diff --git a/openstack/common/threadgroup.py b/openstack/common/threadgroup.py
index 31097f1..0f4bbf8 100644
--- a/openstack/common/threadgroup.py
+++ b/openstack/common/threadgroup.py
@@ -85,7 +85,7 @@ class ThreadGroup(object):
     def thread_done(self, thread):
         self.threads.remove(thread)
 
-    def stop(self):
+    def _stop_threads(self):
         current = threading.current_thread()
 
         # Iterate over a copy of self.threads so thread_done doesn't
@@ -99,6 +99,7 @@ class ThreadGroup(object):
             except Exception as ex:
                 LOG.exception(ex)
 
+    def _stop_timers(self):
         for x in self.timers:
             try:
                 x.stop()
@@ -106,6 +107,23 @@ class ThreadGroup(object):
                 LOG.exception(ex)
         self.timers = []
 
+    def stop(self, graceful=False):
+        """stop function has the option of graceful=True/False.
+
+        * In case of graceful=True, wait for all threads to be finished.
+          Never kill threads.
+        * In case of graceful=False, kill threads immediately.
+        """
+        self._stop_timers()
+        if graceful:
+            # In case of graceful=True, wait for all threads to be
+            # finished, never kill threads
+            self.wait()
+        else:
+            # In case of graceful=False(Default), kill threads
+            # immediately
+            self._stop_threads()
+
     def wait(self):
         for x in self.timers:
             try:
diff --git a/tests/unit/test_threadgroup.py b/tests/unit/test_threadgroup.py
index 08446e2..adbb6e5 100644
--- a/tests/unit/test_threadgroup.py
+++ b/tests/unit/test_threadgroup.py
@@ -17,6 +17,8 @@
 Unit Tests for thread groups
 """
 
+import time
+
 from oslotest import base as test_base
 
 from openstack.common import threadgroup
@@ -44,3 +46,27 @@ class ThreadGroupTestCase(test_base.BaseTestCase):
         self.assertTrue(timer._running)
         self.assertEqual(('arg',), timer.args)
         self.assertEqual({'kwarg': 'kwarg'}, timer.kw)
+
+    def test_stop_immediately(self):
+
+        def foo(*args, **kwargs):
+            time.sleep(1)
+        start_time = time.time()
+        self.tg.add_thread(foo, 'arg', kwarg='kwarg')
+        self.tg.stop()
+        end_time = time.time()
+
+        self.assertEqual(0, len(self.tg.threads))
+        self.assertTrue(end_time - start_time < 1)
+
+    def test_stop_gracefully(self):
+
+        def foo(*args, **kwargs):
+            time.sleep(1)
+        start_time = time.time()
+        self.tg.add_thread(foo, 'arg', kwarg='kwarg')
+        self.tg.stop(True)
+        end_time = time.time()
+
+        self.assertEqual(0, len(self.tg.threads))
+        self.assertTrue(end_time - start_time >= 1)