// Detect whether all pipes are closed properly.
		var leakedFDs []int
		pendingFDs.Range(func(k, v any) bool {
			leakedFDs = append(leakedFDs, k.(int))
			return true
		})
		if len(leakedFDs) == 0 {
			break
		}

		select {
		case <-expiredTime.C:
			t.Logf("all descriptors: %v", allFDs)
			t.Fatalf("leaked descriptors: %v", leakedFDs)
		default:
		}
	}
}