Add threading locks in Keep client

diff --git a/sdk/python/arvados.py b/sdk/python/arvados.py
index 4d7f2d845c8fe0fbe0008010ed6577215c4cf561..ebe6bf3121aa07d11292c71d34d9b3ced4074fc4 100644 (file)
--- a/sdk/python/arvados.py
+++ b/sdk/python/arvados.py
@@ -16,6 +16,7 @@ import bz2
 import zlib
 import fcntl
 import time
+import threading
 
 from apiclient import errors
 from apiclient.discovery import build
@@ -789,10 +790,12 @@ class Keep:
 
 class KeepClient:
     def __init__(self):
+        self.lock = threading.Lock()
         self.service_roots = None
 
     def shuffled_service_roots(self, hash):
         if self.service_roots == None:
+            self.lock.acquire()
             keep_disks = api().keep_disks().list().execute()['items']
             roots = (("http%s://%s:%d/" %
                       ('s' if f['service_ssl_flag'] else '',
@@ -801,6 +804,7 @@ class KeepClient:
                      for f in keep_disks)
             self.service_roots = sorted(set(roots))
             logging.debug(str(self.service_roots))
+            self.lock.release()
         seed = hash
         pool = self.service_roots[:]
         pseq = []