From 6a499f9932f6965ce84e97e98d2cd188482e8327 Mon Sep 17 00:00:00 2001
From: Michal Polkorab <michal.polkorab@pantheon.sk>
Date: Mon, 11 Jan 2016 22:28:52 +0100
Subject: [PATCH] Bug 4942 - Barrier send condition updated

 - fixes uncovered case - if a barrier was scheduled and another
   barrier was sent due to exceeded "maxNonBarrierMessages", then we
   would cancel / not enqueue the scheduled barrier because of "sinceLast"
   time - this time is lower than "maxBarrierNanos"

Change-Id: I86f1be2ac0dc76241523ee3b6e6bf12bec90889e
Signed-off-by: Michal Polkorab <michal.polkorab@pantheon.sk>
(cherry picked from commit 62c0db21eb5d45415011647427ba9f7a0dc69302)
---
 .../core/connection/OutboundQueueManager.java    | 15 +++++----------
 .../core/connection/StackedOutboundQueue.java    | 16 ++++++++++++++--
 2 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/openflow-protocol-impl/src/main/java/org/opendaylight/openflowjava/protocol/impl/core/connection/OutboundQueueManager.java b/openflow-protocol-impl/src/main/java/org/opendaylight/openflowjava/protocol/impl/core/connection/OutboundQueueManager.java
index 90db23da..1769face 100644
--- a/openflow-protocol-impl/src/main/java/org/opendaylight/openflowjava/protocol/impl/core/connection/OutboundQueueManager.java
+++ b/openflow-protocol-impl/src/main/java/org/opendaylight/openflowjava/protocol/impl/core/connection/OutboundQueueManager.java
@@ -86,16 +86,11 @@ final class OutboundQueueManager<T extends OutboundQueueHandler> extends
             return;
         }
 
-        final long now = System.nanoTime();
-        final long sinceLast = now - lastBarrierNanos;
-        if (sinceLast >= maxBarrierNanos) {
-            LOG.debug("Last barrier at {} now {}, elapsed {}", lastBarrierNanos, now, sinceLast);
-            // FIXME: we should be tracking requests/responses instead of this
-            if (nonBarrierMessages == 0) {
-                LOG.trace("No messages written since last barrier, not issuing one");
-            } else {
-                scheduleBarrierMessage();
-            }
+        if (currentQueue.isBarrierNeeded()) {
+            LOG.trace("Sending a barrier message");
+            scheduleBarrierMessage();
+        } else {
+            LOG.trace("Barrier not needed, not issuing one");
         }
     }
 
diff --git a/openflow-protocol-impl/src/main/java/org/opendaylight/openflowjava/protocol/impl/core/connection/StackedOutboundQueue.java b/openflow-protocol-impl/src/main/java/org/opendaylight/openflowjava/protocol/impl/core/connection/StackedOutboundQueue.java
index a9876d99..cafd114c 100644
--- a/openflow-protocol-impl/src/main/java/org/opendaylight/openflowjava/protocol/impl/core/connection/StackedOutboundQueue.java
+++ b/openflow-protocol-impl/src/main/java/org/opendaylight/openflowjava/protocol/impl/core/connection/StackedOutboundQueue.java
@@ -51,12 +51,24 @@ final class StackedOutboundQueue extends AbstractStackedOutboundQueue {
     }
 
     Long reserveBarrierIfNeeded() {
+        if (isBarrierNeeded()) {
+            return reserveEntry();
+        }
+        return null;
+    }
+
+    /**
+     * Checks if Barrier Request is the last message enqueued. If not, one needs
+     * to be scheduled in order to collect data about previous messages.
+     * @return true if last enqueued message is Barrier Request, false otherwise
+     */
+    boolean isBarrierNeeded() {
         final long bXid = barrierXid;
         final long fXid = firstSegment.getBaseXid() + flushOffset;
         if (bXid >= fXid) {
             LOG.debug("Barrier found at XID {} (currently at {})", bXid, fXid);
-            return null;
+            return false;
         }
-        return reserveEntry();
+        return true;
     }
 }
-- 
2.36.6