[#930] gc: Stop internal activity by context

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

cmd/frostfs-node/config.go

@@ -1009,7 +1009,7 @@ func initLocalStorage(ctx context.Context, c *cfg) {
 	ls := engine.New(c.engineOpts()...)
 
 	addNewEpochAsyncNotificationHandler(c, func(ev event.Event) {
-		ls.HandleNewEpoch(ev.(netmap2.NewEpoch).EpochNumber())
+		ls.HandleNewEpoch(ctx, ev.(netmap2.NewEpoch).EpochNumber())
 	})
 
 	// allocate memory for the service;

internal/logs/logs.go

@@ -270,7 +270,9 @@ const (
 	ShardCantOpenMetabaseMoveToADegradedMode                                = "can't open metabase, move to a degraded mode"
 	ShardCantInitializeMetabaseMoveToADegradedreadonlyMode                  = "can't initialize metabase, move to a degraded-read-only mode"
 	ShardTryingToRestoreReadwriteMode                                       = "trying to restore read-write mode"
-	ShardStopEventListenerByClosedChannel                                   = "stop event listener by closed channel"
+	ShardStopEventListenerByClosedEventChannel                              = "stop event listener by closed `event` channel"
+	ShardStopEventListenerByClosedStopChannel                               = "stop event listener by closed `stop` channel"
+	ShardStopEventListenerByContext                                         = "stop event listener by context"
 	ShardCouldNotSubmitGCJobToWorkerPool                                    = "could not submit GC job to worker pool"
 	ShardGCIsStopped                                                        = "GC is stopped"
 	ShardWaitingForGCWorkersToStop                                          = "waiting for GC workers to stop..."

pkg/local_object_storage/engine/lock_test.go

@@ -133,7 +133,7 @@ func TestLockUserScenario(t *testing.T) {
 	require.ErrorIs(t, err, meta.ErrLockObjectRemoval)
 
 	// 5.
-	e.HandleNewEpoch(lockerExpiresAfter + 1)
+	e.HandleNewEpoch(context.Background(), lockerExpiresAfter+1)
 
 	inhumePrm.WithTarget(tombAddr, objAddr)
 
@@ -206,7 +206,7 @@ func TestLockExpiration(t *testing.T) {
 	require.ErrorAs(t, err, &objLockedErr)
 
 	// 3.
-	e.HandleNewEpoch(lockerExpiresAfter + 1)
+	e.HandleNewEpoch(context.Background(), lockerExpiresAfter+1)
 
 	// 4.
 	inhumePrm.WithTarget(oidtest.Address(), objectcore.AddressOf(obj))

pkg/local_object_storage/engine/shards.go

@@ -329,14 +329,18 @@ func (e *StorageEngine) SetShardMode(id *shard.ID, m mode.Mode, resetErrorCounte
 }
 
 // HandleNewEpoch notifies every shard about NewEpoch event.
-func (e *StorageEngine) HandleNewEpoch(epoch uint64) {
+func (e *StorageEngine) HandleNewEpoch(ctx context.Context, epoch uint64) {
 	ev := shard.EventNewEpoch(epoch)
 
 	e.mtx.RLock()
 	defer e.mtx.RUnlock()
 
 	for _, sh := range e.shards {
-		sh.NotificationChannel() <- ev
+		select {
+		case <-ctx.Done():
+			return
+		case sh.NotificationChannel() <- ev:
+		}
 	}
 }
 

pkg/local_object_storage/shard/gc.go

@@ -105,6 +105,8 @@ type gc struct {
 
 	remover func(context.Context) gcRunResult
 
+	// eventChan is used only for listening for the new epoch event.
+	// It is ok to keep opened, we are listening for context done when writing in it.
 	eventChan     chan Event
 	mEventHandler map[eventType]*eventHandlers
 }
@@ -155,13 +157,21 @@ func (gc *gc) listenEvents(ctx context.Context) {
 	defer gc.wg.Done()
 
 	for {
-		event, ok := <-gc.eventChan
+		select {
-		if !ok {
+		case <-gc.stopChannel:
-			gc.log.Warn(logs.ShardStopEventListenerByClosedChannel)
+			gc.log.Warn(logs.ShardStopEventListenerByClosedStopChannel)
 			return
-		}
+		case <-ctx.Done():
+			gc.log.Warn(logs.ShardStopEventListenerByContext)
+			return
+		case event, ok := <-gc.eventChan:
+			if !ok {
+				gc.log.Warn(logs.ShardStopEventListenerByClosedEventChannel)
+				return
+			}
 
-		gc.handleEvent(ctx, event)
+			gc.handleEvent(ctx, event)
+		}
 	}
 }
 
@@ -180,6 +190,11 @@ func (gc *gc) handleEvent(ctx context.Context, event Event) {
 	v.prevGroup.Add(len(v.handlers))
 
 	for i := range v.handlers {
+		select {
+		case <-ctx.Done():
+			return
+		default:
+		}
 		h := v.handlers[i]
 
 		err := gc.workerPool.Submit(func() {
@@ -196,6 +211,18 @@ func (gc *gc) handleEvent(ctx context.Context, event Event) {
 	}
 }
 
+func (gc *gc) releaseResources() {
+	if gc.workerPool != nil {
+		gc.workerPool.Release()
+	}
+
+	// Avoid to close gc.eventChan here,
+	// because it is possible that we are close it earlier than stop writing.
+	// It is ok to keep it opened.
+
+	gc.log.Debug(logs.ShardGCIsStopped)
+}
+
 func (gc *gc) tickRemover(ctx context.Context) {
 	defer gc.wg.Done()
 
@@ -204,14 +231,13 @@ func (gc *gc) tickRemover(ctx context.Context) {
 
 	for {
 		select {
+		case <-ctx.Done():
+			// Context canceled earlier than we start to close shards.
+			// It make sense to stop collecting garbage by context too.
+			gc.releaseResources()
+			return
 		case <-gc.stopChannel:
-			if gc.workerPool != nil {
+			gc.releaseResources()
-				gc.workerPool.Release()
-			}
-
-			close(gc.eventChan)
-
-			gc.log.Debug(logs.ShardGCIsStopped)
 			return
 		case <-timer.C:
 			startedAt := time.Now()