refactor: move more background jobs to using job queue

utils/sync.go

@@ -0,0 +1,23 @@
+package utils
+
+import (
+	"sync"
+	"time"
+)
+
+// WaitTimeout waits for the waitgroup for the specified max timeout.
+// Returns true if waiting timed out.
+// See // https://stackoverflow.com/a/32843750/3112139.
+func WaitTimeout(wg *sync.WaitGroup, timeout time.Duration) bool {
+	c := make(chan struct{})
+	go func() {
+		defer close(c)
+		wg.Wait()
+	}()
+	select {
+	case <-c:
+		return false // completed normally
+	case <-time.After(timeout):
+		return true // timed out
+	}
+}