Issue #3290 - review changes, javadoc and todos

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-websocket/websocket-core/src/main/java/org/eclipse/jetty/websocket/core/CloseStatus.java

@@ -172,12 +172,14 @@ public class CloseStatus
         return null;
     }
 
+    // TODO consider defining a precedence for every CloseStatus, and change ChannelState only if higher precedence
     public static boolean isOrdinary(CloseStatus closeStatus)
     {
         switch (closeStatus.getCode())
         {
             case NORMAL:
             case SHUTDOWN:
+            case NO_CODE:
                 return true;
 
             default:

jetty-websocket/websocket-core/src/main/java/org/eclipse/jetty/websocket/core/internal/FrameFlusher.java

@@ -64,6 +64,15 @@ public class FrameFlusher extends IteratingCallback
         this.buffers = new ArrayList<>((maxGather * 2) + 1);
     }
 
+
+    /**
+     * Enqueue a Frame to be written to the endpoint.
+     * @param frame The frame to queue
+     * @param callback The callback to call once the frame is sent
+     * @param batch True if batch mode is to be used
+     * @return returns true if the frame was enqueued and iterate needs to be called, returns false if the
+     * FrameFlusher was closed
+     */
     public boolean enqueue(Frame frame, Callback callback, boolean batch)
     {
         Entry entry = new Entry(frame, callback, batch);

jetty-websocket/websocket-core/src/main/java/org/eclipse/jetty/websocket/core/internal/WebSocketConnection.java

@@ -348,7 +348,7 @@ public class WebSocketConnection extends AbstractConnection implements Connectio
 
             if (!fillingAndParsing)
                 throw new IllegalStateException();
-            if (demand != 0)
+            if (demand != 0) //if demand was canceled, this creates synthetic demand in order to read until EOF
                 return true;
 
             fillingAndParsing = false;