend{},
		runner:  runner,
	}

	// this handler does nothing
	runner.AddHandler("nop", func(t *state.Task, _ *tomb.Tomb) error {
		return nil
	}, nil)

	// install/update related
	runner.AddHandler("prepare-snap", m.doPrepareSnap, m.undoPrepareSnap)
	runner.AddHandler("download-snap", m.doDownloadSnap, m.undoPrepareSnap)
	runner.AddHandler("mount-snap", m.doMountSnap, m.undoMountSnap)
	runner.AddHandler("unlink-current-snap", m.doUnlinkCurrentSnap, m.undoUnlinkCurrentSnap)
	runner.AddHandler("copy-snap-data", m.doCopySnapData, m.undoCopySnapData)
	runner.AddCleanup("copy-snap-data", m.cleanupCopySnapData)
	runner.AddHandler("link-snap", m.doLinkSnap, m.undoLinkSnap)
	runner.AddHandler("start-snap-services", m.startSnapServices, m.stopSnapServices)

	// FIXME: drop the task entirely after a while
	// (having this wart here avoids yet-another-patch)
	runner.AddHandler("cleanup", func(*state.Task, *tomb.Tomb) error { return nil }, nil)

	// FIXME: port to native tasks and rename
	//runner.AddHandler("garbage-collect", m.doGarbageCollect, nil)

	// TODO: refresh-all needs logic at this level, to properly
	// handle the logic for that mode (e.g. skip snaps installed
	// with --devmode, set jailmode from snapstate).

	// remove related
	runner.AddHandler("stop-snap-services", m.stopSnapServices, m.startSnapServices)
	runner.AddHandler("unlink-snap", m.doUnlinkSnap, nil)
	runner.AddHandler("clear-snap", m.doClearSnapData, nil)
	runner.AddHandler("discard-snap", m.doDiscardSnap, nil)

	// test handlers
	runner.AddHandler("fake-install-snap", func(t *state.Task, _ *tomb.Tomb) error {
		return nil
	}, nil)
	runner.AddHandler("fake-install-snap-error", func(t *state.Task, _ *tomb.Tomb) error {
		return fmt.Errorf("fake-install-snap-error errored")
	}, nil)

	return m, nil
}
コード例 #8
0
ファイル: taskrunner_test.go プロジェクト: niemeyer/snapd
func (ts *taskRunnerSuite) TestCleanup(c *C) {
	sb := &stateBackend{}
	st := state.New(sb)
	r := state.NewTaskRunner(st)
	defer r.Stop()

	r.AddHandler("clean-it", func(t *state.Task, tb *tomb.Tomb) error { return nil }, nil)
	r.AddHandler("other", func(t *state.Task, tb *tomb.Tomb) error { return nil }, nil)

	called := 0
	r.AddCleanup("clean-it", func(t *state.Task, tb *tomb.Tomb) error {
		called++
		if called == 1 {
			return fmt.Errorf("retry me")
		}
		return nil
	})

	st.Lock()
	chg := st.NewChange("install", "...")
	t1 := st.NewTask("clean-it", "...")
	t2 := st.NewTask("other", "...")
	chg.AddTask(t1)
	chg.AddTask(t2)
	st.Unlock()

	chgIsClean := func() bool {
		st.Lock()
		defer st.Unlock()
		return chg.IsClean()
	}

	// Mark tasks as done.
	ensureChange(c, r, sb, chg)

