Correct ConnectionPool. Make sure that a connection is not leaked.

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@219 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/app.py

@@ -24,10 +24,9 @@ from ZODB.utils import p64, u64, oid_repr
 class ConnectionPool(object):
     """This class manages a pool of connections to storage nodes."""
 
-    def __init__(self, app, pool_size = 25):
+    def __init__(self, app, max_pool_size = 25):
         self.app = app
-        self.pool_size = 0
-        self.max_pool_size = pool_size
+        self.max_pool_size = max_pool_size
         self.connection_dict = {}
         # Define a lock in order to create one connection to
         # a storage node at a time to avoid multiple connections
@@ -77,24 +76,28 @@ class ConnectionPool(object):
         logging.info('connected to storage node %s:%d', *(conn.getAddress()))
         return conn
 
-    def _dropConnection(self):
-        """Drop a connection."""
+    def _dropConnections(self):
+        """Drop connections."""
         for node_uuid, conn in self.connection_dict.items():
             # Drop first connection which looks not used
             conn.lock()
             try:
-                if not conn.prending() and not self.app.dispatcher.registered(conn.getUUID()):
+                if not conn.pending() and \
+                        not self.app.dispatcher.registered(conn.getUUID()):
+                    del self.connection_dict[conn.getUUID()]
                     conn.close()
-                    break
+                    logging.info('connection to storage node %s:%d closed', 
+                                 *(conn.getAddress()))
+                    if len(self.connection_dict) <= self.max_pool_size:
+                        break
             finally:
                 conn.unlock()
-        logging.info('connection to storage node %s:%d closed', *(conn.getAddress()))
 
     def _createNodeConnection(self, node):
         """Create a connection to a given storage node."""
-        if self.pool_size > self.max_pool_size:
+        if len(self.connection_dict) > self.max_pool_size:
             # must drop some unused connections
-            self._dropConnection()
+            self._dropConnections()
         conn = self._initNodeConnection(node)
         if conn is None:
             return None
@@ -111,12 +114,13 @@ class ConnectionPool(object):
         If no connection exists, create a new one"""
         self.connection_lock_acquire()
         try:
-            if self.connection_dict.has_key(node.getUUID()):
+            uuid = node.getUUID()
+            try:
+                conn = self.connection_dict[uuid]
                 # Already connected to node
-                conn = self.connection_dict[node.getUUID()]
                 conn.lock()
                 return conn
-            else:
+            except KeyError:
                 # Create new connection to node
                 return self._createNodeConnection(node)
         finally:
@@ -126,8 +130,10 @@ class ConnectionPool(object):
         """Explicitly remove connection when a node is broken."""
         self.connection_lock_acquire()
         try:
-            if self.connection_dict.has_key(node.getUUID()):
-                self.connection_dict.pop(node.getUUID())
+            try:
+                del self.connection_dict[node.getUUID()]
+            except KeyError:
+                pass
         finally:
             self.connection_lock_release()
 

neo/connection.py

@@ -127,6 +127,9 @@ class Connection(BaseConnection):
                 em.removeIdleEvent(event)
             self.event_dict.clear()
 
+    def __del__(self):
+        self.close()
+
     def abort(self):
         """Abort dealing with this connection."""
         logging.debug('aborting a socket for %s:%d', *(self.addr))