From e10dc362197d630cc16a2c48cbb4ade48d5064b5 Mon Sep 17 00:00:00 2001
From: Friedrich Lindenberg <friedrich@pudo.org>
Date: Fri, 14 Jun 2013 10:33:57 +0200
Subject: [PATCH] Try to avoid some locking issues.

---
 dataset/persistence/database.py | 18 ++++++++++--------
 dataset/persistence/table.py    |  2 +-
 setup.py                        |  2 +-
 3 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/dataset/persistence/database.py b/dataset/persistence/database.py
index aa9569c..31c83ee 100644
--- a/dataset/persistence/database.py
+++ b/dataset/persistence/database.py
@@ -46,9 +46,15 @@ class Database(object):
     def _release(self):
         if not hasattr(self.local, 'tx'):
             self.lock.release()
+            self.local.must_release = False
         else:
             self.local.must_release = True
 
+    def _release_internal(self):
+        if not hasattr(self.local, 'must_release') and self.local.must_release:
+            self.lock.release()
+            self.local.must_release = False
+
     def begin(self):
         """ Enter a transaction explicitly. No data will be written
         until the transaction has been committed. """
@@ -62,18 +68,14 @@ class Database(object):
         since the transaction was begun permanent. """
         self.local.tx.commit()
         del self.local.tx
-        if not hasattr(self.local, 'must_release'):
-            self.lock.release()
-            del self.local.must_release
+        self._release_internal()
 
     def rollback(self):
         """ Roll back the current transaction, discarding all statements
         executed since the transaction was begun. """
         self.local.tx.rollback()
         del self.local.tx
-        if not hasattr(self.local, 'must_release'):
-            self.lock.release()
-            del self.local.must_release
+        self._release_internal()
 
     @property
     def tables(self):
@@ -83,7 +85,7 @@ class Database(object):
         set([u'user', u'action'])
         """
         return list(set(self.metadata.tables.keys() +
-            self._tables.keys()))
+                        self._tables.keys()))
 
     def create_table(self, table_name):
         """
@@ -148,7 +150,7 @@ class Database(object):
                 return self.load_table(table_name)
             else:
                 return self.create_table(table_name)
-        finally: 
+        finally:
             self._release()
 
     def __getitem__(self, table_name):
diff --git a/dataset/persistence/table.py b/dataset/persistence/table.py
index cd42de6..d48a0db 100644
--- a/dataset/persistence/table.py
+++ b/dataset/persistence/table.py
@@ -213,7 +213,7 @@ class Table(object):
             if name not in self.table.columns.keys():
                 col = Column(name, type)
                 col.create(self.table,
-                       connection=self.database.engine)
+                           connection=self.database.executable)
         finally:
             self.database._release()
 
diff --git a/setup.py b/setup.py
index 28ad7f9..cc0c74b 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,7 @@ from setuptools import setup, find_packages
 
 setup(
     name='dataset',
-    version='0.3.5',
+    version='0.3.6',
     description="Toolkit for Python-based data processing.",
     long_description="",
     classifiers=[