	// First time it errors, then it works, then it's ignored.
	c.Assert(chgIsClean(), Equals, false)
	c.Assert(called, Equals, 0)
	r.Ensure()
	r.Wait()
	c.Assert(chgIsClean(), Equals, false)
	c.Assert(called, Equals, 1)
	r.Ensure()
	r.Wait()
	c.Assert(chgIsClean(), Equals, true)
	c.Assert(called, Equals, 2)
	r.Ensure()
	r.Wait()
	c.Assert(chgIsClean(), Equals, true)
	c.Assert(called, Equals, 2)
}
コード例 #9
0
ファイル: taskrunner_test.go プロジェクト: clobrano/snappy
func (ts *taskRunnerSuite) TestPrematureChangeReady(c *C) {
	sb := &stateBackend{}
	st := state.New(sb)
	r := state.NewTaskRunner(st)
	defer r.Stop()

	ch := make(chan bool)
	r.AddHandler("block-undo", func(t *state.Task, tb *tomb.Tomb) error { return nil },
		func(t *state.Task, tb *tomb.Tomb) error {
			ch <- true
			<-ch
			return nil
		})
	r.AddHandler("fail", func(t *state.Task, tb *tomb.Tomb) error {
		return errors.New("BAM")
	}, nil)

	st.Lock()
	chg := st.NewChange("install", "...")
	t1 := st.NewTask("block-undo", "...")
	t2 := st.NewTask("fail", "...")
	chg.AddTask(t1)
	chg.AddTask(t2)
	st.Unlock()

	r.Ensure() // Error
	r.Wait()
	r.Ensure() // Block on undo
	<-ch

	defer func() {
		ch <- true
		r.Wait()
	}()

	st.Lock()
	defer st.Unlock()

	if chg.Status().Ready() {
		c.Errorf("Change considered ready prematurely")
	}

	c.Assert(chg.Err(), IsNil)

	select {
	case <-chg.Ready():
		c.Errorf("Change considered ready prematurely")
	default:
	}
}
コード例 #10
0
ファイル: assertmgr.go プロジェクト: niemeyer/snapd
// Manager returns a new assertion manager.
func Manager(s *state.State) (*AssertManager, error) {
	runner := state.NewTaskRunner(s)

	runner.AddHandler("validate-snap", doValidateSnap, nil)

	db, err := sysdb.Open()
	if err != nil {
		return nil, err
	}

	s.Lock()
	ReplaceDB(s, db)
	s.Unlock()

	return &AssertManager{runner: runner}, nil
}
コード例 #11
0
ファイル: devicemgr.go プロジェクト: clobrano/snappy
// Manager returns a new device manager.
func Manager(s *state.State) (*DeviceManager, error) {
	runner := state.NewTaskRunner(s)

	keypairMgr, err := asserts.OpenFSKeypairManager(dirs.SnapDeviceDir)
	if err != nil {
		return nil, err

	}

	m := &DeviceManager{state: s, keypairMgr: keypairMgr, runner: runner}

	runner.AddHandler("generate-device-key", m.doGenerateDeviceKey, nil)
	runner.AddHandler("request-serial", m.doRequestSerial, nil)

	return m, nil
}
コード例 #12
0
ファイル: devicemgr.go プロジェクト: niemeyer/snapd
// Manager returns a new device manager.
func Manager(s *state.State, hookManager *hookstate.HookManager) (*DeviceManager, error) {
	runner := state.NewTaskRunner(s)

	keypairMgr, err := asserts.OpenFSKeypairManager(dirs.SnapDeviceDir)
	if err != nil {
		return nil, err

	}

	m := &DeviceManager{state: s, keypairMgr: keypairMgr, runner: runner}

	hookManager.Register(regexp.MustCompile("^prepare-device$"), newPrepareDeviceHandler)

	runner.AddHandler("generate-device-key", m.doGenerateDeviceKey, nil)
	runner.AddHandler("request-serial", m.doRequestSerial, nil)
	runner.AddHandler("mark-seeded", m.doMarkSeeded, nil)

	return m, nil
}
コード例 #13
0
ファイル: ifacemgr.go プロジェクト: niemeyer/snapd
// Manager returns a new InterfaceManager.
// Extra interfaces can be provided for testing.
func Manager(s *state.State, extra []interfaces.Interface) (*InterfaceManager, error) {
	runner := state.NewTaskRunner(s)
	m := &InterfaceManager{
		state:  s,
		runner: runner,
		repo:   interfaces.NewRepository(),
	}
	if err := m.initialize(extra); err != nil {
		return nil, err
	}

