remove error return from Wait and Stop

overlord/assertstate/assertmgr.go

@@ -47,11 +47,9 @@ func (m *AssertManager) Ensure() error {
 }
 
 // Stop implements StateManager.Stop.
-func (m *AssertManager) Stop() error {
-	return nil
+func (m *AssertManager) Stop() {
 }
 
 // Wait implements StateManager.Wait.
-func (m *AssertManager) Wait() error {
-	return nil
+func (m *AssertManager) Wait() {
 }

overlord/ifacestate/export_test.go

@@ -26,7 +26,3 @@ import (
 func (m *InterfaceManager) Repository() *interfaces.Repository {
 	return m.repo
 }
-
-func (m *InterfaceManager) Wait() {
-	m.runner.Wait()
-}

overlord/ifacestate/ifacemgr.go

@@ -104,13 +104,12 @@ func (m *InterfaceManager) Ensure() error {
 }
 
 // Wait implements StateManager.Wait.
-func (m *InterfaceManager) Wait() error {
+func (m *InterfaceManager) Wait() {
 	m.runner.Wait()
-	return nil
 }
 
 // Stop implements StateManager.Stop.
-func (m *InterfaceManager) Stop() error {
+func (m *InterfaceManager) Stop() {
 	m.runner.Stop()
-	return nil
+
 }

overlord/overlord.go

@@ -126,11 +126,8 @@ func (o *Overlord) Run() {
 func (o *Overlord) Stop() error {
 	o.loopTomb.Kill(nil)
 	err1 := o.loopTomb.Wait()
-	err2 := o.stateEng.Stop()
-	if err1 != nil {
-		return err1
-	}
-	return err2
+	o.stateEng.Stop()
+	return err1
 }
 
 // StateEngine returns the state engine used by the overlord.

overlord/snapstate/snapmgr.go

@@ -119,13 +119,11 @@ func (m *SnapManager) Ensure() error {
 }
 
 // Wait implements StateManager.Wait.
-func (m *SnapManager) Wait() error {
+func (m *SnapManager) Wait() {
 	m.runner.Wait()
-	return nil
 }
 
 // Stop implements StateManager.Stop.
-func (m *SnapManager) Stop() error {
+func (m *SnapManager) Stop() {
 	m.runner.Stop()
-	return nil
 }

overlord/stateengine.go

@@ -36,11 +36,11 @@ type StateManager interface {
 	Ensure() error
 
 	// Wait asks manager to wait for all running activities to finish.
-	Wait() error
+	Wait()
 
 	// Stop asks the manager to terminate all activities running concurrently.
 	// It must not return before these activities are finished.
-	Stop() error
+	Stop()
 }
 
 // StateEngine controls the dispatching of state changes to state managers.
@@ -105,16 +105,12 @@ func (se *StateEngine) AddManager(m StateManager) {
 
 // Stop asks all managers to terminate activities running concurrently.
 // It returns the first error found after all managers are stopped.
-func (se *StateEngine) Stop() error {
+func (se *StateEngine) Stop() {
 	if len(se.managers) > 0 {
 		for _, m := range se.managers {
-			err := m.Stop()
-			if err != nil {
-				return err
-			}
+			m.Stop()
 		}
 		se.initialize = append(se.initialize, se.managers...)
 		se.managers = nil
 	}
-	return nil
 }

overlord/stateengine_test.go

@@ -57,14 +57,12 @@ func (fm *fakeManager) Ensure() error {
 	return fm.ensureError
 }
 
-func (fm *fakeManager) Stop() error {
+func (fm *fakeManager) Stop() {
 	*fm.calls = append(*fm.calls, "stop:"+fm.name)
-	return fm.stopError
 }
 
-func (fm *fakeManager) Wait() error {
+func (fm *fakeManager) Wait() {
 	*fm.calls = append(*fm.calls, "wait:"+fm.name)
-	return fm.stopError
 }
 
 var _ overlord.StateManager = (*fakeManager)(nil)
@@ -148,36 +146,10 @@ func (ses *stateEngineSuite) TestStop(c *C) {
 	c.Assert(err, IsNil)
 	c.Check(calls, HasLen, 4)
 
-	err = se.Stop()
-	c.Assert(err, IsNil)
+	se.Stop()
 	c.Check(calls, DeepEquals, []string{"init:mgr1", "init:mgr2", "ensure:mgr1", "ensure:mgr2", "stop:mgr1", "stop:mgr2"})
 
 	err = se.Ensure()
 	c.Assert(err, IsNil)
 	c.Check(calls, DeepEquals, []string{"init:mgr1", "init:mgr2", "ensure:mgr1", "ensure:mgr2", "stop:mgr1", "stop:mgr2", "init:mgr1", "init:mgr2", "ensure:mgr1", "ensure:mgr2"})
 }
-
-func (ses *stateEngineSuite) TestStopError(c *C) {
-	s := state.New(nil)
-	se := overlord.NewStateEngine(s)
-
-	calls := []string{}
-
-	err1 := errors.New("boom1")
-	err2 := errors.New("boom2")
-
-	mgr1 := &fakeManager{name: "mgr1", calls: &calls, stopError: err1}
-	mgr2 := &fakeManager{name: "mgr2", calls: &calls, stopError: err2}
-
-	se.AddManager(mgr1)
-	se.AddManager(mgr2)
-
-	err := se.Ensure()
-	c.Assert(err, IsNil)
-	c.Check(calls, HasLen, 4)
-
-	err = se.Stop()
-	c.Check(err, Equals, err1)
-	c.Check(calls, DeepEquals, []string{"init:mgr1", "init:mgr2", "ensure:mgr1", "ensure:mgr2", "stop:mgr1"})
-
-}