Review commit

Author: matthiasgeihs

backend/ethereum/channel/conclude.go

@@ -54,8 +54,8 @@ func (a *Adjudicator) ensureConcluded(ctx context.Context, req channel.Adjudicat
 	subErr := make(chan error, 1)
 	waitCtx, cancel := context.WithCancel(ctx)
 	go func() {
+		defer cancel()
 		subErr <- sub.Read(ctx, events)
-		cancel()
 	}()
 
 	// In final Register calls, as the non-initiator, we optimistically wait for
@@ -107,7 +107,7 @@ func (a *Adjudicator) conclude(ctx context.Context, req channel.AdjudicatorReq,
 		err = errors.WithMessage(a.callConclude(ctx, req, subStates), "calling conclude")
 	}
 	if IsErrTxFailed(err) {
-		a.log.Warn("Calling conclude(Final) failed, waiting for event anyways...")
+		a.log.WithError(err).Warn("Calling conclude(Final) failed, waiting for event anyways...")
 	} else if err != nil {
 		return err
 	}
@@ -133,8 +133,10 @@ func (a *Adjudicator) isConcluded(ctx context.Context, sub *subscription.EventSu
 	return false, errors.WithMessage(<-subErr, "reading past events")
 }
 
-// isForceExecuted returns whether a channel is already concluded.
-func (a *Adjudicator) isForceExecuted(ctx context.Context, c channel.ID) (bool, error) {
+// isForceExecuted returns whether a channel is in the forced execution phase.
+func (a *Adjudicator) isForceExecuted(_ctx context.Context, c channel.ID) (bool, error) {
+	ctx, cancel := context.WithCancel(_ctx)
+	defer cancel()
 	sub, err := subscription.NewEventSub(ctx, a.ContractBackend, a.bound, updateEventType(c), startBlockOffset)
 	if err != nil {
 		return false, errors.WithMessage(err, "subscribing")
@@ -148,8 +150,12 @@ func (a *Adjudicator) isForceExecuted(ctx context.Context, c channel.ID) (bool,
 		subErr <- sub.ReadPast(ctx, events)
 	}()
 	// Read all events and check for force execution.
+	var lastEvent *subscription.Event
 	for _e := range events {
-		e := _e.Data.(*adjudicator.AdjudicatorChannelUpdate)
+		lastEvent = _e
+	}
+	if lastEvent != nil {
+		e := lastEvent.Data.(*adjudicator.AdjudicatorChannelUpdate)
 		if e.Phase == phaseForceExec {
 			return true, nil
 		}