	// interface tasks might touch more than the immediate task target snap, serialize them
	runner.SetBlocked(func(_ *state.Task, running []*state.Task) bool {
		return len(running) != 0
	})

	runner.AddHandler("connect", m.doConnect, nil)
	runner.AddHandler("disconnect", m.doDisconnect, nil)
	runner.AddHandler("setup-profiles", m.doSetupProfiles, m.doRemoveProfiles)
	runner.AddHandler("remove-profiles", m.doRemoveProfiles, m.doSetupProfiles)
	runner.AddHandler("discard-conns", m.doDiscardConns, m.undoDiscardConns)
	return m, nil
}
コード例 #14
0
ファイル: taskrunner_test.go プロジェクト: niemeyer/snapd
func (ts *taskRunnerSuite) TestTaskSerialization(c *C) {
	ensureBeforeTick := make(chan bool, 1)
	sb := &stateBackend{
		ensureBefore:     time.Hour,
		ensureBeforeSeen: ensureBeforeTick,
	}
	st := state.New(sb)
	r := state.NewTaskRunner(st)
	defer r.Stop()

	ch1 := make(chan bool)
	ch2 := make(chan bool)
	r.AddHandler("do1", func(t *state.Task, _ *tomb.Tomb) error {
		ch1 <- true
		ch1 <- true
		return nil
	}, nil)
	r.AddHandler("do2", func(t *state.Task, _ *tomb.Tomb) error {
		ch2 <- true
		return nil
	}, nil)

	// start first do1, and then do2 when nothing else is running
	startedDo1 := false
	r.SetBlocked(func(t *state.Task, running []*state.Task) bool {
		if t.Kind() == "do2" && (len(running) != 0 || !startedDo1) {
			return true
		}
		if t.Kind() == "do1" {
			startedDo1 = true
		}
		return false
	})

	st.Lock()
	chg := st.NewChange("install", "...")
	t1 := st.NewTask("do1", "...")
	chg.AddTask(t1)
	t2 := st.NewTask("do2", "...")
	chg.AddTask(t2)
	st.Unlock()

	r.Ensure() // will start only one, do1

	select {
	case <-ch1:
	case <-time.After(2 * time.Second):
		c.Fatal("do1 wasn't called")
	}

	c.Check(ensureBeforeTick, HasLen, 0)
	c.Check(ch2, HasLen, 0)

	r.Ensure() // won't yet start anything new

	c.Check(ensureBeforeTick, HasLen, 0)
	c.Check(ch2, HasLen, 0)

	// finish do1
	select {
	case <-ch1:
	case <-time.After(2 * time.Second):
		c.Fatal("do1 wasn't continued")
	}

	// getting an EnsureBefore 0 call
	select {
	case <-ensureBeforeTick:
	case <-time.After(2 * time.Second):
		c.Fatal("EnsureBefore wasn't called")
	}
	c.Check(sb.ensureBefore, Equals, time.Duration(0))

	r.Ensure() // will start do2

	select {
	case <-ch2:
	case <-time.After(2 * time.Second):
		c.Fatal("do2 wasn't called")
	}

	// no more EnsureBefore calls
	c.Check(ensureBeforeTick, HasLen, 0)
}
コード例 #15
0
ファイル: taskrunner_test.go プロジェクト: niemeyer/snapd
func (ts *taskRunnerSuite) TestRetryAfterDuration(c *C) {
	ensureBeforeTick := make(chan bool, 1)
	sb := &stateBackend{
		ensureBefore:     time.Hour,
		ensureBeforeSeen: ensureBeforeTick,
	}
	st := state.New(sb)
	r := state.NewTaskRunner(st)
	defer r.Stop()

