From b135d9ab189dfd7443f895aa96160e22666cb266 Mon Sep 17 00:00:00 2001
From: Robert Varga <robert.varga@pantheon.tech>
Date: Mon, 5 Jun 2017 19:50:52 +0200
Subject: [PATCH] BUG-8403: fix DONE state propagation

The DONE state detection logic in replayMessages() was flawed, as
we checked the current state, which is guaranteed to be SuccessorState.

We should be checking the previous state, available from the successor
state. As it turns out we can do this very cleanly by setting the flag
when the successor state gets the previous state assigned.

This also has better performance, as we do not touch the volatile
field multiple times.

Change-Id: Ica2246160bf8fee7aa134bbacb45857235405f6a
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
---
 .../databroker/actors/dds/AbstractProxyTransaction.java   | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractProxyTransaction.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractProxyTransaction.java
index 1eff70f6d9..3a463e5190 100644
--- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractProxyTransaction.java
+++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/AbstractProxyTransaction.java
@@ -147,13 +147,15 @@ abstract class AbstractProxyTransaction implements Identifiable<TransactionIdent
         }
 
         State getPrevState() {
-            return prevState;
+            return Verify.verifyNotNull(prevState, "Attempted to access previous state, which was not set");
         }
 
         void setPrevState(final State prevState) {
             Verify.verify(this.prevState == null, "Attempted to set previous state to %s when we already have %s",
                     prevState, this.prevState);
             this.prevState = Preconditions.checkNotNull(prevState);
+            // We cannot have duplicate successor states, so this check is sufficient
+            this.done = DONE.equals(prevState);
         }
 
         // To be called from safe contexts, where successor is known to be completed
@@ -626,10 +628,8 @@ abstract class AbstractProxyTransaction implements Identifiable<TransactionIdent
         final SuccessorState local = getSuccessorState();
         final State prevState = local.getPrevState();
 
-        final boolean isDone = DONE.equals(state)
-                || state instanceof SuccessorState && ((SuccessorState) state).isDone();
         final AbstractProxyTransaction successor = successorHistory.createTransactionProxy(getIdentifier(),
-            isSnapshotOnly(), isDone);
+            isSnapshotOnly(), local.isDone());
         LOG.debug("{} created successor {}", this, successor);
         local.setSuccessor(successor);
 
-- 
2.36.6