for #516, moved the "disconnect check" step out of pool and back into base.py. dialects have

is_disconnect() method now.  simpler design which also puts control of the ultimate "execute" call back into the hands of the dialects.

3 files changed, 11 insertions, 5 deletions

diff --git a/lib/sqlalchemy/engine/base.py b/lib/sqlalchemy/engine/base.py
index 80d93e61c..f5b4b377e 100644
--- a/lib/sqlalchemy/engine/base.py
+++ b/lib/sqlalchemy/engine/base.py
@@ -246,10 +246,9 @@ class Dialect(sql.AbstractDialect):
 
         return clauseelement.compile(dialect=self, parameters=parameters)
 
-    def get_disconnect_checker(self):
-        """Return a callable that determines if an SQLError is caused by a database disconnection."""
-
-        return lambda x: False
+    def is_disconnect(self, e):
+        """Return True if the given DBAPI error indicates an invalid connection"""
+        raise NotImplementedError()
 
 
 class ExecutionContext(object):
@@ -576,6 +575,8 @@ class Connection(Connectable):
         try:
             context.dialect.do_execute(context.cursor, context.statement, context.parameters, context=context)
         except Exception, e:
+            if self.dialect.is_disconnect(e):
+                self.__connection.invalidate(e=e)
             self._autorollback()
             if self.__close_with_result:
                 self.close()
@@ -585,6 +586,8 @@ class Connection(Connectable):
         try:
             context.dialect.do_executemany(context.cursor, context.statement, context.parameters, context=context)
         except Exception, e:
+            if self.dialect.is_disconnect(e):
+                self.__connection.invalidate(e=e)
             self._autorollback()
             if self.__close_with_result:
                 self.close()
diff --git a/lib/sqlalchemy/engine/default.py b/lib/sqlalchemy/engine/default.py
index ceecee364..9431e13a0 100644
--- a/lib/sqlalchemy/engine/default.py
+++ b/lib/sqlalchemy/engine/default.py
@@ -99,6 +99,9 @@ class DefaultDialect(base.Dialect):
     def defaultrunner(self, connection):
         return base.DefaultRunner(connection)
 
+    def is_disconnect(self, e):
+        return False
+        
     def _set_paramstyle(self, style):
         self._paramstyle = style
         self._figure_paramstyle(style)
diff --git a/lib/sqlalchemy/engine/strategies.py b/lib/sqlalchemy/engine/strategies.py
index 2f3b45199..1b760fca8 100644
--- a/lib/sqlalchemy/engine/strategies.py
+++ b/lib/sqlalchemy/engine/strategies.py
@@ -86,7 +86,7 @@ class DefaultEngineStrategy(EngineStrategy):
                 if tk in kwargs:
                     pool_args[k] = kwargs.pop(tk)
             pool_args['use_threadlocal'] = self.pool_threadlocal()
-            pool = poolclass(creator, disconnect_checker=dialect.get_disconnect_checker(), **pool_args)
+            pool = poolclass(creator, **pool_args)
         else:
             if isinstance(pool, poollib._DBProxy):
                 pool = pool.get_pool(*cargs, **cparams)