Vastly improved queueing of FrameBytes, by appending at the end of the queue (instead of iterating over the queue).

Also, implemented a better fix for the missing flush() in case of missing handlers: now instead of flushing in the write
completion handler (which could lead to stack overflows), we use the same mechanism employed for FrameBytes,
where we avoid stack overflows by dispatching to a new thread after few recursive invocations.

jetty-spdy/spdy-core/src/main/java/org/eclipse/jetty/spdy/StandardSession.java

@@ -820,15 +820,21 @@ public class StandardSession implements ISession, Parser.Listener, Handler<Stand
 
     private void append(FrameBytes frameBytes)
     {
-        enqueue(frameBytes, false);
+        synchronized (queue)
+        {
+            int index = queue.size();
+            while (index > 0)
+            {
+                FrameBytes element = queue.get(index - 1);
+                if (element.compareTo(frameBytes) >= 0)
+                    break;
+                --index;
+            }
+            queue.add(index, frameBytes);
+        }
     }
 
     private void prepend(FrameBytes frameBytes)
-    {
-        enqueue(frameBytes, true);
-    }
-
-    private void enqueue(FrameBytes frameBytes, boolean prepend)
     {
         synchronized (queue)
         {
@@ -836,8 +842,7 @@ public class StandardSession implements ISession, Parser.Listener, Handler<Stand
             while (index < queue.size())
             {
                 FrameBytes element = queue.get(index);
-                int comparison = element.compareTo(frameBytes);
+                if (element.compareTo(frameBytes) <= 0)
-                if (comparison > 0 || prepend && comparison == 0)
                     break;
                 ++index;
             }
@@ -854,7 +859,6 @@ public class StandardSession implements ISession, Parser.Listener, Handler<Stand
             flushing = false;
         }
         frameBytes.complete();
-        flush();
     }
 
     @Override
@@ -874,37 +878,36 @@ public class StandardSession implements ISession, Parser.Listener, Handler<Stand
 
     private <C> void complete(final Handler<C> handler, final C context)
     {
-        if (handler != null)
+        // Applications may send and queue up a lot of frames and
+        // if we call Handler.completed() only synchronously we risk
+        // starvation (for the last frames sent) and stack overflow.
+        // Therefore every some invocation, we dispatch to a new thread
+        Integer invocations = handlerInvocations.get();
+        if (invocations >= 4)
         {
-            // Applications may send and queue up a lot of frames and
+            execute(new Runnable()
-            // if we call Handler.completed() only synchronously we risk
-            // starvation (for the last frames sent) and stack overflow.
-            // Therefore every some invocation, we dispatch to a new thread
-            Integer invocations = handlerInvocations.get();
-            if (invocations >= 4)
             {
-                execute(new Runnable()
+                @Override
+                public void run()
                 {
-                    @Override
+                    if (handler != null)
-                    public void run()
-                    {
                         notifyHandlerCompleted(handler, context);
-                        flush();
-                    }
-                });
-            }
-            else
-            {
-                handlerInvocations.set(invocations + 1);
-                try
-                {
-                    notifyHandlerCompleted(handler, context);
                     flush();
                 }
-                finally
+            });
-                {
+        }
-                    handlerInvocations.set(invocations);
+        else
-                }
+        {
+            handlerInvocations.set(invocations + 1);
+            try
+            {
+                if (handler != null)
+                    notifyHandlerCompleted(handler, context);
+                flush();
+            }
+            finally
+            {
+                handlerInvocations.set(invocations);
             }
         }
     }
@@ -967,7 +970,8 @@ public class StandardSession implements ISession, Parser.Listener, Handler<Stand
         @Override
         public int compareTo(FrameBytes that)
         {
-            return getStream().getPriority() - that.getStream().getPriority();
+            // If this.stream.priority > that.stream.priority => -1 (this.stream has less priority than that.stream)
+            return that.getStream().getPriority() - getStream().getPriority();
         }
 
         @Override