core/tracker: unlock mutex (#2027)

Unlock mutex before doing any i/o in core/tracker/incldelay.go.

category: bug
ticket: #2028

core/scheduler/scheduler.go

@@ -149,10 +149,12 @@ func (s *Scheduler) GetDutyDefinition(ctx context.Context, duty core.Duty) (core
 
 	epoch := duty.Slot / int64(slotsPerEpoch)
 	if !s.isEpochResolved(epoch) {
-		return nil, errors.New("epoch not resolved yet")
+		return nil, errors.New("epoch not resolved yet",
+			z.Str("duty", duty.String()), z.I64("epoch", epoch))
 	}
 	if s.isEpochTrimmed(epoch) {
-		return nil, errors.New("epoch already trimmed")
+		return nil, errors.New("epoch already trimmed",
+			z.Str("duty", duty.String()), z.I64("epoch", epoch))
 	}
 
 	defSet, ok := s.getDutyDefinitionSet(duty)

core/tracker/incldelay.go

@@ -31,20 +31,32 @@ func NewInclDelayFunc(eth2Cl eth2wrap.Client, dutiesFunc dutiesFunc) func(contex
 // newInclDelayFunc extends NewInclDelayFunc with abstracted callback.
 func newInclDelayFunc(eth2Cl eth2wrap.Client, dutiesFunc dutiesFunc, callback func([]int64)) func(context.Context, core.Slot) error {
 	// dutyStartSlot is the first slot we can instrument (since dutiesFunc will not have duties from older slots).
-	var dutyStartSlot int64
-	var dssMutex sync.Mutex
+	var (
+		dutyStartSlot int64
+		dssMutex      sync.Mutex
+	)
 
-	return func(ctx context.Context, current core.Slot) error {
+	// getOrSetStartSlot returns a previously set duty start slot and true or it sets it and returns false.
+	getOrSetStartSlot := func(slot int64) (int64, bool) {
 		dssMutex.Lock()
 		defer dssMutex.Unlock()
 
+		if dutyStartSlot == 0 {
+			dutyStartSlot = slot
+			return 0, false
+		}
+
+		return dutyStartSlot, true
+	}
+
+	return func(ctx context.Context, current core.Slot) error {
 		// blockSlot the block we want to instrument.
 		blockSlot := current.Slot - inclDelayLag
 
-		if dutyStartSlot == 0 {
-			dutyStartSlot = current.Slot // Set start slot.
+		startSlot, ok := getOrSetStartSlot(current.Slot)
+		if !ok { // Set start slot.
 			return nil
-		} else if blockSlot < dutyStartSlot {
+		} else if blockSlot < startSlot {
 			return nil // Still need to wait
 		}
 
@@ -56,7 +68,7 @@ func newInclDelayFunc(eth2Cl eth2wrap.Client, dutiesFunc dutiesFunc, callback fu
 		var delays []int64
 		for _, att := range atts {
 			attSlot := att.Data.Slot
-			if int64(attSlot) < dutyStartSlot {
+			if int64(attSlot) < startSlot {
 				continue
 			}