cleanup of code

swim/gossip.go

@@ -131,8 +131,8 @@ func (g *gossip) Start() {
 	g.state.running = true
 
 	// schedule repeat execution in the background
-	g.state.protocolPeriodStop, g.state.protocolPeriodWait = schedule(g.ProtocolPeriod, g.ComputeProtocolDelay, g.node.clock)
-	g.state.protocolRateChannel, _ = schedule(g.AdjustProtocolRate, func() time.Duration {
+	g.state.protocolPeriodStop, g.state.protocolPeriodWait = scheduleRepeaditly(g.ProtocolPeriod, g.ComputeProtocolDelay, g.node.clock)
+	g.state.protocolRateChannel, _ = scheduleRepeaditly(g.AdjustProtocolRate, func() time.Duration {
 		return time.Second
 	}, g.node.clock)
 

swim/memberlist_test.go

@@ -25,7 +25,6 @@ import (
 	"testing"
 
 	"github.com/benbjohnson/clock"
-
 	"github.com/stretchr/testify/suite"
 	"github.com/uber/ringpop-go/util"
 )

swim/schedule.go

@@ -6,8 +6,18 @@ import (
 	"github.com/benbjohnson/clock"
 )
 
-// TODO rename to scheduleRepeaditly
-func schedule(what func(), delayFn func() time.Duration, clock clock.Clock) (stop chan bool, wait <-chan bool) {
+// scheduleRepeaditly runs a function in the background continually with a
+// dynamically computed delay in between invocations. The returned channels can
+// be used to stop the background execution and a channel that will be unblocked
+// when the background task is completely stopped.
+//
+//   stop, wait := scheduleRepeaditly(func(){..}, func() time.Duration { return time.Second }, clock)
+//   time.sleep(time.Duration(10) * time.Second)
+//   // stop the background task
+//   close(stop)
+//   // wait till the background task is terminated
+//   <-wait
+func scheduleRepeaditly(what func(), delayFn func() time.Duration, clock clock.Clock) (stop chan bool, wait <-chan bool) {
 	stop = make(chan bool)
 
 	internalWait := make(chan bool)
@@ -28,5 +38,3 @@ func schedule(what func(), delayFn func() time.Duration, clock clock.Clock) (sto
 
 	return stop, wait
 }
-
-// TODO add schedule once with a quit channel to cancel it for use in the update rollup

swim/state_transitions_test.go

@@ -110,28 +110,28 @@ func (s *StateTransitionsSuite) TestSuspectDisabled() {
 func (s *StateTransitionsSuite) TestSuspectBecomesFaulty() {
 	s.m.MakeSuspect(s.suspect.Address, s.suspect.Incarnation)
 	member, _ := s.m.Member(s.suspect.Address)
-	s.Require().NotNil(member, "expected cannot be nil")
+	s.Require().NotNil(member, "expected member, cannot be nil")
 
 	s.stateTransitions.ScheduleSuspectToFaulty(*member)
 	s.NotNil(s.stateTransitions.timer(member.Address), "expected state transtition timer to be set")
 
 	s.clock.Add(5 * time.Second)
 	member, _ = s.m.Member(s.suspect.Address)
-	s.Require().NotNil(member, "expected cannot be nil")
+	s.Require().NotNil(member, "expected member, cannot be nil")
 	s.Equal(Faulty, member.Status, "expected member to be faulty")
 }
 
 func (s *StateTransitionsSuite) TestFaultyBecomesTombstone() {
 	s.m.MakeFaulty(s.suspect.Address, s.suspect.Incarnation)
 	member, _ := s.m.Member(s.suspect.Address)
-	s.Require().NotNil(member, "expected cannot be nil")
+	s.Require().NotNil(member, "expected member, cannot be nil")
 
 	s.stateTransitions.ScheduleFaultyToTombstone(*member)
 	s.NotNil(s.stateTransitions.timer(member.Address), "expected state transtition timer to be set")
 
 	s.clock.Add(10 * time.Second)
 	member, _ = s.m.Member(s.suspect.Address)
-	s.Require().NotNil(member, "expected cannot be nil")
+	s.Require().NotNil(member, "expected member, cannot be nil")
 	s.Equal(Tombstone, member.Status, "expected member to be tombstone")
 }
 
@@ -140,7 +140,7 @@ func (s *StateTransitionsSuite) TestTombstoneBecomesEvicted() {
 	s.m.MakeAlive(s.suspect.Address, s.suspect.Incarnation)
 	s.m.MakeTombstone(s.suspect.Address, s.suspect.Incarnation)
 	member, _ := s.m.Member(s.suspect.Address)
-	s.Require().NotNil(member, "expected cannot be nil")
+	s.Require().NotNil(member, "expected member, cannot be nil")
 
 	s.stateTransitions.ScheduleTombstoneToEvict(*member)
 	s.NotNil(s.stateTransitions.timer(member.Address), "expected state transtition timer to be set")
@@ -156,7 +156,7 @@ func (s *StateTransitionsSuite) TestTombstoneBecomesEvicted() {
 func (s *StateTransitionsSuite) TestTimerCreated() {
 	s.m.MakeAlive(s.suspect.Address, s.suspect.Incarnation)
 	member, _ := s.m.Member(s.suspect.Address)
-	s.Require().NotNil(member, "expected cannot be nil")
+	s.Require().NotNil(member, "expected member, cannot be nil")
 
 	old := s.stateTransitions.timer(member.Address)
 	s.Require().Nil(old, "expected timer to be nil")