load and tpc_finish must be serialized

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@186 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/app.py

@@ -166,13 +166,13 @@ class Application(object):
         # Internal attribute distinct between thread
         self.local_var = local()
         # Lock definition :
-        # _return_lock is used to return data from thread to ZODB
+        # _load_lock is used to make loading and storing atmic
         # _oid_lock is used in order to not call multiple oid
         # generation at the same time
         # _cache_lock is used for the client cache
         lock = Lock()
-        self._return_lock_acquire = lock.acquire
-        self._return_lock_release = lock.release
+        self._load_lock_acquire = lock.acquire
+        self._load_lock_release = lock.release
         lock = Lock()
         self._oid_lock_acquire = lock.acquire
         self._oid_lock_release = lock.release
@@ -351,15 +351,19 @@ class Application(object):
     def load(self, oid, version=None):
         """Load an object for a given oid."""
         # First try from cache
+        self._load_lock_acquire()
+        try:
             self._cache_lock_acquire()
             try:
                 if oid in self.mq_cache:
-                logging.debug('oid %s is cached', dump(oid))
+                    logging.debug('load oid %s is cached', dump(oid))
                     return loads(self.mq_cache[oid][1]), self.mq_cache[oid][0]
             finally:
                 self._cache_lock_release()
             # Otherwise get it from storage node
             return self._load(oid, cache=1)[:2]
+        finally:
+            self._load_lock_release()
 
 
     def loadSerial(self, oid, serial):
@@ -570,7 +574,8 @@ class Application(object):
         """Finish current transaction."""
         if self.txn is not transaction:
             return
-
+        self._load_lock_acquire()
+        try:
             # Call function given by ZODB
             if f is not None:
                 f(self.tid)
@@ -605,6 +610,8 @@ class Application(object):
                 self._cache_lock_release()
             self._clear_txn()
             return self.tid
+        finally:
+            self._load_lock_release()
 
 
     def undo(self, transaction_id, txn, wrapper):