Allow utils.worker to be joined explicitly

r2/r2/lib/utils/utils.py

@@ -785,14 +785,17 @@ class Worker:
             fn = self.q.get()
             try:
                 fn()
+                self.q.task_done()
             except:
                 import traceback
                 print traceback.format_exc()
-                
 
     def do(self, fn):
         self.q.put(fn)
 
+    def join(self):
+        self.q.join()
+
 worker = Worker()
 
 def cols(lst, ncols):