[chore] Use chan struct{} instead of bool to reduce space (#12232)

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

exporter/internal/queue/batcher.go

@@ -29,7 +29,7 @@ type BaseBatcher struct {
 	queue    exporterqueue.Queue[internal.Request]
 	// TODO: Remove when the -1 hack for testing is removed.
 	maxWorkers int
-	workerPool chan bool
+	workerPool chan struct{}
 	exportFunc func(ctx context.Context, req internal.Request) error
 	stopWG     sync.WaitGroup
 }
@@ -50,11 +50,11 @@ func newBaseBatcher(batchCfg exporterbatcher.Config,
 	exportFunc func(ctx context.Context, req internal.Request) error,
 	maxWorkers int,
 ) BaseBatcher {
-	var workerPool chan bool
+	var workerPool chan struct{}
 	if maxWorkers > 0 {
-		workerPool = make(chan bool, maxWorkers)
+		workerPool = make(chan struct{}, maxWorkers)
 		for i := 0; i < maxWorkers; i++ {
-			workerPool <- true
+			workerPool <- struct{}{}
 		}
 	}
 	return BaseBatcher{
@@ -80,7 +80,7 @@ func (qb *BaseBatcher) flush(ctx context.Context, req internal.Request, dones []
 			done(err)
 		}
 		if qb.workerPool != nil {
-			qb.workerPool <- true
+			qb.workerPool <- struct{}{}
 		}
 	}()
 }

exporter/internal/queue/default_batcher.go

@@ -20,7 +20,7 @@ type DefaultBatcher struct {
 	currentBatchMu sync.Mutex
 	currentBatch   *batch
 	timer          *time.Timer
-	shutdownCh     chan bool
+	shutdownCh     chan struct{}
 }
 
 func (qb *DefaultBatcher) resetTimer() {
@@ -38,7 +38,7 @@ func (qb *DefaultBatcher) startReadingFlushingGoroutine() {
 			// Read() blocks until the queue is non-empty or until the queue is stopped.
 			ctx, req, done, ok := qb.queue.Read(context.Background())
 			if !ok {
-				qb.shutdownCh <- true
+				close(qb.shutdownCh)
 				return
 			}
 
@@ -139,7 +139,7 @@ func (qb *DefaultBatcher) Start(_ context.Context, _ component.Host) error {
 		return nil
 	}
 
-	qb.shutdownCh = make(chan bool, 1)
+	qb.shutdownCh = make(chan struct{}, 1)
 
 	if qb.batchCfg.FlushTimeout == 0 {
 		qb.timer = time.NewTimer(math.MaxInt)