Speed up StackedOutboundQueue.reserve()

[openflowjava.git] / openflow-protocol-impl / src / main / java / org / opendaylight / openflowjava / protocol / impl / core / connection / StackedOutboundQueue.java

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 3c3ceee3fba0c624915984f0ac1d0ef03942ca15..efe71aa77ec3f484ec7ae43c76a2367611837e32 100644 (file)
--- 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
@@ -36,8 +36,9 @@ final class StackedOutboundQueue implements OutboundQueue {
     private final List<StackedSegment> uncompletedSegments = new ArrayList<>(2);
     private final OutboundQueueManager<?> manager;
 
-    private volatile long lastXid = -1;
+    private volatile long allocatedXid = -1;
     private volatile long barrierXid = -1;
+    private volatile long lastXid = -1;
 
     @GuardedBy("unflushedSegments")
     private Integer shutdownOffset;
@@ -62,6 +63,8 @@ final class StackedOutboundQueue implements OutboundQueue {
             LOG.debug("Adding segment {}", newSegment);
             unflushedSegments.add(newSegment);
         }
+
+        allocatedXid = uncompletedSegments.get(uncompletedSegments.size() - 1).getEndXid();
     }
 
     /*
@@ -73,27 +76,31 @@ final class StackedOutboundQueue implements OutboundQueue {
         final StackedSegment fastSegment = firstSegment;
 
         if (xid >= fastSegment.getBaseXid() + StackedSegment.SEGMENT_SIZE) {
-            LOG.debug("Queue {} falling back to slow reservation for XID {}", this, xid);
+           if (xid >= allocatedXid) {
+                // Multiple segments, this a slow path
+                LOG.debug("Queue {} falling back to slow reservation for XID {}", this, xid);
 
-            // Multiple segments, this a slow path
-            synchronized (unflushedSegments) {
-                LOG.debug("Queue {} executing slow reservation for XID {}", this, xid);
+                synchronized (unflushedSegments) {
+                    LOG.debug("Queue {} executing slow reservation for XID {}", this, xid);
 
-                // Shutdown was scheduled, need to fail the reservation
-                if (shutdownOffset != null) {
-                    LOG.debug("Queue {} is being shutdown, failing reservation", this);
-                    return null;
-                }
+                    // Shutdown was scheduled, need to fail the reservation
+                    if (shutdownOffset != null) {
+                        LOG.debug("Queue {} is being shutdown, failing reservation", this);
+                        return null;
+                    }
 
-                // Ensure we have the appropriate segment for the specified XID
-                final StackedSegment slowSegment = firstSegment;
-                final int slowOffset = (int) (xid - slowSegment.getBaseXid());
-                Verify.verify(slowOffset >= 0);
+                    // Ensure we have the appropriate segment for the specified XID
+                    final StackedSegment slowSegment = firstSegment;
+                    final int slowOffset = (int) (xid - slowSegment.getBaseXid());
+                    Verify.verify(slowOffset >= 0);
 
-                // Now, we let's see if we need to allocate a new segment
-                ensureSegment(slowSegment, slowOffset);
+                    // Now, we let's see if we need to allocate a new segment
+                    ensureSegment(slowSegment, slowOffset);
 
-                LOG.debug("Queue {} slow reservation finished", this);
+                    LOG.debug("Queue {} slow reservation finished", this);
+                }
+            } else {
+                LOG.debug("Queue {} XID {} is already backed", this, xid);
             }
         }