	ch := make(chan bool)
	ask := 0
	r.AddHandler("ask-for-retry", func(t *state.Task, _ *tomb.Tomb) error {
		ask++
		if ask == 1 {
			return &state.Retry{After: time.Minute}
		}
		ch <- true
		return nil
	}, nil)

	st.Lock()
	chg := st.NewChange("install", "...")
	t := st.NewTask("ask-for-retry", "...")
	chg.AddTask(t)
	st.Unlock()

	tock := time.Now()
	restore := state.MockTime(tock)
	defer restore()
	r.Ensure() // will run and be rescheduled in a minute
	select {
	case <-ensureBeforeTick:
	case <-time.After(2 * time.Second):
		c.Fatal("EnsureBefore wasn't called")
	}

	st.Lock()
	defer st.Unlock()
	c.Check(t.Status(), Equals, state.DoingStatus)

	c.Check(ask, Equals, 1)
	c.Check(sb.ensureBefore, Equals, 1*time.Minute)
	schedule := t.AtTime()
	c.Check(schedule.IsZero(), Equals, false)

	state.MockTime(tock.Add(5 * time.Second))
	sb.ensureBefore = time.Hour
	st.Unlock()
	r.Ensure() // too soon
	st.Lock()

	c.Check(t.Status(), Equals, state.DoingStatus)
	c.Check(ask, Equals, 1)
	c.Check(sb.ensureBefore, Equals, 55*time.Second)
	c.Check(t.AtTime().Equal(schedule), Equals, true)

	state.MockTime(schedule)
	sb.ensureBefore = time.Hour
	st.Unlock()
	r.Ensure() // time to run again
	select {
	case <-ch:
	case <-time.After(2 * time.Second):
		c.Fatal("handler wasn't called")
	}

	// wait for handler to finish
	r.Wait()

	st.Lock()
	c.Check(t.Status(), Equals, state.DoneStatus)
	c.Check(ask, Equals, 2)
	c.Check(sb.ensureBefore, Equals, time.Hour)
	c.Check(t.AtTime().IsZero(), Equals, true)
}
コード例 #16
0
ファイル: change_test.go プロジェクト: pedronis/snappy
func (ts *taskRunnerSuite) TestAbortLanes(c *C) {

	names := strings.Fields("t11 t12 t21 t22 t31 t32 t41 t42")

	for _, test := range abortLanesTests {
		sb := &stateBackend{}
		st := state.New(sb)
		r := state.NewTaskRunner(st)
		defer r.Stop()

		st.Lock()
		defer st.Unlock()

		c.Assert(len(st.Tasks()), Equals, 0)

		chg := st.NewChange("install", "...")
		tasks := make(map[string]*state.Task)
		for _, name := range names {
			tasks[name] = st.NewTask("do", name)
			chg.AddTask(tasks[name])
		}
		tasks["t12"].WaitFor(tasks["t11"])
		tasks["t21"].WaitFor(tasks["t12"])
		tasks["t22"].WaitFor(tasks["t21"])
		tasks["t31"].WaitFor(tasks["t12"])
		tasks["t32"].WaitFor(tasks["t31"])
		tasks["t41"].WaitFor(tasks["t22"])
		tasks["t41"].WaitFor(tasks["t32"])
		tasks["t42"].WaitFor(tasks["t41"])

		c.Logf("-----")
		c.Logf("Testing setup: %s", test.setup)

		statuses := make(map[string]state.Status)
		for s := state.DefaultStatus; s <= state.ErrorStatus; s++ {
			statuses[strings.ToLower(s.String())] = s
		}

		items := strings.Fields(test.setup)
		seen := make(map[string]bool)
		for i := 0; i < len(items); i++ {
			item := items[i]
			parts := strings.Split(item, ":")
			if parts[0] == "*" {
				for _, name := range names {
					if !seen[name] {
						parts[0] = name
						items = append(items, strings.Join(parts, ":"))
					}
				}
				continue
			}
			seen[parts[0]] = true
			task := tasks[parts[0]]
			task.SetStatus(statuses[parts[1]])
			if len(parts) > 2 {
				lanes := strings.Split(parts[2], ",")
				for _, lane := range lanes {
					n, err := strconv.Atoi(lane)
					c.Assert(err, IsNil)
					task.JoinLane(n)
				}
			}
		}

