fix: reserve wg caused data race in tests

pkg/storer/storer.go

@@ -37,6 +37,7 @@ import (
 	localmigration "github.com/ethersphere/bee/pkg/storer/migration"
 	"github.com/ethersphere/bee/pkg/swarm"
 	"github.com/ethersphere/bee/pkg/topology"
+	"github.com/ethersphere/bee/pkg/util"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/spf13/afero"
 	"github.com/syndtr/goleveldb/leveldb"
@@ -467,7 +468,7 @@ type DB struct {
 	directUploadLimiter chan struct{}
 
 	reserve          *reserve.Reserve
-	reserveWg        sync.WaitGroup
+	reserveWg        *util.WaitingCounter
 	reserveBinEvents *events.Subscriber
 	baseAddr         swarm.Address
 	batchstore       postage.Storer
@@ -549,6 +550,7 @@ func New(ctx context.Context, dirPath string, opts *Options) (*DB, error) {
 			wakeupDuration: opts.ReserveWakeUpDuration,
 		},
 		directUploadLimiter: make(chan struct{}, pusher.ConcurrentPushes),
+		reserveWg:           new(util.WaitingCounter),
 	}
 
 	if db.validStamp == nil {
@@ -595,7 +597,9 @@ func (db *DB) Close() error {
 	bgReserveWorkersClosed := make(chan struct{})
 	go func() {
 		defer close(bgReserveWorkersClosed)
-		db.reserveWg.Wait()
+		if c := db.reserveWg.Wait(5 * time.Second); c > 0 {
+			db.logger.Warning("db shutting down with running goroutines")
+		}
 	}()
 
 	bgCacheWorkersClosed := make(chan struct{})

pkg/util/waitingcounter.go

@@ -0,0 +1,39 @@
+// Copyright 2023 The Swarm Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package util
+
+import (
+	"sync/atomic"
+	"time"
+)
+
+type WaitingCounter atomic.Int32
+
+func (r *WaitingCounter) Add(c int32) {
+	(*atomic.Int32)(r).Add(c)
+}
+
+func (r *WaitingCounter) Done() {
+	r.Add(-1)
+}
+
+func (r *WaitingCounter) Wait(waitFor time.Duration) (runningGoroutines int) {
+	finish := time.Now().Add(waitFor)
+	for {
+		runningGoroutines = int((*atomic.Int32)(r).Load())
+
+		if runningGoroutines == 0 {
+			return
+		} else if runningGoroutines < 0 {
+			panic("number of running goroutines can not be negative")
+		}
+
+		if time.Now().After(finish) {
+			return
+		}
+
+		time.Sleep(100 * time.Millisecond)
+	}
+}