- forward updated labels/annotations for downward API compat

- refactor queue.Pod construction to take functional options, privatize Pod fields
- refactor DelayFIFO and HistoricalFIFO to offer consistent, more useful Pop() funcs
- refactor pod update processing changes; long term we should somehow combine with the special pod config source that we are using for mirror pods
- task launch timer cleanup

contrib/mesos/pkg/queue/delay.go

@@ -302,12 +302,18 @@ func (f *DelayFIFO) Get(id string) (UniqueID, bool) {
 
 // Variant of DelayQueue.Pop() for UniqueDelayed items
 func (q *DelayFIFO) Await(timeout time.Duration) UniqueID {
-	cancel := make(chan struct{})
-	ch := make(chan interface{}, 1)
+	var (
+		cancel = make(chan struct{})
+		ch     = make(chan interface{}, 1)
+		t      = time.NewTimer(timeout)
+	)
+	defer t.Stop()
+
 	go func() { ch <- q.pop(cancel) }()
+
 	var x interface{}
 	select {
-	case <-time.After(timeout):
+	case <-t.C:
 		close(cancel)
 		x = <-ch
 	case x = <-ch:
@@ -319,13 +325,19 @@ func (q *DelayFIFO) Await(timeout time.Duration) UniqueID {
 	return nil
 }
 
-// Variant of DelayQueue.Pop() for UniqueDelayed items
-func (q *DelayFIFO) Pop() UniqueID {
-	return q.pop(nil).(UniqueID)
+// Pop blocks until either there is an item available to dequeue or else the specified
+// cancel chan is closed. Callers that have no interest in providing a cancel chan
+// should specify nil, or else WithoutCancel() (for readability).
+func (q *DelayFIFO) Pop(cancel <-chan struct{}) UniqueID {
+	x := q.pop(cancel)
+	if x == nil {
+		return nil
+	}
+	return x.(UniqueID)
 }
 
 // variant of DelayQueue.Pop that implements optional cancellation
-func (q *DelayFIFO) pop(cancel chan struct{}) interface{} {
+func (q *DelayFIFO) pop(cancel <-chan struct{}) interface{} {
 	next := func() *qitem {
 		q.lock()
 		defer q.unlock()

contrib/mesos/pkg/queue/delay_test.go

@@ -358,7 +358,7 @@ func TestDFIFO_sanity_check(t *testing.T) {
 
 	// pop last
 	before := time.Now()
-	x := df.Pop()
+	x := df.Pop(nil)
 	assert.Equal(a.(*testjob).instance, 2)
 
 	now := time.Now()
@@ -395,7 +395,7 @@ func TestDFIFO_Offer(t *testing.T) {
 	}
 
 	before := time.Now()
-	x := dq.Pop()
+	x := dq.Pop(nil)
 
 	now := time.Now()
 	waitPeriod := now.Sub(before)

contrib/mesos/pkg/queue/historical.go

@@ -220,22 +220,28 @@ func (f *HistoricalFIFO) Poll(id string, t EventType) bool {
 
 // Variant of DelayQueue.Pop() for UniqueDelayed items
 func (q *HistoricalFIFO) Await(timeout time.Duration) interface{} {
-	cancel := make(chan struct{})
-	ch := make(chan interface{}, 1)
-	go func() { ch <- q.CancelablePop(cancel) }()
+	var (
+		cancel = make(chan struct{})
+		ch     = make(chan interface{}, 1)
+		t      = time.NewTimer(timeout)
+	)
+	defer t.Stop()
+
+	go func() { ch <- q.Pop(cancel) }()
+
 	select {
-	case <-time.After(timeout):
+	case <-t.C:
 		close(cancel)
 		return <-ch
 	case x := <-ch:
 		return x
 	}
 }
-func (f *HistoricalFIFO) Pop() interface{} {
-	return f.CancelablePop(nil)
-}
 
-func (f *HistoricalFIFO) CancelablePop(cancel <-chan struct{}) interface{} {
+// Pop blocks until either there is an item available to dequeue or else the specified
+// cancel chan is closed. Callers that have no interest in providing a cancel chan
+// should specify nil, or else WithoutCancel() (for readability).
+func (f *HistoricalFIFO) Pop(cancel <-chan struct{}) interface{} {
 	popEvent := (Entry)(nil)
 	defer func() {
 		f.carrier(popEvent)

contrib/mesos/pkg/queue/historical_test.go

@@ -75,7 +75,7 @@ func TestFIFO_basic(t *testing.T) {
 	lastInt := _int(0)
 	lastUint := _uint(0)
 	for i := 0; i < amount*2; i++ {
-		switch obj := f.Pop().(type) {
+		switch obj := f.Pop(nil).(type) {
 		case _int:
 			if obj <= lastInt {
 				t.Errorf("got %v (int) out of order, last was %v", obj, lastInt)
@@ -100,7 +100,7 @@ func TestFIFO_addUpdate(t *testing.T) {
 	got := make(chan *testObj, 2)
 	go func() {
 		for {
-			got <- f.Pop().(*testObj)
+			got <- f.Pop(nil).(*testObj)
 		}
 	}()
 
@@ -126,7 +126,7 @@ func TestFIFO_addReplace(t *testing.T) {
 	got := make(chan *testObj, 2)
 	go func() {
 		for {
-			got <- f.Pop().(*testObj)
+			got <- f.Pop(nil).(*testObj)
 		}
 	}()
 
@@ -158,24 +158,24 @@ func TestFIFO_detectLineJumpers(t *testing.T) {
 	done := make(chan struct{})
 	go func() {
 		defer close(done)
-		if e, a := 13, f.Pop().(*testObj).value; a != e {
+		if e, a := 13, f.Pop(nil).(*testObj).value; a != e {
 			err = fmt.Errorf("expected %d, got %d", e, a)
 			return
 		}
 
 		f.Add(&testObj{"foo", 14}) // ensure foo doesn't jump back in line
 
-		if e, a := 1, f.Pop().(*testObj).value; a != e {
+		if e, a := 1, f.Pop(nil).(*testObj).value; a != e {
 			err = fmt.Errorf("expected %d, got %d", e, a)
 			return
 		}
 
-		if e, a := 30, f.Pop().(*testObj).value; a != e {
+		if e, a := 30, f.Pop(nil).(*testObj).value; a != e {
 			err = fmt.Errorf("expected %d, got %d", e, a)
 			return
 		}
 
-		if e, a := 14, f.Pop().(*testObj).value; a != e {
+		if e, a := 14, f.Pop(nil).(*testObj).value; a != e {
 			err = fmt.Errorf("expected %d, got %d", e, a)
 			return
 		}

contrib/mesos/pkg/queue/interface.go

@@ -59,7 +59,7 @@ type FIFO interface {
 	// ready, they are returned in the order in which they were added/updated.
 	// The item is removed from the queue (and the store) before it is returned,
 	// so if you don't successfully process it, you need to add it back with Add().
-	Pop() interface{}
+	Pop(cancel <-chan struct{}) interface{}
 
 	// Await attempts to Pop within the given interval; upon success the non-nil
 	// item is returned, otherwise nil
@@ -101,3 +101,5 @@ type UniqueDeadlined interface {
 	UniqueID
 	Deadlined
 }
+
+func WithoutCancel() <-chan struct{} { return nil }