Fixed race condition on import in errorcodes.lookup

Fixes #382.

1 files changed, 8 insertions, 2 deletions

diff --git a/lib/errorcodes.py b/lib/errorcodes.py
index 12c300f..aa5a723 100644
--- a/lib/errorcodes.py
+++ b/lib/errorcodes.py
@@ -38,11 +38,17 @@ def lookup(code, _cache={}):
         return _cache[code]
 
     # Generate the lookup map at first usage.
+    tmp = {}
     for k, v in globals().iteritems():
         if isinstance(v, str) and len(v) in (2, 5):
-            _cache[v] = k
+            tmp[v] = k
 
-    return lookup(code)
+    assert tmp
+
+    # Atomic update, to avoid race condition on import (bug #382)
+    _cache.update(tmp)
+
+    return _cache[code]
 
 
 # autogenerated data: do not edit below this point.