Use a (non-blocking) lock to prevent two simultaneous reconnection attemps to...

Use a (non-blocking) lock to prevent two simultaneous reconnection attemps to master instead of a simple variable.


git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@266 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/dispatcher.py

@@ -15,7 +15,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
-from threading import Thread
+from threading import Thread, Lock
 from Queue import Empty, Queue
 
 from neo.protocol import PING, Packet, CLIENT_NODE_TYPE, FINISH_TRANSACTION
@@ -36,7 +36,7 @@ class Dispatcher(Thread):
         # and thus redispatch answer to the original thread
         self.message_table = {}
         # Indicate if we are in process of connection to master node
-        self.connecting_to_master_node = 0
+        self.connecting_to_master_node = Lock()
 
     def run(self):
         while 1:
@@ -66,7 +66,9 @@ class Dispatcher(Thread):
         This can be called either at bootstrap or when
         client got disconnected during process"""
         # Indicate we are trying to connect to avoid multiple try a time
-        self.connecting_to_master_node = 1
+        acquired = self.connecting_to_master_node.acquire(blocking=0)
+        if acquired:
+            try:
                 from neo.client.handler import ClientEventHandler
                 if app.pt is not None:
                     app.pt.clear()
@@ -139,4 +141,5 @@ class Dispatcher(Thread):
 
                 logging.info("connected to primary master node %s:%d" %app.primary_master_node.getServer())
                 app.master_conn = conn
-        self.connecting_to_master_node = 0
+            finally:
+                self.connecting_to_master_node.release()

neo/client/handler.py

@@ -101,8 +101,6 @@ class ClientEventHandler(EventHandler):
         elif self.app.primary_master_node is not None and uuid == \
                  self.app.primary_master_node.getUUID():
             logging.critical("connection to primary master node failed")
-            if self.dispatcher.connecting_to_master_node == 0:
-                logging.critical("trying reconnection to master node...")
             self.dispatcher.connectToPrimaryMasterNode(app, conn)
         else:
             # Connection to a storage node failed
@@ -124,8 +122,6 @@ class ClientEventHandler(EventHandler):
             app.master_conn.close()
             app.master_conn = None
             app.primary_master_node = None
-            if self.dispatcher.connecting_to_master_node == 0:
-                logging.critical("trying reconnection to master node...")
             self.dispatcher.connectToPrimaryMasterNode(app, conn)
         else:
             node = app.nm.getNodeByServer(conn.getAddress())
@@ -145,8 +141,6 @@ class ClientEventHandler(EventHandler):
             app.primary_master_node = -1
         if app.master_conn is not None and uuid == app.primary_master_node.getUUID():
             logging.critical("connection timeout to primary master node expired")
-            if self.dispatcher.connecting_to_master_node == 0:
-                logging.critical("trying reconnection to master node...")
             self.dispatcher.connectToPrimaryMasterNode(app, conn)
         else:
             node = app.nm.getNodeByServer(conn.getAddress())
@@ -165,8 +159,6 @@ class ClientEventHandler(EventHandler):
             app.primary_master_node = -1
         if app.master_conn is not None and uuid == app.primary_master_node.getUUID():
             logging.critical("primary master node is broken")
-            if self.dispatcher.connecting_to_master_node == 0:
-                logging.critical("trying reconnection to master node...")
             self.dispatcher.connectToPrimaryMasterNode(app, conn)
         else:
             node = app.nm.getNodeByServer(conn.getAddress())