		c.Logf("Aborting with: %v", test.abort)

		chg.AbortLanes(test.abort)

		c.Logf("Expected result: %s", test.result)

		seen = make(map[string]bool)
		var expected = strings.Fields(test.result)
		var obtained []string
		for i := 0; i < len(expected); i++ {
			item := expected[i]
			parts := strings.Split(item, ":")
			if parts[0] == "*" {
				var expanded []string
				for _, name := range names {
					if !seen[name] {
						parts[0] = name
						expanded = append(expanded, strings.Join(parts, ":"))
					}
				}
				expected = append(expected[:i], append(expanded, expected[i+1:]...)...)
				i--
				continue
			}
			name := parts[0]
			seen[parts[0]] = true
			obtained = append(obtained, name+":"+strings.ToLower(tasks[name].Status().String()))
		}

		c.Assert(strings.Join(obtained, " "), Equals, strings.Join(expected, " "), Commentf("setup: %s", test.setup))
	}
}
コード例 #17
0
ファイル: taskrunner_test.go プロジェクト: niemeyer/snapd
func (ts *taskRunnerSuite) TestSequenceTests(c *C) {
	sb := &stateBackend{}
	st := state.New(sb)
	r := state.NewTaskRunner(st)
	defer r.Stop()

	ch := make(chan string, 256)
	fn := func(label string) state.HandlerFunc {
		return func(task *state.Task, tomb *tomb.Tomb) error {
			st.Lock()
			defer st.Unlock()
			ch <- task.Summary() + ":" + label
			var isSet bool
			if task.Get(label+"-block", &isSet) == nil && isSet {
				ch <- task.Summary() + ":" + label + "-block"
				st.Unlock()
				<-tomb.Dying()
				st.Lock()
				ch <- task.Summary() + ":" + label + "-unblock"
			}
			if task.Get(label+"-retry", &isSet) == nil && isSet {
				task.Set(label+"-retry", false)
				ch <- task.Summary() + ":" + label + "-retry"
				return &state.Retry{}
			}
			if task.Get(label+"-error", &isSet) == nil && isSet {
				ch <- task.Summary() + ":" + label + "-error"
				return errors.New("boom")
			}
			if task.Get(label+"-set-ready", &isSet) == nil && isSet {
				switch task.Status() {
				case state.DoingStatus:
					task.SetStatus(state.DoneStatus)
				case state.UndoingStatus:
					task.SetStatus(state.UndoneStatus)
				}
			}
			return nil
		}
	}
	r.AddHandler("do", fn("do"), nil)
	r.AddHandler("do-undo", fn("do"), fn("undo"))

	for _, test := range sequenceTests {
		st.Lock()

		// Delete previous changes.
		st.Prune(1, 1)

		chg := st.NewChange("install", "...")
		tasks := make(map[string]*state.Task)
		for _, name := range strings.Fields("t11 t12 t21 t31 t32") {
			if name == "t12" {
				tasks[name] = st.NewTask("do", name)
			} else {
				tasks[name] = st.NewTask("do-undo", name)
			}
			chg.AddTask(tasks[name])
		}
		tasks["t21"].WaitFor(tasks["t11"])
		tasks["t21"].WaitFor(tasks["t12"])
		tasks["t31"].WaitFor(tasks["t21"])
		tasks["t32"].WaitFor(tasks["t21"])
		st.Unlock()

		c.Logf("-----")
		c.Logf("Testing setup: %s", test.setup)

		statuses := make(map[string]state.Status)
		for s := state.DefaultStatus; s <= state.ErrorStatus; s++ {
			statuses[strings.ToLower(s.String())] = s
		}

