lease: remove 'promote' field (to be squashed)

Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>

lease/lessor.go

@@ -148,9 +148,6 @@ type lessor struct {
 	stopC chan struct{}
 	// doneC is a channel whose closure indicates that the lessor is stopped.
 	doneC chan struct{}
-
-	// 'true' when lessor just started promoting after recovery
-	promoting bool
 }
 
 func NewLessor(b backend.Backend, minLeaseTTL int64) Lessor {
@@ -164,10 +161,9 @@ func newLessor(b backend.Backend, minLeaseTTL int64) *lessor {
 		b:           b,
 		minLeaseTTL: minLeaseTTL,
 		// expiredC is a small buffered chan to avoid unnecessary blocking.
-		expiredC:  make(chan []*Lease, 16),
-		stopC:     make(chan struct{}),
-		doneC:     make(chan struct{}),
-		promoting: true,
+		expiredC: make(chan []*Lease, 16),
+		stopC:    make(chan struct{}),
+		doneC:    make(chan struct{}),
 	}
 	l.initAndRecover()
 
@@ -328,19 +324,13 @@ func (le *lessor) Promote(extend time.Duration) {
 	defer le.mu.Unlock()
 
 	le.demotec = make(chan struct{})
-	promoting := le.promoting
 
 	// refresh the expiries of all leases.
 	for _, l := range le.leaseMap {
-		ext := extend
-		if promoting {
-			// randomize expiry with 士10%, otherwise leases of same TTL
-			// will expire all at the same time,
-			ext += computeRandomDelta(l.ttl)
-		}
-		l.refresh(ext)
+		// randomize expiry with 士10%, otherwise leases of same TTL
+		// will expire all at the same time,
+		l.refresh(extend + computeRandomDelta(l.ttl))
 	}
-	le.promoting = false
 }
 
 func computeRandomDelta(seconds int64) time.Duration {

lease/lessor_test.go

@@ -234,7 +234,7 @@ func TestLessorRenewRandomize(t *testing.T) {
 
 	now := monotime.Now()
 
-	// first extend after recovery should randomize expiries
+	// extend after recovery should randomize expiries
 	le.Promote(0)
 
 	for _, l := range le.leaseMap {
@@ -244,17 +244,6 @@ func TestLessorRenewRandomize(t *testing.T) {
 			t.Fatalf("expected randomized expiry, got %d seconds (ttl: 3600)", leftSeconds)
 		}
 	}
-
-	// second extend should not be randomized
-	le.Promote(0)
-
-	for _, l := range le.leaseMap {
-		leftSeconds := uint64(float64(l.expiry-now) * float64(1e-9))
-		pc := (float64(leftSeconds-3600) / float64(3600)) * 100
-		if pc > .5 || pc < -.5 { // should be close to original ttl 3600
-			t.Fatalf("expected 3600-sec left, got %d", leftSeconds)
-		}
-	}
 }
 
 func TestLessorDetach(t *testing.T) {