Merge pull request #31 from ksauzz/fix/race-conditions

Fix race conditions

krbticket/command.py

@@ -2,9 +2,13 @@
 import logging
 import os
 import subprocess
+import threading
 from retrying import retry
 
 logger = logging.getLogger(__name__)
+# fasteners is for interprocess multiprocessing
+# threading.Lock is for multithreading
+lock = threading.Lock()
 
 
 class KrbCommand():
@@ -59,6 +63,12 @@ def kdestroy(config):
             commands.append(config.ccache_name)
         return KrbCommand._call(config, commands)
 
+    @staticmethod
+    def cache_exists(config):
+        with lock:
+            with fasteners.InterProcessLock(config.ccache_cmd_lockfile):
+                return os.path.isfile(config.ccache_name)
+
     @staticmethod
     def _call(config, commands):
 
@@ -78,5 +88,6 @@ def retriable_call():
             custom_env["LC_ALL"] = "C"
             return subprocess.check_output(commands, universal_newlines=True, env=custom_env)
 
-        with fasteners.InterProcessLock(config.ccache_cmd_lockfile):
-            return retriable_call()
+        with lock:
+            with fasteners.InterProcessLock(config.ccache_cmd_lockfile):
+                return retriable_call()

krbticket/ticket.py

@@ -1,4 +1,3 @@
-import os
 from datetime import datetime
 import logging
 import threading
@@ -100,7 +99,7 @@ def get_instance(**kwargs):
 
     @staticmethod
     def cache_exists(config):
-        return os.path.isfile(config.ccache_name)
+        return KrbCommand.cache_exists(config)
 
     @staticmethod
     def init(principal, keytab=None, **kwargs):
@@ -158,3 +157,16 @@ def parseDatetime(str):
             expires=parseDatetime(expires),
             service_principal=service_principal,
             renew_expires=parseDatetime(renew_expires))
+
+    @staticmethod
+    def _destroy():
+        """
+        destroy internal ticket registry
+
+        stop all updaters belonging to a ticket registered in registry, and remove all entiries
+        """
+        with KrbTicket.__instances_lock__:
+            for (key, ticket) in KrbTicket.__instances__.items():
+                ticket.updater().stop()
+                KrbCommand.kdestroy(ticket.config)
+            KrbTicket.__instances__ = {}

tests/test_ticket.py

@@ -4,6 +4,9 @@
 import os
 import subprocess
 
+def teardown_function(function):
+    KrbTicket._destroy()
+
 
 def test_init(config):
     KrbCommand.kdestroy(config)

tests/test_updater.py

@@ -8,7 +8,7 @@
 
 
 def teardown_function(function):
-    KrbTicket.__instances__ = {}
+    KrbTicket._destroy()
 
 
 def test_updater(config):