		// Reset and prepare initial task state.
		st.Lock()
		for _, t := range chg.Tasks() {
			t.SetStatus(state.DefaultStatus)
			t.Set("do-error", false)
			t.Set("do-block", false)
			t.Set("undo-error", false)
			t.Set("undo-block", false)
		}
		for _, item := range strings.Fields(test.setup) {
			if item == "chg:abort" {
				chg.Abort()
				continue
			}
			kv := strings.Split(item, ":")
			if strings.HasPrefix(kv[1], "was-") {
				tasks[kv[0]].SetStatus(statuses[kv[1][4:]])
			} else {
				tasks[kv[0]].Set(kv[1], true)
			}
		}
		st.Unlock()

		// Run change until final.
		ensureChange(c, r, sb, chg)

		// Compute order of events observed.
		var events []string
		var done bool
		for !done {
			select {
			case ev := <-ch:
				events = append(events, ev)
				// Make t11/t12 and t31/t32 always show up in the
				// same order if they're next to each other.
				for i := len(events) - 2; i >= 0; i-- {
					prev := events[i]
					next := events[i+1]
					switch strings.Split(next, ":")[1] {
					case "do-unblock", "undo-unblock":
					default:
						if prev[1] == next[1] && prev[2] > next[2] {
							events[i], events[i+1] = next, prev
							continue
						}
					}
					break
				}
			default:
				done = true
			}
		}

		c.Logf("Expected result: %s", test.result)
		c.Assert(strings.Join(events, " "), Equals, test.result, Commentf("setup: %s", test.setup))

		// Compute final expected status for tasks.
		finalStatus := make(map[string]state.Status)
		// ... default when no handler is called
		for tname := range tasks {
			finalStatus[tname] = state.HoldStatus
		}
		// ... overwrite based on relevant setup
		for _, item := range strings.Fields(test.setup) {
			if item == "chg:abort" && strings.Contains(test.setup, "t12:was-doing") {
				// t12 has no undo so must hold if asked to abort when was doing.
				finalStatus["t12"] = state.HoldStatus
			}
			kv := strings.Split(item, ":")
			if !strings.HasPrefix(kv[1], "was-") {
				continue
			}
			switch strings.TrimPrefix(kv[1], "was-") {
			case "do", "doing", "done":
				finalStatus[kv[0]] = state.DoneStatus
			case "abort", "undo", "undoing", "undone":
				if kv[0] == "t12" {
					finalStatus[kv[0]] = state.DoneStatus // no undo for t12
				} else {
					finalStatus[kv[0]] = state.UndoneStatus
				}
			case "was-error":
				finalStatus[kv[0]] = state.ErrorStatus
			case "was-hold":
				finalStatus[kv[0]] = state.ErrorStatus
			}
		}
		// ... and overwrite based on events observed.
		for _, ev := range events {
			kv := strings.Split(ev, ":")
			switch kv[1] {
			case "do":
				finalStatus[kv[0]] = state.DoneStatus
			case "undo":
				finalStatus[kv[0]] = state.UndoneStatus
			case "do-error", "undo-error":
				finalStatus[kv[0]] = state.ErrorStatus
			case "do-retry":
				if kv[0] == "t12" && finalStatus["t11"] == state.ErrorStatus {
					// t12 has no undo so must hold if asked to abort on retry.
					finalStatus["t12"] = state.HoldStatus
				}
			}
		}

		st.Lock()
		var gotStatus, wantStatus []string
		for _, task := range chg.Tasks() {
			gotStatus = append(gotStatus, task.Summary()+":"+task.Status().String())
			wantStatus = append(wantStatus, task.Summary()+":"+finalStatus[task.Summary()].String())
		}
		st.Unlock()

		c.Logf("Expected statuses: %s", strings.Join(wantStatus, " "))
		comment := Commentf("calls: %s", test.result)
		c.Assert(strings.Join(gotStatus, " "), Equals, strings.Join(wantStatus, " "), comment)
	}
}