[ONOS-2885] Resolve flow installation failure bug
There is a time gap between
controller is elected as the master of a switch
and
controller actually becomes the master of a switch (receives ROLE_REPLY).
During this time gap, OF messages destined for the switch will be sent to this controller.
However, the OF message can only be sent to the switch after controller receives the ROLE_REPLY.
Change-Id: I32d68384226e272658a0c9de2d32ae9e1cc39b6a
diff --git a/openflow/api/src/main/java/org/onosproject/openflow/controller/OpenFlowSwitch.java b/openflow/api/src/main/java/org/onosproject/openflow/controller/OpenFlowSwitch.java
index 1b6810b..51a2ce4 100644
--- a/openflow/api/src/main/java/org/onosproject/openflow/controller/OpenFlowSwitch.java
+++ b/openflow/api/src/main/java/org/onosproject/openflow/controller/OpenFlowSwitch.java
@@ -30,6 +30,14 @@
/**
* Writes the message to the driver.
*
+ * Note:
+ * Calling {@link #sendMsg(OFMessage)} does NOT guarantee the messages to be
+ * transmitted on the wire in order, especially during role transition.
+ * The messages may be reordered at the switch side.
+ *
+ * Calling {@link #sendMsg(List)} guarantee the messages inside the list
+ * to be transmitted on the wire in order.
+ *
* @param msg the message to write
*/
void sendMsg(OFMessage msg);