make threadmanager variables instance-specific

diff --git a/sfa/util/threadmanager.py b/sfa/util/threadmanager.py
old mode 100755 (executable)
new mode 100644 (file)
index 5f80670..b47b818
--- a/sfa/util/threadmanager.py
+++ b/sfa/util/threadmanager.py
@@ -31,9 +31,11 @@ class ThreadManager:
     ThreadManager executes a callable in a thread and stores the result
     in a thread safe queue. 
     """
-    results = Queue()
-    errors = Queue()
-    threads = []
+
+    def __init__(self):
+        self.results = Queue()
+        self.errors = Queue()
+        self.threads = []
 
     def run (self, method, *args, **kwds):
         """