# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@logilab.fr>
# Date 1372250155 -7200
# Node ID 6a4070e2849da12a1abc0eb73cd67e3d06d9c812
# Parent  1e145b36edf0f215864491cdde70e28a00215c67
[connection] handle and explicitly life cycle on Connection

Like ClientConnection, Connection object need to be explicitly started and stop.
They aims to be used as context manager.

diff -r 1e145b36edf0 -r 6a4070e2849d server/session.py
--- a/server/session.py	Wed Jun 26 14:00:32 2013 +0200
+++ b/server/session.py	Wed Jun 26 14:35:55 2013 +0200
@@ -435,6 +435,7 @@
         # using super(Connection, self) confuse some test hack
         RequestSessionBase.__init__(self, session.vreg)
         #: connection unique id
+        self._open = None
         self.connectionid = cnxid
         #: self._session_handled
         #: are the life cycle of this Connection automatically controlled by the
@@ -504,6 +505,21 @@
             self._set_user(session.user)
 
 
+    # live cycle handling ####################################################
+
+    def __enter__(self):
+        assert self._open is None # first opening
+        self._open = True
+        return self
+
+    def __exit__(self, exctype=None, excvalue=None, tb=None):
+        assert self._open # actually already open
+        self.free_cnxset(ignoremode=True)
+        self.clear()
+        self._open = False
+
+
+
     # shared data handling ###################################################
 
     @property
@@ -1308,19 +1324,19 @@
             except KeyError:
                 cnx = Connection(self, cnxid=cnxid, session_handled=True)
                 self._cnxs[cnxid] = cnx
+                cnx.__enter__()
         return cnx
 
     def close_cnx(self, cnx):
         """Close a Connection related to a session"""
         assert cnx._session_handled
-        cnx.free_cnxset(ignoremode=True)
+        cnx.__exit__()
         self._cnxs.pop(cnx.connectionid, None)
         try:
             if self.__threaddata.cnx is cnx:
                 del self.__threaddata.cnx
         except AttributeError:
             pass
-        cnx.clear()
 
     def set_cnx(self, cnxid=None):
         """set the default connection of the current thread to <cnxid>