Changes from review

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

jetty-websocket/websocket-core-common/src/main/java/org/eclipse/jetty/websocket/core/Extension.java

@@ -13,12 +13,15 @@
 
 package org.eclipse.jetty.websocket.core;
 
+import java.io.Closeable;
+import java.io.IOException;
+
 /**
  * Interface for WebSocket Extensions.
  * <p>
  * That {@link Frame}s are passed through the Extension via the {@link IncomingFrames} and {@link OutgoingFrames} interfaces
  */
-public interface Extension extends IncomingFrames, OutgoingFrames
+public interface Extension extends IncomingFrames, OutgoingFrames, Closeable
 {
 
     void init(ExtensionConfig config, WebSocketComponents components);
@@ -26,7 +29,7 @@ public interface Extension extends IncomingFrames, OutgoingFrames
     /**
      * Used to clean up any resources after connection close.
      */
-    default void close()
+    default void close() throws IOException
     {
     }
 

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

@@ -62,9 +62,17 @@ public class ExtensionStack implements IncomingFrames, OutgoingFrames, Dumpable
 
     public void close()
     {
-        for (Extension e : extensions)
+        for (Extension ext : extensions)
         {
-            e.close();
+            try
+            {
+                ext.close();
+            }
+            catch (Throwable t)
+            {
+                if (LOG.isDebugEnabled())
+                    LOG.debug("Extension Error During Close", t);
+            }
         }
     }
 

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

@@ -184,6 +184,7 @@ public class FrameFlusher extends IteratingCallback
     {
         try (AutoLock l = lock.lock())
         {
+            // TODO: find a way to not create exception if cause is null.
             closedCause = cause == null ? new ClosedChannelException()
             {
                 @Override

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

@@ -151,7 +151,15 @@ public class PerMessageDeflateExtension extends AbstractExtension implements Dem
     public void close()
     {
         // TODO: use IteratingCallback.close() instead of creating exception with failFlusher methods.
-        ClosedChannelException exception = new ClosedChannelException();
+        ClosedChannelException exception = new ClosedChannelException()
+        {
+            @Override
+            public Throwable fillInStackTrace()
+            {
+                return this;
+            }
+        };
+        incomingFlusher.close();
         incomingFlusher.failFlusher(exception);
         outgoingFlusher.failFlusher(exception);
         releaseInflater();

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

@@ -83,6 +83,7 @@ public abstract class TransformingFlusher
      */
     public void failFlusher(Throwable t)
     {
+        // TODO: find a way to close the flusher in non error case without exception.
         boolean failed = false;
         try (AutoLock l = lock.lock())
         {
@@ -91,6 +92,10 @@ public abstract class TransformingFlusher
                 failure = t;
                 failed = true;
             }
+            else
+            {
+                failure.addSuppressed(t);
+            }
         }
 
         if (failed)